Piping system

Abstract

Provided is a piping system that can improve flow rate while enabling miniaturization. The piping system (1) for forming a flow path comprises: a vertical pipe (3); a horizontal pipe (4) that is between an inflow port (2b) and the vertical pipe (3); a first elbow (51) that is between the inflow port (2b) and the horizontal pipe (4); a second elbow (52) that is between the horizontal pipe (4) and the vertical pipe (3) and has a smaller radius of curvature than the first elbow (51); and a protruding member (6) that is on the inner peripheral side of the second elbow (52) at the upstream end (3a) of the vertical pipe (3) and partially reduces the flow path cross-sectional area of the flow path.

Description

Piping System

[0001] The present disclosure relates to piping systems.

[0002] Patent Document 1 discloses a siphon gutter system. The siphon gutter system disclosed in Patent Document 1 includes an eaves gutter, a siphon generating section that includes a cylindrical section that penetrates a water collection port formed on the bottom surface of the eaves gutter and that generates a siphon phenomenon, and an elbow. The elbow is installed downstream of the siphon gutter system. The elbow includes a curved pipe section and receiving ports provided on both ends of the curved pipe section. When viewed in cross section on a plane including the pipe axis of the curved pipe section, the radius of curvature of the inner wall surface on the inner periphery of the curved pipe section is greater than 64 mm and less than 100 mm.

[0003] Japanese Patent Application Laid-Open No. 2019-120068

[0004] The technique disclosed in Patent Document 1 is expected to improve the flow rate, but the elbow becomes relatively large.

[0005] The present disclosure provides a piping system that allows for increased flow rate while enabling compactness.

[0006] A piping system according to one aspect of the present disclosure is a piping system that forms a flow path and includes a vertical pipe, a horizontal pipe between an inlet and the vertical pipe, a first elbow between the inlet and the horizontal pipe, a second elbow between the horizontal pipe and the vertical pipe and having a smaller radius of curvature than the first elbow, and a protrusion member located on at least one of the inner circumferential side of the second elbow at the downstream end of the horizontal pipe and the inner circumferential side of the second elbow at the upstream end of the vertical pipe, which partially reduces the flow path cross-sectional area of ​​the flow path.

[0007] Aspects of the present disclosure can improve flow rates while allowing for compactness.

[0008]

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the inventor(s) provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0010] Unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Each drawing described in the following embodiments is a schematic drawing, and the ratios of the size and thickness of each component in each drawing do not necessarily reflect the actual dimensional ratios. Furthermore, the dimensional ratios of each component are not limited to the ratios shown in the drawings.

[0011] In the following description, when it is necessary to distinguish between multiple components, prefixes such as "first" and "second" are added to the names of the components. However, when the components can be distinguished from each other by the symbols attached to them, the prefixes such as "first" and "second" may be omitted in consideration of readability of the text.

[0012] [1. Embodiments] [1.1 First Embodiment] [1.1.1 Configuration] FIG. 1 is a schematic diagram of a piping system 1 according to a first embodiment. The piping system 1 is used to transport a fluid with a Reynolds number of 4000 or greater. A fluid with a Reynolds number of 4000 or greater is considered to be a fluid whose flow within a cylinder becomes turbulent. Examples of fluids include liquids (drinking water, heat source water, wastewater, oil, etc.), gases (air, steam, etc.), and gas-liquid two-phase flow (a mixture of liquid and gas). In this embodiment, the piping system 1 is used as a drainage system. The piping system 1 is a gutter system that receives rainwater from the roof 11a of a building 11 and channels it to a manhole 21 on the ground 20. The piping system 1 forms a rainwater flow path. The rainwater collected in the manhole 21 flows from the manhole 21 through an underground pipe 22 and into a storm sewer. The building 11 is, for example, a non-residential facility such as a store, office, factory, building, school, welfare facility, or hospital, and a residential facility such as a detached house, an apartment building, or each dwelling unit of a detached house or apartment building. Non-residential facilities also include theaters, movie theaters, public halls, amusement parks, complexes, department stores, hotels, inns, kindergartens, libraries, museums, art galleries, underground shopping malls, stations, airports, etc.

[0013] The piping system 1 includes an eaves gutter 2, a vertical pipe 3, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protruding member 6, and a drain 7.

[0014] The eaves gutter 2 collects rainwater from the roof 11a of the building 11. The eaves gutter 2 is installed under the roof 11a of the building 11. As an example, the eaves gutter 2 is arranged at the eaves edge of the roof 11a. In particular, the eaves gutter 2 is arranged so as to extend along the eaves edge of the roof 11a. The eaves gutter 2 is shaped like a long bucket. The eaves gutter 2 has a bottom wall 2a. An inlet 2b is formed in the bottom wall 2a depending on the overall design of the piping system 1. The inlet 2b is, for example, a circular opening. In a rain gutter system, the inlet 2b is also referred to as a water collection inlet, a drain outlet, or a drop outlet. As an example, the eaves gutter 2 may be formed by extrusion molding of a resin material. The eaves gutter 2 may include a core material to reinforce the overall strength of the eaves gutter 2. The core material may be made of, for example, metal. As another example, the eaves gutter 2 may be formed from a metal plate, for example, a steel plate (also called a coil).

[0015] The drain 7 is disposed at the inlet 2b of the eaves gutter 2. The drain 7 reduces the generation of vortices and the entrainment of air at the inlet 2b. The drain 7 may contribute to the generation of the siphoning phenomenon. The drain 7 may have a known configuration.

[0016] In the piping system 1, the vertical pipe 3 is not directly connected to the inlet 2b, but is connected to the inlet 2b via the horizontal pipe 4, the first elbow 51, and the second elbow 52.

[0017] The standpipe 3 defines a vertical flow path. The standpipe 3 is fixed to the wall 11b of the building 11. In a gutter system, the standpipe 3 is also called a downspout. The standpipe 3 is installed to drain rainwater from the inlet 2b. The standpipe 3 allows rainwater from the inlet 2b to flow vertically. The standpipe 3 is straight. A cross section perpendicular to the central axis C3 of the standpipe 3 is circular. The standpipe 3 is arranged so that the direction of the central axis C3 of the standpipe 3 coincides with the up-down direction (vertical direction). The standpipe 3 has an upstream end 3a and a downstream end 3b. The upstream end 3a is the end of the standpipe 3 that is connected to the inlet 2b (the upper end in FIG. 1 ). The downstream end 3b is the end of the standpipe 3 that is inserted into the manhole 21 (the lower end in FIG. 1 ). In FIG. 1 , a pipe cover 30 is arranged to prevent rainwater from flowing into the manhole 21 through a gap between the upright pipe 3 and the manhole 21 .

[0018] The horizontal pipe 4 defines a flow path that intersects the vertical direction. In a gutter system, the horizontal pipe 4 is also called a call gutter. The horizontal pipe 4 is a portion for flowing rainwater from the building 11 from the inlet 2b to the standpipe 3. The horizontal pipe 4 is located between the inlet 2b for rainwater from the building 11 and the standpipe 3. The horizontal pipe 4 is a straight pipe. The cross section perpendicular to the central axis C4 of the horizontal pipe 4 is circular. The horizontal pipe 4 is fixed so that the central axis C4 of the horizontal pipe 4 is inclined relative to the up-down direction (vertical direction). The horizontal pipe 4 has an upstream end 4a and a downstream end 4b. The upstream end 4a is the end of the horizontal pipe 4 that is connected to the inlet 2b (the left end in FIG. 1 ). The downstream end 4b is the end of the horizontal pipe 4 that is connected to the standpipe 3 (the right end in FIG. 1 ).

[0019] As an example, the material of the standpipe 3 and the horizontal pipe 4 is rigid polyvinyl chloride. The dimensions of the standpipe 3 and the horizontal pipe 4, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0020] Table 1 shows an example of the nominal diameter of VP rigid polyvinyl chloride pipe in the standard for rigid polyvinyl chloride pipe (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipe." In Table 1, the units of outer diameter (standard dimension), thickness (minimum dimension), and approximate inner diameter are mm.

[0021]

[0022] Table 2 shows an example of the nominal diameter of a VU rigid polyvinyl chloride pipe in the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes." In Table 2, the units of outer diameter (standard dimension), thickness (minimum dimension), and approximate inner diameter are mm.

[0023]

[0024] The first elbow 51 and the second elbow 52 change the direction of the flow path. The first elbow 51 and the second elbow 52 are connection joints that connect flow paths with different directions, such as a vertical pipe and a horizontal pipe.

[0025] 2 is a cross-sectional view of the first elbow 51. The first elbow 51 has a curved pipe portion (bent portion) 510 and sockets 511, 512. The curved pipe portion 510 and the sockets 511, 512 are formed as a continuous, integrated unit. The material of the first elbow 51, i.e., the material of the curved pipe portion 510, is rigid polyvinyl chloride.

[0026] The curved pipe portion 510 has openings 511a and 512a at both ends. The curved pipe portion 510 is cylindrical, but the pipe axis (center line) A51 of the curved pipe portion 510 is curved rather than linear. In other words, the curved pipe portion 510 has a curved pipe axis A51. The pipe axis A51 of the curved pipe portion 510 defines the pipe axis of the first elbow 51.

[0027] Figure 2 is a cross-sectional view of the first elbow 51 taken along a plane including the pipe axis A51 of the curved pipe portion 510. The inner diameter of the curved pipe portion 510 of the first elbow 51 in Figure 2 is approximately uniform. In Figure 2, R51 indicates the radius of curvature of the pipe axis A51. The radius of curvature R51 of the pipe axis A51 defines the radius of curvature of the first elbow 51. O51 indicates the center of a circle that defines the radius of curvature R51.

[0028] 2, θ51 indicates the angle between center lines C511 and C512 of openings 511a and 512a at both ends of first elbow 51 in a cross section taken along a plane including pipe axis A51 of first elbow 51. θ51 is, for example, 91.17° as specified in JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage."

[0029] In FIG. 2 , δ51 is the diameter [mm] of the openings 511a and 512a of the bent pipe portion 510. δ51 may be determined taking into consideration the target drainage capacity of the piping system 1, etc. δ51 may be set in accordance with the standard of JIS K 6739, "Rigid Polyvinyl Chloride Pipe Fittings for Drainage." δ51 may be set, for example, to satisfy the standard dimensions of the nominal diameter specified in JIS K 6739. According to JIS K 6739, "Rigid Polyvinyl Chloride Pipe Fittings for Drainage," when the nominal diameter is 75 mm, 100 mm, or 125 mm, the standard dimensions are 77.2 mm, 98.8 mm, and 125 mm.

[0030] 2, in a cross section of the first elbow 51 taken along a plane including the pipe axis A51, the curved pipe section 510 has an inner surface 510a on the inner circumferential side and an inner surface 510b on the outer circumferential side. The inner surfaces 510a, 510b are curved as a whole. Here, in a cross section of the first elbow 51 taken along a plane including the pipe axis A51, the radius of curvature of the inner surface 510a is greater than 54 mm and less than 125 mm.

[0031] The sockets 511 and 512 are provided at both ends of the curved pipe portion 510. The sockets 511 and 512 are provided to connect piping members to the first elbow 51. In this embodiment, the socket 511 is connected to the upstream end 4a of the horizontal pipe 4, and the socket 512 is connected to the drain 7. The sockets 511 and 512 are cylindrical and surround the openings 511a and 512a of the curved pipe portion 510, respectively. In Figure 2, the sockets 511 and 512 have the same shape.

[0032] 2 shows D51, d51, and l51 as dimensions of the socket 511 of the first elbow 51. l51 is the length of the socket 511 (or the length of the socket 512) in a cross section taken along a plane including the pipe axis A51 of the curved pipe portion 510. D51 is the outer diameter [mm] of the socket 511 (or the socket 512). d51 is the inner diameter [mm] of the socket 511 (or the socket 512). The dimensions D51, d51, and l51 of the first elbow 51 may be set in accordance with, for example, the standard JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage."

[0033] 3 is a cross-sectional view of the second elbow 52. The second elbow 52 has a curved pipe portion (bent portion) 520 and sockets 521 and 522. The curved pipe portion 520 and the sockets 521 and 522 are formed as a continuous, integrated unit. The material of the second elbow 52, ​​i.e., the material of the curved pipe portion 520, is rigid polyvinyl chloride.

[0034] The curved pipe portion 520 has openings 521 a, 522 a at both ends. The curved pipe portion 520 is cylindrical, but the pipe axis (center line) A52 of the curved pipe portion 520 is curved rather than linear. In other words, the curved pipe portion 520 has a curved pipe axis A52. The pipe axis A52 of the curved pipe portion 520 defines the pipe axis of the second elbow 52.

[0035] Figure 3 is a cross-sectional view of the second elbow 52 taken along a plane including the pipe axis A52 of the curved pipe portion 520. The inner diameter of the curved pipe portion 520 of the second elbow 52 in Figure 3 is approximately uniform. In Figure 3, R52 indicates the radius of curvature of the pipe axis A52. The radius of curvature R52 of the pipe axis A52 defines the radius of curvature of the second elbow 52. O52 indicates the center of a circle that defines the radius of curvature R52.

[0036] 3, θ52 indicates the angle between center lines C521, C522 of openings 521a, 522a at both ends of second elbow 52 in a cross section taken along a plane including pipe axis A52 of second elbow 52. θ52 is, for example, 91.17° as specified in JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage."

[0037] In FIG. 3 , δ52 is the diameter [mm] of the openings 521a and 522a of the bent pipe portion 520. δ52 may be determined taking into consideration the target drainage capacity of the piping system 1, etc. δ52 may be set in accordance with the standard of JIS K 6739, "Rigid Polyvinyl Chloride Pipe Fittings for Drainage." δ52 may be set, for example, to satisfy the standard dimensions of the nominal diameter specified in JIS K 6739. According to JIS K 6739, "Rigid Polyvinyl Chloride Pipe Fittings for Drainage," when the nominal diameter is 75 mm, 100 mm, or 125 mm, the standard dimensions are 77.2 mm, 98.8 mm, and 125 mm.

[0038] As shown in FIG. 3 , in a cross section of the second elbow 52 taken along a plane including the pipe axis A52, the curved pipe portion 520 has an inner surface 520a on the inner circumferential side and an inner surface 520b on the outer circumferential side. The inner surface 520a has a corner 520c. The corner 520c is located in the middle portion of the inner surface 520a between the openings 521a and 522a. The corner 520c has an R-shape. In a cross section of the second elbow 52 taken along a plane including the pipe axis A52, the radius of curvature of the corner 520c is 0 mm or more and 54 mm or less, preferably 0 mm or more and 2 mm or less. The inner surface 520b does not have a corner like the corner 520c. The inner surface 520b is curved overall.

[0039] The sockets 521, 522 are provided at both ends of the curved pipe portion 520. The sockets 521, 522 are provided to connect piping members to the second elbow 52. In this embodiment, the socket 521 is connected to the upstream end 3a of the standpipe 3, and the socket 522 is connected to the downstream end 4b of the horizontal pipe 4. The sockets 521, 522 are cylindrical and surround the openings 521a, 522a of the curved pipe portion 520, respectively. In Figure 3, the sockets 521, 522 have the same shape.

[0040] 3 shows D52, d52, and l52 as dimensions of the socket 521 of the second elbow 52. l52 is the length of the socket 521 (or the length of the socket 522) in a cross section taken along a plane including the pipe axis A52 of the curved pipe portion 520. D52 is the outer diameter [mm] of the socket 521 (or the socket 522). d52 is the inner diameter [mm] of the socket 521 (or the socket 522). The dimensions D52, d52, and l52 of the second elbow 52 may be set in accordance with, for example, JIS K 6739 "Rigid polyvinyl chloride pipe fittings for drainage."

[0041] In this embodiment, the first elbow 51 and the second elbow 52 have the same nominal diameter. An angle θ51 between center lines C511, C512 of openings 511a, 512a at both ends of the first elbow 51 in a cross section taken along a plane including the pipe axis A51 of the first elbow 51 is equal to an angle θ52 between center lines C521, C522 of openings 521a, 522a at both ends of the second elbow 52 in a cross section taken along a plane including the pipe axis A52 of the second elbow 52. Meanwhile, a radius of curvature R52 of the second elbow 52 is smaller than the radius of curvature R51 of the first elbow 51. Thus, the first elbow 51 and the second elbow 52 have different shapes.

[0042] In this embodiment, the first elbow 51 and the second elbow 52 are 90° elbows. In this case, the horizontal distance between the inlet 2b and the standpipe 3 can be increased while shortening the length of the horizontal pipe 4. In particular, the first elbow 51 is a 90° large bend elbow (so-called LL) defined in JIS K 6739. The second elbow 52 is a 90° large bend elbow (so-called DL) defined in JIS K 6739. The 90° elbow defined in JIS K 6739 is smaller and more aesthetically pleasing than the 90° large bend elbow defined in JIS K 6739. Therefore, the aesthetic appeal of the exterior of the piping system 1 can be improved. The piping system 1 can be made less noticeable relative to the building 11. Pipe materials of a common standard can be used for the first elbow 51 and the second elbow 52, ​​facilitating installation of the piping system 1.

[0043] The piping system 1 includes a first elbow 51 and a second elbow 52. The direction of the flow path changes in each of the first elbow 51 and the second elbow 52. When the direction of the flow path changes, pressure loss due to separation can be a factor in a decrease in flow rate. In this embodiment, the radius of curvature R52 of the second elbow 52 is smaller than the radius of curvature R51 of the first elbow 51. Therefore, the pressure loss caused by the second elbow 52 tends to be larger than the pressure loss caused by the first elbow 51. In order to reduce the decrease in flow rate due to the pressure loss caused by the second elbow 52, ​​a protrusion member 6 is provided.

[0044] 1 , the protruding member 6 is located downstream of the second elbow 52. More specifically, the protruding member 6 is located on the inner circumferential side of the second elbow 52 within the standpipe 3, which is the straight pipe section downstream of the second elbow 52, ​​and is used to partially reduce the flow path cross-sectional area of ​​the standpipe 3.

[0045] Fig. 4 is a perspective view of the downstream portion of the second elbow 52 of the piping system 1. Fig. 5 is an exploded perspective view of the downstream portion of the second elbow 52 of the piping system 1. Fig. 6 is a cross-sectional view of the downstream portion of the second elbow 52 of the piping system 1. Fig. 7 is an exploded cross-sectional view of the downstream portion of the second elbow 52 of the piping system 1. Fig. 8 is a cross-sectional view taken along line A-A of Fig. 7.

[0046] In this embodiment, the vertical pipe 3 is made up of a plurality of pipe materials. The vertical pipe 3 includes a first straight pipe portion 31 and a second straight pipe portion 32.

[0047] The first straight pipe section 31 is directly connected to the downstream side of the second elbow 52. Therefore, the first straight pipe section 31 is an upstream portion of the vertical pipe 3.

[0048] The first straight pipe section 31 has a main body section 311 and a socket 312 .

[0049] The main body 311 has a straight pipe shape. As shown in Fig. 7 , the main body 311 has openings 311a and 311b at a first end (upper end in Fig. 7 ) and a second end (lower end in Fig. 7 ), respectively. In the standpipe 3, the first end of the first straight pipe section 31 defines the upstream end 3a of the standpipe 3.

[0050] The socket 312 is provided at the second end of the main body 311. The socket 312 is provided to connect the second straight pipe section 32 to the first straight pipe section 31. The socket 312 has a cylindrical shape that surrounds the opening 311b of the main body 311.

[0051] The second straight pipe section 32 is connected to the downstream side of the first straight pipe section 31. Therefore, the second straight pipe section 32 is the downstream part of the standpipe 3. The second straight pipe section 32 has a straight pipe shape. A first end (upper end in FIG. 1 ) of the second straight pipe section 32 is connected to the socket 312 of the first straight pipe section 31. A second end (lower end in FIG. 1 ) of the second straight pipe section 32 defines the downstream end 3b of the standpipe 3. The second end of the second straight pipe section 32 becomes the downstream opening point 3c of the standpipe 3 (see FIG. 1 ).

[0052] In the vertical pipe 3, the main body 311 of the first straight pipe portion 31 and the second straight pipe portion 32 have the same inner diameter. The inner diameters of the main body 311 of the first straight pipe portion 31 and the second straight pipe portion 32 define the flow path cross-sectional area of ​​the vertical pipe 3.

[0053] In this embodiment, the protruding member 6 is formed integrally with the first straight pipe portion 31. The protruding member 6 and the first straight pipe portion 31 will be further described below.

[0054] 9 to 15 show the protrusion member 6 and the first straight pipe portion 31. FIG. 9 is a perspective view of the protrusion member 6 and the first straight pipe portion 31. FIG. 10 is a side view of the protrusion member 6 and the first straight pipe portion 31. FIG. 11 is a plan view of the protrusion member 6 and the first straight pipe portion 31. FIG. 12 is a bottom view of the protrusion member 6 and the first straight pipe portion 31. FIG. 13 is a cross-sectional view taken along line B-B in FIG. 11. FIG. 14 is a perspective cross-sectional view taken along line CC in FIG. 11. FIG. 15 is a cross-sectional view taken along line D-D in FIG. 13.

[0055] As shown in Figures 6, 8, and 13, the protruding member 6 has a first end 6a and a second end 6b. The first end 6a and the second end 6b are both ends of the protruding member 6 in the longitudinal direction. The longitudinal direction of the protruding member 6 corresponds to the flow direction of the fluid in the standpipe 3. The flow direction of the fluid in the standpipe 3 coincides with the direction of the central axis C3 of the standpipe 3. The first end 6a is closer to the second elbow 52 than the second end 6b. In this embodiment, the first end 6a is the upstream end, and the second end 6b is the downstream end.

[0056] In a plane passing through the central axes C521, C522 of the openings 521a, 522a of the second elbow 52, ​​the surface of the protrusion member 6 has a curved shape that protrudes from the first wall surface 31b toward the second wall surface 31c. The height of the protrusion member 6 varies along the direction of the central axis C3 of the standpipe 3. In this embodiment, the protrusion member 6 has a top 6e between the first end 6a and the second end 6b. The top 6e is the highest part of the protrusion member 6. The height of the protrusion member 6 increases monotonically from the first end 6a toward the top 6e. The height of the protrusion member 6 decreases monotonically from the top 6e toward the second end 6b. The protrusion member 6 minimizes the flow path cross-sectional area of ​​the standpipe 3 at the top 6e.

[0057] 11, 12 and 15. When viewed from the direction of the central axis C3 of the standpipe 3, the protruding member 6 has a shape in which the center is recessed more than the both sides, thereby improving the flow rate.

[0058] From another perspective, it is sufficient that the protruding member 6 has a shape that protrudes from the inner periphery toward the outer periphery of the second elbow 52 so as to produce the Coanda effect in the straight pipe section (first straight pipe section 31) on the downstream side of the second elbow 52. In other words, it is sufficient that the protruding member 6 has a shape that produces the Coanda effect in the straight pipe section (first straight pipe section 31) on the downstream side of the second elbow 52. This makes it possible to improve the flow rate while making the device more compact.

[0059] The protruding member 6 is provided on the first straight pipe section 31 of the vertical pipe 3. More specifically, the protruding member 6 is provided on the first straight pipe section 31 so as to protrude from a first wall surface 31b on the inner circumferential side of the second elbow 52 in the first straight pipe section 31 to a second wall surface 31c on the outer circumferential side of the second elbow 52 in the first straight pipe section 31. Here, the first wall surface 31b is a portion of the inner circumferential surface 31a of the first straight pipe section 31 on the inner circumferential side of the second elbow 52 (for example, half of the inner circumferential side). The second wall surface 31c is a portion of the inner circumferential surface 31a of the first straight pipe section 31 on the outer circumferential side of the second elbow 52 (for example, half of the outer circumferential side). The inner circumferential surface 31a of the first straight pipe section 31 is composed of the first wall surface 31b and the second wall surface 31c.

[0060] In this way, by providing the protruding member 6 on the first straight pipe section 31 of the standpipe 3, a reduced region P where the flow path cross-sectional area of ​​the piping system 1 is smaller than the flow path cross-sectional area of ​​the standpipe 3 exists downstream of the second elbow 52 between the corner 520c on the inner periphery of the second elbow 52 and the opening 311b of the first straight pipe section 31. The reduced region P is the region of the standpipe 3 where the protruding member 6 exists.

[0061] 9 and 10 , the first end 6 a of the protruding member 6 protrudes to the outside from the opening 311 a of the first straight pipe section 31. Therefore, when the second elbow 52 and the first straight pipe section 31 are connected, as shown in FIG. 6 , the first end 6 a of the protruding member 6 protrudes from the opening 521 a into the curved pipe section 520 of the second elbow 52 and covers a part of the inner surface 520 a of the curved pipe section 520. In other words, the protruding member 6 does not necessarily have to be contained within the first straight pipe section 31, and the first end 6 a of the protruding member 6 may extend from the first straight pipe section 31 into the curved pipe section 520 of the second elbow 52. In this way, when the first end 6 a of the protruding member 6 is located within the curved pipe section 520 of the second elbow 52, ​​it is preferable that the first end 6 a of the protruding member 6 coincides with the corner 520 c of the inner surface 520 a of the curved pipe section 520. In this way, the protruding member 6 exists across the curved pipe portion 520 of the second elbow 52 and the first straight pipe portion 31, so it is possible to smoothly connect the inner surface 520a of the curved pipe portion 520 of the second elbow 52 to the first wall surface 31b of the inner circumferential surface 31a of the first straight pipe portion 31. This can reduce the effect of a step that may occur at the boundary between the curved pipe portion 520 of the second elbow 52 and the first straight pipe portion 31.

[0062] As shown in FIGS. 9 to 11 , the first straight pipe section 31 further has markings 313. The markings 313 indicate information regarding the assembly of the first straight pipe section 31. In this embodiment, the markings 313 indicate the direction in which the first straight pipe section 31 is connected to the second elbow 52. The markings 313 in FIG. 9 are arrows indicating the direction in which the first straight pipe section 31 is connected to the second elbow 52. In FIGS. 9 to 11 , four markings 313 are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the upstream end of the first straight pipe section 31. The markings 313 may be letters, figures, symbols, three-dimensional shapes, colors, or combinations thereof that are recognizable by human perception. In this embodiment, the markings 313 are located on the outer peripheral surface of the first straight pipe section 31 so as not to be hidden by the socket 521 of the second elbow 52 when the first straight pipe section 31 is connected to the second elbow 52. However, the mark 313 may be located on the outer surface of the first straight pipe section 31 in a position that is hidden by the receiving port 521 of the second elbow 52 when the first straight pipe section 31 is connected to the second elbow 52 .

[0063] As described above, by providing the protrusion member 6 on the first straight pipe section 31, a reduced area P where the flow path cross-sectional area of ​​the vertical pipe 3 is smaller than the opening 311b exists between the corner 520c of the second elbow 52 and the opening 311b.

[0064] Next, the function of the protruding member 6 will be described.

[0065] FIG. 16 is a diagram illustrating a simulation of pressure distribution when water flows through a piping system 100 of a comparative example. The piping system 100 of the comparative example differs from the piping system 1 in that it does not have a protruding member 6. In FIG. 16, darker colors indicate lower pressure. In particular, pressure loss is large at the portion indicated by R in FIG. 16, and the presence of such a portion with high pressure loss can be a major factor in reducing the flow rate. The pressure loss at the portion indicated by R in FIG. 16 is thought to be due to separation. This separation occurs when water separates from the first wall surface 31b of the standpipe 3 downstream of the corner 520c of the second elbow 52. That is, as indicated by arrow F in FIG. 16, water flowing in from the upstream side initially flows along the pipe wall 200, but after the corner 520c of the second elbow 52, ​​it may separate from the first wall surface 31b of the standpipe 3. This separation is particularly noticeable when the water flow velocity is high. The faster the flow velocity, the wider the area where pressure loss occurs.

[0066] In the piping system 1, the flow path direction changes significantly at the second elbow 52, ​​and pressure loss due to separation can contribute to a decrease in flow rate. The protruding member 6 is located at the end of the riser pipe 3 on the second elbow 52 side (upstream end 3a). In particular, the protruding member 6 is located on the inner circumferential side of the riser pipe 3 (left side in FIG. 1 ) of the second elbow 52. The apex 6e of the protruding member 6 is closer to the first end 6a than the second end 6b, and the first end 6a is closer to the second elbow 52 than the second end 6b. The protruding member 6 generates a fluid flow from the first end 6a to the second end 6b. The presence of the protruding member 6 is expected to (1) facilitate fluid flow along the pipe wall more easily than in the absence of the protruding member 6, and (2) reduce the number of areas where pressure loss may occur. Therefore, the protruding member 6 can reduce pressure loss due to separation downstream from the second elbow 52, ​​thereby improving flow rate. The piping system 1 can be made smaller in size simply by providing the protruding member 6, because the radius of curvature of the second elbow 52 can be made smaller than the radius of curvature of the first elbow 51. Therefore, the protruding member 6 can improve the flow rate while enabling size reduction. The protruding member 6 is located inside the standpipe 3, and is therefore inconspicuous when viewed as the piping system 1 as a whole. This is expected to improve the aesthetic appearance of the piping system 1 as a whole.

[0067] Next, an example of dimensions of the piping system 1 will be described.

[0068] 6 and 8 . In the riser pipe 3, the inner diameter of the flow path is the diameter of the riser pipe 3, and the direction of the flow path is the direction of the central axis C3 of the riser pipe 3. The diameter of the riser pipe 3 is defined as d, and the length of the protruding member 6 in the direction of the central axis C3 of the riser pipe 3 is defined as L. In the piping system 1, it is preferable that 0.5d≦L≦5.0d. This can further reduce the pressure loss caused by the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization.

[0069] 6 and 8, the apex 6e of the protruding member 6 is the portion of the reduced portion P where the flow path cross-sectional area is smallest. The distance between the corner 520c of the second elbow 52 and the apex 6e in the direction of the central axis C3 of the standpipe 3 is defined as D1. In the piping system 1, it is preferable that 0≦D1≦0.5d. This can further reduce the pressure loss caused by the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization.

[0070] In Figure 8, the distance between the top 6e and the downstream end (second end 6b) in the direction of the central axis C3 of the standpipe 3 is designated as D3. D3 is expressed as D3 = L - D1. In the piping system 1, it is preferable that D3 > D1. This can further reduce the pressure loss caused by the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization.

[0071] 11 and 13 . In a plane passing through the central axes C521, C522 of the sockets 521, 522 of the second elbow 52, ​​the distance between the top 6e and the second wall surface 31c is defined as D2. In the piping system 1, it is preferable that 0.60d≦D2≦0.95d. This can further reduce pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling compactness. Here, it is preferable that the height of the protruding member 6 at the top 6e is H. H is expressed as H=d−D2. In the piping system 1, it is preferable that 0.05d≦H≦0.40d. This can further reduce pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling compactness.

[0072] Referring to FIG. 15 , the maximum value of the flow path cross-sectional area of ​​the standpipe 3 (maximum flow path cross-sectional area) is A, and the minimum value of the flow path cross-sectional area of ​​the standpipe 3 (minimum flow path cross-sectional area) is A1. The minimum value of the flow path cross-sectional area of ​​the standpipe 3 is the flow path cross-sectional area at the top 6e of the protruding member 6. In the piping system 1, it is preferable that (A-A1) / A≦0.5. Preferably, it is preferable that (A-A1) / A≦0.4. This can further reduce pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling miniaturization. Here, the maximum value of the cross-sectional area of ​​the protruding member 6 is A2. A2 is also the cross-sectional area of ​​the protruding member 6 at the top 6e of the protruding member 6. A2 is A2=A-A1. That is, in the piping system 1, it is preferable that A2 / A≦0.5, and preferably A1 / A≦0.4.

[0073] See FIG. 1 . In the vertical pipe 3, the first straight pipe section 31 is shorter than the second straight pipe section 32. The length of the first straight pipe section 31 is preferably 1.0 m or less. The first straight pipe section 31 is provided with a protruding member 6. This makes it easier to arrange the protruding member 6 near the second elbow 52. This allows for an improvement in flow rate while enabling a compact design. Furthermore, the first straight pipe section 31 provided with the protruding member 6 is easier to carry.

[0074] Referring to FIG. 1 , in the piping system 1, the height at which the siphoning effect is effective refers to the height at which the piping is not divided, there is no portion completely open to the outside air, and the siphoning effect is maintained. The height at which the siphoning effect is effective is expressed as the vertical distance between the upstream opening point and the downstream opening point of the piping system 1. The upstream opening point of the piping system 1 is a portion on the upstream side of the piping system that is open to the outside air. The downstream opening point of the piping system 1 is a portion on the downstream side of the piping system 1 that is open to the outside air. There is no portion completely open to the outside air between the upstream opening point and the downstream opening point of the piping system 1. In other words, the downstream opening point is a point that is open to atmospheric pressure and where the siphoning effect stops. Therefore, the upstream opening point and the downstream opening point can be said to be the upstream and downstream ends of the range at which the siphoning effect is maintained in the piping system 1. It is believed that the greater the difference in potential energy between the upstream opening point and the downstream opening point of the piping system 1, the greater the flow rate due to the improved flow velocity caused by the siphoning effect. Here, the downstream opening point of the piping system 1 is the downstream opening point 3c of the standpipe 3. Ideally, the upstream opening point of the piping system 1 is the inlet 2b, but it is preferable to set it to the upstream end (first end 6a) of the protruding member 6 in terms of performance assurance. The vertical distance between the upstream end (first end 6a) of the protruding member 6 and the downstream opening point 3c of the standpipe 3 is preferably 2.0 m or more. This improves the flow rate.

[0075] See Figure 1. If the horizontal pipe 4 is too long, the effect of the decrease in flow velocity in the horizontal pipe 4 will be significant. Therefore, the length of the horizontal pipe 4 should be 2.0 m or less. This will reduce the decrease in flow velocity in the horizontal pipe 4 and improve the flow rate.

[0076] See FIG. 1 . If the distance between the inlet 2b and the first elbow 51 is too long, pressure loss at the first elbow 51 may increase. Therefore, the distance between the inlet 2b and the first elbow 51 should be 0.5 m or less. The distance between the inlet 2b and the first elbow 51 can be considered to be the distance between the bottom surface of the eaves gutter 2 where the inlet 2b is located and the socket 512 of the first elbow 51. In this embodiment, the first elbow 51 is directly connected to the drain 7 at the inlet 2b. Therefore, the distance between the inlet 2b and the first elbow 51 is 0.0 m. This improves the flow rate.

[0077] The piping system 1 described above has a protruding member 6. The protruding member 6 is located on the inner periphery of the second elbow 52 at the upstream end 3a of the standpipe 3. In particular, the protruding member 6 is located inside the first straight pipe section 31 of the standpipe 3. The protruding member 6 can reduce the occurrence of pressure loss due to separation that can occur when the direction of water flow changes from the horizontal pipe 4 to the standpipe 3, and can realize an improvement in the flow rate. Therefore, in the piping system 1, the occurrence of pressure loss can be reduced throughout the entire piping system 1, and the flow rate can be improved.

[0078] [1.1.2 Effects, etc.] The piping system 1 described above comprises the stand pipe 3, the horizontal pipe 4 located between the inlet 2b and the stand pipe 3, the first elbow 51 located between the inlet 2b and the horizontal pipe 4, the second elbow 52 located between the horizontal pipe 4 and the stand pipe 3 and having a smaller radius of curvature than the first elbow 51, and the protrusion member 6 located on the inner circumferential side of the second elbow 52 at the upstream end 3a of the stand pipe 3, which partially reduces the flow path cross-sectional area of ​​the flow path. This configuration can improve the flow rate while enabling miniaturization.

[0079] In the piping system 1, the first elbow 51 and the second elbow 52 are 90° elbows. This configuration allows the horizontal pipe 4 to be shortened in length while increasing the distance between the inlet 2b and the standpipe 3 in the horizontal direction.

[0080] In the piping system 1, the vertical pipe 3 includes a first straight pipe section 31 directly connected to the downstream side of the second elbow 52, ​​and a second straight pipe section 32 connected to the downstream side of the first straight pipe section 31. The protruding member 6 is located on the first straight pipe section 31. The length of the first straight pipe section 31 is 1.0 m or less. This configuration improves the flow rate while enabling miniaturization. Furthermore, the first straight pipe section 31 provided with the protruding member 6 is easy to carry.

[0081] In the piping system 1, the protruding member 6 is located on the inner periphery of the second elbow 52 at the upstream end 3a of the standpipe 3. The vertical distance between the upstream end (first end 6a) of the protruding member 6 and the downstream open point 3c of the standpipe 3 is 2.0 m or more. This configuration can improve the flow rate while enabling miniaturization.

[0082] In the piping system 1, the length of the horizontal pipe 4 is 2.0 m or less. This configuration can improve the flow rate while enabling miniaturization.

[0083] In the piping system 1, the distance between the inlet 2b and the first elbow 51 is 0.5 m or less. This configuration can improve the flow rate while enabling miniaturization.

[0084] In the piping system 1, the first elbow 51 is a 90° large bend elbow specified in JIS K 6739. This configuration eliminates the need to use a dedicated part for the first elbow 51, and therefore reduces the cost of installing the piping system 1.

[0085] In the piping system 1, the second elbow 52 is a 90° elbow defined in JIS K 6739. This configuration eliminates the need to use a dedicated part for the second elbow 52, ​​thereby reducing the cost of installing the piping system 1.

[0086] In the piping system 1, if the maximum value of the flow path cross-sectional area is A and the minimum value of the flow path cross-sectional area is A1, then (A-A1) / A≦0.5. This configuration can improve the flow rate while enabling miniaturization.

[0087] In the piping system 1, when the inner diameter of the flow path (the diameter of the standpipe 3) is d and the length of the protruding member 6 in the flow path direction (the direction of the central axis C3 of the standpipe 3) is L, the relationship 0.5d≦L≦5.0d is satisfied. This configuration can improve the flow rate while enabling miniaturization.

[0088] In the piping system 1, the protruding member 6 has a top 6e located between the upstream end (first end 6a) and the downstream end (second end 6b) that minimizes the cross-sectional area of ​​the flow path. When the inner diameter of the flow path (the diameter of the standpipe 3) is d and the height of the protruding member 6 at the top 6e is H, the relationship is 0.05d≦H≦0.40d. This configuration can improve the flow rate while enabling miniaturization.

[0089] [1.2 Second Embodiment] [1.2.1 Configuration] FIG. 17 is a schematic diagram of a piping system 1A according to a second embodiment.

[0090] The piping system 1A includes an eaves gutter 2, a vertical pipe 3A, a horizontal pipe 4A, a first elbow 51, a second elbow 52, ​​a protruding member 6, and a drain 7.

[0091] Unlike the standpipe 3, the standpipe 3A does not have a first straight pipe portion 31 on which the protruding member 6 is provided. The standpipe 3A may be configured from a single pipe material or multiple pipe materials.

[0092] 17 , the protruding member 6 is located upstream of the second elbow 52. More specifically, the protruding member 6 is located on the inner circumferential side of the second elbow 52 within the horizontal pipe 4, which is a straight pipe section upstream of the second elbow 52, ​​and is used to partially reduce the flow path cross-sectional area of ​​the horizontal pipe 4.

[0093] Fig. 18 is a perspective view of the upstream portion of the second elbow 52 of the piping system 1A. Fig. 19 is an exploded perspective view of the upstream portion of the second elbow 52 of the piping system 1A.

[0094] The horizontal pipe 4A is made up of a plurality of pipe materials and includes a first straight pipe section 41 and a second straight pipe section 42.

[0095] The first straight pipe section 41 is directly connected to the upstream side of the second elbow 52. Therefore, the first straight pipe section 41 is a downstream portion of the horizontal pipe 4.

[0096] The first straight pipe section 41 has a main body section 411 and a socket 412 .

[0097] The main body 411 has a straight pipe shape. As shown in Fig. 19 , the main body 411 has openings 411a and 411b at a first end (the right end in Fig. 19 ) and a second end (the left end in Fig. 19 ), respectively. In the horizontal pipe 4A, the first end of the first straight pipe section 41 defines the downstream end 4b of the horizontal pipe 4.

[0098] The socket 412 is provided at the second end of the main body 411. The socket 412 is provided to connect the second straight pipe section 42 to the first straight pipe section 41. The socket 412 has a cylindrical shape that surrounds the opening 411b of the main body 411.

[0099] The second straight pipe section 42 is connected to the upstream side of the first straight pipe section 41. Therefore, the second straight pipe section 42 is the upstream part of the horizontal pipe 4A. The second straight pipe section 42 has a straight pipe shape. A first end (the right end in FIG. 17 ) of the second straight pipe section 42 is connected to the socket 412 of the first straight pipe section 41. A second end (the left end in FIG. 17 ) of the second straight pipe section 42 defines the upstream end 4a of the horizontal pipe 4A.

[0100] In the horizontal pipe 4A, the main body 411 of the first straight pipe section 41 and the second straight pipe section 42 have the same inner diameter. The inner diameters of the main body 411 of the first straight pipe section 41 and the second straight pipe section 42 define the flow path cross-sectional area of ​​the horizontal pipe 4A.

[0101] In this embodiment, the protruding member 6 is formed integrally with the first straight pipe portion 41 .

[0102] In this embodiment, the length direction of the protruding member 6 corresponds to the flow direction of the fluid through the horizontal pipe 4A. The flow direction of the fluid through the horizontal pipe 4A coincides with the direction of the central axis C4 of the horizontal pipe 4A. The first end 6a is closer to the second elbow 52 than the second end 6b. In this embodiment, the first end 6a is the downstream end, and the second end 6b is the upstream end.

[0103] The protruding member 6 is provided on the first straight pipe section 41 of the horizontal pipe 4A. More specifically, the protruding member 6 is provided on the first straight pipe section 41 so as to protrude from a first wall surface 41b on the inner circumferential side of the second elbow 52 of the first straight pipe section 41 to a second wall surface 41c on the outer circumferential side of the second elbow 52 of the first straight pipe section 41. Here, the first wall surface 41b is a portion of the inner circumferential surface 31a of the first straight pipe section 41 on the inner circumferential side of the second elbow 52 (for example, half of the inner circumferential side). The second wall surface 41c is a portion of the inner circumferential surface 41a of the first straight pipe section 41 on the outer circumferential side of the second elbow 52 (for example, half of the outer circumferential side). The inner circumferential surface 41a of the first straight pipe section 41 is composed of the first wall surface 41b and the second wall surface 41c.

[0104] In this way, by providing the protruding member 6 on the first straight pipe section 41 of the horizontal pipe 4A, a reduced area P, where the flow path cross-sectional area of ​​the piping system 1A is smaller than the flow path cross-sectional area of ​​the horizontal pipe 4A, exists upstream of the second elbow 52 between the corner 520c on the inner periphery of the second elbow 52 and the opening 411b of the first straight pipe section 41. The reduced area P is the area of ​​the horizontal pipe 4A where the protruding member 6 exists.

[0105] As shown in Fig. 19 , the first end 6a of the protruding member 6 protrudes to the outside from the opening 411a of the first straight pipe section 41. Therefore, when the second elbow 52 and the first straight pipe section 41 are connected, as shown in Fig. 18 , the first end 6a of the protruding member 6 protrudes from the opening 522a into the curved pipe section 520 of the second elbow 52 and covers a part of the inner surface 520a of the curved pipe section 520. The first end 6a of the protruding member 6 coincides with the corner 520c of the inner surface 520a of the curved pipe section 520. In this way, because the protruding member 6 exists across the curved pipe section 520 of the second elbow 52 and the first straight pipe section 41, the influence of a step that may occur at the boundary between the curved pipe section 520 of the second elbow 52 and the first straight pipe section 41 can be reduced.

[0106] Next, the function of the protruding member 6 will be described. In the piping system 1A, there is an area downstream of the second elbow 52 where pressure loss due to separation is likely to occur. The protruding member 6 is located at the end of the horizontal pipe 4A on the second elbow 52 side (downstream end 4b). In particular, the protruding member 6 is located on the inner circumferential side of the second elbow 52 in the horizontal pipe 4 (the lower side in FIG. 17 ). In the protruding member 6, the apex 6e is closer to the first end 6a than the second end 6b, and the first end 6a is closer to the second elbow 52 than the second end 6b. In the protruding member 6, a fluid flow occurs from the second end 6b toward the first end 6a. The presence of the protruding member 6 can guide the fluid to the area downstream of the second elbow 52 where pressure loss due to separation is likely to occur. This is expected to reduce the number of areas where pressure loss may occur. Therefore, the protruding member 6 can reduce pressure loss due to separation downstream of the second elbow 52 and improve flow rate. The piping system 1A can be made smaller in size simply by providing the protruding member 6, because the radius of curvature of the second elbow 52 can be made smaller than the radius of curvature of the first elbow 51. Therefore, the protruding member 6 can improve the flow rate while enabling a smaller size. The protruding member 6 is located inside the horizontal pipe 4A, and is therefore inconspicuous when viewed as a whole piping system 1A. This is expected to improve the aesthetic appearance of the piping system 1A as a whole.

[0107] Next, an example of dimensions of the piping system 1A will be described.

[0108] See Figure 18. In the horizontal pipe 4A, the inner diameter of the flow path is the diameter of the horizontal pipe 4A, and the direction of the flow path is the direction of the central axis C4 of the horizontal pipe 4A. The diameter of the horizontal pipe 4A is d, and the length of the protruding member 6 in the direction of the central axis C4 of the horizontal pipe 4A is L. In the piping system 1A, it is preferable that 0.5d≦L≦5.0d. This can further reduce pressure loss caused by the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization.

[0109] 18, the apex 6e of the protruding member 6 is the portion of the contracted portion P where the flow path cross-sectional area is smallest. The distance between the corner 520c of the second elbow 52 and the apex 6e in the direction of the central axis C4 of the horizontal pipe 4A is defined as D1. In the piping system 1A, it is preferable that 0≦D1≦0.5d. This can further reduce pressure loss caused by the second elbow 52. This can improve the flow rate while enabling miniaturization.

[0110] In Figure 18, the distance between the apex 6e and the upstream end (second end 6b) in the flow path direction (the direction of the central axis C4 of the horizontal pipe 4A) is defined as D3. D3 is calculated as D3 = L - D1. In the piping system 1A, it is preferable that D3 > D1. This can further reduce pressure loss caused by the second elbow 52. This allows for an improvement in flow rate while enabling miniaturization.

[0111] Refer to FIG. 18 . In a plane passing through the central axes C521, C522 of the sockets 521, 522 of the second elbow 52, ​​the distance between the top 6e and the second wall surface 41c is defined as D2. In the piping system 1A, it is preferable that 0.60d≦D2≦0.95d. This can further reduce pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling compactness. Here, the height of the protruding member 6 at the top 6e is defined as H. H is expressed as H=d−D2. In the piping system 1A, it is preferable that 0.05d≦H≦0.40d. This can further reduce pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling compactness.

[0112] The flow path cross-sectional area of ​​the horizontal pipe 4A is defined as A, and the minimum value of the flow path cross-sectional area of ​​the horizontal pipe 4A is defined as A1. The minimum value of the flow path cross-sectional area of ​​the horizontal pipe 4A is the flow path cross-sectional area at the top 6e of the protruding member 6. In the piping system 1A, it is preferable that (A-A1) / A≦0.5. Preferably, it is preferable that (A-A1) / A≦0.4. This can further reduce the pressure loss caused by the second elbow 52. Therefore, it is possible to improve the flow rate while enabling miniaturization. Here, it is defined that the maximum value of the cross-sectional area of ​​the protruding member 6 is A2. A2 is also the cross-sectional area of ​​the protruding member 6 at the top 6e of the protruding member 6. A2 is A2=A-A1. That is, in the piping system 1A, it is preferable that A2 / A≦0.5, and preferably A1 / A≦0.4.

[0113] See Figure 17. In the horizontal pipe 4A, the first straight pipe section 41 is shorter than the second straight pipe section 42. The length of the first straight pipe section 41 is preferably 1.0 m or less. The first straight pipe section 41 is provided with a protruding member 6. This makes it easier to arrange the protruding member 6 near the second elbow 52. This allows for an improvement in flow rate while enabling a compact design. Furthermore, the first straight pipe section 41 provided with the protruding member 6 is easier to carry.

[0114] The piping system 1A described above has a protruding member 6. The protruding member 6 is located on the inner periphery of the second elbow 52 at the downstream end 4b of the horizontal pipe 4A. In particular, the protruding member 6 is located within the first straight pipe section 41 of the horizontal pipe 4A. The protruding member 6 can reduce pressure loss caused by separation that can occur when the water changes direction from the horizontal pipe 4 to the upright pipe 3, thereby improving the flow rate. Therefore, the piping system 1A can reduce pressure loss throughout the entire piping system 1A and improve the flow rate.

[0115] [1.2.2 Effects, etc.] The piping system 1A described above comprises a stand pipe 3A, a horizontal pipe 4A located between the inlet 2b and the stand pipe 3A, a first elbow 51 located between the inlet 2b and the horizontal pipe 4A, a second elbow 52 located between the horizontal pipe 4A and the stand pipe 3A and having a smaller radius of curvature than the first elbow 51, and a protrusion member 6 located at the downstream end 4b of the horizontal pipe 4A on the inner circumferential side of the second elbow 52, ​​which partially reduces the flow path cross-sectional area of ​​the flow path (the flow path cross-sectional area of ​​the horizontal pipe 4A). This configuration can improve the flow rate while enabling miniaturization.

[0116] [1.3 Embodiment 3] [1.3.1 Configuration] Fig. 20 is a schematic diagram of a piping system 1B according to embodiment 2. The piping system 1B includes a tee 110, a second upright pipe 111, a second eaves gutter 112, a third elbow 113, a second horizontal pipe 114, and a second drain 115 in addition to the eaves gutter 2, the upright pipe 3, the horizontal pipe 4, the first elbow 51, the second elbow 52, ​​the protruding member 6, and the drain 7.

[0117] The tee 110 has a first receiving port 110a facing upward, a second receiving port 110b facing downward, and a third receiving port 110c facing sideways. The tee 110 merges the fluid flowing in from the first receiving port 110a with the fluid flowing in from the third receiving port 110c, and discharges the combined fluid from the second receiving port 110b. The angle between the central axis of the first receiving port 110a and the central axis of the third receiving port 110c is 90° or less. As an example, the angle between the central axis of the first receiving port 110a and the central axis of the third receiving port 110c is set to 88.83°. As an example, the material of the tee 110 is hard polyvinyl chloride.

[0118] The first receiving port 110a is connected to the downstream end 3b of the standpipe 3. The second receiving port 110b is connected to the second standpipe 111. The third receiving port 110c is connected to the second eaves gutter 112 via a third elbow 113 and a second horizontal pipe 114.

[0119] The second standpipe 111 is installed to drain water from the standpipe 3 to the manhole 21. In this embodiment, the second standpipe 111 has the same pipe diameter as the standpipe 3. For example, the second standpipe 111 is the same size as the standpipe 3. The second standpipe 111 is straight. The cross section perpendicular to the central axis of the second standpipe 111 is circular. The second standpipe 111 is arranged so that the direction of the central axis of the second standpipe 111 coincides with the up-down direction (vertical direction). The second standpipe 111 has an upstream end 111a and a downstream end 111b. The upstream end 111a is connected to the second receiving port 110b of the tee 110. The downstream end 111b is inserted into the manhole 21. A piping cover 30 is arranged to prevent rainwater from flowing into the manhole 21 through a gap between the second upright pipe 111 and the manhole 21.

[0120] The second eaves gutter 112 collects rainwater from roofs or eaves below the roof 11a of the building 11. For example, the second eaves gutter 112 is installed below the eaves gutter 2. The second eaves gutter 112 is shaped like a long bucket. The second eaves gutter 112 has a bottom wall 112a. A second inlet 112b, different from the inlet 2b, is formed in the bottom wall 112a according to the overall design of the piping system 1B. The second inlet 112b is, for example, a circular opening. As an example, the second eaves gutter 112 may be formed by extrusion molding of a resin material. The second eaves gutter 112 may include a core material to reinforce the overall strength of the second eaves gutter 112. The core material may be made of, for example, metal. As another example, the second eaves gutter 112 may be formed from a metal plate, for example, a steel plate (also called a coil).

[0121] The second drain 115 is disposed at the second inlet 112b of the second eaves gutter 112. The second drain 115 does not necessarily have to have a configuration that can contribute to the occurrence of the siphoning phenomenon. The second drain 115 may have a well-known configuration.

[0122] The third elbow 113 changes the direction of the flow path. The third elbow 113 is a connecting joint that connects flow paths with different directions. The third elbow 113 has a curved pipe portion 1130 and sockets 1131 and 1132 at both ends of the curved pipe portion 1130. In the third elbow 113, the socket 1132 is connected to the second drain 115, and thereby to the second inlet 112b. The socket 1131 is connected to the second standpipe 111. As an example, the material of the third elbow 113 may be rigid polyvinyl chloride. The dimensions of the third elbow 113 may be set in accordance with the standard JIS K 6739, "Rigid Polyvinyl Chloride Pipe Joints for Drainage."

[0123] The second horizontal pipe 114 is installed to drain water from the second eaves gutter 112 to the manhole section 21. In this embodiment, the second horizontal pipe 114 is straight. The cross section perpendicular to the central axis of the second horizontal pipe 114 is circular. The second horizontal pipe 114 is arranged so that the central axis of the second horizontal pipe 114 intersects the up-down direction (vertical direction). The second horizontal pipe 114 has an upstream end 114a and a downstream end 114b. The upstream end 114a is connected to the receiving port 1131 of the third elbow 113. The downstream end 114b is connected to the third receiving port 110c of the tee 110.

[0124] As an example, the material of the second standpipe 111 and the second horizontal pipe 114 is rigid polyvinyl chloride. The dimensions of the second standpipe 111 and the second horizontal pipe 114, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0125] In the piping system 1B described above, the vertical distance L11 between the second elbow 52 and the tee 110 is 2.0 m or more. This allows the fluid from the second inlet 112b to merge with the fluid from the inlet 2b, while improving the flow rate.

[0126] [1.3.2 Effects, etc.] The piping system 1B described above further includes a tee 110 having a first receiving port 110a facing upward, a second receiving port 110b facing downward, and a third receiving port 110c facing sideways. The first receiving port 110a is connected to the downstream end 3b of the standpipe 3. The third receiving port 110c is connected to a second inlet 112b different from the inlet 2b. The vertical distance between the second elbow 52 and the tee 110 is 2.0 m or more. This configuration can improve the flow rate while allowing the fluid from the second inlet 112b to merge with the fluid from the inlet 2b.

[0127] 21 is a schematic diagram of a piping system 1C according to embodiment 4. The piping system 1C includes a piping 12 in addition to an eaves gutter 2, a vertical pipe 3, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protruding member 6, and a drain 7.

[0128] The pipe 12 has a larger diameter than the standpipe 3. For example, the pipe 12 is one size or more larger than the standpipe 3. The pipe 12 is installed to drain water from the standpipe 3 to the manhole 21. The pipe 12 is also called a curing pipe.

[0129] The pipe 12 has a straight pipe shape. A cross section perpendicular to the central axis of the pipe 12 is circular. The pipe 12 is arranged so that the direction of the central axis of the pipe 12 coincides with the up-down direction (vertical direction). The pipe 12 has an upstream end 12a and a downstream end 12b. The downstream end 3b of the standpipe 3 is inserted into the upstream end 12a. The downstream end 12b is inserted into the manifold 21. In Figure 21, a pipe cover 30 is arranged to prevent rainwater from flowing into the manifold 21 through a gap between the pipe 12 and the manifold 21.

[0130] As an example, the material of the pipe 12 is rigid polyvinyl chloride. The dimensions of the pipe 12, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0131] In the piping system 1C, the length L12 of the portion of the riser 3 inserted into the piping 12 is 1.0 m or more. This makes it possible to stabilize the flow of fluid from the riser 3 to the piping 12.

[0132] [1.4.2 Effects, etc.] In the piping system 1C described above, the downstream end 3b of the riser pipe 3 is inserted into the pipe 12, which has a larger diameter than the riser pipe 3. The length of the portion of the riser pipe 3 inserted into the pipe 12 is 1.0 m or more. This configuration stabilizes the flow of fluid from the riser pipe 3 to the pipe 12.

[0133] 22 is a schematic diagram of a piping system 1D according to embodiment 5. The piping system 1D includes an increaser 130 and a second standpipe 131 in addition to an eaves gutter 2, a standpipe 3, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protruding member 6, and a drain 7.

[0134] The increaser 130 has a first socket 130a facing upward and a second socket 130b facing downward. The second socket 130b is larger than the first socket 130a. The inner diameter of the increaser 130 increases from the first socket 130a toward the second socket 130b. In this embodiment, the central axes of the first socket 130a and the second socket 130b are aligned.

[0135] The first receiving port 130a is connected to the downstream end 3b of the riser 3. The second receiving port 130b is connected to the second riser 131.

[0136] For example, the material of the increaser 130 is rigid polyvinyl chloride. The dimensions of the increaser 130 may be set in accordance with the standard of JIS K 6739 "Rigid polyvinyl chloride pipe joints for drainage," for example.

[0137] The second standpipe 131 has a larger pipe diameter than the standpipe 3. For example, the second standpipe 131 is larger than the standpipe 3 by one size or more. The second standpipe 131 is installed to drain water from the standpipe 3 to the manhole 21.

[0138] The second standpipe 131 has a straight pipe shape. A cross section perpendicular to the central axis of the second standpipe 131 is circular. The second standpipe 131 is arranged so that the direction of the central axis of the second standpipe 131 coincides with the up-down direction (vertical direction). The second standpipe 131 has an upstream end 131a and a downstream end 131b. The upstream end 131a is connected to the second receiving port 130b of the increaser 130. The downstream end 131b is inserted into the manifold 21. A piping cover 30 is arranged to prevent rainwater from flowing into the manifold 21 through a gap between the second standpipe 131 and the manifold 21.

[0139] As an example, the material of the second standpipe 131 is rigid polyvinyl chloride. The dimensions of the second standpipe 131, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0140] In the piping system 1D, the distance L13 between the second elbow 52 and the increaser 130 in the vertical direction is 2.0 m or more. This makes it possible to stabilize the flow of fluid from the upright pipe 3 to the second upright pipe 131.

[0141] [1.5.2 Effects, etc.] The piping system 1D described above further includes an increaser 130 having an upward-facing first receiver 130a and a downward-facing second receiver 130b with an inner diameter larger than that of the first receiver 130a. The first receiver 130a is connected to the downstream end 3b of the standpipe 3. The vertical distance between the second elbow 52 and the increaser 130 is 2.0 m or more. This configuration stabilizes the flow of fluid from the standpipe 3 to the second standpipe 131.

[0142] [1.6 Sixth Embodiment] [1.6.1 Configuration] Fig. 23 is a schematic diagram of a piping system 1E according to a sixth embodiment. The piping system 1E is used to sprinkle water from an eaves gutter 2 onto a second roof 11c below a roof 11a. As an example, the roof 11a may be a main roof, and the second roof 11c may be a eaves. In Fig. 23, the second roof 11c is a folded-plate roof.

[0143] The piping system 1E includes an eaves gutter 2, a vertical pipe 3, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protruding member 6, a drain 7, as well as a third elbow 140 and a pipe 141.

[0144] The third elbow 140 changes the direction of the flow path. The third elbow 140 is a connecting joint that connects flow paths with different directions. The third elbow 140 has a curved pipe portion 1400 and sockets 1401 and 1402 at both ends of the curved pipe portion 1400. In the third elbow 140, the socket 1401 is connected to the downstream end 3b of the standpipe 3. The socket 1402 is connected to the piping 141. As an example, the material of the third elbow 140 may be rigid polyvinyl chloride. The dimensions of the third elbow 140 may be set in accordance with the standard JIS K 6739, "Rigid polyvinyl chloride pipe fittings for drainage."

[0145] The pipe 141 is installed to discharge a fluid (rainwater in this embodiment) onto the second roof 11c. The pipe 141 is also called a sprinkler pipe.

[0146] The piping 141 includes a second horizontal pipe 142 and a fourth elbow 143 .

[0147] The second horizontal pipe 142 has a straight pipe shape. A cross section perpendicular to the central axis of the second horizontal pipe 142 is circular. The second horizontal pipe 142 is arranged so that the central axis of the second horizontal pipe 142 intersects the up-down direction (vertical direction). The second horizontal pipe 142 has an upstream end 142a and a downstream end 142b. The upstream end 142a is connected to the socket 1402 of the third elbow 140. The second horizontal pipe 142 has one or more discharge ports 142c between the upstream end 142a and the downstream end 142b. Figure 23 shows three discharge ports 142c. Each discharge port 142c penetrates the pipe wall of the second horizontal pipe 142. As an example, the inner diameter of the discharge ports 142c is 75 mm, and the discharge ports 142c are arranged at a pitch of 250 mm.

[0148] As an example, the material of the second horizontal pipe 142 is rigid polyvinyl chloride. The dimensions of the second horizontal pipe 142, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) of JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0149] The fourth elbow 143 changes the direction of the flow path. The fourth elbow 143 has a curved pipe portion 1430 and sockets 1431, 1432 at both ends of the curved pipe portion 1430. In the fourth elbow 143, the socket 1431 is connected to the downstream end 142b of the second horizontal pipe 142. The socket 1432 is the downstream end of the pipe 141. The socket 1432 is used as a discharge port at the end of the pipe 141. In this embodiment, the opening 1432a of the socket 1432 is partially blocked. Preferably, the opening 1432a is blocked by 50% or more. In other words, the flow path cross-sectional area of ​​the opening 1432a is reduced by 50% or more. This makes it easier for the fluid to be discharged from the discharge port 142c.

[0150] For example, the material of the fourth elbow 143 may be rigid polyvinyl chloride. The dimensions of the fourth elbow 143 may be set in accordance with the standard of JIS K 6739 "Rigid polyvinyl chloride pipe joints for drainage," for example.

[0151] In the piping system 1E, the length of the piping 141 is 1.0 m or more. The length of the piping 141 is determined by the length of the second horizontal pipe 142. This allows the fluid to be discharged over a sufficient range of the second roof 11c.

[0152] In the piping system 1E, the distance L14 between the second elbow 52 and the third elbow 140 in the vertical direction is 2.0 m or more. This allows the flow of fluid from the standpipe 3 to the piping 141 to be stabilized.

[0153] [1.6.2 Effects, etc.] The piping system 1E described above further includes a third elbow 140 connected to the downstream end 3b of the standpipe 3, and a pipe 141 connected downstream of the third elbow 140. The length of the pipe 141 is 1.0 m or more. The opening 1432a at the downstream end of the pipe 141 is blocked by 50% or more. The pipe 141 has one or more discharge ports 143c penetrating the pipe wall of the pipe 141 (second horizontal pipe 142). The distance L14 between the second elbow 52 and the third elbow 140 in the vertical direction is 2.0 m or more. This configuration allows the fluid to be stably discharged from the discharge ports 143c and the openings 1432a.

[0154] 24 is a schematic diagram of a piping system 1F according to embodiment 7. The piping system 1F includes a second eaves gutter 150 and a pipe 151 in addition to a eaves gutter 2, a vertical pipe 3, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protruding member 6, and a drain 7.

[0155] The second eaves gutter 150 receives rainwater from, for example, the eaves of the building 11. The second eaves gutter 150 is installed under the eaves of the building. The second eaves gutter 150 is shaped like a long bucket. The second eaves gutter 150 forms a second flow path that extends in a direction intersecting the vertical direction. The second eaves gutter 150 has a bottom wall 150a. The bottom wall 150a forms the bottom wall of the second flow path.

[0156] The second eaves gutter 150 has a drop outlet in the bottom wall 150a. The drop outlet of the second eaves gutter 150 is connected to the manhole via a standpipe separate from the standpipe 3.

[0157] The second eaves gutter 150 overlaps at least a portion of the socket 521 of the second elbow 52 in the vertical direction. The second eaves gutter 150 has an opening 150b in the portion that overlaps with the socket 521 of the second elbow 52 in the vertical direction. The opening 150b is a through-hole that penetrates the bottom wall 150a of the second eaves gutter 150. The inner diameter of the opening 150b is larger than the outer diameter of the downpipe 3. The second eaves gutter 150 may be formed by extrusion molding of a resin material. The second eaves gutter 150 may include a core material to reinforce the strength of the entire second eaves gutter 150. The core material may be made of, for example, metal. As another example, the second eaves gutter 150 may be formed from a metal plate, for example, a steel plate (also called a coil).

[0158] The pipe 151 has a larger diameter than the standpipe 3. The pipe 151 penetrates the bottom wall 150a of the second flow path of the second eaves gutter 150 while being separated from the second flow path of the second eaves gutter 150. In this embodiment, the pipe 151 is arranged to penetrate an opening 150b in the bottom wall 150a of the second eaves gutter 150. The pipe 151 is also referred to as a penetration pipe. The pipe 151 has a first member 152 and a second member 153. As an example, the material of the first member 152 and the second member 153 may be rigid polyvinyl chloride.

[0159] The first member 152 has a first cylindrical portion 152a and a first flange portion 152b. The first cylindrical portion 152a covers the entire periphery of the opening 150b and penetrates the opening 150b. The first cylindrical portion 152a extends upward from the upper surface of the bottom wall 150a of the second eaves gutter 150 and downward from the lower surface of the bottom wall 150a. The position of the upper end of the first cylindrical portion 152a is set so that fluid is less likely to flow into the first cylindrical portion 152a from the second flow path of the second eaves gutter 150. In this embodiment, the upper end of the first cylindrical portion 152a is above the upper end of the second eaves gutter 150. The lower end of the first cylindrical portion 152a is below the lower surface of the bottom wall 150a of the second eaves gutter 150. The first flange 152b of the second eaves gutter 150 protrudes outward from the first cylindrical portion 152a and is positioned so as to contact the upper surface of the bottom wall 150a and to cover the entire periphery of the opening 150b.

[0160] The second member 153 has a second cylindrical portion 153a and a second flange portion 153b. The second cylindrical portion 153a covers the entire periphery of the first cylindrical portion 152a below the bottom wall 150a. The second flange portion 153b protrudes outward from the second cylindrical portion 153a and is disposed in contact with the underside of the bottom wall 150a so as to cover the entire periphery of the opening 150b.

[0161] In this embodiment, the first cylindrical portion 152 a and the second cylindrical portion 153 a are straight tubular portions, and the cross sections perpendicular to their central axes are circular. In this embodiment, the first flange portion 152 b and the second flange portion 153 b are plate-shaped portions, and the cross sections perpendicular to their central axes are circular.

[0162] In the piping system 1F, the standpipe 3 is arranged so as to pass through the piping 151. This allows the standpipe 3 to be arranged separately from the second flow path of the second eaves gutter 150, even if the second eaves gutter 150 is present.

[0163] In this embodiment, the inner diameter of the pipe 151 is 5 mm or more larger than the outer diameter of the standpipe 3. The inner diameter of the pipe 151 is determined by the inner diameter of the first cylindrical portion 152a.

[0164] [1.7.2 Effects, etc.] In the piping system 1F, the riser pipe 3 passes through a pipe 151 having a larger diameter than the riser pipe 3. The pipe 151 penetrates the bottom wall 150a of the second flow path while being separated from the second flow path extending in a direction intersecting the vertical direction. The inner diameter of the pipe 151 is 5 mm or more larger than the outer diameter of the riser pipe 3. This configuration allows the riser pipe 3 to be arranged separately from the second flow path.

[0165] 25 is a schematic diagram of a piping system 1G according to embodiment 8. The piping system 1G includes, in addition to the eaves gutter 2, the standpipe 3, the horizontal pipe 4, the first elbow 51, the second elbow 52, ​​the protruding member 6, and the drain 7, a second eaves gutter 160, a pipe 161, a tee 164, a second standpipe 1650, a third standpipe 1651, a second horizontal pipe 1652, a fourth standpipe 1653, a second drain 166, and a third elbow 167.

[0166] The second eaves gutter 160 receives rainwater from, for example, the eaves of the building 11. The second eaves gutter 160 is installed under the eaves of the building 11. The second eaves gutter 160 is shaped like a long bucket. The second eaves gutter 160 forms a second flow path extending in a direction intersecting the vertical direction. The second eaves gutter 160 has a bottom wall 160a. The bottom wall 160a constitutes the bottom wall of the second flow path. The second eaves gutter 160 has a first opening 160b and a second opening 160c in the bottom wall 160a. The first opening 160b is located in a portion that overlaps with the socket 521 of the second elbow 52 in the vertical direction. The first opening 160b is a through-hole that penetrates the bottom wall 160a of the second eaves gutter 160. The inner diameter of the first opening 160b is larger than the outer diameter of the standpipe 3. The second opening 160c is used as a drop opening.

[0167] The second eaves gutter 160 may be formed by extrusion molding of a resin material. The second eaves gutter 160 may include a core material to reinforce the strength of the entire second eaves gutter 160. The core material may be made of metal, for example. As another example, the second eaves gutter 160 may be formed of a metal plate, for example, a steel plate (also called a coil).

[0168] The pipe 161 has a larger pipe diameter than the standpipe 3. For example, the pipe 161 is larger than the standpipe 3 by one size or more. The pipe 161 penetrates the bottom wall 160a of the second flow path of the second eaves gutter 160 while being flow path separated from the second flow path. In the present embodiment, the pipe 161 is arranged to penetrate the first opening 160b of the bottom wall 160a of the second eaves gutter 160. The pipe 161 has a first member 162 and a second member 163. As an example, the material of the first member 162 and the second member 163 may be rigid polyvinyl chloride.

[0169] The first member 162 has a first cylindrical portion 162a and a first flange portion 162b. The first cylindrical portion 162a covers the entire periphery of the first opening 160b and penetrates the first opening 160b. The first cylindrical portion 162a does not extend above the upper surface of the bottom wall 160a of the second eaves gutter 160, but extends below the lower surface of the bottom wall 160a. The lower end of the first cylindrical portion 162a is below the lower surface of the bottom wall 160a of the second eaves gutter 160. The first flange portion 162b of the second eaves gutter 160 protrudes outward from the upper end of the first cylindrical portion 162a and is positioned so as to contact the upper surface of the bottom wall 160a and cover the entire periphery of the first opening 160b.

[0170] The second member 163 has a second cylindrical portion 163a and a second flange portion 163b. The second cylindrical portion 163a covers the entire periphery of the first cylindrical portion 162a below the bottom wall 160a. The second flange portion 163b protrudes outward from the second cylindrical portion 163a and is disposed in contact with the underside of the bottom wall 160a so as to cover the entire periphery of the first opening 160b.

[0171] In this embodiment, the first cylindrical portion 162a and the second cylindrical portion 163a are straight tubular portions, and the cross sections perpendicular to their central axes are circular. In this embodiment, the first flange portion 162b and the second flange portion 163b are plate-shaped portions, and the cross sections perpendicular to their central axes are circular.

[0172] The T-shirt 164 has a first receiving port 164a facing upward, a second receiving port 164b facing downward, and a third receiving port 164c facing sideways. The T-shirt 164 merges the fluid flowing in from the first receiving port 164a with the fluid flowing in from the third receiving port 164c, and allows the combined fluid to flow out from the second receiving port 164b. The angle between the central axis of the first receiving port 164a and the central axis of the third receiving port 164c is less than 90°. As an example, the angle between the central axis of the first receiving port 164a and the central axis of the third receiving port 164c is set to 88.83°. As an example, the material of the T-shirt 164 is hard polyvinyl chloride.

[0173] The first receiving port 164a is connected to the first opening 160b of the second eaves gutter 160 via a second standpipe 1650. The second receiving port 164b is connected to the manhole via a third standpipe 1651. The third receiving port 164c is connected to the second opening 160c of the second eaves gutter 160 via a second horizontal pipe 1652, a fourth standpipe 1653, and a third elbow 167.

[0174] The second riser 1650 connects the pipe 161 and the tee 164. In this embodiment, the second riser 1650 has a larger pipe diameter than the pipe 161. The second riser 1650 is straight. The cross section perpendicular to the central axis of the second riser 1650 is circular. The second riser 1650 is arranged so that the direction of the central axis of the second riser 1650 coincides with the up-down direction (vertical direction). The second riser 1650 has an upstream end 1650a and a downstream end 1650b. The upstream end 1650a is connected to the downstream end of the pipe 161. In this embodiment, the second cylindrical portion 163a of the second member 163 of the pipe 161 is inserted into the upstream end 1650a of the second riser 1650. The downstream end 1650 b is connected to the first socket 164 a of the tee 164 .

[0175] The third standpipe 1651 is installed to drain water from the tee 164 into the manhole. In this embodiment, the third standpipe 1651 has the same pipe diameter as the second standpipe 1650. For example, the third standpipe 1651 is the same size as the second standpipe 1650. The third standpipe 1651 is straight. The cross section perpendicular to the central axis of the third standpipe 1651 is circular. The third standpipe 1651 is arranged so that the direction of the central axis of the third standpipe 1651 coincides with the up-down direction (vertical direction). The upstream end of the third standpipe 1651 is connected to the second receiving port 164b of the tee 164. The downstream end of the third standpipe 1651 is inserted into the manhole.

[0176] The second drain 166 is disposed at the second opening 160c of the second eaves gutter 160. The second drain 166 does not necessarily have to have a configuration that can contribute to the occurrence of the siphoning phenomenon. The second drain 166 may have a well-known configuration.

[0177] The third elbow 167 changes the direction of the flow path. The third elbow 167 is a connector that connects flow paths with different directions. The third elbow 167 has a curved pipe portion 1670 and sockets 1671 and 1672 at both ends of the curved pipe portion 1670. In the third elbow 167, the socket 1672 is connected to the second drain 166 via the fourth upright pipe 1653, and thereby to the second opening 160c. The socket 1671 is connected to the third socket 164c of the tee 164 via the second horizontal pipe 1652. For example, the material of the third elbow 167 may be rigid polyvinyl chloride. The dimensions of the third elbow 167 may be set in accordance with the standard JIS K 6739, "Rigid Polyvinyl Chloride Pipe Joints for Drainage."

[0178] The fourth standpipe 1653 connects between the second opening 160c and the third elbow 167. The fourth standpipe 1653 is straight. A cross section perpendicular to the central axis of the fourth standpipe 1653 is circular. The fourth standpipe 1653 is arranged so that the direction of the central axis of the fourth standpipe 1653 coincides with the up-down direction (vertical direction). The fourth standpipe 1653 has an upstream end 1653a and a downstream end 1653b. The upstream end 1653a is connected to the second drain 166. The downstream end 1653b is connected to the socket 1672 of the third elbow 167.

[0179] The second horizontal pipe 1652 connects the third elbow 167 and the tee 164. The second horizontal pipe 1652 is straight. The cross section perpendicular to the central axis of the second horizontal pipe 1652 is circular. The second horizontal pipe 1652 is arranged so that the direction of the central axis of the second horizontal pipe 1652 intersects the up-down direction (vertical direction). The second horizontal pipe 1652 has an upstream end 1652a and a downstream end 1652b. The upstream end 1652a is connected to the socket 1671 of the third elbow 167. The downstream end 1652b is connected to the third socket 164c of the tee 110.

[0180] As an example, the second riser pipe 1650, the third riser pipe 1651, the second horizontal pipe 1652, and the fourth riser pipe 1653 have the same pipe diameter. The material of the second riser pipe 1650, the third riser pipe 1651, the second horizontal pipe 1652, and the fourth riser pipe 1653 is rigid polyvinyl chloride. The dimensions of the second riser pipe 1650, the third riser pipe 1651, the second horizontal pipe 1652, and the fourth riser pipe 1653, such as the outer diameter and thickness, may be set in accordance with the standard for rigid polyvinyl chloride pipes (general) in JIS K 6741 "Rigid Polyvinyl Chloride Pipes."

[0181] In the piping system 1G, the downstream end 3b of the standpipe 3 is inserted from above into the first cylindrical portion 162a of the piping 161. As a result, the downstream end 3b of the standpipe 3 is inserted into the first opening 160b. The length L16 of the portion of the standpipe 3 inserted into the first opening 160b is 40 mm or more, which stabilizes the flow of fluid from the second flow path to the first opening 160b and the flow of fluid from the standpipe 3 to the first opening 160b.

[0182] [1.8.2 Effects, etc.] The piping system 1G described above further includes a tee 164 having a first receiving port 164a facing upward, a second receiving port 164b facing downward, and a third receiving port 164c facing sideways. The first receiving port 164a is connected to a first opening 160b in a bottom wall 160a of a second flow path extending in a direction intersecting the vertical direction. The third receiving port 164c is connected to a second opening 160c in the bottom wall 160a of the second flow path. The downstream end 3b of the riser pipe 3 is inserted into the first opening 160b. The length L16 of the portion of the riser pipe 3 inserted into the first opening 160b is 40 mm or more. This configuration enables stabilization of the flow of fluid from the second flow path to the first opening 160b and the flow of fluid from the riser pipe 3 to the first opening 160b.

[0183] 26 is a schematic diagram of a piping system 1H according to embodiment 9. In addition to the eaves gutter 2, the stand pipe 3, the horizontal pipe 4, the first elbow 51, the second elbow 52, ​​the protruding member 6, and the drain 7, the piping system 1H includes a second eaves gutter 160, a pipe 161, a tee 164H, a second stand pipe 1650, a third stand pipe 1651, a second horizontal pipe 1652, a second drain 166, and a third elbow 167H.

[0184] The cheese 164H has a first receiving opening 164a, a second receiving opening 164b, and a third receiving opening 164c, similar to the cheese 164. In the cheese 164H, the angle between the central axis of the first receiving opening 164a and the central axis of the third receiving opening 164c is 45°.

[0185] Similar to the third elbow 167, the third elbow 167H has a curved pipe portion 1670 and sockets 1671 and 1672 on both ends of the curved pipe portion 1670. In the third elbow 167H, the angle between the central axes of the sockets 1671 and 1672 is 45°.

[0186] In the piping system 1H as well, the downstream end 3b of the standpipe 3 is inserted from above into the first cylindrical portion 162a of the piping 161. As a result, the downstream end 3b of the standpipe 3 is inserted into the first opening 160b. The length L16 of the portion of the standpipe 3 inserted into the first opening 160b is 40 mm or more, which stabilizes the flow of fluid from the second flow path to the first opening 160b and the flow of fluid from the standpipe 3 to the first opening 160b.

[0187] [1.9.2 Effects, etc.] The piping system 1H described above further includes a tee 164H having a first receiving port 164a facing upward, a second receiving port 164b facing downward, and a third receiving port 164c facing sideways. The first receiving port 164a is connected to a first opening 160b in a bottom wall 160a of a second flow path extending in a direction intersecting the vertical direction. The third receiving port 164c is connected to a second opening 160c in a bottom wall 160a of the second flow path. The downstream end 3b of the riser pipe 3 is inserted into the first opening 160b. The length L16 of the portion of the riser pipe 3 inserted into the first opening 160b is 40 mm or more. This configuration enables stabilization of the flow of fluid from the second flow path to the first opening 160b and the flow of fluid from the riser pipe 3 to the first opening 160b.

[0188] [1.10 Tenth Embodiment] [1.10.1 Configuration] Fig. 27 is a schematic diagram of a piping system 1I according to a tenth embodiment. The piping system 1I includes an eaves gutter 2, a standpipe 3I, a horizontal pipe 4, a first elbow 51, a second elbow 52, ​​a protrusion member 6I, and a drain 7. The piping system 1I according to the tenth embodiment differs from the piping system 1 according to the first embodiment in the protrusion member 6I and the standpipe 3I.

[0189] The standpipe 3I is composed of multiple pipes. The standpipe 3I includes straight pipes 31I and 32I and a connecting joint 33I that connects the straight pipes 31I and 32I. The straight pipe 31I is the downstream portion of the standpipe 3I, and the straight pipe 32I is the upstream portion of the standpipe 3I. In this embodiment, the straight pipe 31I is longer than the straight pipe 32I. A first end (upper end in FIG. 27 ) of the straight pipe 32I defines the upstream end 3a of the standpipe 3I, a second end (lower end in FIG. 27 ) of the straight pipe 32I is connected to the first end (upper end in FIG. 1 ) of the straight pipe 31I via the connecting joint 33I, and a second end (lower end in FIG. 27 ) of the straight pipe 31I defines the downstream end 3b of the standpipe 3I.

[0190] 27, the protruding member 6I is located downstream of the second elbow 52. More specifically, the protruding member 6I is located on the inner circumferential side of the second elbow 52 within the standpipe 3I, which is a straight pipe section downstream of the second elbow 52, ​​and is used to partially reduce the flow path cross-sectional area of ​​the standpipe 3I.

[0191] The protrusion member 6I is disposed in a straight pipe that is disposed downstream of a bent pipe (elbow) that changes the direction of the flow path, and is used to partially reduce the flow path cross-sectional area of ​​the straight pipe. In the piping system 1I, the straight pipe 32I of the standpipe 3I is disposed downstream of the second elbow 52 that changes the direction of the flow path. The protrusion member 6I is disposed so that at least a portion of the standpipe 3I is a straight pipe. In this embodiment, at least a portion of the standpipe 3I is a straight pipe 32I.

[0192] The protruding member 6I, together with the straight pipe 32I in which the protruding member 6I is arranged, constitutes a piping member 10I. In this embodiment, the piping member 10I is formed not of the entire vertical pipe 3I but of a part (straight pipe 32I) of the vertical pipe 3I, and therefore is easy to transport.

[0193] Fig. 28 is a perspective view of a configuration example of the piping member 10I, and Fig. 29 is an exploded perspective view of the piping member 10I. As can be seen from Fig. 28 and Fig. 29, the piping member 10I includes a straight pipe 32I of a vertical pipe 3I and a protrusion member 6I.

[0194] As shown in FIG. 29, the protruding member 6I has a size, that is, a length, a width, and a height (thickness), that allows it to be placed inside the straight pipe 32I of the vertical pipe 3I.

[0195] In this embodiment, the protruding member 6I and the straight pipe 32I of the upright pipe 3I are separate bodies and can be made of different materials. Examples of materials for the protruding member 6I include resins such as polyvinyl chloride (PVC), rigid polyvinyl chloride (rigid PVC), PMMA, ABS, and ASA, and metals such as steel, aluminum, and stainless steel (corrosion-resistant metals). In particular, the difference between the linear expansion coefficient of the material of the protruding member 6I and the linear expansion coefficient of the material of the portion to which the protruding member 6I is attached (in this embodiment, the straight pipe 32I of the upright pipe 3I) is 4.7 × 10 －５ Preferably, 3.5 x 10 or less －５ This reduces the possibility of the protruding member 6I peeling off due to expansion and contraction caused by temperature differences (for example, temperature differences between summer and winter). As an example, the material of the protruding member 6I may be ASA, and the material of the standpipe 3I may be PVC.

[0196] The protruding member 6I has a first surface 60a and a second surface 60b. The first surface 60a faces the inner circumferential surface 30a of the standpipe 3I. The second surface 60b is located on the opposite side of the first surface 60a and acts on (comes into contact with) the fluid flowing through the flow path. The first surface 60a and the second surface 60b are both surfaces of the protruding member 6I in a first direction. The first direction corresponds to the height of the protruding member 6I.

[0197] The protruding member 6I has a third end 6c and a fourth end 6d in a second direction perpendicular to the first direction. The second direction corresponds to the width of the protruding member 6I. The third end 6c and the fourth end 6d are opposite ends of the protruding member 6I in the width direction. The width direction of the protruding member 6I is perpendicular to the direction of the central axis C3 of the stand pipe 3I. The protruding member 6I has an outer shape that is mirror-symmetrical with respect to a plane perpendicular to the second direction.

[0198] The protrusion member 6I has a first end 6a and a second end 6b in a third direction perpendicular to the first and second directions. The third direction corresponds to the length of the protrusion member 6I. The first end 6a and the second end 6b are both ends of the protrusion member 6I in the longitudinal direction. The longitudinal direction of the protrusion member 6I coincides with the direction of the central axis C3 of the standpipe 3I. Therefore, the third direction is also a direction along the flow path of the standpipe 3I. The first end 6a faces upstream, and the second end 6b faces downstream. In the protrusion member 6I, a fluid flow occurs from the first end 6a to the second end 6b.

[0199] FIG. 30 is a cross-sectional view of the piping member 10I. FIG. 31 is an enlarged view of P1 in FIG. 30. FIG. 32 is a cross-sectional view taken along line A-A in FIG. 30. FIG. 33 is a cross-sectional view with a portion of the piping member 10I cut away. FIG. 34 is a plan view of the piping member 10I. FIG. 35 is a bottom view of the piping member 10I. FIG. 36 is a cross-sectional view taken along line X-X in FIG. 32. FIG. 37 is a cross-sectional view taken along line XI-XI in FIG. 32. FIG. 38 is a cross-sectional view taken along line XII-XII in FIG. 32. FIG. 39 is a cross-sectional view taken along line XIII-XIII in FIG. 32.

[0200] Also, Figure 40 is a front view of the protruding member 6I (view of the protruding member 6I from the second surface 60b). Figure 41 is a rear view of the protruding member 6I (view of the protruding member 6I from the first surface 60a). Figure 42 is a side view of the protruding member 6I (view of the protruding member 6I from the third end 6c). Figure 43 is another side view of the protruding member 6I (view of the protruding member 6I from the fourth end 6d).

[0201] As shown in FIG. 41 , the first surface 60 a has an outer periphery 601 and a central portion 602 .

[0202] The outer peripheral portion 601 is used to fix the protruding member 6I to the standpipe 3I. As shown in FIGS. 34 to 39 , the outer peripheral portion 601 is a portion of the first surface 60a that can come into contact with the inner peripheral surface 30a. The shape of the outer peripheral portion 601 is set so that it can come into contact with the inner peripheral surface 30a of the standpipe 3I. For example, the outer peripheral portion 601 has a convex shape when viewed from the direction of the central axis C3 of the standpipe 3I. The radius of curvature of the first surface 60a is set based on the radius of curvature of the inner peripheral surface 30a so that substantially no gap occurs between the first surface 60a and the inner peripheral surface 30a of the standpipe 3I.

[0203] 41, the outer peripheral portion 601 extends along the entire periphery of the first surface 60a, and therefore surrounds the central portion 602 along the entire periphery.

[0204] The outer peripheral portion 601 has a groove 603. The groove 603 runs along at least a portion of the outer periphery of the first surface 60a. The groove 603 is used to apply an adhesive to fix the protruding member 6I to the standpipe 3I. For example, the groove 603 can be used as a guide for applying the adhesive to the first surface 60a of the protruding member 6I. This facilitates the assembly work of the piping member 10I or the installation work of the piping system 1I, and reduces the likelihood of the protruding member 6I falling off or being left unattached.

[0205] In this embodiment, the groove 603 extends along the entire outer periphery of the first surface 60 a. In Fig. 41, the groove 603 is composed of groove portions 603 a, 603 b, 603 c, and 603 d that extend along the sides of the first surface 60 a on the first end 6 a, second end 6 b, third end 6 c, and fourth end 6 d sides, respectively.

[0206] In this embodiment, the groove 603 is located at a distance of 1 mm to 15 mm from the outer periphery of the first surface 60 a. That is, the grooves 603 a, 603 b, 603 c, and 603 d are located at a distance of 1 mm to 15 mm from the sides of the first surface 60 a on the first end 6 a, second end 6 b, third end 6 c, and fourth end 6 d sides.

[0207] In this embodiment, as shown in Figure 48 (described later), the cross-sectional shape of the groove 603 is triangular. The groove 603 has a first inner surface 6031 and a second inner surface 6032. The first inner surface 6031 corresponds to a first direction (the height of the protruding member 6I) in which the first surface 60a and the second surface 60b face each other. The second inner surface 6032 corresponds to a second direction (the width of the protruding member 6I) perpendicular to the first direction. This makes it easier to fix the protruding member 6I to the standpipe 3I with an adhesive.

[0208] When manufacturing the protrusion member 6I using a resin molding technique, it is possible to divide the mold for the protrusion member 6I in the second direction of the protrusion member 6I. As described above, the groove 603 has the first inner surface 6031 and the second inner surface 6032, and therefore is easy to form using a mold. This makes it possible to reduce the manufacturing cost of the protrusion member 6I.

[0209] 48 , the width W4 of the groove 603 is 0.5 mm or more and 3.0 mm or less. The depth d4 of the groove 603 is 0.2 mm or more and 2.0 mm or less. This makes it easier to fix the protruding member 6I to the straight pipe (vertical pipe 3I) with adhesive.

[0210] The central portion 602 is a portion of the first surface 60a that is recessed from the outer peripheral portion 601. As a result, as shown in FIGS. 36 to 39 , even when the outer peripheral portion 601 contacts the inner peripheral surface 30a, a gap is formed between at least a portion of the central portion 602 and the inner peripheral surface 30a. The central portion 602 can function as a buffer for excess adhesive used to secure the protruding member 6I to the standpipe 3I. This allows the central portion 602 to receive excess adhesive applied to the first surface 60a of the protruding member 6I, reducing the possibility of the adhesive spilling out of the protruding member 6I. This reduces the possibility of a decrease in flow rate due to such adhesive spillage.

[0211] The central portion 602 is composed of a first region 602a on the third end 6c side of the protruding member 6I and a second region 602b on the fourth end 6d side of the protruding member 6I. The first region 602a and the second region 602b are flat surfaces. The first region 602a is inclined so as to move away from the inner circumferential surface 30a as it moves toward the third end 6c. The second region 602b is inclined so as to move away from the inner circumferential surface 30a as it moves toward the fourth end 6d. The first region 602a and the second region 602b are rectangular, and the dimension in the second direction is shorter than the dimension in the third direction. The dimension in the second direction of each of the first region 602a and the second region 602b is 5% to 20% of the maximum dimension W1 of the first surface 60a in the second direction. Therefore, in this embodiment, the dimension W3 of the central portion 602 in the second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other is 10% to 40% of the maximum dimension W1 of the first surface 60a in the second direction, which further reduces the overflow of adhesive that secures the protruding member 6I to the straight pipe (vertical pipe 3I).

[0212] In this embodiment, the central portion 602 is line-symmetrical about the center line of the protruding member 6I in the second direction (the width of the protruding member 6I). Therefore, the first region 602a and the second region 602b are line-symmetrical about the center line of the protruding member 6I in the second direction (the width of the protruding member 6I). This further reduces the overflow of adhesive that fixes the protruding member 6I to the straight pipe (upright pipe 3I).

[0213] As described above, the outer peripheral portion 601 completely surrounds the central portion 602. That is, in the protruding member 6I, the central portion 602 is completely surrounded by the outer peripheral portion 601. This further reduces the overflow of adhesive that fixes the protruding member 6I to the standpipe 3I.

[0214] When the protruding member 6I is manufactured by a resin molding technique, it is preferable to provide a gate in a portion of the mold corresponding to the central portion 602. Even if a gate residue occurs, the central portion 602 is a portion of the first surface 60a that is recessed from the outer peripheral portion 601. Therefore, it is possible to reduce the possibility that the gate residue will get in the way when fixing the protruding member 6I to the standpipe 3I.

[0215] As shown in Figures 30, 32 to 35, and 40, the second surface 60b includes a main surface 61 and first and second side surfaces 62, 63. As shown in Figures 30, 32 to 33, the main surface 61 extends from the first end 6a toward the second end 6b. As shown in Figures 34 and 35, the main surface 61 faces the center of the stand pipe 3I when viewed from the direction of the central axis C3 of the stand pipe 3I. The first side surface 62 and the second side surface 63 are on both sides of the main surface 61 when viewed from the direction of the central axis C3 of the stand pipe 3I. The first side surface 62 is located on the third end 6c side of the main surface 61 (left side in Figure 34), and the second side surface 63 is located on the fourth end 6d side of the main surface 61 (right side in Figure 34).

[0216] In the protruding member 6I, the main surface 61 and the first and second side surfaces 62, 63 of the second surface 60b can come into contact with the fluid flowing inside the standpipe 3I. As shown in Fig. 32 , the protruding member 6I causes a flow F1 along the main surface 61, a flow F2 along the first side surface 62, and a flow F3 along the second side surface 63. Because the main surface 61 and the first and second side surfaces 62, 63 can come into contact with the fluid, it is preferable that the surface roughness of the main surface 61 and the first and second side surfaces 62, 63 be small, as this can be expected to improve the flow rate.

[0217] The protrusion member 6I has a first separation wall 64 for promoting separation of the flow F1 and the flow F2. The presence of the first separation wall 64 can make it easier for the flow F2 to separate from the flow F1. The first separation wall 64 is located between the main surface 61 and the first side surface 62. In this embodiment, the first separation wall 64 is the boundary between the main surface 61 and the first side surface 62. In other words, the boundary between the main surface 61 and the first side surface 62 forms a wall between a flow path having the main surface 61 as its bottom surface and a flow path having the first side surface 62 as its bottom surface. The first separation wall 64 can be formed by having both the main surface 61 and the first side surface 62 have a concave shape.

[0218] The protrusion member 6I has a second separation wall 65 to promote separation of the flow F1 and the flow F3. The presence of the second separation wall 65 can make it easier for the flow F3 to separate from the flow F1. The second separation wall 65 is located between the main surface 61 and the second side surface 63. In this embodiment, the second separation wall 65 is the boundary between the main surface 61 and the second side surface 63. In other words, the boundary between the main surface 61 and the second side surface 63 forms a wall between a flow path having the main surface 61 as its bottom surface and a flow path having the second side surface 63 as its bottom surface. The second separation wall 65 can be formed by having both the main surface 61 and the second side surface 63 have a concave shape.

[0219] As shown in Figures 30, 33, 34, and 40 to 43, the protrusion member 6I has an end face 66 at the first end 6a. The end face 66 intersects with the central axis C3 of the standpipe 3I. In this embodiment, the end face 66 is perpendicular to the central axis C3 of the standpipe 3I. The first end 6a of the protrusion member 6I has a small thickness. In contrast, because the protrusion member 6I has the end face 66, the possibility of damage to the first end 6a of the protrusion member 6I can be reduced.

[0220] As shown in Figures 30, 37, and 41 to 43, the protrusion member 6I has a protrusion 67. The protrusion 67 is used to connect or position the standpipe 3I and the protrusion member 6I. The protrusion 67 is arranged on the first surface 60a. The protrusion 67 is shaped to fit into the hole 3d on the inner circumferential surface of the standpipe 3I. In this embodiment, the standpipe 3I has a pair of holes 3d at the upstream end 3a. The holes 3d are formed as through holes. The protrusion member 6I has a pair of protrusions 67 that fit into the pair of holes 3d, respectively. By fitting the pair of protrusions 67 into the pair of holes 3d, the protrusion member 6I is positioned relative to the standpipe 3I.

[0221] As shown in Figures 30, 31, and 40 to 43, the protrusion member 6I has an end face 68 at the second end 6b. The end face 68 intersects with the central axis C3 of the standpipe 3I. In this embodiment, the end face 68 is perpendicular to the central axis C3 of the standpipe 3I. The end face 68 has an opening 69. The opening 69 is connected to the internal space of the protrusion member 6I.

[0222] Figure 44 is an exploded perspective view of the protrusion member 6I, and Figure 45 is another exploded perspective view of the protrusion member 6I. As can be seen from Figures 44 and 45, the protrusion member 6I is composed of a first portion 610 and a second portion 620, which are separate bodies. The first portion 610 is a portion of the protrusion member 6I on the side of the third end 6c in the second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other. The second portion 620 is a portion of the protrusion member 6I on the side of the fourth end 6d in the second direction.

[0223] 46 is a side view of the first part 610. The first part 610 occupies half of the protruding member 6I on the third end 6c side. The first part 610 has a first outer part 611, a first boss 612, first ribs 613 and 614, a receiving part 615, and a recess 616.

[0224] The first outer portion 611 defines the outer shape of the third end 6c of the protruding member 6I. The first outer portion 611 has a hollow shape with an opening 611b on a third surface 611a facing the second part 620. Because the first outer portion 611 is hollow, the amount of material required can be reduced compared to a solid first outer portion 611. The first outer portion 611 includes the first surface 60a, the second surface 60b, the first end 6a, the second end 6b, the end face 66, the protrusion 67, the end face 68, and first portions 60a1, 60b1, 6a1, 6b1, 66a, 67a, 68a, and 69a on the third end 6c side of the opening 69. The first portion 60a1 of the first surface 60a includes a first portion 601a of the outer periphery 601 and a first region 602a of the central portion 602. The first portion 601a of the outer circumferential portion 601 includes, as a first portion of the groove 603, a groove portion 603a, a first portion 603c1 of the groove portion 603c, and a first portion 603d1 of the groove portion 603d.

[0225] The first boss 612 extends from the inner surface of the first outer portion 611 toward the second portion 620 along the second direction. The first boss 612 is cylindrical. The first boss 612 has a hole 612a into which a second boss 622 (described later) fits. In this embodiment, the first portion 610 has two first bosses 612. The two first bosses 612 are aligned along the third direction.

[0226] The first ribs 613, 614 extend within the first outer portion 611 in a direction perpendicular to the second direction and connect two points on the inner surface of the first outer portion 611. The first rib 613 extends along the third direction. The first rib 614 extends along the first direction. In this embodiment, the first portion 610 has two first ribs 614. The two first ribs 614 are aligned along the third direction. Although the first outer portion 611 is hollow, the presence of the first ribs 613, 614 reduces a decrease in strength of the first portion 610.

[0227] The receiving portion 615 is formed around the opening 611b of the third surface 611a. The receiving portion 615 has a shape that fits a peripheral wall portion 625 (described later). In this embodiment, the receiving portion 615 is a step portion formed around the entire periphery of the opening 621b.

[0228] The recess 616 is used to connect the first part 610 and the second part 620. The recess 616 is a portion of the first part 610 into which a protrusion 626 (described later) of the second part 620 fits. The recess 616 is formed on the first surface 60a side of the first part 610. In this embodiment, the recess 616 is an opening located on the first surface 60a. The recess 616 is rectangular. The recess 616 is located in a position recessed from a portion of the first surface 60a that can contact the inner circumferential surface 30a. This reduces the possibility that the recess 616 will get in the way when fixing the protrusion member 6I to the standpipe 3I. More specifically, as shown in FIGS. 41 and 42 , the recess 616 is located in the central portion 602, not the outer circumferential portion 601, of the first surface 60a. In this embodiment, the first part 610 has two recesses 616. The two recesses 616 are located on the first end 6a side and the second end 6b side in the central portion 602 of the first surface 60a. In particular, the recess 616 on the first end 6a side is located between the two protrusions 67 in the third direction.

[0229] 47 is a side view of the second part 620. The second part 620 occupies half of the protruding member 6I on the side of the fourth end 6d. The second part 620 has a second outer part 621, a second boss 622, second ribs 623 and 624, a peripheral wall part 625, and a protrusion 626.

[0230] The second outer portion 621 defines the outer shape of the fourth end 6d of the protruding member 6I. The second outer portion 621 is hollow, with an opening 621b on a fourth surface 621a facing the first part 610. Because the second outer portion 621 is hollow, the amount of material required can be reduced compared to a solid second outer portion 621. The second outer portion 621 includes the first surface 60a, the second surface 60b, the first end 6a, the second end 6b, the end face 66, the protrusion 67, the end face 68, and second portions 60a2, 60b2, 6a2, 6b2, 66b, 67b, 68b, and 69b on the fourth end 6d side of the opening 69. The second portion 60a2 of the first surface 60a includes a second portion 601b of the outer periphery 601 and a second region 602b of the central portion 602. The second portion 601b of the outer circumferential portion 601 includes, as the second portion of the groove 603, a groove portion 603b, a second portion 603c2 of the groove portion 603c, and a second portion 603d2 of the groove portion 603d.

[0231] The second boss 622 extends from the inner surface of the second outer portion 621 toward the first part 610 in the second direction. The second boss 622 is coupled to the first boss 612. The second boss 622 is cylindrical. The second boss 622 is sized to fit into the hole 612a of the first boss 612. The second boss 622 is coupled to the first boss 612 by fitting into the hole 612a of the first boss 612. In this embodiment, the second part 620 has two second bosses 622. The two second bosses 622 are aligned along the third direction.

[0232] The second ribs 623, 624 extend within the second outer shell 621 in a direction perpendicular to the second direction and connect two points on the inner surface of the second outer shell 621. The second rib 623 extends along the third direction. The second rib 624 extends along the first direction. In this embodiment, the second part 620 has two second ribs 624. The two second ribs 624 are aligned along the third direction. Although the second outer shell 621 is hollow, the presence of the second ribs 623, 624 reduces a decrease in strength of the second part 620.

[0233] The peripheral wall portion 625 protrudes from the periphery of the opening 621b in the fourth surface 621a toward the third end 6c and surrounds the opening 621b in the fourth surface 621a. In the present embodiment, the peripheral wall portion 625 has a shape that surrounds the entire periphery of the opening 621b. The peripheral wall portion 625 has a shape that fits inside the receiving portion 615.

[0234] The protrusion 626 is used to connect the first portion 610 and the second portion 620. The protrusion 626 is adapted to fit into the recess 616. By fitting the protrusion 626 into the recess 616 in this manner, separation between the first portion 610 and the second portion 620 is reduced. The protrusion 626 extends toward the third end 6c. The protrusion 626 is formed on the first surface 60a side of the second portion 620. In this embodiment, the protrusion 626 includes a long plate-shaped spring portion 626a and a claw portion 626b at the tip of the spring portion 626a. The protrusion 626 is fixed to the recess 616 by fitting the claw portion 626b into the recess 616. The protrusion 626 is located in a recessed position on the first surface 60a relative to a portion that can contact the inner circumferential surface 30a. This reduces the possibility that the protrusion 626 will get in the way when fixing the protruding member 6I to the standpipe 3I. 41 and 43 , the protrusion 626 is located in the central portion 602 of the first surface 60a, not in the outer periphery 601. In this embodiment, the second portion 620 includes two protrusions 626. The two protrusions 626 are located on the first end 6a side and the second end 6b side in the central portion 602 of the first surface 60a. In particular, the protrusion 626 on the first end 6a side is located between the two protrusions 67 in the third direction.

[0235] The protrusion member 6I is assembled by joining the first part 610 and the second part 620 so that the third surface 611a of the first part 610 and the fourth surface 621a of the second part 620 face each other. Figure 48 is a cross-sectional view of the protrusion member 6I. As can be seen from Figures 42 and 48, when the protrusion member 6I is assembled, the protrusion 626 fits into the recess 616, the second boss 622 is joined to the first boss 612, and the peripheral wall portion 625 fits into the receiving portion 615.

[0236] In the protruding member 6I, the tip of the second boss 622 is between the tip of the protrusion 626 and the fourth surface 621a in the second direction. Therefore, when the first part 610 and the second part 620 are joined, the protrusion 626 contacts the first part 610 rather than the second boss 622 and fits into the recess 616. This allows the second boss 622 to be positioned relative to the first boss 612. This makes it easier to join the first part 610 and the second part 620. In the second direction, the tip of the second boss 622 is between the tip of the protrusion 626 and the tip of the peripheral wall part 625. Therefore, after the second boss 622 is joined to the first boss 612, the peripheral wall part 625 fits into the receiving part 615. This makes it easier to position the peripheral wall part 625 relative to the receiving part 615. This makes it easier to join the first part 610 and the second part 620.

[0237] By joining the first part 610 and the second part 620, the first parts 60a1, 60b1, 6a1, 6b1, 66a, 67a, 68a, 69a of the first part 610 and the second parts 60a2, 60b2, 6a2, 6b2, 66b, 67b, 68b, 69b of the second part 620 are joined together to form the first surface 60a, the second surface 60b, the first end 6a, the second end 6b, the end surface 66, the protrusion 67, the end surface 68, and the opening 69.

[0238] In this manner, in the protrusion member 6I, the first portion 610 on the third end 6c side in the second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other and the second portion 620 on the fourth end 6d side in the second direction are separate bodies. Therefore, the first portion 610 and the second portion 620 can be manufactured separately using a molding technique using a mold, such as injection molding. This simplifies the configuration of the mold required to manufacture the protrusion member 6I compared to manufacturing the protrusion member 6I as a single part using a molding technique using a mold. This reduces the cost of the mold itself, and as a result, reduces the manufacturing cost of the protrusion member 6I.

[0239] Because the first outer portion 611 and the second outer portion 621 are hollow, the amount of material required can be reduced compared to when they are solid. Unlike when the protruding member 6I is manufactured as a single part by molding using a mold, when the protruding member 6I is hollow, openings can be provided not in the first surface 60a but in the third surface 611a of the first outer portion 611 and the fourth surface 621a of the second outer portion 621. This increases the area of ​​the first surface 60a that can be used for bonding the protruding member 6I.

[0240] In the protrusion member 6I, the interior of the first outer portion 611 and the interior of the second outer portion 621 form the internal space of the protrusion member 6I. Fluid may enter the internal space of the protrusion member 6I through the gap between the first portion 610 and the second portion 620. If the fluid is water, it may freeze due to a drop in temperature. In this case, the water expands as it turns to ice, which may cause damage to the protrusion member 6I. In this embodiment, the peripheral wall portion 625 of the second portion 620 fits inside the receiving portion 615 of the first portion 610, thereby reducing the possibility of fluid entering through the gap between the first portion 610 and the second portion 620. Furthermore, in the protrusion member 6I, the opening 69 on the end surface 68 connects to the interior of the first outer portion 611 and the interior of the second outer portion 621. Therefore, water that has entered the internal space of the protrusion member 6I can be drained through the opening 69. This reduces the possibility of damage to the protruding member 61 due to fluid such as water accumulating in the internal space of the protruding member 61. In other words, the opening 69 functions as a drain hole.

[0241] FIG. 49 is an explanatory diagram of the attachment of the protruding member 6I. The protruding member 6I is disposed on the inner circumferential surface 30a of the straight pipe 32I of the stand pipe 3I. An adhesive is applied to the first surface 60a, and the protruding member 6I is attached to the straight pipe 32I by the adhesive. As described above, the outer peripheral portion 601 of the first surface 60a has a groove 603. The groove 603 can be used as a guide for applying adhesive to the first surface 60a of the protruding member 6I. This facilitates the attachment of the protruding member 6I and reduces the likelihood of the protruding member 6I falling off or being left unattached. The central portion 602 of the first surface 60a is recessed from the outer peripheral portion 601, so it can function as a buffer for excess adhesive. This allows excess adhesive applied to the first surface 60a of the protruding member 6I to be received by the central portion 602, reducing the likelihood of it spilling out of the protruding member 6I. In this embodiment, the protrusion member 6I is positioned relative to the straight pipe 32I by fitting the pair of protrusions 67 into the pair of holes 3d, respectively. By fitting the pair of protrusions 67 into the pair of holes 3d, respectively, the possibility of the protrusion member 6I falling off the straight pipe 32I can be reduced compared to when adhesive alone is used. Here, the protrusion 67 is composed of a first portion 67a of the first part 610 and a second portion 67b of the second part 620. By inserting the protrusion 67 into the holes 3d, the possibility of the protrusion 67 separating into the first portion 67a and the second portion 67b is reduced. This makes it easier to maintain the bonded state between the first part 610 and the second part 620.

[0242] 50 is an explanatory diagram of the installation of the piping member 10I. The piping member 10I is arranged on the downstream side of the second elbow 52 with the upstream end 3a inserted into the socket 521 of the second elbow 52. When the piping member 10I is connected to the socket 521 of the second elbow 52, ​​the pair of holes 3d of the standpipe 3I are hidden by the socket 521.

[0243] By disposing the protruding member 6I, the flow path cross-sectional area of ​​the piping member 10I is not constant, and there is a reduced portion where the flow path cross-sectional area of ​​the piping member 10I is smaller than the cross-sectional area of ​​the straight pipe 32I. The protruding member 6I is located closer to the upstream end 3a of the standpipe 3I than to the downstream end 3b of the standpipe 3I. In this embodiment, the protruding member 6I is located at the upstream end 3a of the standpipe 3I. In other words, the protruding member 6I reduces the flow path at the upstream end 3a of the standpipe 3I that connects to the second elbow 52.

[0244] In this embodiment, the piping member 10I includes a protruding member 6I. The presence of the protruding member 6I is expected to (1) facilitate water flow along the pipe wall more easily than without the protruding member 6I, and (2) reduce the number of areas where pressure loss may occur. Therefore, the protruding member 6I reduces pressure loss caused by separation downstream from the second elbow 52, ​​thereby improving flow rate. Unlike the technology described in Patent Document 1, the piping member 10I does not require a large radius of curvature on the inner circumferential surface of the inner circumferential side of the second elbow 52, ​​simply by including the protruding member 6I, thereby enabling miniaturization. Therefore, the protruding member 6I can improve flow rate while enabling miniaturization. The protruding member 6I is located inside the upright pipe 3I, making it less noticeable when viewed from the perspective of the piping system 1I as a whole. This is expected to improve the aesthetic appearance of the piping system 1I as a whole.

[0245] Furthermore, the protruding member 6I has a protrusion 6i in a region between the apex 6e and the second end 6b. Compared to when the protrusion 6i is not present, the path of the flow (mainly the flow F1) along the protruding member 6I can be extended. This promotes the Coanda effect of the protruding member 6I, and the flow rate can be improved. Furthermore, the presence of the protrusion 6i makes it possible to improve the strength of the region of the protruding member 6I between the apex 6e and the second end 6b.

[0246] The shape of the protruding member 6I will be described in more detail.

[0247] As can be seen from Figures 30, 32, and 34 to 39, the shape (cross-sectional shape) of the protrusion member 6I when viewed from the direction of the central axis C3 of the standpipe 3I changes along the direction of the central axis C3 of the standpipe 3I.

[0248] 30, the height of the protruding member 6I varies along the direction of the central axis C3 of the stand pipe 3I. In this embodiment, the protruding member 6I has a top portion 6e and a protruding portion 6i.

[0249] The top 6e is located between the first end 6a and the second end 6b. The top 6e is the highest part of the protruding member 6I. The top 6e makes the flow path cross-sectional area of ​​the standpipe 3I the smallest.

[0250] The protrusion 6i extends from a portion between the top 6e and the second end 6b toward the center of the standpipe 3I when viewed from the direction of the central axis C3 of the standpipe 3I. In this embodiment, the protrusion 6i is located at the second end 6b. The protrusion 6i does not protrude beyond the top 6e when viewed from the direction of the central axis C3 of the standpipe 3I.

[0251] The height of the protruding member 6I increases monotonically from the first end 6a toward the apex 6e. The height of the protruding member 6I decreases monotonically from the apex 6e toward the second end 6b. In this embodiment, the height of the protruding member 6I decreases from the apex 6e to the protruding portion 6i, and then increases or decreases according to the shape of the protruding portion 6i.

[0252] 30 , in a cross section perpendicular to the width direction of the protruding member 6I, the main surface 61 includes a curved shape at the apex 6e that protrudes toward the second wall surface 30c. This improves the flow rate. From another perspective, the main surface 61 only needs to have a shape that protrudes toward the second wall surface 30c so as to produce the Coanda effect on the downstream side of the second elbow 52. In other words, the main surface 61 only needs to have a shape that produces the Coanda effect on the downstream side of the second elbow 52. This improves the flow rate while enabling miniaturization.

[0253] See Figures 30 and 31. If the dimension of the protrusion 6i as viewed from the direction of the central axis C3 of the riser pipe 3I is a and the inner diameter of the riser pipe 3I is d, then 0.01d≦a≦0.05d holds. This allows for an improvement in the flow rate. If the dimension of the protrusion 6i as viewed from the direction of the central axis C3 of the riser pipe 3I is b and the inner diameter of the riser pipe 3I is d, then 0.01d≦b≦0.05d holds. This allows for an improvement in the flow rate.

[0254] In Figure 31, the shape of the protruding member 6I when the height of the protruding member 6I monotonically decreases from the apex 6e toward the second end 6b is shown by a two-dot chain line. The dimensions a and b of the protruding portion 6i can be set based on the shape shown by the two-dot chain line. The dimension a may be the maximum amount of protrusion from the shape shown by the two-dot chain line. The dimension b may be the distance between the upstream and downstream boundaries of the shape shown by the two-dot chain line and the protruding portion 6i.

[0255] In a cross section perpendicular to the width direction of the protruding member 6I, the protruding portion 6i includes a curved shape that protrudes toward the second wall surface 30c. This improves the flow rate. From another perspective, the protruding portion 6i may have a shape that protrudes toward the second wall surface 30c to generate the Coanda effect. In other words, the protruding portion 6i may have a shape that generates the Coanda effect downstream of the apex 6e. This improves the flow rate. Here, when the radius of curvature of the upstream corner 6j1 and the downstream corner 6j2 of the protruding portion 6i as viewed from the width direction of the protruding member 6I is r, r≦a or r≦b holds. Preferably, r≦a and r≦b hold. Note that the upstream corner 6j1 and the downstream corner 6j2 may have different radii of curvature.

[0256] As shown in Figure 32, the protrusion 6i is located at the second end 6b and is formed across the entire width of the second end 6b.

[0257] 35, at least a part of the protruding portion 6i has a convex shape when viewed from the direction of the central axis C3 of the standpipe 3I, which can contribute to reducing pressure loss in the protruding member 6I.

[0258] Referring to Figure 30, the protrusion member 6I induces a flow F1 along the protrusion member 6I, mainly along the main surface 61. The protrusion member 6I has a protrusion 6i at a portion between the apex 6e and the second end 6b. Referring to Figure 31, a flow F4 can occur along the protrusion 6i downstream of the flow F1. As a result, the path of the flow F1 can be extended compared to when the protrusion 6i is not present. This promotes the Coanda effect by the protrusion member 6I, and the flow rate can be improved. Furthermore, the protrusion 6i itself generates the Coanda effect, making it easier to induce the flow F4.

[0259] As can be seen from FIGS. 34 to 39, the shape of the main surface 61 when viewed from the direction of the central axis C3 of the standpipe 3I changes along the direction of the central axis C3 of the standpipe 3I.

[0260] 34 and 36, when viewed from the direction of the central axis C3 of the standpipe 3I, at least a portion of the main surface 61 has a concave shape. At least a portion of the main surface 61 is a portion of the main surface 61 on the first end 6a side. In other words, the main surface 61 has a concave shape at the first end 6a. When viewed from the direction of the central axis C3 of the standpipe 3I, the radius of curvature of at least a portion of the main surface 61 (first end 6a) is equal to or less than the radius of curvature of the inner circumferential surface 30a of the standpipe 3I. This reduces pressure loss in the protruding member 6I.

[0261] As shown in Figures 34 to 38, the main surface 61 is concave at the first end 6a but convex at the second end 6b. In other words, the shape of the main surface 61, as viewed from the direction of the central axis C3 of the standpipe 3I, changes from concave to convex from the first end 6a to the second end 6b. This facilitates flow along the main surface 61 of the protruding member 6I. In this embodiment, as shown in Figure 38, the shape of the main surface 61, as viewed from the direction of the central axis C3 of the standpipe 3I, is convex at the top 6e. The shape of the main surface 61, as viewed from the direction of the central axis C3 of the standpipe 3I, is convex from the top 6e to the second end 6b. In this embodiment, the protruding member 6I has a flat portion 6f between the first end 6a and the top 6e. As shown in Figure 37, at the flat portion 6f, the main surface 61 is flat when viewed from the direction of the central axis C3 of the standpipe 3I.

[0262] Within the concave area of ​​the main surface 61, the center of the concave shape of the main surface 61, i.e., the lowest part of the concave shape, is located closer to the center than the ends in the width direction of the protrusion member 61. Within the convex area of ​​the main surface 61, the center of the convex shape of the main surface 61, i.e., the highest part of the convex shape, is located closer to the center than the ends in the width direction of the protrusion member 61. In this embodiment, the center of the convex shape of the main surface 61 coincides with the center of the protrusion member 6I in the width direction.

[0263] As can be seen from FIGS. 34 to 39, the shapes of the first side surface 62 and the second side surface 63 when viewed from the direction of the central axis C3 of the standpipe 3I change along the direction of the central axis C3 of the standpipe 3I.

[0264] 34 and 36, when viewed from the direction of the central axis C3 of the standpipe 3I, at least a portion of the first side surface 62 is concave. At least a portion of the first side surface 62 is a portion of the first side surface 62 on the first end 6a side. In other words, the first side surface 62 has a concave shape at the first end 6a. This reduces pressure loss at the protruding member 6I.

[0265] 34 and 36, when viewed from the direction of the central axis C3 of the standpipe 3I, at least a portion of the second side surface 63 is concave. At least a portion of the second side surface 63 is a portion of the second side surface 63 on the first end 6a side. In other words, the second side surface 63 is concave at the first end 6a. This reduces pressure loss at the protruding member 6I.

[0266] The shape of the first side surface 62, as viewed from the direction of the central axis C3 of the standpipe 3I, remains concave from the first end 6a to the second end 6b. As can be seen from Figures 38 and 39, the depth of the concave shape of the first side surface 62 becomes shallower from the top 6e to the second end 6b. This allows the flow F2 along the first side surface 62 to smoothly merge with the flow F1 along the main surface 61 downstream of the protruding member 6I.

[0267] The shape of the second side surface 63 as viewed from the direction of the central axis C3 of the standpipe 3I remains concave from the first end 6a to the second end 6b. As can be seen from Figures 38 and 39, the depth of the concave shape of the second side surface 63 becomes shallower from the top 6e to the second end 6b. This allows the flow F3 along the second side surface 63 to smoothly merge with the flow F1 along the main surface 61 downstream of the protruding member 6I.

[0268] Referring to Figure 32, the first side surface 62 and the second side surface 63 of the protrusion member 6I are symmetrical with respect to the center line of the protrusion member 6I along the central axis C3 of the standpipe 3I. This can improve the flow rate.

[0269] As shown in FIG. 32 , the width of the protruding member 6I varies along the direction of the central axis C3 of the standpipe 3I. The width of the protruding member 6I refers to the width of the protruding member 6I at the portion closest to the inner circumferential surface 30a of the standpipe 3I. In this embodiment, the width of the protruding member 6I corresponds to the width of the first surface 60a of the protruding member 6I. The protruding member 6I has a first varying portion 6g, where the direction of the width change, and a second varying portion 6h, between the first end 6a and the second end 6b. The first varying portion 6g is located between the first end 6a and the apex 6e, more specifically, the flat portion 6f. The second varying portion 6h is located between the apex 6e and the second end 6b. The width of the protruding member 6I monotonically increases from the first end 6a to the first varying portion 6g. The width of the protruding member 6I monotonically decreases from the first varying portion 6g to the second varying portion 6h. The width of the protruding member 6I monotonically increases from the second transition portion 6h toward the second end 6b. The width of the protruding member 6I is largest at the first transition portion 6g. The width of the protruding member 6I at the first transition portion 6g is the maximum dimension of the first surface in a second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b of the protruding member 6I face each other. The width of the protruding member 6I at the first transition portion 6g is, for example, 50 mm or more and 100 mm or less. For example, the width of the protruding member 6I at the first transition portion 6g is 60 mm when the inner diameter of the standpipe 3I corresponds to a nominal diameter of 75 mm, 78 mm when the inner diameter of the standpipe 3I corresponds to a nominal diameter of 100 mm, and 96 mm when the inner diameter of the standpipe 3I corresponds to a nominal diameter of 125 mm. This facilitates the process of fixing the protruding member to the straight pipe with adhesive. As shown in Figure 34, the maximum width of the protruding member 6I as viewed from the direction of the central axis C3 of the standpipe 3I (the width at the first transition portion 6g) is defined as W1. If the inner diameter of the standpipe 3I is d, then 0.38 ≤ W1 ≤ 1.00d, preferably 0.50d ≤ W1 ≤ 0.90d. Here, if the maximum value of the distance between the first separating wall 64 and the second separating wall 65 as viewed from the direction of the central axis C3 of the standpipe 3I is W2, then 0.3d ≤ W2 ≤ 0.7d, where W2 ≤ W1.

[0270] The width of the main surface 61 narrows from the first end 6a to the second end 6b, at least from the first end 6a to the apex 6e. This configuration allows the flows F2 and F3 along the first side surface 62 and the second side surface 63 to smoothly merge with the flow F1 along the main surface 61 downstream of the protruding member 6I. In this embodiment, the width of the main surface 61 decreases monotonically from the first end 6a to the second end 6b.

[0271] The first side surface 62 includes a portion whose width increases from the first end 6 a toward the second end 6 b. More specifically, the portion of the first side surface 62 on the first end 6 a side increases in width from the first end 6 a toward the second end 6 b. This configuration can reduce pressure loss. In this embodiment, the portion of the first side surface 62 on the first end 6 a side includes the portion of the first side surface 62 from the first end 6 a to the flat portion 6 f.

[0272] The second side surface 63 includes a portion whose width increases from the first end 6 a toward the second end 6 b. More specifically, the portion of the second side surface 63 on the first end 6 a side increases in width from the first end 6 a toward the second end 6 b. This configuration can reduce pressure loss. In this embodiment, the portion of the second side surface 63 on the first end 6 a side includes the portion of the second side surface 63 from the first end 6 a to the flat portion 6 f.

[0273] The first and second separation walls 64 and 65 are formed on a portion of the protruding member 6I, not the entire portion, in the direction of the central axis C3 of the standpipe 3I. More specifically, the first and second separation walls 64 and 65 are present in a predetermined range from the first end 6a along the direction of the central axis C3 of the standpipe 3I. The predetermined range is the range from the first end 6a to the flat portion 6f.

[0274] The distance between the first separation wall 64 and the second separation wall 65 becomes shorter from the first end 6 a toward the second end 6 b. This configuration separates the flows F2 and F3 along the first and second side faces 62 and 63 from the flow F1 along the main surface 61 on the upstream side of the protrusion member 6I, and allows the flows F2 and F3 along the first and second side faces 62 and 63 to smoothly merge with the flow F1 along the main surface 61 on the downstream side of the protrusion member 6I.

[0275] The heights of the first separation wall 64 and the second separation wall 65 decrease from the first end 6 a toward the second end 6 b. This configuration separates the flows F2 and F3 along the first and second side faces 62 and 63 from the flow F1 along the main surface 61 on the upstream side of the protrusion member 6I, and allows the flows F2 and F3 along the first and second side faces 62 and 63 to smoothly merge with the flow F1 along the main surface 61 on the downstream side of the protrusion member 6I.

[0276] See Figure 38. When viewed from the direction of the central axis C3 of the standpipe 3I, the distance between the top 6e of the protruding member 6I and the second wall surface 30c is defined as D1. It is preferable that 0.60d≦D1≦0.95d be satisfied for the protruding member 6I. This can further reduce pressure loss caused by separation downstream from the second elbow 52. This can therefore improve the flow rate while enabling miniaturization.

[0277] The height of the top 6e of the protruding member 6I as viewed from the direction of the central axis C3 of the standpipe 3I is defined as H1. H1 is determined by the equation H1 = d - D1. It is preferable that the protruding member 6I satisfy the relationship 0.05d≦H1≦0.40d. This can further reduce the occurrence of pressure loss due to separation downstream from the second elbow 52. This can improve the flow rate while enabling miniaturization.

[0278] The maximum flow path cross-sectional area of ​​the vertical pipe 3I is defined as A. The maximum flow path cross-sectional area A can be calculated from the inner diameter d of the vertical pipe 3I. In other words, A = π(d / 2) ２ The cross-sectional area of ​​the protruding member 6I at the top 6e is defined as A1. In the protruding member 6I, it is preferable that A1 / A≦0.5, and more preferably that A1 / A≦0.4. This can further reduce the occurrence of pressure loss due to separation downstream from the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization. The minimum value of the flow path cross-sectional area of ​​the piping member 10I is defined as A2. A2 is the flow path cross-sectional area at the top 6e of the protruding member 6I. A2 is A2=A−A1. In the protruding member 6I, it is preferable that 0.5≦A2 / A<1, and more preferably that 0.6≦A2 / A<1. This can further reduce the occurrence of pressure loss due to separation downstream from the second elbow 52. Therefore, the flow rate can be improved while enabling miniaturization.

[0279] As described above, the protrusion member 6I has an end surface 68 at the second end 6b. Figure 42 is a comparison diagram between the protrusion member 6I of this embodiment and the protrusion member 600 without the end surface 68. The protrusion member 600 is identical to the protrusion member 6I except for the lack of the end surface 68. In the protrusion member 600, the second end 6b is tapered when viewed in the width direction of the protrusion member 600. At the second end 6b, the height of the protrusion member 600 becomes zero. From Figure 42, it can be seen that the protrusion member 6I has a shape in which the portion of the protrusion member 600 on the second end 6b side is cut in a direction perpendicular to the central axis C3 of the standpipe 3I. The height of the protrusion member 6I decreases monotonically from the apex 6e toward the protruding portion 6i. If the length of the protrusion member 6I were extended downstream, the protrusion member 6I would have a hypothetical portion where the height of the protrusion member 6I becomes zero. The portion where the height of the protruding member 6I is 0 may correspond to the second end 6 b of the protruding member 600 .

[0280] The protruding member 6I can have a smaller dimension in the direction of the central axis C3 of the vertical pipe 3I than the protruding member 600. In particular, the protruding member 6I has a shape in which the portion of the protruding member 600 on the second end 6b side that protrudes from the straight pipe 32I is cut off. In other words, when the protruding member 600 is placed in the straight pipe 32I, the portion on the second end 6b side of the protruding member 600 protrudes outward from the second end of the straight pipe 32I. The second end 6b of the protruding member 600 is thin and therefore easily damaged. Therefore, when the protruding member 600 is placed in the straight pipe 32I, there is a possibility that the protruding member 600 will be damaged during transportation, etc.

[0281] In contrast, the protruding member 6I has an end surface 68, and the position of the end surface 68 is set so that the protruding member 6I is contained within the straight pipe 32I in the direction of the central axis C3 of the vertical pipe 3I, as shown in Figure 30. In this embodiment, the length of the protruding member 6I (the distance between the first end 6a and the second end 6b) is shorter than the length of the straight pipe 32I. That is, in the piping member 10I, the entire protruding member 6I is located within the straight pipe 32I. This allows the protruding member 6I to be protected by the straight pipe 32I, compared to when only a portion of the protruding member 6I protrudes from the straight pipe 32I. This reduces the possibility of damage to the protruding member 6I.

[0282] The protruding member 6I has the advantage that the dimension of the upright pipe 3I in the direction of the central axis C3 can be made smaller than that of the protruding member 600, thereby preventing breakage. Such a change in shape between the protruding member 6I and the protruding member 600 can also cause a change in pressure loss. Therefore, the change in pressure loss caused by the difference in shape between the protruding member 6I and the protruding member 600 was evaluated. Figure 43 is a graph showing the change in pressure loss due to the protruding member 6I compared to the protruding member 600.

[0283] 43, the vertical axis represents the pressure loss in the piping member 10I. The horizontal axis represents the length percentage (%). The length percentage (%) is the percentage of the distance from the apex 6 e to the second end 6 b of the protruding member 6I relative to the distance from the apex 6 e to the second end 6 b of the protruding member 600.

[0284] In Figures 30 and 42, the distance between the first end 6a and the second end 6b of the protruding member 6I in the direction of the central axis C3 of the standpipe 3I is represented by L'. The distance between the top 6e and the second end 6b of the protruding member 6I in the direction of the central axis C3 of the standpipe 3I is represented by L2'. In Figure 42, the distance between the first end 6a and the second end 6b of the protruding member 600 in the direction of the central axis C3 of the standpipe 3I is represented by L. The distance between the top 6e and the second end 6b of the protruding member 600 in the direction of the central axis C3 of the standpipe 3I is represented by L2. The distance between the second end 6b of the protruding member 6I and the second end 6b of the protruding member 600 in the direction of the central axis C3 of the standpipe 3I is represented by ΔL. L2 = L2' + ΔL, and L = L' + ΔL. The length percentage [%] is calculated by L2' / L2 x 100.

[0285] In FIG. 43 , a length ratio of 100% indicates that the shape of the protruding member 6I is identical to the shape of the protruding member 600. A length ratio of 0% indicates that the shape of the protruding member 6I extends from the first end 6a to the apex 6e. The height of the protruding member 6I decreases monotonically from the apex 6e to the second end 6b. Therefore, as the length ratio decreases, the height of the protruding member 6I at the second end 6b increases. From FIG. 43 , it can be seen that the effect of reducing pressure loss decreases as the length ratio decreases. However, the relationship between the length ratio and pressure loss is not linear; instead, pressure loss increases exponentially with decreasing length ratio. In other words, the increase in pressure loss with decreasing length ratio is relatively gradual. In other words, it can be said that the decrease in the effect of reducing pressure loss with decreasing length ratio is limited. Taking these points into consideration, L2′ is set to satisfy the following condition. That is, if the height of the protruding member 6I at the top 6e is H1 and the height of the protruding member 6I at the second end 6b is H2, then 0.05H1≦H2≦0.90H1. This allows for an improved flow rate while still enabling miniaturization. In particular, the length of the protruding member 6I can be made shorter than that of the protruding member 600. This allows for a more compact protruding member 6I. Furthermore, compared to the protruding member 600, the protruding member 6I has fewer thin portions downstream of the protruding member 6I, which may reduce the possibility of breakage of the protruding member 6I.

[0286] Here, it is preferable that the relationship between L and ΔL in the protruding member 600 be 0.5d≦L≦5.0d. This can further reduce pressure loss due to separation downstream from the second elbow 52. Therefore, the flow rate can be improved while still enabling miniaturization. As described above, L = L1 + L2' + ΔL. If the reduction in height of the protruding member 600 per unit length from the apex 6e to the second end 6b is constant, then (H1 - H2) / L2' = H2 / ΔL. In other words, ΔL = H2 / (H1 - H2) × L2'. Therefore, the formula 0.5d≦L≦5.0d can be rewritten using L1 and L2' as 0.5d≦L1 + H1 / (H1 - H2) × L2' ≦5.0d. Therefore, in the protrusion member 6I, if the inner diameter of the straight pipe 32I is d, the distance between the first end 6a and the top 6e in the direction of the central axis C3 of the straight pipe 32I is L1, and the distance between the top 6e and the second end 6b in the direction of the central axis C3 of the straight pipe 32I is L2', then it is preferable that 0.5d≦L1+H1 / (H1-H2)×L2'≦5.0d.

[0287] [1.10.2 Effects, etc.] The protruding member 6I described above is disposed in a straight pipe (standpipe 3I) located downstream of an elbow (second elbow 52) that changes the direction of the flow path, partially reducing the flow path cross-sectional area of ​​the straight pipe. The protruding member 6I includes a first surface 60a having an outer circumferential portion 601 that can contact the inner circumferential surface of the straight pipe (inner circumferential surface 30a of the standpipe 3I), and a second surface 60b located opposite the first surface 60a and acting on the fluid flowing through the flow path. The outer circumferential portion 601 has a groove 603 along at least a portion of the outer periphery of the first surface 60a. This configuration improves flow rate while enabling compactness and reduces manufacturing costs. Furthermore, this configuration facilitates the process of fixing the protruding member 6I to the straight pipe with an adhesive.

[0288] In the protruding member 6I, the groove 603 is located 1 mm to 15 mm away from the outer periphery of the first surface. The width of the groove 603 is 0.5 mm to 3.0 mm. The depth of the groove 603 is 0.2 mm to 2.0 mm. This configuration makes it easier to fix the protruding member 6I to the straight pipe with an adhesive.

[0289] In the protrusion member 6I, the groove 603 has a first inner surface 6031 corresponding to a first direction in which the first surface 60a and the second surface 60b face each other, and a second inner surface 6032 corresponding to a second direction perpendicular to the first direction. This configuration makes it easier to fix the protrusion member 6I to a straight pipe with an adhesive.

[0290] In the protruding member 6I, if the inner diameter of the straight pipe (vertical pipe 3I) is d, the maximum dimension of the first surface in the second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other is 0.5d to 1.0d. This configuration makes it easy to fix the protruding member 6I to the straight pipe with an adhesive.

[0291] The protruding member 6I described above is disposed within a straight pipe (standpipe 3I) located downstream of an elbow (second elbow 52) that changes the flow path direction, partially reducing the flow path cross-sectional area of ​​the straight pipe. The protruding member 6I includes a first surface 60a facing the inner circumferential surface of the straight pipe (inner circumferential surface 30a of the standpipe 3I) and a second surface 60b located opposite the first surface 60a and acting on the fluid flowing through the flow path. The first surface 60a includes an outer circumferential portion 601 that can contact the inner circumferential surface 30a and a central portion 602 recessed from the outer circumferential portion 601. This configuration improves flow rate while enabling compact size and reduces manufacturing costs. Furthermore, this configuration reduces the overflow of adhesive that secures the protruding member 6I to the straight pipe.

[0292] In the protruding member 6I, the dimension of the central portion 602 in a second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other is 10% to 40% of the maximum dimension of the first surface 60a in the second direction. This configuration can further reduce the overflow of adhesive that secures the protruding member 6I to the straight pipe.

[0293] In the protruding member 6I, the central portion 602 is symmetrical in the second direction with respect to the center line of the protruding member 6I. This configuration can further reduce the overflow of adhesive that fixes the protruding member 6I to the straight pipe.

[0294] In the protruding member 6I, the central portion 602 is entirely surrounded by the outer peripheral portion 601. This configuration can further reduce the overflow of adhesive that fixes the protruding member 6I to the straight pipe.

[0295] The protruding member 6I described above is disposed in a straight pipe (standpipe 3I) located downstream of an elbow (second elbow 52) that changes the direction of the flow path, thereby partially reducing the flow path cross-sectional area of ​​the straight pipe. The protruding member 6I includes a first surface 60a facing the inner circumferential surface of the straight pipe (inner circumferential surface 30a of the standpipe 3I) and a second surface 60b opposite the first surface 60a that acts on the fluid flowing through the flow path. The protruding member 6I includes a first portion 610 on the third end 6c side in a second direction perpendicular to the first direction in which the first surface 60a and the second surface 60b face each other, and a second portion 620 on the fourth end 6d side in the second direction. The second portion 620 has a protrusion 626 on the first surface 60a side of the second portion 620 that extends toward the third end 6c. The first portion 610 has a recess 616 on the first surface 60a side of the first portion 610 into which the protrusion 626 fits. The protrusion 626 and the recess 616 are located in a recessed position relative to the portion of the first surface 60a that can contact the inner circumferential surface 30a. This configuration improves the flow rate while enabling miniaturization, and reduces manufacturing costs. Furthermore, this configuration reduces the possibility of separation between the first portion 610 and the second portion 620.

[0296] In the protruding member 6I, the first surface 60a includes an outer peripheral portion 601 that can come into contact with the inner peripheral surface 30a, and a central portion 602 that is recessed from the outer peripheral portion 601. The protrusions 626 and the recesses 616 are located in the central portion 602. This configuration reduces the possibility that the protrusions 626 and the recesses 616 will get in the way when the protruding member 6I is fixed to a straight pipe.

[0297] In the protrusion member 6I, the first part 610 has a hollow first outer part 611 having an opening 611b on a third surface 611a facing the second part 620, and a first boss 612 extending from the first outer part 611 toward the second part 620. The second part 620 has a hollow second outer part 621 having an opening 621b on a fourth surface 621a facing the first part 610, and a second boss 622 extending from the second outer part 621 toward the first part 610 and coupled to the first boss 612. This configuration can further reduce the possibility of separation between the first part 610 and the second part 620.

[0298] In the protruding member 6I, the tip of the second boss 622 is located between the tip of the protrusion 626 and the fourth surface 621a in the second direction. This configuration makes it easier to join the first part 610 and the second part 620 together.

[0299] In the protruding member 6I, the second outer portion 621 has a peripheral wall portion 625 that protrudes from the periphery of the opening 621b in the fourth surface 621a toward the third end 6c and surrounds the opening 621b in the fourth surface 621a. The first outer portion 611 has a receiving portion 615 around the opening 611b in the third surface 611a into which the peripheral wall portion 625 fits. In the second direction, the tip of the second boss 622 is located between the tip of the protrusion 626 and the tip of the peripheral wall portion 625. This configuration reduces the possibility of fluid entering through a gap between the first part 610 and the second part 620. Furthermore, this configuration facilitates the process of connecting the first part 610 and the second part 620.

[0300] The protruding member 6I has a first end 6a facing the upstream side in the third direction along the flow path, a second end 6b facing the downstream side, and a top portion 6e located between the first end 6a and the second end 6b and minimizing the flow path cross-sectional area of ​​the straight pipe (vertical pipe 3I). This configuration can improve the flow rate while enabling miniaturization.

[0301] The protruding member 6I has a protruding portion 6i that extends from a portion between the top portion 6e and the second end 6b toward the center of the straight pipe (vertical pipe 3I) when viewed from the third direction, but does not protrude beyond the top portion 6e. This configuration can improve the flow rate while enabling miniaturization.

[0302] In the protruding member 6I, if the distance between the first end 6a and the second end 6b in the third direction is L and the distance between the first end 6a and the top 6e in the third direction is L1, then 0.1L≦L1≦0.5L. This configuration can improve the flow rate while enabling miniaturization.

[0303] In the protruding member 6I, when the maximum flow path cross-sectional area of ​​the straight pipe (vertical pipe 3I) is A and the cross-sectional area of ​​the protruding member 6I at the top 6e is A1, A1 / A≦0.5. This configuration can improve the flow rate.

[0304] The protruding member 6I has an end face 68 at the second end 6b that intersects with the third direction. If the height at the top 6e is H1 and the height at the second end 6b is H2, then 0.05H1≦H2≦0.90H1 is satisfied. This configuration can improve the flow rate while enabling miniaturization.

[0305] The piping member 10I described above includes a protruding member 6I and a straight pipe (vertical pipe 3I), and the protruding member 6I is fixed to the straight pipe (vertical pipe 3I) with an adhesive. This configuration can improve the flow rate while enabling miniaturization and reducing manufacturing costs.

[0306] The piping system 1I described above includes a standpipe 3I, a horizontal pipe 4 between the inlet 2b and the standpipe 3I, a first elbow 51 between the inlet 2b and the horizontal pipe 4, a second elbow 52 between the horizontal pipe 4 and the standpipe 3I, and a protruding member 6I arranged such that at least a portion of the standpipe 3I is a straight pipe. The protruding member 6I is fixed to the straight pipe (standpipe 3I) with an adhesive. This configuration enables miniaturization while improving flow rate and reducing manufacturing costs.

[0307] [2. Modifications] The embodiments of the present disclosure are not limited to the above-described first to tenth embodiments. Various modifications of the above-described first to tenth embodiments are possible depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described first to tenth embodiments are listed below. The modifications described below can be applied in appropriate combinations.

[0308] In the following, reference will be made to the symbols used in embodiment 1, even though they are applicable to any of the above embodiments 1 to 10. However, this is merely to simplify the description and is not intended to exclude application to embodiments 2 to 10.

[0309] In one modified example, the protruding members 6 may be provided on both the standpipe 3 and the horizontal pipe 4. That is, the piping system 1 may include a protruding member 6 that is located on the inner periphery of the second elbow 52 at the second elbow 52 side end of at least one of the straight pipe sections on the upstream and downstream sides of the second elbow 52 and that partially reduces the flow path cross-sectional area of ​​the straight pipe section. Note that the protruding members 6 provided on the standpipe 3 and the horizontal pipe 4 do not necessarily have to have the same shape and dimensions, and may have different shapes and dimensions.

[0310] In the above embodiment, the second elbow 52 and the first straight pipe section 31 are formed separately, but the second elbow 52 and the first straight pipe section 31 may be formed integrally. This also enables the size to be reduced while improving the flow rate. In this case, the socket 521 may not be necessary in the second elbow 52. The mark 313 may also not be necessary in the first straight pipe section 31. Similarly, the second elbow 52 and the first straight pipe section 41 may be formed integrally.

[0311] In one modified example, the first end 6a of the protruding member 6 does not necessarily have to coincide with the corner 520c of the second elbow 52. FIG. 53 is a cross-sectional view of the downstream portion of the second elbow 52 of a piping system 1 according to one modified example. In FIG. 53, the first end 6a protrudes from the corner 520c. In other words, the protruding amount of the protruding member 6 from the first straight pipe section 31 is large. The inner diameter of the straight pipe (horizontal pipe 4) connected to the socket 522 of the second elbow 52 is defined as d. Typically, the inner diameter d of the horizontal pipe 4 is equal to the inner diameter d of the standpipe 3. The distance between the corner 520c and the first end 6a is defined as G1. It is preferable that G1 < d / 50. In this case, the possibility that the protrusion of the first end 6a from the corner 520c will affect the fluid flow can be reduced. FIG. 54 is a cross-sectional view of the downstream portion of the second elbow 52 of a piping system 1 according to another modified example. In Figure 54, the first end 6a is recessed from the corner 520c. In other words, the amount of protrusion of the protruding member 6 from the first straight pipe section 31 is small. In this case, the inner diameter of the straight pipe (horizontal pipe 4) connected to the socket 522 of the second elbow 52 is defined as d, and the distance between the corner 520c and the first end 6a is defined as G2. It is preferable that G2 be smaller than d / 20. In this case, the possibility that the first end 6a not reaching the corner 520c will affect the flow of fluid can be reduced.

[0312] In one modified example, the riser pipe 3I may be configured with a single pipe material instead of multiple pipe materials. Even in this case, the protruding member 6I may be arranged so that at least a portion of the riser pipe 3I is a straight pipe. In this case, the at least a portion of the riser pipe 3I is the entire riser pipe 3I.

[0313] In one modified example, the straight pipe sections such as the vertical pipe 3 and horizontal pipe 4 may be made up of multiple pipe materials instead of a single pipe material.

[0314] In one modified example, each of the first and second elbows 51, 52 may be selected from a 90° elbow (so-called DL) specified in JIS K 6739, a 90° large bend elbow (so-called LL) specified in JIS K 6739, and a 45° elbow (so-called 45L). The dimensions of the first and second elbows 51, 52 do not necessarily have to be set in accordance with the standard of JIS K 6739 "Rigid polyvinyl chloride pipe joints for drainage."

[0315] In one modification, the shape and dimensions of the protruding member 6 are not limited to those in the first to tenth embodiments.

[0316] In one modified example, the protruding member 6I may not have an end surface 68. For example, the second end 6b of the protruding member 6I may have a tapered shape when viewed in the width direction of the protruding member 6I. This is the same configuration as the protruding member 600 shown in FIG. 52. In this case, the distance between the top 6e and the second end 6b in the direction of the central axis C3 of the standpipe 3I is defined as L2. L2 may be L2 = L - L1, and preferably L2 > L1. This can further reduce pressure loss due to separation downstream from the second elbow 52. This allows for an improved flow rate while enabling compactness. Furthermore, if the inner diameter of the standpipe 3I is d and the distance between the first end 6a and the second end 6b in the direction of the central axis C3 of the standpipe 3I is L, then 0.5d ≦ L ≦ 5.0d may be satisfied. This can improve the flow rate.

[0317] In one modification, the protruding member 6I may not have the protrusion 6i.

[0318] In one modified example, the second direction may correspond to the height of the protrusion member 61. That is, in the protrusion member 61, the first portion 610 may be configured as an upstream portion, and the second portion 620 may be configured as a downstream portion, which are separate components.

[0319] In one modified example, the protruding member 6I does not necessarily have to have an outer shape that is mirror-symmetrical with respect to a plane perpendicular to the second direction.

[0320] In one modified example, the first portion 610 does not have to occupy the half of the protruding member 61 on the third end 6c side, and the second portion 620 does not have to occupy the half of the protruding member 61 on the fourth end 6d side.

[0321] In one modified example, the position of the protrusion 6i is not limited to the second end 6b, but may be between the top 6e and the second end 6b. In one modified example, the protrusion member 6I may have a plurality of protrusions 6i between the top 6e and the second end 6b. The protrusions 6i may be formed integrally with the protrusion member 6I, or may be formed separately and attached thereto.

[0322] In one modified example, the first side surface 62 and the second side surface 63 of the protrusion member 6I may have a shape that is asymmetric with respect to the center line of the protrusion member 6I along the central axis C3 of the stand pipe 3I. The shapes of the first side surface 62 and the second side surface 63 may be individually set depending on the installation environment of the piping system 1I or the piping member 10I, and do not necessarily have to be a shape that is symmetric with respect to the center line of the protrusion member 6I along the central axis C3 of the stand pipe 3I.

[0323] In one modification, the protruding member 6I does not necessarily have to have an end surface 66 .

[0324] In one modified example, the shape, number, and arrangement of the protrusions 67 of the protrusion member 6I may be changed as appropriate depending on the shape, number, and arrangement of the holes 3d of the standpipe 3I. For example, the first portion 67a and the second portion 67b of the protrusion 67 may also serve as gates when forming the first portion 610 and the second portion 620 of the protrusion member 6I by injection molding. The holes 3d may be cutouts. The position of the holes 3d is not limited to the upstream end portion 3a. The protrusions 67 and the holes 3d are preferably provided so as to facilitate positioning of the protrusion member 6I relative to the standpipe 3I. However, the protrusion member 6I does not necessarily have to have the protrusions 67.

[0325] In one variant, the protruding member 6I does not need to be entirely contained within the riser pipe 3I. In particular, the fourth end 6d of the protruding member 6I may protrude to the outside from the riser pipe 3I.

[0326] In one modified example, the shape and size of part or all of the piping system 1 may be different from those of the above-described Embodiments 1 to 10. For example, unlike the above-described Embodiments 1 to 10, in the piping system 1, the shape of the second elbow 52 and / or the shape of the standpipe 3 may be polygonal rather than circular.

[0327] In one modified example, the material of each component of the piping system 1 does not necessarily have to be rigid polyvinyl chloride. The material of each component of the piping system 1 may be determined according to the requirements of the piping system 1, and may be, for example, a synthetic resin such as polyethylene. Furthermore, the material of each component of the piping system 1 may be a metal instead of a synthetic resin.

[0328] In one modification, the first straight pipe section 31 may not have the mark 313 .

[0329] In one modified example, the piping system 1 does not necessarily have to include the eaves gutter 2. For example, if the building 11 has a structure with an inlet (water collection port) such as a balcony, the first elbow 51 of the piping system 1 may be connected to the inlet (water collection port) of the building 11.

[0330] In one modified example, the drain 7 may have a structure that is generally not considered to contribute to the occurrence or promotion of the siphoning phenomenon. In one modified example, the piping system 1 does not necessarily have to include the drain 7. The drain 7 is not an essential component of the piping system 1, and may be provided as appropriate taking into consideration the installation environment of the piping system 1, etc.

[0331] In one modification of the sixth embodiment, the pipe 141 may not include the fourth elbow 143 .

[0332] In one modified example, the piping system 1 is not limited to a gutter system, which is a type of drainage system, but may also be applied to other drainage systems such as a sewage system, or to water supply systems such as a drinking water system. That is, the protrusion member or piping member may be used in a system that supplies or drains water. The piping system 1 may also be a piping system for transporting a target fluid within a facility such as a factory. That is, the fluid transported by the piping system 1 is not limited to rainwater.

[0333] [3. Aspects] As is clear from the above-described embodiment and modifications, the present disclosure includes the following aspects.

[0334] [Aspect 1] A piping system forming a flow path, comprising: a vertical pipe, a horizontal pipe between an inlet and the vertical pipe, a first elbow between the inlet and the horizontal pipe, a second elbow between the horizontal pipe and the vertical pipe and having a smaller radius of curvature than the first elbow, and one or more protrusion members located on at least one of an inner peripheral side of the second elbow at the downstream end of the horizontal pipe and an inner peripheral side of the second elbow at the upstream end of the vertical pipe, the protrusion members partially reducing a flow path cross-sectional area of ​​the flow path. [Aspect 2] The piping system of Aspect 1, wherein the first elbow and the second elbow are 90° elbows. [Aspect 3] The piping system of Aspect 1 or 2, wherein the standpipe includes a first straight pipe section directly connected to the downstream side of the second elbow and a second straight pipe section connected to the downstream side of the first straight pipe section, wherein the one or more protruding members are located on the first straight pipe section, and wherein the length of the first straight pipe section is 1.0 m or less. [Aspect 4] The piping system of any one of Aspects 1 to 3, wherein the one or more protruding members are located on the inner periphery of the second elbow at the upstream end of the standpipe, and wherein the one or more protruding members are separate from the standpipe. [Aspect 5] The piping system of any one of Aspects 1 to 4, wherein the one or more protruding members are located on the inner periphery of the second elbow at the upstream end of the standpipe, and wherein the distance in the vertical direction between the upstream ends of the one or more protruding members and the downstream opening point of the standpipe is 2.0 m or more. [Aspect 6] The piping system of any one of Aspects 1 to 5, wherein the length of the horizontal pipe is 2.0 m or less. [Aspect 7] The piping system of any one of Aspects 1 to 6, wherein the distance between the inlet and the first elbow is 0.5 m or less. [Aspect 8] The piping system of any one of Aspects 1 to 7, wherein the first elbow is a 90° large bend elbow as defined in JIS K 6739. [Aspect 9] The piping system of any one of Aspects 1 to 8, wherein the second elbow is a 90° elbow as defined in JIS K 6739. [Aspect 10] The piping system of any one of Aspects 1 to 9, wherein, where A is the maximum value of the flow path cross-sectional area and A1 is the minimum value of the flow path cross-sectional area, (A-A1) / A≦0.5.[Aspect 11] The piping system according to any one of Aspects 1 to 10, wherein 0.5d≦L≦5.0d is satisfied, where d is an inner diameter of the flow path and L is a length of the protruding member in the direction of the flow path.

[0335] [Aspect 12] The piping system of any one of Aspects 1 to 11, wherein the one or more protruding members have a vertex that is located between an upstream end and a downstream end and that minimizes the cross-sectional area of ​​the flow path, and where d is an inner diameter of the flow path and H is a height of the protruding member at the vertex, 0.05d≦H≦0.40d.

[0336] The second to twelfth aspects above are optional elements.

[0337] The present disclosure is applicable to a piping system, particularly to a piping system including an elbow.

[0338] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I Piping system 2b Inlet 3, 3A, 3I Vertical pipe 3a Upstream end 3c Downstream opening point 31 First straight pipe section 32 Second straight pipe section 4, 4A Horizontal pipe 4b Downstream end 51 First elbow 52 Second elbow 520c Corner 6, 6I Projecting member 6a First end (upstream end) 6b Second end 6e Top 7 Drain

Claims

1. A piping system that forms a flow path, comprising: a vertical pipe; a horizontal pipe between an inlet and the vertical pipe; a first elbow between the inlet and the horizontal pipe; a second elbow between the horizontal pipe and the vertical pipe and having a smaller radius of curvature than the first elbow; and one or more protrusion members that are located on at least one of the inner periphery of the second elbow at the downstream end of the horizontal pipe and the inner periphery of the second elbow at the upstream end of the vertical pipe, and that partially reduce the flow path cross-sectional area of ​​the flow path.

2. The piping system of claim 1, wherein the first elbow and the second elbow are 90° elbows.

3. The piping system of claim 1, wherein the vertical pipe includes a first straight pipe section directly connected to the downstream side of the second elbow and a second straight pipe section connected to the downstream side of the first straight pipe section, the one or more protruding members are on the first straight pipe section, and the length of the first straight pipe section is 1.0 m or less.

4. The piping system of claim 1, wherein the one or more protruding members are located on the inner circumferential side of the second elbow at the upstream end of the standpipe, and the one or more protruding members are separate from the standpipe.

5. The piping system of claim 1, wherein the one or more protruding members are located on the inner periphery of the second elbow at the upstream end of the standpipe, and the vertical distance between the upstream end of the one or more protruding members and the downstream opening point of the standpipe is 2.0 m or more.

6. The piping system according to claim 1 or 2, wherein the horizontal pipe has a length of 2.0 m or less.

7. The piping system according to claim 1 or 2, wherein the distance between the inlet and the first elbow is 0.5 m or less.

8. The piping system according to claim 1, wherein the first elbow is a 90° large bend elbow specified in JIS K 6739.

9. The piping system according to claim 1 or 8, wherein the second elbow is a 90° elbow as specified in JIS K 6739.

10. The piping system of claim 1, wherein, where A is the maximum value of the flow path cross-sectional area and A1 is the minimum value of the flow path cross-sectional area, (A-A1) / A≦0.

5.

11. The piping system according to claim 1, wherein, when the inner diameter of the flow path is d and the length of the protruding member in the direction of the flow path is L, 0.5d≦L≦5.0d.

12. The piping system of claim 1, wherein the one or more protruding members have a vertex that is located between the upstream end and the downstream end and that minimizes the cross-sectional area of ​​the flow path, and where d is the inner diameter of the flow path and H is the height of the vertex of the protruding member, 0.05d≦H≦0.40d.

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