Piping system

Abstract

To provide a piping system capable of improving workability.SOLUTION: A piping system 100 includes a first piping member 10 having a socket 11, and a second piping member 20 connected to the socket 11, wherein a first pass-through portion 13 is provided on an outer peripheral surface of the socket 11, a protruding portion 23 is provided on an outer peripheral surface of the second piping member 20, the protruding portion 23 is fitted into the first pass-through portion 13, and the protruding portion 23 does not protrude from an outermost diameter of the first piping member 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piping system. [Background technology]

[0002] A known joint uses a clamp to secure the joint to a pipe when connecting the joint to the pipe. For example, Patent Document 1 discloses that the clamp is integrally formed with the joint and clamps the joint to the pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-31840 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the opposing part of the fastening member of the clamp is positioned outside the outer diameter of the joint. This means that there is a risk of interference when installing in a small space, and installation locations are limited. As such, there is room for improvement in installation work using the clamp.

[0005] In view of the above-mentioned circumstances, the present disclosure aims to provide a piping system that enables improved workability. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention proposes the following aspects. <1> A piping system according to one embodiment of the present invention includes: a first piping member having a socket; a second piping member connected to the socket; Equipped with A first through portion is provided on the outer peripheral surface of the socket, A convex portion is provided on the outer peripheral surface of the second piping member, The protrusion fits into the first through-portion, The protrusion does not protrude from the outermost diameter of the first piping member. <2> The aforementioned <1> The piping system described in The first piping member includes a joint member and a cover that covers the joint member, The cover has the receptacle, The first through portion is provided on an outer peripheral surface of the socket of the cover, The protrusion may be fitted into the first through-portion of the cover. <3> The aforementioned <2> In the piping system described in , the first penetration portion of the cover may be disposed outside the first piping member in the longitudinal direction of the first piping member. <4> The aforementioned <1> from <3> In the piping system described in any one of the above, the first piping member may be an electric fusion joint. <5> The aforementioned <4> The piping system described in The electrofusion joint comprises a joint member and a cover that covers the joint member, A terminal is provided on the outer peripheral surface of the electric fusion joint, The cover may be provided with a second through-portion into which the terminal fits. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to achieve the effect of improving workability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a piping system according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view of the piping system shown in FIG. [Figure 3] FIG. 2 is a plan view of the first piping member shown in FIG. [Figure 4] FIG. 2 is a front view of the second piping member shown in FIG. [Figure 5] FIG. 3 is a cross-sectional view taken along the arrows VV in FIG. 2. [Figure 6] FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 2. [Figure 7] FIG. 4 is an exploded plan view showing a piping system according to a modified example of the first embodiment. [Figure 8] FIG. 4 is a cross-sectional view showing a piping system according to a modified example of the first embodiment. [Figure 9] FIG. 10 is an exploded plan view of a piping system according to a second embodiment of the present disclosure. [Figure 10] FIG. 10 is an exploded plan view showing a piping system according to a modified example of the second embodiment. [Figure 11] FIG. 10 is a partial cross-sectional view showing a piping system according to a third embodiment of the present disclosure. [Figure 12] FIG. 11 is a plan view showing a piping system according to a modified example of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment Hereinafter, a piping system according to a first embodiment of the present disclosure will be described with reference to FIGS. FIG. 1 is a perspective view showing a piping system 100 according to a first embodiment. FIG. 2 is a plan view of the piping system 100 shown in FIG. 1. As shown in FIGS. 1 and 2, the piping system 100 includes a first piping member 10 and a second piping member 20. In this embodiment, as shown in FIGS. 1 and 2, the second piping member 20 is connected to one end of the first piping member 10 along the longitudinal direction of the piping system 100. Alternatively, the second piping member 20 may be connected to both ends of the first piping member 10 along the longitudinal direction of the piping system 100.

[0010] As shown in Fig. 3, the first piping member 10 has a first piping member main body 12 and a socket 11 provided at an end in the axial direction, which is the direction in which the central axis of the first piping member 10 extends. In this embodiment, the socket 11 is provided at both ends of the first piping member main body 12. The socket 11 may also be provided at one end of the first piping member main body 12. In this embodiment, the socket 11 of the first piping member 10 serves as a socket into which the second piping member 20, which will be described later, is inserted. The first piping member 10 is formed in a hollow cylindrical shape. The central axes of the first piping member 10, the second piping member 20, the joint member 10-1, and the cover 30 (described later) are arranged coaxially with a common axis. In this embodiment, this common axis is referred to as an axis O1. The axis O1 is the axis of the piping system 100. The direction perpendicular to the axis O1 is called the radial direction, and the direction going around the axis O1 is called the circumferential direction. For example, extrusion molding and injection molding can be used to form the first piping member 10. In particular, extrusion molding makes it easy to form the first piping member 10 into a long shape or with a large diameter.

[0011] The first piping member 10 is formed of, for example, a thermoplastic resin. As the thermoplastic resin, it is preferable to use a polyolefin-based resin similar to that of the second piping member 20 described later.

[0012] 1 and 2, the second piping member 20 is connected to the socket 11 of the first piping member 10. As shown in Fig. 4, the second piping member 20 has a second piping member main body 22 provided at one end side and an insertion port 21 provided at the other end side in the direction of the axis O1. The insertion port 21 of the second piping member 20 is connected to the insertion port 11 of the first piping member 10. The second piping member main body 22 of the second piping member 20 is formed in a hollow cylindrical shape. The insertion port 21 extends outward in the direction of the axis O1 from the end of the second piping member main body 22 in the direction of the axis O1. The insertion port 21 is a hollow cylinder coaxial with the second piping member main body 22. In this embodiment, the outer diameter of the insertion port 21 is smaller than the outer diameter of the second piping member main body 22. The inner circumferential surface of the insertion port 21 is continuous with the inner circumferential surface of the second piping member main body 22. The insertion port 21 and the second piping member main body 22 may be butt-welded (welded in a butted state), in which case, a circumferentially extending protrusion (so-called bead) may be provided on each of the inner and outer circumferential surfaces between them.

[0013] The insertion port 21 of the second piping member 20 is inserted radially inward into the socket 11 of the first piping member 10. Therefore, the first piping member body 12 of the first piping member 10 has a length and an inner diameter that allow the insertion port 21 of the second piping member 20 to be inserted a required length. The insertion port 21 of one of the second piping members 20 to be connected may be inserted into one end (receptacle 11) of the first piping member 10, and the insertion port 21 of the other of the second piping members 20 to be connected may be inserted into the other end (receptacle 11) of the first piping member 10. In the first piping member 10, the side into which the insertion port 21 of one of the second piping members 20 is inserted is one socket 11, and the side into which the insertion port 21 of the other second piping member 20 is inserted is the other socket 11. In this way, the second piping member 20 has sockets 11 at both longitudinal ends. 1 and 2 show a state in which the insertion port 21 of the second piping member 20 is inserted into the socket 11 on only one side in the longitudinal direction.

[0014] The second piping member 20 is preferably made of a thermoplastic resin such as a polyolefin-based resin. A second piping member 20 made of a polyolefin-based resin has a higher tensile breaking elongation measured in accordance with JIS K 6815-1 and JIS K 6815-3 than a rigid polyvinyl chloride pipe. While the tensile breaking elongation of a rigid polyvinyl chloride pipe is 50 to 150%, the tensile breaking elongation of a polyolefin-based resin pipe is 350% or more. In particular, by the extrapolation method specified in ISO / TR9080, a PE100 high-density polyethylene pipe has a tensile breaking elongation of 500% or more, which can better prevent damage caused by earthquakes.

[0015] The polyolefin resin is not particularly limited, but suitable examples include polyethylene, polypropylene, polybutene, atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, poly-α-olefin, etc. Among these, it is desirable to use polyethylene from the viewpoint of strength, etc. Furthermore, when selecting polyethylene, it is desirable to appropriately select any of low-density polyethylene, medium-density polyethylene, high-density polyethylene, etc. depending on the durability required for the second piping member 20. From the viewpoint of not affecting earthquake resistance, durability, water quality, etc., the second piping member 20 made of polyethylene resin can be used. In particular, when the second piping member 20 is used as a drinking water pipe, a high-density polyethylene resin pipe is preferable.

[0016] The specific gravity of the thermoplastic resin is not particularly limited, but is, for example, 942 to 953 kg / m3. The specific heat of the thermoplastic resin is not particularly limited, but is, for example, 1.9 to 2.3 kJ / kg [K]. The thermal conductivity of the thermoplastic resin is not particularly limited, but is, for example, 0.46 to 0.5 W / m K. The thermoplastic resin may be a composition containing additives such as pigments, ultraviolet absorbers, antioxidants, and lubricants. The melting point of the thermoplastic resin (ie, the melting temperature of the second piping member 20) is not particularly limited, but is preferably 125 to 260°C, and more preferably 125 to 150°C.

[0017] The second piping member 20 may have a multi-layer structure having a surface layer on at least one of the outer circumferential surface and the inner circumferential surface. For example, by having a surface layer containing an ethylene-vinyl alcohol copolymer resin, the second piping member 20 may be a pipe for any purpose, such as a drinking water pipe, a gas pipe, or a sewer pipe, because the surface layer containing an ethylene-vinyl alcohol copolymer resin makes it difficult for gases such as hydrogen, oxygen, propane, and butane, and hydrocarbons such as gasoline and benzene, to permeate.

[0018] The surface layer may contain, for example, at least one of inorganic fibers and organic fibers. Examples of inorganic fibers include glass fibers, carbon fibers, silicon-titanium-carbon composite fibers, boron fibers, and metal fibers. Examples of organic fibers include aramid fibers, vinylon fibers, polyester fibers, and polyamide fibers. When the surface layer contains these fibers, the tensile strength of the second piping member 20 can be increased and thermal expansion can be further suppressed. The surface layer may also contain a fluororesin. When the surface layer contains fluorine, resistance (chemical resistance) to acids, alkalis, and the like can be improved. Furthermore, a layer similar to the above-mentioned surface layer may be provided within the wall of the second piping member 20.

[0019] The SDR value, which is the ratio of the outer diameter D to the wall thickness T of the second piping member 20, is preferably 13.5 or less. If the SDR value exceeds 13.5, the pipe wall becomes too thin and may not be able to withstand the internal pressure of the fluid when the fluid flows inside. If the SDR value is too low, the pipe wall becomes too thick and may not be able to ensure a sufficient flow rate. For this reason, the lower limit of the SDR value is preferably 6 or more, and more preferably 7.4 or more.

[0020] Generally, in pipe thickness design, for pipes with water flowing inside, the relationship that follows the Naday equation shown in equation (1) below is known to represent the tensile circumferential stress (tensile stress generated in the circumferential direction in the cross section of the pipe) generated in the pipe due to the internal water pressure. σ=P(Dt) / 2t …(1) formula In equation (1), σ is the tensile circumferential stress generated in the pipe (MPa), P is the internal water pressure (MPa), D is the outer diameter of the pipe (mm), and t is the thickness of the pipe (mm).

[0021] Based on the Naday equation mentioned above, it is preferable to design the pipe thickness so that the stress generated at the design internal pressure (maximum allowable stress) has a safety factor of 2 for the 50-year creep strength of polyethylene water distribution pipes. For example, this relationship can be expressed by the following equation (2). σ50 / S1=Pd(Dt) / 2t …(2) formula In equation (2), σ50 is the 50-year creep strength of polyethylene water distribution pipe (10 MPa), S1 is the safety factor for σ50 (assumed to be 2 here), and Pd is the maximum allowable pressure (hydrostatic pressure 0.75 × water hammer pressure 0.25 = 1.0 PMa). By modifying the above equation (2), the value of SDR (Standard Dimension Ratio) can be calculated using the following equation (3). SDR=D / t=1+(2σ50) / Pd·S1=1+(2×10) / (1×2)=11…(3) formula

[0022] According to the pipe thickness design for water pipes, which was calculated with the aforementioned safety factor of 2, it is clear that an SDR value of 11 is preferable, but if the purpose is to rehabilitate pipes such as polyethylene sewer pipes, where the internal pressure of the pipe can be estimated to be low, an SDR value of 13.5 or less is desirable. Furthermore, if the standard SDR value for polyethylene water pipes is 11, the SDR value will be less than SDR6 when the flow rate drops by 40% (calculated based on a flow velocity coefficient of 140 and a hydraulic gradient of 3%), so an SDR value of 6 or more is preferable.

[0023] The second piping member 20 is a pipe housed inside the existing piping 1, but is a self-supporting pipe, unlike the thin, non-self-supporting pipes with inner linings used in conventional technology. Moreover, it is preferable that the second piping member 20 be a resin pipe with little deformation and an ovality of 4.5 mm or less. The measurement method for the ovality of the second piping member 20 should preferably comply with the Japan Water Works Association standard: JWWAK144 (Polyethylene Pipe for Water Distribution). Measure each dimension of the resin pipe at 23±2°C with a measuring device such as a caliper at least 24 hours after its manufacture, and allow it to condition for at least four hours before measurement. Furthermore, if the temperature measurement is outside of 23±2°C, such as when measuring dimensions outdoors, convert the measured values ​​to dimensions at 23°C using the following formula (4).

[0024] L23={1+α×(23-t)}×Lt…(4) formula In equation (4), L23 is the dimension at 23°C (converted value), α is the linear expansion coefficient (1 / °C) (polyethylene pipe for water distribution: 12.0 × 10-5), t is the temperature at the time of measurement (°C), and Lt is the dimension at t°C (measured value). For example, in equation (4), if the outer diameter of a straight pipe with a nominal diameter of 100 is measured at an air temperature of 35°C (the temperature of the resin pipe is also 35°C) and the measured value is 125.9 mm, the converted value at 23°C will be 125.7 mm as calculated by the following formula. D23={1+12.0×10-5×(23-35)}×125.9=125.7mm

[0025] The second piping member 20 applied to this embodiment preferably has a deflection rate of 5% or less. The deflection rate is preferably measured in accordance with the Japan Water Works Association standard: JWWA K144 (polyethylene pipe for water distribution).

[0026] A first through-portion 13 is provided on the outer peripheral surface of the first piping member 10. More specifically, the first through-portion 13 is provided in the socket 11 of the first piping member 10. The first through-portion 13 is a through-hole that penetrates from the outer peripheral surface to the inner peripheral surface of the first piping member 10. In this embodiment, the first through-portion 13 is provided on both longitudinal end sides of the first piping member 10. The first through-portion 13 may be provided on one longitudinal end side of the first piping member 10. The first through-portion 13 on the one end side may have a first through-portion 13′ on the opposite side as viewed from the arrow (radial direction) in FIG. 2 . The first through-portion 13 on the other end side may have a first through-portion 13′ on the opposite side as viewed from the arrow (radial direction) in FIG. 2 . The first through-portion 13 and the first through-portion 13′ are arranged point-symmetrically about the center point O of the first piping member 10 as viewed from the axis O1 direction. In this embodiment, one first through-portion 13 is provided on one end side of the first piping member 10, but the number of first through-portions 13 is not limited to one.

[0027] A convex portion (first convex portion) 23 is provided on the outer peripheral surface of the second piping member 20. In detail, the convex portion 23 has a shape that protrudes in the circumferential direction on the outer peripheral surface of the insertion port 21 of the second piping member 20.

[0028] The protrusion 23 of the second piping member 20 fits into the first through-hole 13 of the first piping member 10. When the insertion opening 21 of the second piping member 20 is inserted into the receiving opening 11 of the first piping member 10, the protrusion 23 of the second piping member 20 is inserted so as to fit into the first through-hole 13 of the first piping member 10. This allows the first piping member 10 and the second piping member 20 to be securely fixed together.

[0029] A specific example of the first through-hole portion 13 of the first piping member 10 and the protrusion portion 23 of the second piping member 20 will be described. The first through portion 13 is, for example, an L-shaped through hole as shown in Figures 1 to 3. Specifically, the first through portion 13 has a longitudinal through portion 13A and a circumferential through portion 13B. The longitudinal through-portion 13A has one end connected to the socket end portion 11A which is the end portion of the socket 11, and extends in a direction along the longitudinal direction of the first piping member . The circumferential through-portion 13B is connected to the other end of the longitudinal through-portion 13A and extends in the circumferential direction (perpendicular direction) to the longitudinal through-portion 13A. In this manner, the L-shaped first through portion 13 (longitudinal through portion 13A, circumferential through portion 13B) is provided in the socket 11 of the first piping member 10. This first through portion 13 may have a first through portion 13' (longitudinal through portion 13A', circumferential through portion 13B') provided on the opposite side when viewed from the arrow direction (radial direction) in FIG. 2. In this manner, the first through portion 13 and the first through portion 13' are arranged point-symmetrically with respect to the center point O of the first piping member 10 when viewed from the direction of the axis O1. When the first through portion 13 is L-shaped, as shown in Figure 2, the circumferential through portion 13B of the first through portion 13 on the front side (13B shown in the solid line in Figure 2) extends downward from the longitudinal through portion 13A, and the circumferential through portion 13B' of the first through portion 13' on the rear side (13B' shown in the dashed line in Figure 2) extends upward from the longitudinal through portion 13A. The second piping member 20 may be provided with a protrusion 23' that fits into the first through-hole 13'.

[0030] The protrusion 23 of the second piping member 20 that fits into the above-mentioned L-shaped first through-hole 13 is, for example, cylindrical. The protrusion 23 is provided on the outer peripheral surface of the insertion port 21 of the second piping member 20 on the second piping member main body 22 side, as shown in FIG.

[0031] When the second piping member 20 is inserted into the first piping member 10, the second piping member 20 is inserted so that the protrusion 23 of the second piping member 20 fits into the longitudinal through-portion 13A of the first through-portion 13 of the first piping member 10. Specifically, the protrusion 23 is pushed along the longitudinal through-portion 13A up to the circumferential through-portion 13B. Then, the second piping member 20 and the first piping member 10 are rotated relative to each other about the axis O1, and the protrusion 23 is moved along the circumferential through-portion 13B to the end of the circumferential through-portion 13B. FIGS. 1 and 2 show a state in which the protrusion 23 has been pushed up to the circumferential through-portion 13B. The width 13Aw (mm) of the longitudinal through portion 13A and the width 13Bw (mm) of the circumferential through portion 13B are widths that allow the width 23w (diameter if the protrusion 23 is cylindrical) (mm) of the protrusion 23 to fit and move. It is preferable that the width 13Aw (mm) of the longitudinal through portion 13A and the width 13Bw of the circumferential through portion 13B are equal. When the width 13Aw of the longitudinal through-portion 13A and the width 13Bw of the circumferential through-portion 13B are equal, and the width 23w of the protrusion 23 is 5 mm, the width 13Aw of the longitudinal through-portion 13A and the width 13Bw of the circumferential through-portion 13B are preferably 5 mm or more and 6 mm or less. When the width 23w of the protrusion 23 is 5 mm and the width 13Aw of the longitudinal through-portion 13A and the width 13Bw of the circumferential through-portion 13B are less than 5 mm, the insertion workability becomes difficult. When the width 23w of the protrusion 23 is 5 mm and the width 13Aw of the longitudinal through-portion 13A and the width 13Bw of the circumferential through-portion 13B are greater than 6 mm, the strength of the first piping member 10 may be affected. The width of the protrusion 23 of the second piping member 20 (or the diameter if the protrusion 23 is cylindrical) may be any width that allows it to fit into the longitudinal through-hole 13A and the circumferential through-hole 13B. The protrusion 23 is made of, for example, PE100, has a diameter 23w of 5 mm, and a height 23h of 5 mm. The width 13Aw of the longitudinal through portion 13A and the width 13Bw of the circumferential through portion 13B can be measured using a measuring device such as a vernier caliper, for example.

[0032] The tip end of the circumferential through portion 13B may be provided with a locking portion 24 that is bulged in the width 13Bw direction of the circumferential through portion 13B so that the protrusion 23 can be easily locked.

[0033] The convex portion 23 of the second piping member 20 does not protrude from the outermost diameter of the first piping member 10. In other words, when the convex portion 23 of the second piping member 20 is fitted into the first through portion 13 of the first piping member 10, the tip of the convex portion 23 of the second piping member 20 does not protrude from the outer peripheral surface of the first piping member 10. When the convex portion 23 of the second piping member 20 is fitted into the first through portion 13 of the first piping member 10, the tip of the convex portion 23 of the second piping member 20 is flush with or positioned radially inward from the outer peripheral surface of the first piping member 10. In this embodiment, the outermost diameter of the first piping member 10 is the diameter 20R (mm) of the first piping member 10. As shown in FIG. 4, the total diameter 23R (mm) of the height 23h (mm) of the protrusion 23 and the diameter 21R (mm) of the insertion port 21 of the second piping member 20 is equal to or less than the diameter 10R (mm) of the first piping member 10. If the protrusion 23 of the second piping member 20 protrudes from the outermost diameter of the first piping member 10, there is a risk that the protrusion 23 will interfere during installation.

[0034] In the example of the third embodiment described below, the first piping member is an electrofusion joint 10-E, and terminals (first terminal 52, second terminal 57) are provided on the outer peripheral surface of the electrofusion joint 10-E. In this case, the outermost diameter of the first piping member (electrofusion joint 10-E) is a diameter 10-ER (mm) which is the sum of the heights 52R, 57R (mm) of the terminals (first terminal 52, second terminal 57) and the diameter 21R (mm) of the insertion port 21 of the electrofusion joint 10-E. The protrusion 23 of the second piping member 20 does not protrude from the outermost diameter of the electrofusion joint 10-E. When the first piping member 10 is an electrofusion joint 10-E, the protrusion 23 may protrude from the outer peripheral surface of the electrofusion joint 10-E, but the diameter 23R is equal to or smaller than the outermost diameter of the electrofusion joint 10-E.

[0035] The convex portion 23 of the second piping member 20 is formed, for example, by creating a cylindrical protrusion from the same material as the second piping member 20, providing a recess in the outer peripheral surface of the insertion port 21 of the second piping member 20 into which the protrusion can fit, and inserting the cylindrical protrusion into this recess. Alternatively, the second piping member 20 including the convex portion 23 may be molded by injection molding, or the convex portion 23 may be formed by cutting it out on a lathe.

[0036] The first through portion 13 of the first piping member 10 may be produced by cutting using an NC lathe or an MC lathe, for example, or may be formed by injection molding.

[0037] The piping system 100 according to this embodiment is configured so that the convex portion 23 of the second piping member 20 fits into the first through-hole 13 of the first piping member 10, and the convex portion 23 does not protrude beyond the outermost diameter of the first piping member 10. This configuration allows installation without interference even in narrow spaces. Therefore, the piping system 100 according to this embodiment can improve installation efficiency.

[0038] <Modification of the first embodiment> A piping system 100-1 according to a modified example of the first embodiment will be described with reference to Figures 7 and 8. In the modified example of the first embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with the differences being mainly described. FIG. 7 is an exploded plan view showing a piping system 100-1 according to a modified example of the first embodiment. A piping system 100-1 according to a modification of the first embodiment includes a first piping member 10 and a second piping member 20. In the piping system 100-1 according to the modification of the first embodiment, the first piping member 10 includes a joint member (first joint member) 10-1 and a cover 30. FIG. 8 shows a state in which the first piping member 10 (first joint member 10-1, cover 30) and the second piping member 20 are connected. In this embodiment, as shown in FIGS. 7 and 8, the second piping member 20 is connected to both ends of the first piping member 10 along the longitudinal direction of the piping system 100-1. Alternatively, the second piping member 20 may be connected to one end of the first piping member 10 along the longitudinal direction of the piping system 100-1.

[0039] The second piping member 20 of the modified example of the first embodiment is similar to the second piping member 20 of the first embodiment described above. The joint member 10-1 is formed in a hollow cylindrical shape.

[0040] The cover 30 covers the outer peripheral surface of the joint part 10-1 in the circumferential direction. The cover 30 has a curved shape when viewed from the direction of the axis O1 of the cover 30. When viewed from the direction of the axis O1, the cover 30 is not a circular shape formed continuously all the way around, but rather a C-shape. In this way, the cover 30 covers a portion of the outer peripheral surface of the joint part 10-1 in the circumferential direction. The cover 30 has a socket 11 provided at an end of the cover 30 in the direction of the axis O1. In this embodiment, the socket 11 is provided at both ends of the cover 30. The socket 11 may be provided at one end of the cover 30. Cover 30 is provided with through-holes (first through-holes) 13 of the first embodiment described above on the outer peripheral surface of socket 11. First through-holes 13 of the modified first embodiment include L-shaped through-holes (longitudinal through-hole 13A, circumferential through-hole 13B) similar to first through-holes 13 of the first embodiment described above.

[0041] The first through portion 13 of the cover 30 is disposed outside the first piping member 10 in the direction of the axis O1 (longitudinal direction) when the first piping member 10 and the second piping member 20 are connected. With this configuration, with the outer circumferential surface of the coupling member 10-1 covered by the cover 30, the convex portion 23 of the second piping member 20 can be fitted into the first penetrating portion 13 of the cover 30. As a result, even when an existing coupling member is used, the outer circumferential surface of the existing coupling member can be covered with the cover 30, and the second piping member 20 can be connected to the existing coupling member.

[0042] The cover 30 can be made of a thermoplastic resin such as a polyvinyl chloride resin. Examples of polyvinyl chloride resins include polyvinyl chloride homopolymers, copolymers of vinyl chloride monomers with other monomers having unsaturated bonds copolymerizable with the vinyl chloride monomers, and graft copolymers in which vinyl chloride monomers are graft-copolymerized onto polymers other than polyvinyl chloride resins. The polyvinyl chloride resins may be used alone or in combination of two or more. When a resin such as a thermoplastic resin is used for the cover 30, the thickness of the cover 30 is, for example, 2 mm to 3 mm. The cover 30 is formed by, for example, injection molding or extrusion molding.

[0043] Similar to the piping system 100 according to the first embodiment described above, the piping system 100-1 according to the modified example of the first embodiment is configured such that the convex portion 23 of the second piping member 20 fits into the first penetration portion 13 of the cover 30, and the convex portion 23 does not protrude beyond the outermost diameter of the cover 30. This configuration allows for installation without interference even in narrow spaces. Therefore, the piping system 100-1 according to this embodiment can improve installation efficiency.

[0044] Second Embodiment A piping system 100A according to a second embodiment will be described with reference to Fig. 9. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with the differences being mainly described. FIG. 9 is an exploded plan view of a piping system 100A according to the second embodiment. In the first embodiment, the through portion (first through portion) 13 is L-shaped, but in the second embodiment, the through portion (first through portion) 15 is hole-shaped.

[0045] A piping system 100A according to the second embodiment includes a first piping member 10A and a second piping member 20A. In this embodiment, as shown in Fig. 9, the second piping member 20A is connected to one end of the first piping member 10A along the longitudinal direction of the piping system 100A. The second piping member 20A may be connected to both ends of the first piping member 10A along the longitudinal direction of the piping system 100A. The first piping member 10A has an outer peripheral surface provided with a first through-portion 15. More specifically, the first through-portion 15 is provided in the socket 11 of the first piping member 10A. The first through portion 15 is, for example, a circular through hole as shown in FIG. 9 . The first through portion 15 is a through hole that penetrates from the outer peripheral surface to the inner peripheral surface of the first piping member 10A. In this embodiment, the first through portion 15 is provided at both longitudinal end sides of the first piping member 10A. The first through portion 15 may be provided at one longitudinal end side of the first piping member 10A. The first through portion 15 at one end side may have a first through portion 15′ provided on the opposite side as viewed from the arrow (radial direction) in FIG. 9 . The first through portion 15 at the other end side may have a first through portion 15′ provided on the opposite side as viewed from the arrow (radial direction) in FIG. 9 . The first through portion 15 and the first through portion 15′ are arranged point-symmetrically with respect to the center point O of the first piping member 10A as the center as viewed from the axis O1 direction. In this embodiment, two first through-holes 15 are provided on one end side of the first piping member 10A, but the number of first through-holes 15 is not limited to two. The first through portion 15 is not limited to a circular shape, but may be, for example, an elliptical shape or a rectangular shape.

[0046] A convex portion (second convex portion) 25 that can be fitted into the first through-hole 15 of the first piping member 10A is provided on the outer peripheral surface of the second piping member 20A. The convex portion 25 has a shape that protrudes in the circumferential direction on the outer peripheral surface of the insertion port 21 of the second piping member 20A. The convex portion 25 is, for example, hemispherical. The shape of the convex portion 25 is not limited to hemispherical, and it may be, for example, cylindrical.

[0047] The protrusion 25 of the second piping member 20A fits into the first through-hole 15 of the first piping member 10A. When the insertion port 21 of the second piping member 20A is inserted into the socket 11 of the first piping member 10A, the protrusion 25 of the second piping member 20A is inserted so as to fit into the first through-hole 15 of the first piping member 10A. This allows the first piping member 10A and the second piping member 20A to be securely fixed together.

[0048] The width of the first through-portion 15 of the first piping member 10A may be sufficient as long as the protrusion 25 of the second piping member 20A can be fitted thereto. For example, if the protrusion 25 is circular, the first through-portion 15 is also preferably circular. In this case, for example, the outer diameter of the first through-portion 15 is preferably a large diameter, greater than or equal to the outer diameter of the protrusion 25 but not greater than 1.0 mm. For example, if the outer diameter of the first through-portion 15 is 5 mm, the outer diameter of the protrusion 25 is preferably 5 mm or greater but not greater than 6 mm. If the outer diameter of the first through-portion 15 is smaller than the outer diameter of the protrusion 25, the protrusion 25 may not fully fit into the first through-portion 15 when inserted, which may result in damage to the protrusion 25 and the first through-portion 15. Furthermore, a poor fitting force may be generated, resulting in poor joining or other problems. It is even more preferable that the outer diameter of the first through-portion 15 be a large diameter, greater than or equal to the outer diameter of the protrusion 25 but not greater than 1.0 mm. For example, when the outer diameter of the first penetrating portion 15 is 5 mm, the outer diameter of the convex portion 25 is more preferably 5.5 mm or more and 6 mm or less. The protrusion 25 of the second piping member 20 may have any size as long as it can be fitted into the first through-hole 15 of the first piping member 10A. The protrusion 25 is made of, for example, PE100, has an outer diameter of 5 mm, and a height of 5 mm.

[0049] As in the first embodiment, the convex portion 25 of the second piping member 20A does not protrude from the outermost diameter of the first piping member 10A. That is, when the convex portion 25 of the second piping member 20A is fitted into the first through portion 15 of the first piping member 10A, the tip of the convex portion 25 of the second piping member 20A does not protrude from the outer peripheral surface of the first piping member 10A. The total diameter 23R (mm) of the height (mm) of the protrusion 25 and the diameter 21R (mm) of the insertion port 21 of the second piping member 20A is equal to or smaller than the diameter (mm) of the first piping member 10A. If the protrusion 25 of the second piping member 20A protrudes beyond the outermost diameter of the first piping member 10, there is a risk that the protrusion 25 will interfere during installation.

[0050] In the example of the third embodiment described below, the first piping member is an electrofusion joint 10-E, and terminals (first terminal 52, second terminal 57) are provided on the outer peripheral surface of the electrofusion joint 10-E. In this case, the outermost diameter of the first piping member (electrofusion joint 10-E) is a diameter 10-ER (mm) which is the sum of the heights 52R, 57R (mm) of the terminals (first terminal 52, second terminal 57) and the diameter 21R (mm) of the insertion port 21 of the electrofusion joint 10-E. The protrusion 25 of the second piping member 20 does not protrude from the outermost diameter of the electrofusion joint 10-E. When the first piping member 10A is an electrofusion joint 10-E, the protrusion 25 may protrude from the outer peripheral surface of the electrofusion joint 10-E, but the diameter 23R is equal to or smaller than the outermost diameter of the electrofusion joint 10-E.

[0051] The convex portion 25 of the second piping member 20A is formed, for example, by creating a hemispherical protrusion using the same material as the second piping member 20A and adhering this hemispherical protrusion to the outer peripheral surface of the insertion port 21 of the second piping member 20A.

[0052] The first through portion 15 of the first piping member 10A may be produced by cutting using an NC lathe, or may be formed by injection molding, for example.

[0053] The piping system 100A according to this embodiment is configured such that the protrusion 25 of the second piping member 20A fits into the first through-hole 15 of the first piping member 10A, and the protrusion 25 does not protrude beyond the outermost diameter of the first piping member 10A. This configuration allows for installation without interference even in narrow spaces. Therefore, the piping system 100A according to this embodiment can improve installation efficiency.

[0054] <Modification of the second embodiment> A piping system 100A-1 according to a modified example of the second embodiment will be described with reference to Fig. 10. In the modified example of the second embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be omitted, with the differences being mainly described. FIG. 10 is an exploded plan view showing a piping system 100A-1 according to a modified example of the second embodiment. A piping system 100A-1 according to a modification of the second embodiment includes a first piping member 10A and a second piping member 20A. In the piping system 100A-1 according to the modification of the second embodiment, the first piping member 10A includes a joint member (first joint member) 10A-1 and a cover 30A. In this embodiment, as shown in FIG. 10 , the second piping member 20A is connected to both ends of the first piping member 10A along the longitudinal direction of the piping system 100A-1. Alternatively, the second piping member 20A may be connected to one end of the first piping member 10A along the longitudinal direction of the piping system 100A-1.

[0055] The second piping member 20A of the modified example of the second embodiment is similar to the second piping member 20A of the second embodiment described above. The joint member 10A-1 is formed in a hollow cylindrical shape.

[0056] The cover 30A covers the outer peripheral surface of the joint part 10A-1 in the circumferential direction. The cover 30A has a curved shape when viewed from the direction of the axis O1 of the cover 30A. When viewed from the direction of the axis O1, the cover 30A is not a circular shape formed continuously all the way around, but rather a C-shape. In this way, the cover 30A covers a portion of the outer peripheral surface of the joint part 10A-1 in the circumferential direction. The cover 30A has a socket 11 provided at an end of the cover 30A in the direction of the axis O1. In this embodiment, the socket 11 is provided at both ends of the cover 30A. The socket 11 may be provided at one end of the cover 30A. Cover 30A is provided with through-holes (first through-holes) 15 of the second embodiment described above on the outer peripheral surface of socket 11. First through-holes 15 of the modified second embodiment include circular through-holes 15, similar to first through-holes 15 of the second embodiment described above.

[0057] The first through portion 15 of the cover 30A is disposed outside the first piping member 10A in the direction of the axis O1 (longitudinal direction) when the first piping member 10A and the second piping member 20A are connected to each other. With this configuration, with the outer circumferential surface of the coupling member 10-1 covered by the cover 30A, the convex portion 25 of the second piping member 20A can be fitted into the first penetrating portion 15 of the cover 30A. As a result, even when an existing coupling member is used, the outer circumferential surface of the existing coupling member can be covered with the cover 30A, and the second piping member 20A can be connected to the existing coupling member.

[0058] The cover 30A can be made of a thermoplastic resin such as a polyvinyl chloride resin. Examples of polyvinyl chloride resins include polyvinyl chloride homopolymers, copolymers of vinyl chloride monomers with other monomers having unsaturated bonds copolymerizable with the vinyl chloride monomers, and graft copolymers in which vinyl chloride monomers are graft-copolymerized onto polymers other than polyvinyl chloride resins. The polyvinyl chloride resins may be used alone or in combination of two or more. When a resin such as a thermoplastic resin is used for the cover 30A, the thickness of the cover 30A is, for example, 2 mm to 3 mm. The cover 30A is formed by, for example, injection molding or extrusion molding.

[0059] Similar to the piping system 100A according to the second embodiment described above, the piping system 100A-1 according to the modified example of the second embodiment is configured such that the convex portion 25 of the second piping member 20A fits into the first penetration portion 15 of the cover 30A, and the convex portion 25 does not protrude beyond the outermost diameter of the cover 30A. This configuration allows for installation without interference even in narrow spaces. Therefore, the piping system 100A-1 according to this embodiment can improve installation efficiency.

[0060] Third Embodiment A piping system according to a third embodiment of the present disclosure will be described below with reference to Fig. 11. In the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof will be omitted, with the differences being mainly described. The first piping member 10 and the first joint member 10-1 of the first embodiment, and the first piping member 10A and the first joint member 10A-1 of the second embodiment constitute an electrofusion joint 10-E of the third embodiment. Fig. 11 shows an example of a piping system 200 according to this embodiment. The piping system 200 employs the configuration of an electrofusion joint 10-E as shown in Fig. 11. Fig. 11 shows an electrofusion joint 10-E according to this embodiment provided with a first terminal 52, a first indicator 55, a second terminal 57, and a second indicator 59, which will be described later.

[0061] The electrofusion joint 10-E has a through-hole (first through-hole) 13 provided on its outer circumferential surface. The first through-hole 13 may be an L-shaped through-hole having a longitudinal through-hole 13A and a circumferential through-hole 13B, as in the first embodiment. Alternatively, the first through-hole 13 may be a circular through-hole, as in the first through-hole 15 of the second embodiment.

[0062] 11 , the piping system 200 includes an electrofusion joint 10-E and a second piping member 20. In this embodiment, the second piping member 20 is connected to one end of the electrofusion joint 10-E along the longitudinal direction of the piping system 200. However, the piping system 200 may also be configured such that the second piping member 20 is connected to both ends of the electrofusion joint 10-E along the longitudinal direction of the piping system 200.

[0063] The electric fusion joint 10-E includes a hollow cylindrical joint body 12-E made of the same resin as that constituting the second piping member 20, and a heating wire (described later) spirally arranged on the inner periphery of the joint body 12-E. The inner periphery of the joint body 12-E is provided with a fusion portion. The fusion portion is formed by inserting a heating wire into a spiral notch groove formed on the inner periphery of the joint body 12-E. Specifically, the electric fusion joint 10-E includes a joint body 12-E, a first heating portion 51, a first terminal 52, a first indicator 55, a second heating portion 56, a second terminal 57, and a second indicator 59.

[0064] A first heating portion 51 is provided on the inner peripheral surface of the joint body 12-E on the socket 11 side at one end in the length direction. The first heating portion 51 has a first heating wire 61 inserted into a first notched groove formed in a spiral shape on the inner circumferential surface side of the joint body 12-E. The opening portion of the first notched groove may have a spiral shape with the axis O1 of the joint body 12-E as the central axis and the distance from the central axis to the inner circumferential surface as the radius, for example. However, the first heating wire 61 may also be embedded in the joint body 12-E without the first notched groove.

[0065] The first terminal 52 is provided on the outer peripheral surface of the joint (electrofusion joint 10-E). More specifically, the first terminal 52 is provided on the outer peripheral surface of one socket 11 of the electrofusion joint 10-E. The first terminal 52 is provided to pass current through the first heating wire 61 when electrically fusing the second piping member 20 to the first heating portion 51. For simplicity of illustration in Fig. 11, the wire withdrawal hole and the first terminal 52 are shown in the same position, but in reality they are formed in positions spaced apart around the circumferential direction of the joint body 12-E. The first terminal 52 is connected to the connection wire 36 of the controller 35 for passing current. In this embodiment, the first heating wire 61 is connected to a second heating wire 62 described below, and a voltage is applied between the first terminal 52 and the second terminal 57. However, if the first heating wire 61 is not connected to the second heating wire 62, a voltage may be applied to the first heating wire 61 via the first terminal 52. In this case, the first terminals 52 may be provided at intervals in the circumferential direction on the peripheral surface of the socket 11 side of one end of the joint body 12-E.

[0066] The first indicator 55 is provided on the outer peripheral surface of the joint (electrofusion joint 10-E). More specifically, the first indicator 55 is provided on the outer peripheral surface of the joint body 12-E. The first indicator 55 is embedded in a recess (first recess) 54 provided on the outer peripheral surface of the joint body 12-E. The first indicator 55 protrudes radially outward from the first recess 54 during electrofusion, when power is supplied to the first heating wire 61 via the first terminal 52. The protrusion of the first indicator 55 makes it possible to confirm that the first heating element 51 has been reliably electrofused to the second piping member 20 to which it is connected. The first indicator 55 may be formed in a color different from that of the electrofusion joint 10-E so that it is easily visible even in dark installation spaces. In this case, the first indicator 55 may be colored by dyeing, printing, imprinting, or the like, and the color may be fluorescent or the like. The first indicator 55 may be integrally molded with the joint body 12-E using the same material, or may be integrally molded with a different material. Alternatively, the first indicator 55 may be formed from a material different from that of the joint body 12-E and attached to the joint body 12-E. The first indicator 55 is provided to confirm whether the first heating portion 51 has fused.

[0067] A second heating portion 56 is provided on the inner peripheral surface of the joint body 12-E on the socket 11 side at the other end in the length direction. The second heating portion 56 has a second heating wire 62 inserted into a second notched groove formed in a spiral shape on the inner circumferential surface side of the joint body 12-E. The opening portion of the second notched groove may have a spiral shape with the axis O1 of the joint body 12-E as the central axis and the distance from the central axis to the inner circumferential surface as the radius, for example. The second heat generating portion 56 is configured in substantially the same manner as the first heat generating portion 51. In this embodiment, the winding direction and number of turns of the spiral formed by the first heating wire 61 and the second heating wire 62 are not particularly limited.

[0068] The second terminal 57 is provided on the outer peripheral surface of the joint (electrofusion joint 10-E). More specifically, the second terminal 57 is provided on the outer peripheral surface of the other socket 11 of the electrofusion joint 10-E. The second terminal 57 is provided to pass current through the second heating wire 62 when electrically fusing the second piping member 20 to the second heating portion 56. For simplicity of illustration, the wire outlet hole and the second terminal 57 are shown in the same position in Fig. 11. The second terminal 57 is connected to the connection wire 36 of the controller 35 for passing current. In this embodiment, the first heating wire 61 is connected to the second heating wire 62, and a voltage is applied between the first terminal 52 and the second terminal 57. However, if the first heating wire 61 is not connected to the second heating wire 62, a voltage may be applied to the second heating wire 62 via the second terminal 57. In this case, the second terminals 57 may be provided at intervals in the circumferential direction on the peripheral surface of the other end of the joint body 12-E on the socket 11 side.

[0069] The second indicator 59 is provided on the outer peripheral surface of the joint (electrofusion joint 10-E). More specifically, the second indicator 59 is provided on the outer peripheral surface of the joint body 12-E. The second indicator 59 is embedded in a recess (second recess) 60 provided on the outer peripheral surface of the joint body 12-E. The second indicator 59 protrudes radially outward from the second recess 60 during electrofusion, when power is supplied to the second heating wire 62 via the second terminal 57. The protrusion of the second indicator 59 makes it possible to confirm that the second heating element 56 has been reliably electrofused to the second piping member 20 to which it is connected. The second indicator 59 may be formed in a color different from that of the electrofusion joint 10-E so that it is easily visible even in dark installation spaces. In this case, the second indicator 59 may be colored by dyeing, printing, imprinting, or the like, and the color may be fluorescent or the like. The second indicator 59 may be integrally molded with the joint body 12-E using the same material, or may be integrally molded with a different material. Alternatively, the second indicator 59 may be formed from a material different from that of the joint body 12-E and attached to the joint body 12-E. The second indicator 59 is provided to confirm whether the second heating portion 56 has fused. As described above, the second heat generating portion 56 is configured in substantially the same manner as the first heat generating portion 51.

[0070] The first heating wire 61 and the second heating wire 62 may be made of nichrome, iron-chromium alloy, copper-nickel alloy, copper-manganese alloy, iron-nickel alloy, manganese, copper-nickel-manganese alloy, nickel-chromium alloy, chromel, etc. The first heating wire 61 and the second heating wire 62 may be coated or uncoated. 11, the first heating wire 61 is connected to the second heating wire 62. Therefore, electricity can be applied to the first heating wire 61 and the second heating wire 62 using both the first terminal 52 and the second terminal 57.

[0071] As shown in FIG. 11 , the insertion port 21 of the second piping member 20 is inserted into the socket 11 of the electrofusion joint 10-E, and the connection wire 36 of the power controller 35 is connected to the first terminal 52 and the second terminal 57. Then, the controller 35 applies electricity to the heating wire, causing it to heat up. After applying electricity for a predetermined time with the required amount of power, the electricity is stopped and the wire is cooled. The second piping member 20 can then be joined via the fused portion created by the electrofusion joint 10-E. The application of electricity to the heating wire fuses the inner circumferential surface of the electrofusion joint 10-E and the outer circumferential surface of the second piping member 20 together, allowing the second piping member 20 to be fused as if it were being joined. The fused portion is formed with a predetermined width around the entire circumference of the contact area between the outer circumferential surface of the second piping member 20 and the inner circumferential surface of the electrofusion joint 10-E.

[0072] The piping system 200 according to this embodiment is configured such that the convex portion 23 of the second piping member 20 (the convex portion 25 of the second piping member 20A) fits into the first through portion 13 (the first through portion 15 of the first piping member 10A) of the electrofusion joint 10-E (the first piping members 10, 10A), and the convex portion 23 (the convex portion 25) does not protrude from the outermost diameter of the electrofusion joint 10-E. This configuration allows installation without interference even in narrow spaces. Therefore, the piping system 200 according to this embodiment makes it possible to improve installation ease.

[0073] <Modification of the third embodiment> A piping system 200-1 according to a modified example of the third embodiment will be described with reference to Fig. 12. In the modified example of the third embodiment, the same components as those in the third embodiment are denoted by the same reference numerals, and the description thereof will be omitted, with the differences being mainly described. FIG. 12 is a plan view showing a piping system 200-1 according to a modified example of the third embodiment. A piping system 200-1 according to a modification of the third embodiment includes an electrofusion joint 10-E and a second piping member 20. In the piping system 200-1 according to the modification of the third embodiment, the electrofusion joint 10-E includes a joint member (second joint member) 10-E-1 and a cover 30-1. Fig. 12 shows the electrofusion joint 10-E (second joint member 10-E-1, cover 30-1) and the second piping member 20 connected together.

[0074] The cover 30-1 circumferentially covers the outer peripheral surface of the second joint part 10-E-1. The cover 30-1 has a curved shape when viewed from the direction of the axis O1 of the cover 30-1. When viewed from the direction of the axis O1, the cover 30-1 is not a circular shape formed continuously all the way around, but rather a C-shape. In this way, the cover 30-1 circumferentially covers a portion of the outer peripheral surface of the second joint part 10-E-1. The cover 30-1 has second through-portions 31 and 32 into which the terminals (first terminal 52 and second terminal 57) are fitted. The second through-portion 31 fits with the first terminal 52, and the second through-portion 32 fits with the second terminal 57. The second through-portions 31 and 32 penetrate from the outer peripheral surface to the inner peripheral surface of the cover 30-1.

[0075] The cover 30-1 has fourth through-portions 33 and 34 into which indicators (first indicator 55, second indicator 59) fit. The fourth through-portion 33 fits with the first indicator 55, and the fourth through-portion 34 fits with the second indicator 59. The fourth through-portions 33 and 34 penetrate from the outer peripheral surface to the inner peripheral surface of the cover 30-1. The fourth through-portion 33 is a hole for checking the first indicator 55, and the fourth through-portion 34 is a hole for checking the second indicator 59.

[0076] The cover 30-1 is similar to the covers 30 and 30A except that it includes second through-holes 31 and 32 and fourth through-holes 33 and 34. Fig. 12 shows a configuration including L-shaped through-holes (longitudinal through-hole 13A and circumferential through-hole 13B) like the cover 30 shown in the first embodiment. The cover 30-1 may also include circular through-holes like the cover 30A shown in the second embodiment.

[0077] With this configuration, with the outer peripheral surface of the second joint member 10-E-1 covered by the cover 30-1, the convex portion 23 (25) of the second piping member 20A can be fitted into the first through portion 13 (15) of the cover 30-1. As a result, even when an existing joint member is used, the outer peripheral surface of the existing joint member can be covered with the cover 30-1, and the second piping member 20 (20A) can be connected to the existing joint member.

[0078] An example of an outline of a method for constructing the piping system 100 (100-1, 100A, 100A-1, 200, 200-1) will be described. The insertion port 21 of the second piping member 20 is inserted into the socket 11 of the first piping member 10 (electric fusion joint 10-E). The convex portion 23 (25) of the second piping member 20 is fitted into the first through portion 13 (15) of the first piping member 10 (fitting process). In a piping system 200 (200-1) that employs an electrofusion joint 10-E, the surface of the second piping member 20 that will be joined to the electrofusion joint 10-E is scraped with a scraper (scraping process) before the fitting process. The scraped second piping member 20 can maintain a good joint state for a certain period of time. After the scraping process, the outer surface of the insertion port 21 of the second piping member 20 and the inner surface of the socket 11 of the electrofusion joint 10-E are cleaned (cleaning process). After the fitting step, the connection wire 36 of the power controller 35 is connected to the first terminal 52 and the second terminal 57, and electricity is passed from the controller 35 to the heating wire, causing the heating wire to heat up. By passing electricity through the heating wire, the inner peripheral surface of the electric fusion joint 10-E and the outer peripheral surface of the second piping member 20 are fused to each other (fusion step). The temperature of the heating wire during current passing need only be a temperature that melts the fused portion, and heating is performed at, for example, 230°C. After the fusion step, the electric fusion joint 10-E and the second piping member 20 are cooled (cooling step). In the fitting process of the piping system 100-1 (100A-1), the cover 30 (30A) is attached so that the first penetration portion 13 (15) is aligned with and covers the protrusion 23 (25) of the second piping member 20. In the fitting process of the piping system 200-1, the cover 30-1 is attached so that the second penetration portions 31, 32 are aligned with and covers the terminals (first terminal 52, second terminal 57) (cover attachment process).

[0079] The technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present disclosure. [Explanation of symbols]

[0080] 10, 10A First piping member 10-1, 10A-1 Joint member (first joint member) 10-E Electric fusion joint 10-E-1 Joint member (second joint member) 11 Underbite 12 First piping member body 12-E Fitting body 13,15 Penetration section (first penetration section) 20, 20A Second piping member 21 Insertion port 22 Second piping member body 23 Convex part (first convex part) 25 Convex part (second convex part) 30, 30A, 30-1 Cover 31, 32 Second penetration 52 Terminal 1 55 First Indicator 57 Terminal 2 59 Second Indicator 100, 100-1, 100A, 100A-1, 200, 200-1 Piping System

Claims

1. a first piping member having a socket; a second piping member connected to the socket; Equipped with A first penetration portion is provided on the outer peripheral surface of the socket, a protrusion is provided on an outer peripheral surface of the second piping member, the protrusion fits into the first through-portion, The protrusion does not protrude from the outermost diameter of the first piping member. Piping system.

2. The first piping member includes a joint member and a cover that covers the joint member, The cover has the receptacle, The first through-portion is provided on an outer peripheral surface of the socket of the cover, The protrusion fits into the first penetration portion of the cover. The piping system of claim 1 .

3. The first penetrating portion of the cover is disposed on an outer side of the first piping member in a longitudinal direction of the first piping member. The piping system of claim 2 .

4. The piping system according to claim 1 , wherein the first piping member is an electrofusion joint.

5. The electrofusion joint includes a joint member and a cover that covers the joint member, A terminal is provided on the outer peripheral surface of the electric fusion joint, The cover is provided with a second penetration portion into which the terminal is fitted. The piping system of claim 4.

Images