Piping system

Abstract

To provide a piping system having excellent workability while maintaining a discharge flow rate.SOLUTION: A piping system 1 comprises a composite pipe 300 including a flexible pipe 310 and a coating 320, a first pipe joint 100 to which the composite pipe 300 is connected, and a second pipe joint 200. The first pipe joint has a joint body 101 made of an amorphous transparent resin, a packing 103a that is in contact with the outside of the flexible pipe 310, coming-off prevention rings 104a, 104b that prevent the flexible pipe 310 from coming off, and an annular first movable member 105. The second pipe joint has an outer body member 221 on an outer surface of a pipe end part made of an amorphous transparent resin, a packing 215 that is in contact with the inside of the flexible pipe 310, and an annular second movable member 240. The first movable member 105 and the second movable member 240 are pushed and moved at a connection part connected to the flexible pipe 310 by inserting the flexible pipe 310.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a piping system of flexible pipes using elbow joints and T-junction joints, which allows for both visual inspection of connections after installation and suppression of pressure loss in the system. [Background technology]

[0002] One-touch or one-push fittings, which are systems in which the pipe is inserted a predetermined amount into the fitting, are widely used for flexible pipe fittings. One-touch fittings are fittings in which the connection is completed by inserting the pipe a predetermined amount into the fitting, while one-push fittings are fittings in which a separate waterproof gasket or other protective component is inserted into the end of the pipe beforehand, and then the connection is completed by inserting this and the pipe a predetermined amount into the fitting. In addition to the above, flexible pipe fittings can also be classified by the position of the waterproof gasket (inside or outside the pipe). Classification of pipe fittings based on the position of the waterproof gasket is explained below.

[0003] As a pipe joint for flexible pipes, for example, as disclosed in Patent Document 1, an internal watertight joint is known, which has a watertight gasket of the joint placed inside the pipe and seals off water by contact between the inside of the pipe and the gasket. Internal watertight joints have excellent installation reliability and installation checkability. One reason for their high installation reliability is that, since the watertight surface is inside the pipe, scratches on the outside of the pipe do not directly lead to water leakage because they are not on the watertight surface. Another reason for their high installation checkability is that, because watertightness is achieved internally, the insertion status of the pipe end can be visually checked by providing an insertion check hole on the outside or by using a transparent resin for the outer tube. On the other hand, internal water stop fittings have an inner cylindrical section on the inside of the pipe where the packing is installed, which reduces the cross section of the water flow, resulting in a relatively large pressure loss.For this reason, when elbow fittings or T-branch fittings are used frequently, in particular, there is a possibility that the discharge flow rate will decrease due to pressure loss.

[0004] Furthermore, as a pipe joint for flexible pipes, for example, an external watertight joint, as disclosed in Patent Document 2, is known, which has a watertight gasket of the joint placed on the outside of the pipe and seals the water by contact between the outside of the pipe and the gasket. External watertight joints do not require an inner cylindrical portion on the inside of the pipe to accommodate the gasket, so they have less pressure loss than internal watertight joints. Therefore, for example, even in piping that makes extensive use of elbow joints and T-branch joints, the discharge flow rate can be easily maintained. On the other hand, with external water stop fittings, the water stop surface is on the outside of the pipe, so even small scratches on the outside of the pipe can cause insufficient water stoppage, which can lead to leaks.In addition, with external water stop fittings, it is difficult to visually check the pipe end insertion depth of all connecting parts, including the metal fittings at the ends, which can lead to installation defects due to insufficient checking.

[0005] Furthermore, although metal joints that use an external watertight method and can be visually inspected are known, such as those described in Patent Document 3, they have complicated structures that make them expensive to produce, and it is not possible to fully inspect the installation status. Furthermore, because a watertight section is required on the inside, pressure loss is not small, and so they do not meet the quality demanded by the market. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5800975 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-225857 [Patent Document 3] Patent No. 4890130 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, internal watertight fittings are easy to install, but have the problem that the discharge flow rate is easily reduced when using construction methods that make extensive use of elbow fittings, etc. Furthermore, external watertight fittings tend to maintain the discharge flow rate, but have the problem that they are easily affected by external scratches and it is difficult to check the installation status.

[0008] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a piping system that is easy to install while maintaining a discharge flow rate. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention proposes the following means.

[0010] (1) A piping system of the present invention comprises a composite pipe including a flexible tube and a coating, a first pipe fitting to which the composite pipe is connected, and a second pipe fitting to which the composite pipe is connected, wherein the first pipe fitting has a fitting body made of an amorphous transparent resin, a gasket in contact with the outside of the flexible tube, a retaining ring that prevents the flexible tube from coming off, and a first annular movable member, and the second pipe fitting has an outer body member on the outer surface of the pipe end made of an amorphous transparent resin, a gasket in contact with the inside of the flexible tube, and a second annular movable member, and the first movable member and the second movable member are pushed and moved by the insertion of the flexible tube at a connection portion connected to the flexible tube. With this configuration, a piping system can be provided that includes a first pipe fitting (external watertight fitting) and a second pipe fitting (internal watertight fitting). This allows the user to select whether to use the first pipe fitting (external watertight fitting) or the second pipe fitting (internal watertight fitting) for each fitting. The ends of a pipeline are particularly susceptible to scratches and other damage due to the dark and limited working space, such as inside an equipment cabinet, where light sources are blocked. On the other hand, construction can be performed relatively safely in areas other than the ends, so even if a fitting connecting flexible pipes is an external watertight fitting, the risk of the flexible pipes being scratched is relatively low. In the piping system of the present invention, for example, the first pipe fitting (external watertight fitting) can be used in fittings that connect flexible pipes, such as elbow fittings, and the second pipe fitting (internal watertight fitting) can be used in other fittings (e.g., both ends of the pipeline). The first pipe fitting has a fitting body made of an amorphous transparent resin, and the second pipe fitting has an outer body member on the outer surface of the pipe end made of an amorphous transparent resin. This allows the connection status between the pipe fitting and the flexible pipe to be easily confirmed from the outside. This minimizes pressure loss due to the internal watertight fitting, maintains the discharge flow rate, and creates a piping system with excellent workability. (2) The first movable member and the second movable member may have chamfered portions at their contact ends with the packing. With this configuration, when the first and second movable members are pushed and moved by the insertion of the flexible tube and pass over the packing, the packing can be prevented from coming out of its predetermined position or being twisted off. This makes it easier to ensure the watertightness of the packing. Therefore, the piping system can be easily installed. (3) At least one of the first movable member and the second movable member may have a protrusion that is pressed against the end face of the flexible tube, and the axial length of the protrusion may be a length that does not interfere with the gasket when the connection is complete and is equal to or less than the insertion length of the flexible tube into each pipe joint. With this configuration, the outer diameter of the inner tubular portion is approximately equal to the inner diameter of the flexible tube, so the inner tubular portion can be smoothly inserted into the inner surface of the flexible tube and can be in close contact with it. This makes it easier to ensure watertightness using the packing, resulting in a piping system with excellent workability. (4) At least one of the first movable member and the second movable member may have a protrusion that is pressed against the end face of the flexible tube, and the axial length of the protrusion may be a length that does not interfere with the gasket when the connection is complete and is equal to or less than the insertion length of the flexible tube into each pipe joint. With this configuration, the axial length of the protrusion is long enough that it does not interfere with the gasket when the connection is complete, so when the protrusion and the flexible tube connected to the protrusion are inserted to a predetermined position within the joint, the protrusion does not hinder contact between the flexible tube and the gasket. (5) The first movable member and the second movable member have warning portions, and the warning portions have warning colors on their entire or outer surfaces, and the warning portions are configured to be visible from the outside from all angles at which the warning color can be seen when in the connection complete state, and the warning portions of the first movable member and the second movable member when in the connection complete state may be shown in the same color. With this configuration, it is easy to check whether the flexible pipe is inserted into the fittings sufficiently. Furthermore, when multiple types of fittings are used in the same piping system due to the mixing of watertightness methods, the different installation methods for each fitting can cause confusion for the installer, raising concerns about the risk of water leakage due to poor installation caused by unfamiliarity with the installation procedures. As described above, if the first and second movable members in the fully connected state are displayed in the same color scheme, the appearance of the completed connection state of the installation confirmation section of the first pipe fitting (external watertight fitting) and the second pipe fitting (internal watertight fitting) can be unified. By unifying the appearance of the completed connection state of the installation confirmation section, installers can avoid confusion even when using fittings with different watertightness methods. This allows for a piping system with excellent installation ease while maintaining the discharge flow rate. (6) The coating may include a foamed resin material. With this configuration, the force required to remove the coating is relatively small compared to a non-foamed coating of the same thickness, reducing the possibility of swinging the pipe in the direction of the force applied. This reduces the risk of the pipe being shaken off even if the inner core is inserted into the external watertight joint first. (7) It is preferable that the coating has a single-layer corrugated pipe and support portions arranged on the corrugated pipe at intervals of 50 mm or more and 200 mm or less in the axial direction of the corrugated pipe, the support portions protrude radially inward from the corrugated pipe and have a plurality of support protrusions arranged in a row in the circumferential direction, the foaming ratio of the corrugated pipe is 1.05 times or more and 4.00 times or less, and the thickness of the convex portions that form the outer diameter of the corrugated pipe is 0.4 mm or more. With this configuration, the production cost of the composite pipe can be reduced because the covering is a corrugated pipe, and the heat insulating properties of the corrugated pipe allow the water temperature inside the flexible pipe to be kept constant, preventing freezing. Therefore, the discharge flow rate can be maintained regardless of the temperature while reducing costs. [Effects of the Invention]

[0011] The present invention can provide a piping system that is easy to install while maintaining a discharge flow rate. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram of a piping system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a cross-sectional view of a composite pipe covered with a corrugated pipe. [Figure 3] FIG. 10 is a circumferential cross-sectional view of a support portion of a composite pipe covered with a corrugated pipe. [Figure 4] FIG. 2 is a partially cutaway view of a first pipe joint in the present embodiment. [Figure 5] FIG. 2 is an exploded perspective view of a first pipe joint in the present embodiment. [Figure 6] FIG. 3 is a partially enlarged view of a first pipe joint in the present embodiment. [Figure 7] 3 is a cross-sectional view showing a state in which a first movable member of a first pipe joint in this embodiment is inserted into a flexible pipe. FIG. [Figure 8] 10 is an external view of the first pipe joint in the present embodiment in a connected state. [Figure 9] FIG. 4 is a cross-sectional view of a second pipe joint before being connected to a flexible pipe. [Figure 10] FIG. 10 is a cross-sectional view of the second pipe joint in a state where connection with the flexible pipe is complete. [Figure 11] 10 is an external view of the second pipe joint in the present embodiment in a connected state. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of a piping system 1 according to the present invention will be described with reference to FIGS.

[0014] Fig. 1 is a schematic diagram showing a piping system 1 according to one embodiment of the present invention. As shown in Fig. 1, the piping system 1 includes a composite pipe 300, a first pipe joint (external watertight joint) 100, and a second pipe joint (internal watertight joint) 200. The piping system 1 in this embodiment is constructed using a branching construction method. The branching construction method is a construction method in which piping extending from a water supply / hot water heater is branched using elbow joints, tee joints, etc., and connected to a location of use (e.g., kitchen, bathroom, toilet, etc.). The branching construction method may also be, for example, a pipe cover construction method. The pipe cover construction method is a construction method for renovations that has seen increasing demand in Japan in recent years, in which new piping is installed along the interior walls of old buildings without opening up the walls or floors. In this type of pipe cover construction method, new piping is installed along the interior walls, so a large number of elbow joints are used, particularly to fit along beams and the four corners of the room.

[0015] When using a large number of elbow fittings during renovation, if the second pipe fitting 200 (internal water stop fitting) is used for all of the pipe fittings, pressure loss increases and there is a possibility that the discharge flow rate will decrease compared to before the renovation. When using the internal water stop fitting 200, it is necessary to consider these issues and consider in advance how to reduce the amount of elbows used, such as avoiding piping along the wall and selecting piping routes under the floor or to the ceiling.

[0016] On the other hand, when the first pipe fitting 100 (external water stop fitting) is used, pressure loss is small even when a large number of elbow fittings are used, and detailed prior consideration is not required. However, the external water stop fitting 100 has low workability and construction checkability, and the risk of water leakage is relatively high. In particular, the risk of water leakage near the point of use, where it is often difficult to secure working space, could not be ignored.

[0017] Therefore, the inventors came up with the idea of ​​making it possible to select whether to use the first pipe fitting 100 (external watertight fitting) or the second pipe fitting 200 (internal watertight fitting) for each condition (position, number used, etc.) of the multiple pipe fittings in the same piping system 1.

[0018] In this embodiment, the first pipe fitting 100 (external watertight fitting) is used at the connection between composite pipes 300, and the second pipe fitting 200 (internal watertight fitting) is used at the connection between equipment and the composite pipe 300, such as at the pipe end of the composite pipe 300. The locations and numbers of the first pipe fitting 100 (external watertight fitting) and the second pipe fitting 200 (internal watertight fitting) to be used are not limited, and can be selected appropriately depending on the conditions of the construction site, etc.

[0019] The number of second pipe fittings (internal water stop fittings) used per flow path is preferably eight or less. For example, when a threaded tee is used, second pipe fittings (internal water stop fittings) can be used at the water supply meter outlet, hot water supply branch threaded tee inlet, hot water supply branch threaded tee outlet, hot water heater inlet, hot water heater outlet, bathroom piping primary side (plumber's side: threaded), bathroom piping secondary side (unit bath construction side: threaded connection to the bathroom piping primary side), and hot water tap. Note that threaded tee fittings are used to allow the hot water pipe side to be unscrewed so that the water supply can continue to be used in the event of a leak in the hot water pipe, which places a heavy load on the piping. However, if the main pipe has a nominal diameter of 16 or 20 and the branch pipe has a nominal diameter of 13, and the number of secondary pipe fittings (internal water stop fittings) used per flow path is approximately 20 or less, a discharge flow rate of 8 L / min or more for showers and 6 L / min or more for kitchen faucets can be achieved, depending on the pipe length and routing, as shown in the Better Living Foundation's discharge flow rate test (BLT PI-01). However, in the case of renovation work, customers' judgment criteria are comparisons with the previous discharge flow rate, so a decrease in flow rate can cause dissatisfaction. Here, a single flow path refers to one of the possible pipe patterns that water can pass from the water supply / hot water heater to the point of use (e.g., kitchen, bathroom, toilet, etc.). For example, in Figure 1, a single flow path refers to the flow path extending from water heater A to kitchen faucet B. For example, in Figure 1, a single flow path refers to the flow path extending from water heater A to washing machine faucet C.

[0020] (composite pipe 300) In this embodiment, the composite pipe 300 includes a flexible pipe 310 and a coating 320 . The flexible tube 310 is formed from a resin pipe, a metal pipe, or a composite pipe 300 of a resin pipe and a metal pipe, and the material can be selected arbitrarily based on the quality design according to the application, such as cross-linked polyethylene, polybutene, polyethylene, heat-resistant polyethylene, aluminum, magnesium, or a composite pipe 300 combining these.

[0021] The composite pipe 300 has a coating 320 around the flexible pipe 310. By having the coating 320, the composite pipe 300 can protect the outer surface of the flexible pipe 310 and can prevent the outer surface of the flexible pipe 310 from being scratched.

[0022] The thickness of the coating 320 is preferably 0.4 mm or more. If the thickness is 0.4 mm or more, the coating 320 will not be easily damaged by a drag load at the construction site, and the coating 320 will be prevented from shifting due to an external force, thereby preventing the flexible tube 310 from being exposed. The covering 320 is preferably made of a material containing, for example, a foamed resin. The covering 320 can be made of any material selected from, for example, polyethylene, cross-linked polyethylene, polypropylene, an olefin-based elastomer, or a styrene-based elastomer. From the perspective of suppressing displacement of the covering 320 due to external force, foamed polyethylene, low-density polyethylene, or foamed polypropylene may be used, which moderately deform when subjected to an external force to reduce axial displacement, or an elastomer with moderate friction may be used.

[0023] More specifically, the coating 320 may be a cylindrical coating primarily made of an olefin-based elastomer, with a non-foamed surface layer and a triple-foamed inner layer. This type of coating 320 can provide a non-slip coating 320 due to the rubber-like stickiness of the elastomer, regardless of whether the coating 320 is foamed or not. Alternatively, a 30-fold foamed cross-linked polyethylene coating may be used. A 30-fold foamed cross-linked polyethylene coating is preferable because it provides a non-uniform surface on the flexible tube 310 side due to the unevenness of the foam, making it less slippery. Furthermore, when an external force is applied, the coating 320 collapses, making it more likely to orient itself toward the tube core. This effectively prevents axial displacement and prevents the coating 320 from being displaced by an external force.

[0024] Furthermore, these materials are preferably formed into a corrugated shape with irregularities as shown in FIG. 2, and the distance L1 between the shortest line segment connecting the inner diameter end of the coating 320 (the valley portion of the peak-valley shape excluding the protrusions of the support portion 321) and the outer periphery of the flexible tube 310, which is concentrically disposed around the coating 320, is preferably 3 mm to 5 mm (approximately 4 mm). To maintain this distance, the support portions 321 as shown in FIGS. 2 and 3 are preferably distributed at intervals of 50 mm to 200 mm in the axial direction. The support portions 321 preferably have multiple support protrusions 321a that protrude radially inward from the corrugated tube 320a and are aligned in the circumferential direction. While the number of support protrusions 321a per support portion 321 is not limited, three is preferred, and four is more preferred, from the viewpoint of maintaining the distance between the inner diameter of the coating 320 and the outer periphery of the flexible tube 310. It is preferable that no lubricant such as silicone oil is applied between the flexible tube 310 and the covering 320 (between the flexible tube 310 and the support projections 321a in the case of a corrugated tube).

[0025] The corrugated tube 320a preferably has an expansion ratio of 1.05 to 4.00. It is particularly preferable that the corrugated tube 320a be made of low-density polyethylene with an expansion ratio of 1.20 or more. This type of corrugated tube 320a is suitable because it is less likely to slip because the contact surface with the flexible tube 310 is uneven due to the surface roughness of the foam. Furthermore, when an external force is applied, the coating 320 collapses, making it easier to orient toward the pipe core, thereby preventing axial displacement.

[0026] In order to prevent the coating of the flexible tube 310 from being torn and the outer surface of the flexible tube from being damaged due to dragging during installation, the thickness of the convex portion of the corrugated tube 320a, which is the outer diameter, is preferably 0.4 mm or more.

[0027] (First pipe joint 100) The first pipe fitting 100 in this embodiment will be described with reference to FIGS. The first pipe fitting 100 has a shape that is symmetrical on both sides in the axial direction with the axial center as the reference. Pipes are inserted into the first pipe fitting 100 from both sides in the axial direction. The first pipe fitting 100 connects two compound pipes 300.

[0028] FIG. 4 shows a partially cutaway view of a first pipe joint 100 which is an external watertight joint. As shown in FIG. 4, the first pipe fitting 100 (external watertight fitting) includes a cylindrical fitting body 101 made of an amorphous transparent resin, and a cap 102 provided at the end of the fitting body 101.

[0029] Hereinafter, the direction along the central axis of the joint body 101 will be referred to as the axial direction, and the direction intersecting the central axis in a plan view of the joint body 101 from the axial direction will be referred to as the radial direction. Also, the direction going around the central axis in the plan view will be referred to as the circumferential direction.

[0030] A step 113 is formed on the inner peripheral surface of the axial end of the joint body 101. The step 113 protrudes radially inward from the inner peripheral surface of the joint body 101. The step 113 is provided around the entire circumference in the circumferential direction. At the step 113, the inner diameter of the joint body 101 gradually (step-wise) reduces from the outside to the inside in the axial direction. A first movable member 105 formed separately from the joint body 101 abuts against the step 113. Hereinafter, the portion of the joint body 101 from the end face of the joint body 101 to the step 113 will be referred to as the open end of the joint body 101.

[0031] An outer flange portion 101b and a male thread portion 101c are formed on the outer peripheral surface of each of both axial end portions of the joint body 101. The outer flange portion 101b protrudes radially outward from the joint body 101. The outer flange portion 101b extends around the entire outer circumferential surface of the joint body 101. The male thread portion 101c is formed on the outer peripheral surface of the joint body 101 at a portion located axially outward of the outer flange portion 101b (that is, closer to the end of the joint body 101).

[0032] 4 and 5, the cap 102 is cylindrical in shape and has an outer diameter that gradually decreases in the axial direction. The cap 102 includes a first tube 102a having an internal thread formed on the inner peripheral surface thereof, and a second tube 102b located axially outward of the first tube 102a. The first tube 102a is threaded onto the male thread portion 101c. A step 102d is provided on the inner periphery of the cap 102 at a portion corresponding to the boundary between the first tube 102a and the second tube 102b. The step 102d extends over the entire circumferential direction. The step 102d contacts or is close to the end face of the joint body 101 that faces outward in the axial direction.

[0033] The second cylinder 102b has a smaller diameter than the first cylinder 102a and extends outward in the axial direction from the first cylinder 102a. In the first pipe fitting 100, an accommodating recess 106 for accommodating the watertight portion 103 and the fixing portion 104 is formed between the fitting body 101 and the cap 102. The accommodating recess 106 is formed between the step 102d and the end face of the fitting body 101 that faces outward in the axial direction. The accommodating recess 106 extends around the entire circumferential direction.

[0034] The joint body 101 is formed by, for example, injection molding or cutting a synthetic resin material. The cap 102 is formed, for example, by injection molding of a synthetic resin material, or by cutting, casting, or forging of a metal material. The synthetic resin material can be selected arbitrarily based on quality design depending on the application, such as cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. Other processing methods such as cutting and fusion may also be used. The metal material can be arbitrarily selected from stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc. based on quality design according to the intended use.

[0035] FIG. 6 is a partially enlarged view of the waterproof portion 103 and the fixing portion 104 of the first pipe joint 100. As shown in FIG. 6, at each axial end of the first pipe fitting 100, a packing 103a (sealing member), a base 103b, a retaining ring 104a (first retaining ring), a spacer 104c, and a retaining ring 104b (second retaining ring) are provided in this order toward the end of the fitting body 101. In other words, the fixing part 104 is located closer to the end than the watertight part 103. The packing 103a and the base 103b constitute the water blocking portion 103. The water blocking portion 103 prevents the contents of the flexible tube 310 from leaking out from the first pipe joint 100. The retaining ring 104a, the spacer 104c, and the retaining ring 104b constitute the fixing portion 104. The flexible tube 310 inserted into the first pipe joint 100 is fixed to the first pipe joint 100 by the fixing portion 104.

[0036] The packing 103a (sealing member) is disposed on the inner circumferential surface of the joint body 101. In the illustrated example, one packing 103a is provided, but a plurality of packings 103a may be provided spaced apart in the axial direction. The packing 103a is annular with a circular cross section. The packing 103a extends over the entire circumference. In the illustrated example, an O-ring is used as the packing 103a. The packing 103a may be made of rubber materials such as ethylene propylene diene rubber (EPDM), fluororubber (FKM), vinyl methyl silicone rubber (VMQ), acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), or chloroprene rubber (CR).

[0037] The base 103b is disposed between the packing 103a and the retaining ring 104a. The base 103b prevents contact between the packing 103a and the retaining ring 104a. The base 103b is formed in an annular shape. The base 103b extends over the entire circumference. The base 103b is fitted into the open end of the joint body 101. The base 103b contacts the end of the first step of the joint body 101 that faces outward in the axial direction. The base 103b is hooked onto the first step of the joint body 101 from the outside in the axial direction. The inner diameter of the base 103b is larger than the inner diameter of the packing 103a. The base 103b is formed by, for example, injection molding of a synthetic resin material, or cutting, casting, or forging of a metal material.

[0038] The synthetic resin material can be selected arbitrarily based on quality design depending on the application, such as cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. Other processing methods such as cutting and fusion may also be used.

[0039] The metal material can be arbitrarily selected from stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc. based on quality design according to the intended use. If the first pipe joint 100 does not have the fixing portion 104, it does not have to have the base 103b.

[0040] The retaining rings 104a, 104b and the spacer 104c are arranged on the outside in the axial direction relative to the base 103b. The retaining rings 104a, 104b and the spacer 104c are arranged in an accommodating recess of the joint body 101. The retaining rings 104a, 104b and the spacer 104c are arranged so as to be movable in the axial direction with a slight amount of play relative to the accommodating recess. The retaining ring 104a, the spacer 104c and the retaining ring 104b are arranged in this order from the outside to the inside in the axial direction. The spacer 104c is arranged in the accommodating recess so as to be sandwiched in the axial direction between the retaining ring 104a and the retaining ring 104b.

[0041] The first movable member 105 is housed in the joint body 101 in a detachable state. The first movable member 105 is arranged coaxially with the joint body 101. The two axial ends of the first movable member 105 are the first movable member end and the second movable member end, respectively. When the first movable member 105 is housed in the joint body 101, the first movable member end is located axially outward from the second movable member end. The first movable member end is located within the cap 102 (second cylinder). The second movable member end is located within the joint body 101. The second movable member end is located axially inward from the packing 103a. The first movable member 105 is located inside the packing 103a, the base 103b, the retaining ring 104a, the spacer 104c, and the retaining ring 104b.

[0042] FIG. 7 is a cross-sectional view showing a state in which the first movable member 105 is inserted into the flexible tube 310. As shown in FIG. As shown in FIG. 7, the first movable member 105 is inserted into the end of the flexible tube 310 and is a component for suppressing radially inward deformation of the end. The first movable member 105 comprises an inner cylindrical portion 105c that fits into the end of the flexible tube 310 and a protruding portion 105a that is exposed without fitting into the end of the flexible tube 310. The outer diameter of the inner cylindrical portion 105c is approximately equal to the inner diameter of the flexible tube 310. For example, being approximately equal may mean that the smaller of the outer and inner diameters is within 5% of the larger. The protruding portion 105a is positioned closer to the first end of the first movable member than the center in the axial direction on the first movable member 105. The protruding portion 105a is positioned at the first end of the first movable member. The protruding portion 105a is annular. The protruding portion 105a extends around the entire circumference in the circumferential direction. The outer diameter (maximum outer diameter) of the protrusion 105a is larger than the inner diameter (minimum inner diameter: 113) of the joint body 101. In this embodiment, the outer diameter of the protrusion 105a is larger than the inner diameter (minimum inner diameter) of the joint body 101 over the entire axial length of the protrusion 105a.

[0043] The first movable member 105 is removed from the coupling body 101 and inserted into the end of the flexible tube 310. At this time, the first movable member 105 is placed inside the flexible tube 310 with the protrusion 105a of the first movable member 105 abutting against the end face of the flexible tube 310. At this time, the first movable member 105 also suppresses radial inward deformation of the flexible tube 310. Therefore, when the flexible tube 310 has been completely inserted into the first pipe coupling 100, the retaining rings 104a, 104b firmly bite into the flexible tube 310. The first movable member 105 is made of a material that is more rigid than the material that forms the flexible tube 310, such as a metal material or a resin material. The synthetic resin material can be selected arbitrarily based on quality design depending on the application, such as cross-linked polyethylene, polybutene, polyvinyl chloride (PVC), polysulfone resin (PSU), polycarbonate resin (PC), polyamide resin (PA), polyacetal resin (POM), polyphenylsulfone resin (PPSU), polyphenylene sulfide resin (PPS), glass fiber reinforced PPS, polyvinylidene fluoride (PVDF), etc. Other processing methods such as cutting and fusion may also be used. The metal material can be arbitrarily selected from stainless steel, low alloy steel, carbon steel, low temperature carbon steel, low temperature alloy steel, brass, gunmetal, aluminum alloy, magnesium alloy, etc. based on quality design according to the intended use.

[0044] Incidentally, by storing the first movable member 105 in the joint body 101 prior to installation, it is possible to save space and prevent loss of the first movable member 105. For this reason, it is preferable to store the first movable member 105 in the joint body 101, for example, when packaging the first pipe joint 100.

[0045] A warning color may be applied to part or all of the outer circumferential surface 105b of the protrusion 105a, or to the entire first movable member 105. The warning color is preferably a complementary color to the color of the cap 102, etc. Considering that the color of the cap 102 is usually black, gray, or brown, the warning color is preferably pink or yellow-green. Hereinafter, the part having such an attention-calling color may be referred to as an attention-calling part.

[0046] The coloring of the protrusion 105a may be done with a resin containing a pigment, or with a paint such as a baked paint on a metal surface. The first movable member 105 may be an integrated part having these functions, or may be a composite part combining parts with these functions. In the case of an integrated part, the entire area of ​​the first movable member 105 may be a fluorescent part capable of emitting fluorescence. Examples of resins that constitute the main component of first movable member 105 include polyvinyl chloride, polyethylene, polypropylene, polycarbonate, polyacetal, and ABS. When a fluorescent pigment is blended into the main component resin, examples of components of the fluorescent pigment include titanium oxide, quinacridone red, and higher fatty acid amide. The entire area of ​​first movable member 105 may be a fluorescent portion that is capable of emitting fluorescence.

[0047] The first movable member 105 may also be chamfered at the portion that comes into contact with the packing 103a to provide a guide function that protects the packing 103a from being scratched or coming out of the installation groove when the pipe is inserted. Furthermore, an inner cylindrical portion 105c may be added to protect the packing 103a from diagonal cuts. The components may be integrated components that have these functions, or composite components that combine components with these functions.

[0048] Next, a description will be given of a method for connecting flexible tubes 310 using the first pipe joint 100. This connection method is a method for connecting two flexible tubes 310 using the first pipe joint 100. In this connection method, the two flexible tubes 310 are inserted into different ends of the first pipe joint 100, and the first pipe joint 100 and the flexible tubes 310 are connected.

[0049] The outer diameter of the flexible tube 310 is equal to the outer diameter of the protrusion 105 a of the first movable member 105 or is equal to or smaller than the outer diameter of the protrusion of the first movable member 105 .

[0050] When connecting the first pipe joint 100 and the flexible tube 310, first, the first movable member 105 is pulled out from the joint body 101 as described above. Then, the first movable member 105 is inserted into the flexible tube 310, and the protrusion 105a of the first movable member 105 abuts against the end face of the flexible tube 310 (first step). At this time, the protrusion 105a of the first movable member 105 abuts against the end face (small end) of the flexible tube 310, restricting further advancement of the first movable member 105 into the flexible tube 310. As a result, the protrusion 105a of the first movable member 105 is exposed to the outside from the flexible tube 310. In other words, when the first movable member 105 is inserted into the flexible tube 310, the protrusion 105a of the first movable member 105 and the end face of the flexible tube 310 are aligned in this order from the outside of the flexible tube 310 along the axial direction.

[0051] Thereafter, the flexible tube 310 with the first movable member 105 inserted therein is inserted into the joint body 101 with the protrusion 105a of the first movable member 105 leading the flexible tube 310 (second step). At this time, the protrusion 105a of the first movable member 105 moves over the retaining ring 104b, the spacer 104c, and the retaining ring 104a in the axial direction, in that order. Then, as shown in FIG. 3A , the retaining ring 104a abuts against the base 103b, and the retaining ring 104b abuts against the spacer 104c. In this way, at the connection portion where the first pipe joint 100 is connected to the flexible tube 310, the first movable member 105 is pushed inward in the axial direction by the flexible tube 310 as the flexible tube 310 is inserted into the joint body 101.

[0052] In the first pipe fitting 100 and flexible tube 310 connected as described above, the packing 103a is in close contact (pressure-welded) with the outer circumferential surface of the flexible tube 310. In this state, the flexible tube 310 is disposed inside the fitting body 101. In the first pipe fitting 100 according to this embodiment, the watertight portion 103 is made up of the packing 103a and the base 103b, which abuts against a locking step at the back of the fitting body 101, and obtains surface pressure from the compressive force generated when the flexible tube 310 is inserted and the compressive force generated when internal pressure is applied inside the tube (self-watertightness), thereby sealing off water outside the flexible tube 310 (external watertightness). When the first movable member 105 is inserted into the flexible tube 310, the first movable member 105 suppresses deformation of the flexible tube 310.

[0053] In the first pipe fitting 100 connected as described above, the protrusion 105a of the first movable member 105 abuts against the step 113 (connection complete state). In the connection complete state, if the outer peripheral surface 105b of the protrusion 105a of the first movable member 105 has a warning color, as shown in Fig. 8, the warning color (warning portion) that passes through the fitting main body 101 made of an amorphous transparent resin can be seen from the installation confirmation portion set further back than the main body 101b where the end of 102 contacts. Therefore, whether the flexible tube 310 is in a completely connected state or an incompletely connected state can be reliably determined based on whether the attention color of the protrusion 105a of the first movable member 105 is visible from the installation confirmation unit. That is, when the attention color of the protrusion 105a is not visible from the installation confirmation unit, it can be determined that the flexible tube 310 is in an incompletely connected state because the protrusion 105a is not in the completely connected position. When the attention color of the protrusion 105a is visible from the installation confirmation unit, it can be determined that the flexible tube 310 is in a completely connected state. The attention color of the protrusion 105a is pink or yellow-green, which makes it stand out and further provides contrast with the color of the cap 102, etc. Therefore, the attention color of the protrusion 105a can be easily seen.

[0054] (Second pipe joint 200) The second pipe joint 200 in this embodiment will be described with reference to FIGS.

[0055] As shown in FIGS. 9 and 10, a dissimilar pipe having a threaded joint or the like and a composite pipe 300 are thread-connected via a second pipe joint 200.

[0056] As shown in FIG. 9, the second pipe joint 200 comprises a joint main body 210, an annular body 220, a retaining member 230, and a portion 211b for connection to a different type of pipe, such as by threaded connection. The joint body 210 is made of a metal such as a copper alloy or steel. The joint body 210 includes a first connecting portion 211 and a second connecting portion 212. These connecting portions 211, 212 are arranged in a row along the axis L. The first connecting portion 211 is provided on a first side in the axial direction (the left side in FIG. 9), and the second connecting portion 212 is provided on a second side (the right side in FIG. 9). A compound pipe 300 is connected to the first connecting portion 211. Another compound pipe 300 is connected to the second connecting portion 212.

[0057] The first connecting part 211 is cylindrical and has a male thread 211b formed on its outer surface. As shown in Fig. 10, the end of the compound pipe 300 is fitted onto the outer periphery of the first connecting part 211, and the compound pipe 300 is screwed onto the male thread 211b. The connection between the compound pipe 300 and the first connecting portion 211 is not limited to the above, and a male thread may be provided on the outer periphery of the end of the compound pipe 300, and a female thread may be provided on the inner periphery of the first connecting portion 211. The first connecting portion 211 may have a socket structure into which the end of the compound pipe 300 can be fitted. The second pipe fitting 200 may be provided integrally or inseparably to the end of the compound pipe 300.

[0058] The second connecting portion 212 is formed in a tubular shape that is longer and has a smaller diameter than the first connecting portion 211. As shown in Fig. 10, the compound pipe 300 is fitted onto the outer periphery of the second connecting portion 212. Two rows of packings 215 are provided on the outer surface of the second connecting portion 212. The packings 215 are made of O-rings. The packings 215 seal the gap between the second connecting portion 212 and the compound pipe 300.

[0059] An annular body 220 is provided on the outer periphery of the second connecting portion 212. The annular body 220 surrounds the second connecting portion 212 such that an annular receiving portion 220a is formed between the annular body 220 and the second connecting portion 212. The composite pipe 300 is fitted onto the outer periphery of the second connecting portion 212 by being inserted into the receiving portion 220a.

[0060] The annular body 220 includes an outer body member 221 (light-transmitting member), an inner body member 222 (light-shielding member), and a cap 224. The outer body member 221 is formed in a generally cylindrical shape and constitutes the outer peripheral wall of the body 220. The outer body member 221 is made of a transparent resin such as nylon.

[0061] An inner body member 222 is housed inside outer body member 221 at a second side portion (right side in FIG. 9). The inner body member 222 is made of colored resin. The inner body member 222 includes an annular inner body main body 222a and multiple tapping portions 222d. The tapping portions 222d are formed in a cantilever shape and extend from the inner body main body 222a toward the first connecting portion 211. The multiple tapping portions 222d are aligned in the circumferential direction of the inner body main body 222a. Slits 222s are formed between adjacent tapping portions 222d. As shown in FIG. 9, a tapping protrusion 222e is provided at the tip of each tapping portion 222d so as to protrude radially inward.

[0062] The portion of the annular body 220 where the inner body member 222 is arranged on the second side (the right side in FIG. 9) is an invisible portion 220b. An annular cap 224 is attached to the end portion of the body 220 on the second side (the right end portion in FIG. 9). The portion of the annular body 220 on the first side (the left side in FIG. 9) where the inner body member 222 is not disposed is a see-through portion 220c.

[0063] The receiving portion 220a is provided with a retaining member 230. The retaining member 230 allows the composite pipe 300 to be inserted into the receiving portion 220a while preventing the composite pipe 300 from being pulled out. More specifically, the retaining member 230 includes an annular flange portion 231 and a retaining portion 232. The flange portion 231 is fixed by being sandwiched between the body members 221, 222 and the cap 224. The retaining portion 232 is integrally formed on the inner peripheral edge of the flange portion 231. The retaining portion 232 protrudes from the flange portion 231 toward the first side (the left side in FIG. 9 ) and has a tapered shape that reduces in diameter. As shown in FIG. 10 , the tip of the retaining portion 232 is pressed against and engaged with the outer surface of the flexible tube 310, thereby preventing the flexible tube 310 from being pulled out.

[0064] The receiving portion 220a is provided with a second movable member 240. The second movable member 240 is annular. At least the surface of the second movable member 240 is made of a resin containing a pigment. This pigment may preferably be a fluorescent pigment made of a fluorescent substance. Examples of resins that primarily constitute the second movable member 240 include polyvinyl chloride, polyethylene, polypropylene, polycarbonate, polyacetal, and ABS. When a fluorescent pigment is blended into the primary resin, examples of the fluorescent pigment include titanium oxide, quinacridone red, and higher fatty acid amides. The entire second movable member 240 may be a fluorescent portion capable of emitting fluorescence. The second movable member 240 of the second pipe fitting 200 in this embodiment does not have an inner cylindrical portion. When the second movable member 240 does not have an inner cylindrical portion, it consists only of a protrusion. The axial length of the second movable member 240 (protrusion) is an axial length that does not interfere with the packing 215 when the connection is complete and is equal to or shorter than the insertion length within the fitting. The second movable member 240 of the second pipe joint 200 may have an inner cylindrical portion that fits into the end of the flexible tube 310 .

[0065] Furthermore, it is preferable that the color of the second movable member 240 be complementary to the colors of the joint main body 210 and the inner body member 222. Considering that the joint main body 210 and the inner body member 222 are usually black, gray, or brown, it is preferable that the color of the second movable member 240 be pink or yellow-green.

[0066] The second movable member 240 may be colored with a resin containing a pigment or a paint such as a baked finish on a metal surface. It may also be made of a resin containing a fluorescent pigment (fluorescent material). Examples of resins that primarily constitute the second movable member 240 include polyvinyl chloride, polyethylene, polypropylene, polycarbonate, polyacetal, and ABS. When a fluorescent pigment is blended into the primary resin, examples of the fluorescent pigment include titanium oxide, quinacridone red, and higher fatty acid amides. The second movable member 240 also has a chamfer at the portion that comes into contact with the waterproof gasket. The second movable member 240 may have a guide function to protect the waterproof gasket from damage during pipe insertion or from slipping out of the installation groove, or it may be a composite part incorporating a separate component with this function. The component may be an integrated part with these functions, or a composite part combining components with these functions. In the case of an integrated part, the entire second movable member 240 may be a fluorescent part that can emit fluorescence. In this embodiment, the colored portion of the second movable member 240 serves as the attention-drawing portion.

[0067] As shown in FIGS. 9 and 10, the second movable member 240 integrally includes a movable main body portion 241 and a guide portion 242. The movable main body portion 241 is annular. A ring-shaped guide portion 242 is provided on a first side surface (the left side surface in FIG. 9) of the movable main body portion 241. The guide portion 242 has a guide surface 242b and a step 242d, and has a wedge-shaped cross section. The outer peripheral surface of the guide portion 242 forms the guide surface 242b. The guide surface 242b is tapered, increasing in diameter as it approaches the movable main body portion 241. The outer diameter of the end of the guide surface 242b on the movable main body portion 241 side is smaller than the outer diameter of the movable main body portion 241. A step 242d is formed between the guide surface 242b and the outer peripheral surface of the movable main body portion 241.

[0068] As shown in FIGS. 9 and 10, the second movable member 240 is slidable along the axis L within the receiving portion 220a. 9, when the flexible tube 310 is in an incomplete connection state, the second movable member 240 is positioned in the inner body member 222, i.e., in the non-transparent portion 220b. In particular, before the insertion operation of the flexible tube 310, the second movable member 240 is positioned at the second end portion (the left end portion in FIG. 9) of the receiving portion 220a. As shown in Figure 10, when the flexible tube 310 is in the normal connection position (normal connection state), the guide portion 242 of the second movable member 240 protrudes toward the first side (left side in Figure 10) beyond the inner body member 222 and is positioned in the visible portion 220c.

[0069] Using the second pipe joint 200, for example, the compound pipe 300 and the pipe joint 400 are connected as follows. The pipe joint 400 is screwed onto the male thread 211 b of the first connecting portion 211 . Further, the flexible tube 310 of the composite pipe 300 is inserted into the receiving portion 220a. Then, the end of the flexible tube 310 abuts against the second movable member 240. As the flexible tube 310 is inserted, the second movable member 240 is pushed and moved toward the first side (left side in FIG. 9). Initially, the second movable member 240 is located in the non-transparent portion 220b, and is entirely hidden inside the inner body member 222 and cannot be seen from the outside.

[0070] As shown in FIG. 10, the guide surface 242b eventually comes into contact with the striking protrusion 222e, and the striking portion 222d is warped and deformed radially outward. When the flexible tube 310 is inserted to the correct connection position, the striking protrusion 222e overcomes the guide portion 242 and returns elastically to the inside in the radial direction with force, striking the movable main body portion 241. This generates a clicking sound. By hearing this, it can be confirmed that the flexible tube 310 has reached the correct connection position (connection complete state).

[0071] 11, in the connection completed state, the second movable member 240 protrudes further toward the first side (the left side in FIG. 10) than the inner body member 222 and is positioned in the see-through portion 220c, thereby becoming visible through the transparent outer body member 221. At this time, the portion where the second movable member 240 can be seen from the outside is defined as the installation confirmation portion. Therefore, whether the flexible tube 310 is in a completely connected state or an incompletely connected state can be reliably determined based on whether the second movable member 240 is visible in the installation confirmation unit. That is, when the second movable member 240 is not visible, it can be determined that the flexible tube 310 is in an incompletely connected state. When the second movable member 240 is visible from the installation confirmation unit, it can be determined that the flexible tube 310 is in a completely connected state. The second movable member 240 is pink or yellow-green in color, which makes it easy to see, and further provides contrast with the colors of the joint main body 210 and the inner body member 222. Therefore, the second movable member 240 can be easily seen.

[0072] In a dark place, illumination light is irradiated near the second pipe fitting 200. The illumination light may be a smartphone light, or preferably, a black light if a fluorescent pigment is used for the second movable member 240. Even in complete darkness, illumination light such as a black light can ensure sufficient illumination to confirm the position of the second pipe fitting 200. Alternatively, the approximate position of the second pipe fitting 200 can be determined by manually tracing the compound pipe 300. Therefore, illumination light can be reliably irradiated onto the second pipe fitting 200.

[0073] In this way, it is possible to accurately and easily determine whether the flexible tube 310 has reached a properly connected state.

[0074] Furthermore, it is possible to check whether the connection is good or bad not only during the connection work but also after the connection work has been completed.

[0075] In addition, the color and shape of the inner tube portion etc. hidden by the pipe in the first pipe fitting 100 (external water stop fitting) and the second pipe fitting 200 (internal water stop fitting) may be different, but it is preferable to match the color system of the warning colors of the first pipe fitting 100 (external water stop fitting) and the second pipe fitting 200 (internal water stop fitting).

[0076] As described above, the piping system 1 of this embodiment includes a composite pipe 300 including a flexible tube 310 and a coating 320, a first pipe fitting 100 to which the composite pipe 300 is connected, and a second pipe fitting 200 to which the composite pipe 300 is connected. The first pipe fitting 100 includes a fitting body 101 made of an amorphous transparent resin, a packing 103a that contacts the outside of the flexible tube 310, and a retaining ring that prevents the flexible tube 310 from coming off. The second pipe fitting has an outer body member 221 on the outer surface of the pipe end made of amorphous transparent resin, a gasket 215 in contact with the inside of the flexible tube 310, and an annular second movable member 240, and the first movable member 105 and the second movable member 240 are pushed and moved at the connection portion connected to the flexible tube 310 by inserting the flexible tube 310. With this configuration, a piping system 1 can be created that includes a first pipe fitting 100 (external water stop fitting) and a second pipe fitting 200 (internal water stop fitting). This allows the user to select whether to use the first pipe fitting 100 (external water stop fitting) or the second pipe fitting 200 (internal water stop fitting) for each fitting. At the ends of a pipeline, scratches and other damage are of particular concern because the light source is blocked and the area is dark, or the work space is narrow, for example, because the end is inside an equipment cabinet. On the other hand, construction can be performed relatively safely in areas other than the ends, so there is a relatively low risk of scratches and other damage to the flexible pipes 310, even if the fitting connecting the flexible pipes 310 together is an external water stop fitting 100. In the piping system 1 of the present invention, for example, a first pipe fitting 100 (external watertight fitting) can be used in a fitting portion, such as an elbow fitting, that connects flexible pipes 310, and a second pipe fitting 200 (internal watertight fitting) can be used in other fitting portions (e.g., both ends of the pipeline). The first pipe fitting 100 has a fitting body 101 made of an amorphous transparent resin, and the second pipe fitting 200 has an outer body member 221 on the outer surface of the pipe end, also made of an amorphous transparent resin. This allows the connection state between the first pipe fitting 100 and the second pipe fitting 200 and the flexible pipe 310 to be easily confirmed from the outside. Therefore, the piping system 1 can be made easy to install while minimizing pressure loss due to the internal watertight fitting 200 and maintaining a high discharge flow rate.

[0077] In addition, the first movable member 105 and the second movable member 240 may have chamfered portions at the ends that come into contact with the packings 103a and 215, respectively. With this configuration, when the first movable member 105 and the second movable member 240 are pushed and moved by the insertion of the flexible tube 310 and go over the gaskets 103a, 215, it is possible to prevent the gaskets 103a, 215 from coming out of their predetermined positions or being twisted off. This makes it easy to ensure the watertightness of the gaskets 103a, 215. Therefore, it is possible to provide a piping system 1 that is easy to install.

[0078] At least one of the first movable member 105 and the second movable member 240 may have an inner cylindrical portion 105c disposed inside the flexible tube 310, and the outer diameter of the inner cylindrical portion 105c may be approximately equal to the inner diameter of the flexible tube 310. With this configuration, the outer diameter of the inner cylindrical portion 105c is approximately equal to the inner diameter of the flexible tube 310, so the inner cylindrical portion 105c and the flexible tube 310 connected to the inner cylindrical portion 105c can be smoothly inserted into the joint, thereby providing a piping system 1 with excellent workability.

[0079] Furthermore, at least one of the first movable member 105 and the second movable member 240 has a protrusion 105a that is pressed against the end face of the flexible tube 310, and the axial length of the protrusion 105a may be a length that does not interfere with the gaskets 103a, 215 when the connection is complete, and may be less than the insertion length of the flexible tube 310 into each pipe joint. With this configuration, the length of the protrusion 105a is such that it does not interfere with the packings 103a and 215 when the connection is complete, and therefore when the protrusion 105a and the flexible tube 310 connected to the protrusion 105a are inserted to a predetermined position in the joint, the protrusion 105a does not impede contact between the flexible tube 310 and the packings 103a and 215. This makes it easy to ensure that the packings 103a and 215 can stop water.

[0080] In addition, the first movable member 105 and the second movable member 240 have warning portions, and the warning portions have a warning color on the entire surface or on the outer periphery, and the warning portions are configured to be visible from the entire circumference at an angle at which the warning color can be seen from the outside when in the connection complete state, and the warning portions of the first movable member 105 and the second movable member 240 in the connection complete state may be shown in the same color scheme. This configuration allows easy confirmation of whether the flexible tube 310 is inserted into the fitting. Furthermore, if multiple types of fittings are used within the same piping system 1 due to the mixing of watertightness methods, the installer may be confused by the different installation methods for each fitting, which may lead to concerns about the risk of water leakage due to poor installation caused by inexperience with the installation procedures. As described above, if the warning indicators of the first movable member 105 and the second movable member 240 in the fully connected state are displayed in the same color scheme, the appearance of the completed connection state of the installation confirmation parts of the first pipe fitting (external watertight fitting) and the second pipe fitting 200 (internal watertight fitting) can be unified. By unifying the appearance of the completed connection state of the installation confirmation parts, installers can avoid confusion even when using fittings with different watertightness methods. This allows for a piping system 1 with excellent installation ease while maintaining the discharge flow rate.

[0081] The covering 320 may also include a foamed resin material. This configuration makes the coating more flexible, allowing it to be peeled off relatively easily without applying excessive force, improving workability. Furthermore, the insulating properties of the coating 320 allow the water temperature inside the flexible tube 310 to be kept constant, preventing freezing. Therefore, the same discharge flow rate as that of conventional thermally insulating coatings can be maintained regardless of the air temperature.

[0082] The corrugated tube 320a may also have a single-layer coating 320, and support portions 321 arranged on the corrugated tube 320a at intervals of 50 mm or more and 200 mm or less in the axial direction of the corrugated tube 320a, the support portions 321 having a plurality of support protrusions 321a protruding radially inward from the corrugated tube 320a and arranged in a circumferential direction, the foaming ratio of the corrugated tube 320a may be 1.05 times or more and 4.00 times or less, and the thickness of the protrusions forming the outer diameter of the corrugated tube 320a may be 0.4 mm or more. With this configuration, since the covering 320 is the corrugated pipe 320a, the production cost of the composite pipe 300 can be reduced, and the heat insulating properties of the corrugated pipe 320a can keep the water temperature inside the flexible pipe 310 constant and prevent freezing. Therefore, it is possible to maintain the same discharge flow rate as a conventional thermal covering product regardless of the air temperature while reducing costs.

[0083] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and configuration changes, combinations, deletions, etc. are also included within the scope that does not deviate from the gist of the present invention.

[0084] For example, if a transparent resin that can withstand that strength becomes available through future technological innovation, the main body of the internal watertight joint 200 may be made of transparent resin. The entire annular body 220 may be colored and opaque. An observation window may be provided in the colored and opaque annular body 220, and this observation window may be the see-through portion. It is sufficient that at least a portion of the annular body 220 is the see-through portion. The entire annular body 220 may be the see-through portion. When the connection is complete, the colored portion may be hidden by the flexible tube 310. The first tube 102a may be fitted into the male thread portion 101c. [Explanation of symbols]

[0085] 1 Piping System 100 First joint 101 Joint body 103a Gasket 104a, 104b Retaining ring 105 first movable member 105a Protrusion 105b Outer surface 105c Inner cylinder part 200 Second joint 221 Outer body parts 240 Second movable member 300 Composite pipe 310 Flexible tube 320 Covering

Claims

1. a composite pipe including a flexible pipe and a coating; a first pipe joint to which the composite pipe is connected; a second pipe joint to which the composite pipe is connected, the first pipe joint includes a joint body made of an amorphous transparent resin, a packing in contact with the outside of the flexible tube, a retaining ring that prevents the flexible tube from coming off, and an annular first movable member, the second pipe joint includes an outer body member on the outer surface of the pipe end portion made of an amorphous transparent resin, a packing in contact with the inside of the flexible pipe, and an annular second movable member, the first movable member and the second movable member are pushed and moved at a connection portion connected to the flexible tube by inserting the flexible tube; Piping system.

2. the first movable member and the second movable member have chamfered portions at contact ends with the packing; The piping system of claim 1 .

3. At least one of the first movable member and the second movable member has an inner cylindrical portion disposed within the flexible tube, The outer diameter of the inner cylindrical portion is approximately equal to the inner diameter of the flexible tube. The piping system of claim 1 .

4. At least one of the first movable member and the second movable member has a protrusion that is pressed against an end surface of the flexible tube, the axial length of the protrusion is a length that does not interfere with the packing when the connection is complete and is equal to or less than the insertion length of the flexible tube into each pipe joint; The piping system of claim 1 .

5. the first movable member and the second movable member have an attention-drawing unit, The attention-drawing portion has an attention-drawing color on the entire surface or on the outer circumferential surface, the attention-drawing unit is configured to be visible from the outside at an angle at which the attention-drawing color can be seen from all around the circumference when in a connection-completed state; The attention-drawing portions of the first movable member and the second movable member in the connection-completed state are displayed in the same color. The piping system of claim 1 .

6. The coating includes a foamed resin material. A piping system according to any one of claims 1 to 5.

7. The coating is a single-layer corrugated pipe; Support portions are arranged on the corrugated pipe at intervals of 50 mm or more and 200 mm or less in the axial direction of the corrugated pipe; and the support portion has a plurality of support protrusions that protrude radially inward from the corrugated pipe and are arranged side by side in the circumferential direction, The expansion ratio of the corrugated pipe is 1.05 times or more and 4.00 times or less, The thickness of the convex portion that forms the outer diameter of the corrugated pipe is 0.4 mm or more. A piping system according to any one of claims 1 to 5.

Images