Pipe joint and piping system

Abstract

To restrain cost increase even in cases of supporting connection of insulated piping with various outer diameters.SOLUTION: A pipe joint 10 includes a plurality of socket members 30a, 30b, 30c each having a socket 32a, 32b, 32c into which one end of an insulated pipe 40a, 40b, 40c to be connected is inserted and joined, and a socket-side flow path 331a, 331b, 331c communicating with an internal pipe flow path 401a, 401b, 401c inside the insulated pipe 40a, 40b, 40c, and a joint body 20 to which the socket members 30a, 30b, 30c are joined and which has body flow paths 211ab, 211c that communicate the socket-side flow paths 331a, 331b, 331c, wherein the socket members 30a, 30b, 30c have socket-side insulating air layers 341a, 341b, 341c around the socket-side flow paths 331a, 331b, 331c, and the joint body 20 has body insulating air layers 221ab, 221c around the body flow paths 211ab, 211c.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to pipe fittings and piping systems. [Background technology]

[0002] In recent years, in order to simplify installation work, pipes whose outer surfaces need to be insulated, such as drain pipes in air conditioning systems, have come to use insulated pipes in which a coating layer made of foamable resin is formed on the outer periphery of the pipe body. Furthermore, pipe joints made of synthetic resin that are insulated from the surrounding atmosphere have come to be used as pipe joints connecting insulated pipes. One such pipe joint is known from Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-81072 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, due to the effects of rising outdoor temperatures caused by global warming, there has been a demand for higher moisture resistance in the field of air conditioning piping, and pipe fittings and piping systems with improved insulation properties have been attracting attention. However, if the outer diameter of the insulated pipe is changed, for example by increasing the thickness of the foam layer of the insulated pipe to improve its insulation, the size of the socket of the pipe fitting must be changed.In the pipe fitting described in Patent Document 1, the socket is integrally formed on the fitting body of the water-passing portion, so if the size of the socket is changed, the shape of the entire pipe fitting must be changed, which increases costs.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a pipe fitting and a piping system that can suppress increases in costs even when connecting insulated pipes of various outer diameters. [Means for solving the problem]

[0006] The present invention has the following aspects. (1) One aspect of the pipe fitting according to the present invention is a pipe fitting for connecting a plurality of insulated pipes, comprising a plurality of receiving members, each having a receiving port into which one end of the insulated pipe to be connected is inserted and joined, and a receiving port-side flow path that communicates with an internal flow path within the insulated pipe; and a fitting body to which the plurality of receiving members are joined and having a main body flow path that communicates the plurality of receiving port-side flow paths, wherein the receiving member has a receiving port-side insulating air layer around the receiving port-side flow path, and the fitting body has a main body insulating air layer around the main body flow path.

[0007] The above-described pipe fitting is configured such that multiple receiving members, each having a receiving port into which one end of the insulated pipe to be connected is inserted and joined, are joined to a fitting body having a main body flow path that connects the receiving side flow paths of the multiple receiving members. Therefore, even when connecting insulated pipes of various outer diameters, it is sufficient to change the receiving members, and there is no need to change the fitting body, thereby preventing increases in costs. Furthermore, since the receiving member has a receiving-side insulating air layer around the receiving-side flow path and the fitting body has a main body insulating air layer around the main body flow path, thermal insulation can be improved.

[0008] (2) In the above aspect (1), the receiving member and the joint body may be integrated by adhesive.

[0009] In this case, integration becomes easier and the heat insulating properties can be further improved.

[0010] (3) In the above aspect (1), the receiving member and the joint body may be formed from a resin material that allows the receiving port-side flow path and the body flow path to be visible from the outside.

[0011] In this case, the inlet-side flow path and the main flow path can be seen from the outside, so the state of communication between the inlet-side flow path and the main flow path and the state of fluid flow in the inlet-side flow path and the main flow path can be visually confirmed.

[0012] (4) One aspect of the piping system according to the present invention includes the pipe joint according to any one of the above aspects (1) to (3) and a plurality of insulated pipes connected by the pipe joint.

[0013] In the above-described piping system configuration, the pipe fitting is configured such that multiple receiving members, each having a receiving port into which one end of the insulated pipe to be connected is inserted and joined, are joined to a fitting body having a main body flow path that connects the receiving member-side flow paths of the multiple receiving members, so that even when connecting insulated pipes of various outer diameters, it is sufficient to change the receiving member, and there is no need to change the fitting body, thereby preventing increases in costs. In addition, since the receiving member has a receiving-side insulating air layer around the receiving-side flow path and the fitting body has a main body insulating air layer around the main body flow path, the thermal insulation of the pipe fitting can be improved. [Effects of the Invention]

[0014] According to the present invention, even when it is necessary to connect insulated pipes having various outer diameters, it is possible to suppress an increase in cost. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an exploded perspective view showing a pipe joint according to a first embodiment of the present invention. [Figure 2] 1 is a perspective view showing a pipe joint according to a first embodiment of the present invention. [Figure 3] 1 is an exploded cross-sectional view showing a pipe joint according to a first embodiment of the present invention. [Figure 4] 1 is a cross-sectional view showing a piping system according to a first embodiment of the present invention. [Figure 5] 1 is a perspective cross-sectional view showing a pipe joint according to a first embodiment of the present invention. [Figure 6]1 is a diagram showing an air conditioning system to which a piping system according to a first or second embodiment of the present invention is applied. [Figure 7] FIG. 5 is an exploded perspective view showing a pipe joint according to a second embodiment of the present invention. [Figure 8] FIG. 4 is a perspective view showing a pipe joint according to a second embodiment of the present invention. [Figure 9] FIG. 10 is an exploded perspective cross-sectional view showing a pipe joint according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a perspective view showing a pipe joint according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a pipe joint and a piping system according to an embodiment of the present invention will be described with reference to the drawings.

[0017] [First embodiment] {Pipe fitting 10} As shown in FIG. 1, the pipe fitting 10 according to the first embodiment has a fitting body 20, a receiving member 30a, a receiving member 30b, and a receiving member 30c, and these fitting body 20, receiving member 30a, receiving member 30b, and receiving member 30c are joined together and formed as an integrated unit as shown in FIG. 2.

[0018] <Joint body 20> As shown in Figure 3, the joint body 20 has a main body flow path forming portion 21ab, a main body flow path forming portion 21c, a main body insulating layer forming portion 22ab, a main body insulating layer forming portion 22c, a support portion 23, and a support portion 24.

[0019] The main flow path forming portion 21ab is cylindrical, and its radially inner side forms a main flow path 211ab. The main flow path forming portion 21ab has a main body inner joint portion 212a at one axial end and a main body inner joint portion 212b at the other axial end. The main body inner joint portion 212a is a closed annular shape and has a recessed shape formed by cutting out the main flow path forming portion 21ab in a closed annular shape so as to open to the axially outer side and the radially inner side of the main flow path forming portion 21ab. The main body inner joint portion 212b is a closed annular shape and has a recessed shape formed by cutting out the main flow path forming portion 21ab in a closed annular shape so as to open to the axially outer side and the radially inner side of the main flow path forming portion 21ab.

[0020] The main flow path forming portion 21c is cylindrical and extends perpendicularly radially outward from the axially intermediate position of the main flow path forming portion 21ab, specifically from its central position. The main flow path forming portion 21c has the same inner and outer diameters as the main flow path forming portion 21ab. The main flow path forming portion 21c has a main flow path 211c on its radially inner side. The main flow path 211c is perpendicularly connected to the main flow path 211ab within the main flow path forming portion 21ab. The main flow path forming portion 21c has a main body inner joint portion 212c at its end opposite the axial end of the main flow path forming portion 21ab. The main body inner joint portion 212c is a closed annular shape, and is a concave shape formed by cutting out the main flow path forming portion 21c in the shape of a closed annular ring so as to open to the axially outer side and the radially inner side of the main flow path forming portion 21c.

[0021] The main body insulating layer forming section 22ab is cylindrical with an inner diameter larger than the outer diameter of the main body flow path forming section 21ab, and is arranged coaxially with the main body flow path forming section 21ab so as to cover the main body flow path forming section 21ab on the radially outer side. The main body insulating layer forming section 22ab has the same axial length as the main body flow path forming section 21ab, and their axial positions are aligned. The space between the main body insulating layer forming section 22ab and the main body flow path forming section 21ab on the radially inner side forms a main insulating air layer 221ab. The main body insulating air layer 221ab is arranged around the main body flow path 211ab, overlapping in the axial direction with the main body flow path 211ab so as to surround the main body flow path 211ab on the radially outer side.

[0022] The main body thermal insulation layer forming section 22ab has a main body outer joining section 222a at one axial end and a main body outer joining section 222b at the other axial end. The main body outer joining section 222a is a closed annular shape and has a convex shape that protrudes from the radially inner side of the main body thermal insulation layer forming section 22ab to the axially outer side. The main body outer joining section 222a is located at the same position as the main body inner joining section 212a in the axial direction of the main body thermal insulation layer forming section 22ab. The main body outer joining section 222b is a closed annular shape and has a convex shape that protrudes from the radially inner side of the main body thermal insulation layer forming section 22ab to the axially outer side. The main body outer joining section 222b is located at the same position as the main body inner joining section 212b in the axial direction of the main body thermal insulation layer forming section 22ab.

[0023] The main body insulation layer forming section 22c is cylindrical and extends radially outward perpendicularly from the axially intermediate position of the main body insulation layer forming section 22ab, specifically from the center position, relative to the main body insulation layer forming section 22ab. The main body insulation layer forming section 22c is cylindrical with an inner diameter larger than the outer diameter of the main body flow path forming section 21c, and is arranged coaxially with the main body flow path forming section 21c so as to cover the main body flow path forming section 21c on the radially outer side. Both the inner and outer diameters of the main body insulation layer forming section 22c are equal to those of the main body insulation layer forming section 22ab. The space between the main body insulation layer forming section 22c and the main body flow path forming section 21c on the radially inner side forms a main body insulating air layer 221c.

[0024] The main body insulating air layer 221c is provided around the main body flow path 211c, overlapping in the axial direction with the main body flow path 211c so as to surround the main body flow path 211c radially outward. The main body insulating layer forming section 22c has a main body outer joining section 222c at its end opposite the main body insulating layer forming section 22ab in the axial direction. The main body outer joining section 222c is a closed annular shape and has a convex shape that protrudes from the radial inside of the main body insulating layer forming section 22c to the axial outside. The main body outer joining section 222c is positioned in the axial direction of the main body insulating layer forming section 22c so as to coincide with the main body inner joining section 212c.

[0025] Support section 23 connects the boundary between main flow path forming section 21ab and main flow path forming section 21c and the boundary between main heat insulating layer forming section 22ab and main heat insulating layer forming section 22c. Support section 23 is generally conical in shape and separates main insulating air layer 221c from main insulating air layer 221ab.

[0026] Support section 24 extends radially from main flow path forming section 21ab and main insulation layer forming section 22ab at an intermediate position in the axial direction of main body flow path forming section 21ab and main body insulation layer forming section 22ab, specifically at the center position, to connect main body flow path forming section 21ab, main body insulation layer forming section 22ab, and support section 23. Support section 24 is flat, and extends radially across the center of main body insulating air layer 221ab in the axial direction, dividing main body insulating air layer 221ab into two. Supporting portions 23 and 24 support main flow path forming portions 21ab and 21c on main heat insulating layer forming portions 22ab and 22c.

[0027] The joint body 20 is integrally formed by injection molding of synthetic resin. The joint body 20 is injection molded separately from the receiving member 30a, the receiving member 30b, and the receiving member 30c using a mold different from that used for the receiving member 30a, the receiving member 30b, and the receiving member 30c. Specifically, as will be described later, the joint body 20 is formed from an amorphous resin such as polyvinyl chloride resin or ABS resin, because the receiving member 30a, the receiving member 30b, and the receiving member 30c are bonded together with an adhesive. When the joint body 20 is formed from polyvinyl chloride resin or ABS resin, the joint body 20 can be made entirely of a transparent material so that the main body flow paths 211ab and 211c are visible from the outside of the joint body 20.

[0028] <Receiving member 30a> The receiving member 30a includes a base portion 31a, a receiving port 32a, a receiving port-side flow passage forming portion 33a, and a receiving port-side heat insulating layer forming portion 34a. The base portion 31a is in the shape of a perforated disk. The socket 32a has a socket main body 321a and an abutment portion 322a. The socket main body 321a is cylindrical. The socket main body 321a extends from the inner peripheral edge of the base portion 31a to both axial sides of the base portion 31a. The socket main body 321a extends more axially from the base portion 31a on one axial side of the base portion 31a than on the other axial side. The abutment portion 322a is a perforated disk-like member that extends radially inward from one end of the socket main body 321a on the side that extends less axially from the base portion 31a.

[0029] The inlet-side flow-path forming portion 33a extends from the radially inner side of the abutment portion 322a along the axial direction of the inlet 32a toward the opposite side from the inlet body 321a. The inlet-side flow-path forming portion 33a is cylindrical, with both the inner and outer diameters smaller than those of the inlet body 321a. The inlet-side flow-path forming portion 33a is disposed coaxially with the inlet body 321a. The radially inner side of the inlet-side flow-path forming portion 33a forms the inlet-side flow path 331a. The radially inner side of the abutment portion 322a of the inlet 32a also forms the inlet-side flow path 331a. The inlet-side flow-path forming portion 33a has a inlet-side inner joint portion 332a at its end opposite the inlet body 321a in the axial direction. The inlet-side inner joint portion 332a is a closed annular shape and has a convex shape that protrudes axially outward from the radially inner side of the inlet-side flow-path forming portion 33a. The inner diameter of the receiving port side flow path forming portion 33a is equal to the inner diameter of the portion of the main body flow path forming portion 21ab of the fitting body 20 excluding the main body inner joints 212a, 212b, and the outer diameter of the portion excluding the receiving port side inner joint 332a is equal to the outer diameter of the main body flow path forming portion 21ab of the fitting body 20.

[0030] Socket-side thermal insulation layer forming section 34a extends axially from the outer peripheral edge of base section 31a on the same side as abutment section 322a. Socket-side thermal insulation layer forming section 34a is cylindrical with an inner diameter larger than the outer diameter of socket 32a, and is arranged coaxially with socket 32a and socket-side flow-path forming section 33a so as to cover the radially outer sides of socket 32a and socket-side flow-path forming section 33a. Socket-side thermal insulation layer forming section 34a has an axial length shorter than socket 32a, and is arranged biased toward socket-side flow-path forming section 33a in the axial direction of socket 32a.

[0031] The inlet-side insulating layer forming section 34a has a inlet-side insulating air space 341a between the inlet 32a and the inlet-side flow-path forming section 33a on the radially inner side. The inlet-side insulating air space 341a is provided around the inlet-side flow path 331a, overlapping the inlet-side flow path 331a in the axial direction so as to surround the inlet-side flow path 331a on the radially outer side. The base 31a, the abutment 322a, and the portion of the inlet body 321a between the base 31a and the abutment 322a in the axial direction form a blocking section 35a that blocks the radial gap between one axial end of the inlet-side flow-path forming section 33a and one axial end of the inlet-side insulating layer forming section 34a. The blocking section 35a blocks one axial end of the inlet-side insulating air space 341a.

[0032] The inlet-side thermal insulation layer forming portion 34a has a inlet-side outer joint 342a at its end opposite the base portion 31a in the axial direction. The inlet-side outer joint 342a is a closed annular shape, with a recessed shape formed by cutting out the inlet-side thermal insulation layer forming portion 34a in the closed annular shape so as to open to the axial outside and the radial inside of the inlet-side thermal insulation layer forming portion 34a. The inlet-side outer joint 342a coincides with the inlet-side inner joint 332a in the axial direction of the inlet member 30a. The inner diameter of the inlet-side thermal insulation layer forming portion 34a, excluding the inlet-side outer joint 342a, is equal to the inner diameter of the main body thermal insulation layer forming portion 22ab of the fitting body 20, and the outer diameter is equal to the outer diameter of the main body thermal insulation layer forming portion 22ab of the fitting body 20, excluding the main body outer joints 222a and 222b.

[0033] The receiving member 30a is integrally formed by injection molding of synthetic resin. The receiving member 30a is injection molded separately from the joint body 20 using a mold different from that for the joint body 20. Specifically, as will be described later, the receiving member 30a is bonded to the joint body 20 with an adhesive, and is therefore formed from an amorphous resin such as polyvinyl chloride resin or ABS resin. When the receiving member 30a is formed from polyvinyl chloride resin or ABS resin, the receiving member 30a can be made entirely of a transparent material so that the receiving port-side flow path 331a can be seen from the outside of the receiving member 30a.

[0034] <Receiving member 30b> The receiving member 30b includes a base portion 31b, a receiving port 32b, a receiving port side flow passage forming portion 33b, and a receiving port side heat insulating layer forming portion 34b. The base portion 31b is in the shape of a perforated disk. The socket 32b has a socket main body 321b and an abutment portion 322b. The socket main body 321b is cylindrical. The socket main body 321b extends from the inner peripheral edge of the base portion 31b to both axial sides of the base portion 31b. The socket main body 321b extends more axially from the base portion 31b on one axial side than on the other axial side of the base portion 31b. The abutment portion 322b is a perforated disk-like member that extends radially inward from the end of the socket main body 321b that extends less axially from the base portion 31b.

[0035] The inlet-side flow-path forming portion 33b extends from the radially inner side of the abutment portion 322b along the axial direction of the inlet 32b toward the opposite side from the inlet body 321b. The inlet-side flow-path forming portion 33b is cylindrical, with both the inner and outer diameters smaller than those of the inlet body 321b. The inlet-side flow-path forming portion 33b is disposed coaxially with the inlet body 321b. The radially inner side of the inlet-side flow-path forming portion 33b forms the inlet-side flow path 331b. The radially inner side of the abutment portion 322b of the inlet 32b also forms the inlet-side flow path 331b. The inlet-side flow-path forming portion 33b has a inlet-side inner joint portion 332b at its end opposite the inlet body 321b in the axial direction. The inlet-side inner joint portion 332b is a closed annular shape and has a convex shape that protrudes axially outward from the radially inner side of the inlet-side flow-path forming portion 33b. The inner diameter of the receiving port side flow path forming portion 33b is equal to the inner diameter of the portion of the main body flow path forming portion 21ab of the fitting body 20 excluding the main body inner joints 212a, 212b, and the outer diameter of the portion excluding the receiving port side inner joint 332b is equal to the outer diameter of the main body flow path forming portion 21ab of the fitting body 20.

[0036] Socket-side thermal insulation layer forming section 34b extends axially from the outer peripheral edge of base section 31b on the same side as abutment section 322b. Socket-side thermal insulation layer forming section 34b is cylindrical with an inner diameter larger than the outer diameter of socket 32b, and is arranged coaxially with socket 32b and socket-side flow-path forming section 33b so as to cover the radially outer sides of socket 32b and socket-side flow-path forming section 33b. Socket-side thermal insulation layer forming section 34b has an axial length shorter than socket 32b, and is arranged biased toward socket-side flow-path forming section 33b in the axial direction of socket 32b.

[0037] The inlet-side insulating layer forming section 34b has an inlet-side insulating air space 341b between the inlet 32b and the inlet-side flow-path forming section 33b on the radially inner side. The inlet-side insulating air space 341b is disposed around the inlet-side flow path 331b, overlapping the inlet-side flow path 331b in the axial direction so as to surround the inlet-side flow path 331b on the radially outer side. The base 31b, the abutment 322b, and the portion of the inlet body 321b between the base 31b and the abutment 322b in the axial direction form a blocking section 35b that blocks the radial gap between one axial end of the inlet-side flow-path forming section 33b and one axial end of the inlet-side insulating layer forming section 34b. The blocking section 35b blocks one axial end of the inlet-side insulating air space 341b.

[0038] The inlet-side thermal insulation layer forming portion 34b has a receiving-port-side outer joint 342b at its end opposite the base portion 31b in the axial direction. The receiving-port-side outer joint 342b is a closed annular recess formed by cutting out the receiving-port-side thermal insulation layer forming portion 34b in a closed annular shape so as to open to the axial outside and the radial inside of the receiving-port-side thermal insulation layer forming portion 34b. The receiving-port-side outer joint 342b is positioned in the axial direction of the receiving member 30b at the same position as the receiving-port-side inner joint 332b. The inner diameter of the receiving-port-side thermal insulation layer forming portion 34b, excluding the receiving-port-side outer joint 342b, is equal to the inner diameter of the main body thermal insulation layer forming portion 22ab of the fitting body 20, and the outer diameter of the receiving-port-side thermal insulation layer forming portion 22ab of the fitting body 20, excluding the main body outer joints 222a and 222b.

[0039] The receiving member 30b is integrally formed by injection molding of synthetic resin. The receiving member 30b is injection molded separately from the joint body 20 using a mold different from that for the joint body 20. The receiving member 30b can be formed from the same resin material as the receiving member 30a, and can also be made of a transparent material overall so that the receiving port-side flow path 331b can be seen from the outside.

[0040] <Receiving member 30c> The receiving member 30c includes a base portion 31c, a receiving port 32c, a receiving port-side flow passage forming portion 33c, and a receiving port-side heat insulating layer forming portion 34c. The base portion 31c is in the shape of a perforated disk. The socket 32c has a socket main body 321c and an abutment portion 322c. The socket main body 321c is cylindrical. The socket main body 321c extends from the inner peripheral edge of the base portion 31c to both axial sides of the base portion 31c. The socket main body 321c extends more axially from the base portion 31c on one axial side than on the other axial side. The abutment portion 322c is a perforated disk-like member that extends radially inward from the end of the socket main body 321c that extends less axially from the base portion 31c.

[0041] The inlet-side flow-path forming portion 33c extends from the radially inner side of the abutment portion 322c along the axial direction of the inlet 32c toward the opposite side from the inlet body 321c. The inlet-side flow-path forming portion 33c is cylindrical, with both the inner and outer diameters smaller than those of the inlet body 321c. The inlet-side flow-path forming portion 33c is disposed coaxially with the inlet body 321c. The radially inner side of the inlet-side flow-path forming portion 33c forms the inlet-side flow path 331c. The radially inner side of the abutment portion 322c of the inlet 32c also forms the inlet-side flow path 331c. The inlet-side flow-path forming portion 33c has a inlet-side inner joint portion 332c at its end opposite the base portion 31c in the axial direction. The inlet-side inner joint portion 332c is a closed annular shape and has a convex shape that protrudes axially outward from the radially inner side of the inlet-side flow-path forming portion 33c. The inner diameter of the receiving port side flow path forming portion 33c is equal to the inner diameter of the portion of the main body flow path forming portion 21c of the fitting body 20 excluding the main body inner joint portion 212c, and the outer diameter of the portion excluding the receiving port side inner joint portion 332c is equal to the outer diameter of the main body flow path forming portion 21c of the fitting body 20.

[0042] Socket-side thermal insulation layer forming section 34c extends axially from the outer peripheral edge of base section 31c on the same side as abutment section 322c. Socket-side thermal insulation layer forming section 34c is cylindrical with an inner diameter larger than the outer diameter of socket 32c, and is arranged coaxially with socket 32c and socket-side flow-path forming section 33c so as to cover socket 32c and socket-side flow-path forming section 33c from the radially outer side. Socket-side thermal insulation layer forming section 34c is shorter in the axial direction than socket 32c, and is arranged biased toward socket-side flow-path forming section 33c in the axial direction of socket 32c.

[0043] The inlet-side insulating layer forming section 34c has a inlet-side insulating air layer 341c between the inlet 32c on the radially inner side and the inlet-side flow-path forming section 33c. The inlet-side insulating air layer 341c is provided around the inlet-side flow path 331c, overlapping the inlet-side flow path 331c in the axial direction so as to surround the inlet-side flow path 331c on the radially outer side. The base 31c, the abutment 322c, and the portion of the inlet body 321c between the base 31c and the abutment 322c in the axial direction form a blocking section 35c that blocks the radial gap between one axial end of the inlet-side flow-path forming section 33c and one axial end of the inlet-side insulating layer forming section 34c. The blocking section 35c blocks one axial end of the inlet-side insulating air layer 341c.

[0044] The inlet-side thermal insulation layer forming portion 34c has a receiving-port-side outer joint 342c at its end opposite the base portion 31c in the axial direction. The receiving-port-side outer joint 342c is a closed annular recess formed by cutting out the receiving-port-side thermal insulation layer forming portion 34c in a closed annular shape so as to open to the axial outside and the radial inside of the receiving-port-side thermal insulation layer forming portion 34c. The receiving-port-side outer joint 342c coincides with the receiving-port-side inner joint 332c in the axial direction of the receiving member 30a. The inner diameter of the receiving-port-side thermal insulation layer forming portion 34c, excluding the receiving-port-side outer joint 342c, is equal to the inner diameter of the main body thermal insulation layer forming portion 22c of the fitting body 20, and the outer diameter of the receiving-port-side thermal insulation layer forming portion 22c of the fitting body 20, excluding the main body outer joint 222c.

[0045] The receiving member 30c is integrally formed by injection molding of synthetic resin. The receiving member 30c is injection molded separately from the joint body 20 using a mold different from that for the joint body 20. The receiving member 30c can be formed from the same resin material as the receiving member 30a, and can also be made of a transparent material overall so that the receiving port-side flow path 331c can be seen from the outside.

[0046] 4, the convex body outer joining portion 222a of the body insulation layer forming portion 22ab of the joint body 20 is fitted and bonded to the concave socket side outer joining portion 342a of the socket side insulation layer forming portion 34a of the socket member 30a with adhesive applied therebetween over the entire circumference, and the concave body inner joining portion 212a of the body flow path forming portion 21ab of the joint body 20 is fitted and bonded to the convex socket side inner joining portion 332a of the socket side flow path forming portion 33a of the socket member 30a with adhesive applied therebetween over the entire circumference. This results in the joint body 20 and the socket member 30a being integrated.

[0047] The convex body outer joining portion 222b of the body insulation layer forming portion 22ab of the joint body 20 is fitted and bonded to the concave socket side outer joining portion 342b of the socket side insulation layer forming portion 34b of the socket member 30b with adhesive applied therebetween over the entire circumference, and the concave body inner joining portion 212b of the body flow path forming portion 21ab of the joint body 20 is fitted and bonded to the convex socket side inner joining portion 332b of the socket side flow path forming portion 33b of the socket member 30b with adhesive applied therebetween over the entire circumference. This integrates the joint body 20 and the socket member 30b.

[0048] When the joint body 20 and the receiving members 30a, 30b are integrated, as shown in Fig. 5, the outer peripheral surface of the main body insulating layer forming portion 22ab of the joint body 20 and the outer peripheral surfaces of the receiving port-side insulating layer forming portions 34a, 34b of the receiving members 30a, 30b are arranged on the same cylindrical surface and are continuous in the axial direction. Also, the inner peripheral surface of the main body insulating layer forming portion 22ab of the joint body 20 and the inner peripheral surfaces of the receiving port-side insulating layer forming portions 34a, 34b of the receiving members 30a, 30b are arranged on the same cylindrical surface and are continuous in the axial direction. Also, the outer peripheral surface of the main body flow path forming portion 21ab of the joint body 20 and the outer peripheral surfaces of the receiving port-side flow path forming portions 33a, 33b of the receiving members 30a, 30b are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the main body flow passage forming portion 21ab of the joint main body 20 and the inner peripheral surfaces of the receiving port side flow passage forming portions 33a, 33b of the receiving members 30a, 30b are arranged on the same cylindrical surface and are continuous in the axial direction.

[0049] 4, the convex body outer joining portion 222c of the body insulation layer forming portion 22c of the joint body 20 is fitted and bonded to the concave socket side outer joining portion 342c of the socket side insulation layer forming portion 34c of the socket member 30c with adhesive applied therebetween over the entire circumference, and the concave body inner joining portion 212c of the body flow path forming portion 21c of the joint body 20 is fitted and bonded to the convex socket side inner joining portion 332c of the socket side flow path forming portion 33c of the socket member 30c with adhesive applied therebetween over the entire circumference. This integrates the joint body 20 and the socket member 30c.

[0050] When the fitting body 20 and the receiving member 30c are integrated, as shown in FIG. 5, the outer peripheral surface of the main body insulating layer forming portion 22c of the fitting body 20 and the outer peripheral surface of the receiving port-side insulating layer forming portion 34c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the main body insulating layer forming portion 22c of the fitting body 20 and the inner peripheral surface of the receiving port-side insulating layer forming portion 34c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the outer peripheral surface of the main body flow path forming portion 21c of the fitting body 20 and the outer peripheral surface of the receiving port-side flow path forming portion 33c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the main body flow path forming portion 21c of the fitting body 20 and the inner peripheral surface of the receiving port-side flow path forming portion 33c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction.

[0051] When the fitting body 20 and the receiving members 30a, 30b, and 30c are integrated to form the pipe fitting 10, the central axis of the receiving member 30a and the central axis of the receiving member 30b are arranged on the same straight line, and the central axis of the receiving member 30c is perpendicular to these.

[0052] In the manner described above, the pipe fitting 10 formed by bonding and integrating the receiving member 30a, receiving member 30b, and receiving member 30c to the fitting body 20 has the receiving side flow path 331a of the receiving member 30a, the main body flow path 211ab of the fitting body 20, and the receiving side flow path 331b of the receiving member 30b connected in a linear manner, the main body flow path 211c of the fitting body 20 and the receiving side flow path 331c of the receiving member 30c connected in a linear manner, and the main body flow path 211c and the receiving side flow path 331c connected perpendicularly to the receiving side flow path 331a, the main body flow path 211ab, and the receiving side flow path 331b. In other words, the joint body 20 has a plurality of socket members 30a, 30b and 30c joined together, and has body flow paths 211ab and 211c that communicate these plurality of socket-side flow paths 331a, 331b and 331c.

[0053] In addition, in the pipe fitting 10, the inlet side insulating air layer 341a of the receiving member 30a is connected to the main body insulating air layer 221ab of the fitting main body 20, the main body insulating air layer 221ab of the fitting main body 20 is connected to the inlet side insulating air layer 341b of the receiving member 30b, and the main body insulating air layer 221c of the fitting main body 20 is connected to the inlet side insulating air layer 341c of the receiving member 30c.

[0054] In addition, the pipe fitting 10 is arranged so that the main body insulating air layer 221ab, the main body insulating air layer 221c, the inlet side insulating air layer 341a, the inlet side insulating air layer 341b and the inlet side insulating air layer 341c surround the main body flow path 211ab, the main body flow path 211c, the inlet side flow path 331a, the inlet side flow path 331b and the inlet side flow path 331c radially outward. In pipe fitting 10, main body insulating air layer 221ab, main body insulating air layer 221c, inlet-side insulating air layer 341a, inlet-side insulating air layer 341b, and inlet-side insulating air layer 341c are partitioned by main body flow path forming section 21ab, main body flow path forming section 21c, inlet-side flow path forming section 33a, inlet-side flow path forming section 33b, and inlet-side flow path forming section 33c so as not to communicate with main body flow paths 211ab, main body flow paths 211c, inlet-side flow paths 331a, inlet-side flow paths 331b, and inlet-side flow paths 331c. In pipe fitting 10, main body insulating air layer 221ab, main body insulating air layer 221c, inlet-side insulating air layer 341a, inlet-side insulating air layer 341b, and inlet-side insulating air layer 341c are sealed.

[0055] The pipe fitting 10 is a T-shaped tee fitting.

[0056] {Piping System} As shown in FIG. 4, the piping system 50 according to the first embodiment includes the above-described pipe joint 10 and a plurality of insulated pipes 40a, 40b, and 40c connected by the pipe joint 10.

[0057] One end of the insulated pipe 40a to be connected to the pipe fitting 10 is inserted into the socket 32a of the socket member 30a and bonded. The insulated pipe 40a has a cylindrical flow path forming pipe 402a that forms an internal flow path 401a on the radially inner side, and a cylindrical insulating layer 403a that covers the entire radially outer side of the flow path forming pipe 402a. The flow path forming pipe 402a and the insulating layer 403a are formed coaxially. In the insulated pipe 40a, the flow path forming pipe 402a and the insulating layer 403a are formed integrally.

[0058] Here, the flow path forming pipe 402a is made of a resin harder than the insulating layer 403a, and the insulating layer 403a is made of an expandable resin having higher insulating properties than the flow path forming pipe 402a. The insulating layer 403a may be composed of an insulating layer main body made of an expandable resin having higher insulating properties than the flow path forming pipe 402a and covering the entire radial outside of the flow path forming pipe 402a, and an outer coating layer made of a resin harder than the insulating layer main body and covering the entire radial outside of the insulating layer main body. In other words, the insulating pipe 40a may be a two-layer pipe or a three-layer pipe. Amorphous resins such as polyvinyl chloride resin and ABS resin can be used as the resin forming the flow path forming pipe 402a, and amorphous resins such as expandable polyvinyl chloride resin can be used as the expandable resin.

[0059] When one end of the insulated piping 40a is joined to the socket 32a of the socket member 30a, the insulated piping 40a is fitted into the socket body 321a of the socket 32a and abuts against the abutment portion 322a, and the outer periphery of the insulating layer 403a is bonded to the socket body 321a with an adhesive along the entire periphery. This connects the socket-side flow path 331a of the socket member 30a to the internal flow path 401a in the insulated piping 40a.

[0060] To improve the thermal insulation of the insulated pipe 40a, it is preferable to increase the thickness of the insulating layer 403a. For example, when the insulated pipe 40a is composed of three layers, namely, an outer coating layer, the insulating layer 403a, and the flow path forming pipe 402a, the thickness of the insulating layer 403a is greater than 60% of the thickness of the insulated pipe 40a, preferably 65% ​​or more, more preferably 70% or more, and most preferably 75% or more. When the insulated pipe 40a is composed of two layers, namely, the insulating layer 403a and the flow path forming pipe 402a, the thickness of the insulating layer 403a is greater than 65% of the thickness of the insulated pipe 40a, preferably 70% or more, more preferably 75% or more, and most preferably 80% or more. Furthermore, since the drain near the indoor unit 72 described below has the lowest temperature, it is preferable to set the above heat insulating layer ratio for small diameter pipes with an inner diameter of 25 mm or less connected to the indoor unit 72.

[0061] One end of the insulated pipe 40b to be connected to the pipe fitting 10 is inserted into and bonded to the socket 32b of the socket member 30b. The insulated pipe 40b has a cylindrical flow path forming pipe 402b that forms an internal flow path 401b on the radially inner side, and a cylindrical insulating layer 403b that covers the entire radially outer side of the flow path forming pipe 402b. In the insulated pipe 40b, the flow path forming pipe 402b and the insulating layer 403b are integrally formed. Like the insulating layer 403a, the insulating layer 403b may be composed of an insulating layer main body and an outer coating layer. The insulated pipe 40b can be made of the same resin material as the insulated pipe 40a.

[0062] When one end of the insulated piping 40b is joined to the socket 32b of the socket member 30b, the insulated piping 40b is fitted into the socket body 321b of the socket 32b and abuts against the abutment portion 322b, with the outer periphery of the insulating layer 403b bonded to the socket body 321b with an adhesive along the entire periphery. This connects the socket-side flow path 331b of the socket member 30b to the internal flow path 401b in the insulated piping 40b.

[0063] One end of the insulated pipe 40c to be connected to the pipe fitting 10 is inserted into and bonded to the socket 32c of the socket member 30c. The insulated pipe 40c has a cylindrical flow path forming pipe 402c that forms an internal flow path 401c on the radially inner side, and a cylindrical insulating layer 403c that covers the entire radially outer side of the flow path forming pipe 402c. The insulated pipe 40c is formed by integrally forming the flow path forming pipe 402c and the insulating layer 403c. Like the insulating layer 403a, the insulating layer 403c may be composed of an insulating layer main body and an outer coating layer. The insulated pipe 40c can be formed from the same resin material as the insulated pipe 40a.

[0064] When one end of the insulated piping 40c is joined to the socket 32c of the socket member 30c, the insulated piping 40c is fitted into the socket body 321c of the socket 32c and abuts against the abutment portion 322c, with the outer periphery of the insulating layer 403c bonded to the socket body 321c with an adhesive along the entire periphery. This connects the socket-side flow path 331c of the socket member 30c to the internal flow path 401c in the insulated piping 40c.

[0065] As described above, the pipe fitting 10 is a component for connecting the insulated pipes 40a, 40b, and 40c, and for communicating the in-pipe flow paths 401a, 401b, and 401c.

[0066] Here, in the pipe fitting 10, when the insulated pipes 40a, 40b, and 40c have the same outer diameter, the receiving member 30a, 30b, and 30c can be common parts of the same shape.

[0067] On the other hand, when the outer diameters of insulated pipes 40a and 40b are different, inlet member 30a and inlet member 30b have the same shapes for inlet-side flow path forming portion 33a and inlet-side flow path forming portion 33b and the same shapes for inlet-side thermal insulation layer forming portion 34a and inlet-side thermal insulation layer forming portion 34b, but have different shapes for base portion 31a and inlet 32a and base portion 31b and inlet 32b. That is, inlet body 321a has an inner diameter that matches the outer diameter of insulated pipe 40a, and inlet body 321b has an inner diameter that matches the outer diameter of insulated pipe 40b, so that inlet body 321a and inlet body 321b have different inner diameters.

[0068] Furthermore, when the outer diameters of insulated pipe 40a and insulated pipe 40c are different, inlet member 30a and inlet member 30c have the same shapes for inlet-side flow path forming portion 33a and inlet-side flow path forming portion 33c, and the same shapes for inlet-side thermal insulation layer forming portion 34a and inlet-side thermal insulation layer forming portion 34c, but have different shapes for base portion 31a and inlet 32a, and base portion 31c and inlet 32c. That is, inlet body 321a has an inner diameter that matches the outer diameter of insulated pipe 40a, and inlet body 321c has an inner diameter that matches the outer diameter of insulated pipe 40c, with inlet body 321a and inlet body 321b having different inner diameters.

[0069] Furthermore, when the outer diameters of insulated pipes 40b and 40c are different, inlet member 30b and inlet member 30c have the same shapes for inlet-side flow path forming portion 33b and inlet-side flow path forming portion 33c, and the same shapes for inlet-side thermal insulation layer forming portion 34b and inlet-side thermal insulation layer forming portion 34c, but have different shapes for base portion 31b and inlet 32b, and for base portion 31c and inlet 32c. That is, inlet body 321b has an inner diameter that matches the outer diameter of insulated pipe 40b, and inlet body 321c has an inner diameter that matches the outer diameter of insulated pipe 40c, with inlet body 321a and inlet body 321b having different inner diameters.

[0070] The above describes a case where the inner diameter of the receiving port member 30a's receiving port body 321a is smaller than the inner diameter of the receiving port-side insulating layer forming portion 34a, but this is not limited thereto. Depending on the outer diameter of the insulated piping 40a to be fitted, the inner diameter of the receiving port body 321a may be equal to or larger than the inner diameter of the receiving port-side insulating layer forming portion 34a. Similarly, depending on the outer diameter of the insulated piping 40b to be fitted, the inner diameter of the receiving port body 321b may be equal to or larger than the inner diameter of the inlet-side insulating layer forming portion 34b. Similarly, depending on the outer diameter of the insulated piping 40c to be fitted, the inner diameter of the receiving port body 321c to be fitted may be equal to or larger than the inner diameter of the inlet-side insulating layer forming portion 34c.

[0071] The pipe fitting 10 according to the first embodiment described above is configured such that multiple receiving members 30a, 30b, and 30c, including receiving member 30a having receiving port 32a into which one end of insulated pipe 40a to be connected is inserted and joined, receiving member 30b having receiving port 32b into which one end of insulated pipe 40b to be connected is inserted and joined, and receiving member 30c having receiving port 32c into which one end of insulated pipe 40c to be connected is inserted and joined, are joined to a fitting main body 20 having main flow paths 211ab and 211c that communicate the receiving port-side flow paths 331a, 331b, and 331c of these multiple receiving members 30a, 30b, and 30c. Therefore, even when connecting insulated pipes 40a, 40b, and 40c with various outer diameters, it is sufficient to change receiving members 30a, 30b, and 30c, and there is no need to change fitting main body 20. This reduces costs. Furthermore, since the receiving member 30a has a receiving port side insulating air layer 341a around the receiving port side flow path 331a, the receiving member 30b has a receiving port side insulating air layer 341b around the receiving port side flow path 331b, the receiving member 30c has a receiving port side insulating air layer 341c around the receiving port side flow path 331c, and the fitting body 20 has a main body insulating air layer 221ab around the main body flow path 211ab and a main body insulating air layer 221c around the main body flow path 211c, the insulation properties can be improved.

[0072] In the pipe fitting 10 according to the first embodiment, the receiving members 30a, 30b, 30c and the fitting body 20 are integrated by bonding, which facilitates integration and further improves heat insulation.

[0073] In the pipe fitting 10 of the first embodiment, the receiving members 30a, 30b, 30c and the fitting body 20 are formed from a resin material that allows the receiving side flow paths 331a, 331b, 331c and the main body flow paths 211ab, 211c to be visible from the outside, so that the receiving side flow paths 331a, 331b, 331c and the main body flow paths 211ab, 211c can be seen from the outside of the pipe fitting 10. Therefore, the communication state between the inlet side flow paths 331a, 331b, 331c and the main body flow paths 211ab, 211c, in other words, the joining state between the main body flow path forming portion 21ab, the main body flow path forming portion 21c, the inlet side flow path forming portion 33a, the inlet side flow path forming portion 33b and the inlet side flow path forming portion 33c, and the state of fluid flow in the inlet side flow paths 331a, 331b, 331c and the main body flow paths 211ab, 211c can be visually confirmed.

[0074] The piping system 50 according to the first embodiment has the above-described pipe fitting 10 and the plurality of insulated pipes 40a, 40b, 40c connected by the pipe fitting 10, and therefore the pipe fitting 10 provides the above-described effects. Therefore, even when connecting insulated pipes 40a, 40b, 40c with various outer diameters, it is possible to suppress an increase in costs and improve thermal insulation.

[0075] Note that perforated disc-shaped packings made of foam resin or the like may be provided between the abutment portion 322a of the socket 32a of the pipe fitting 10 and the end face of the insulated pipe 40a, between the abutment portion 322b of the socket 32b and the end face of the insulated pipe 40b, and between the abutment portion 322c of the socket 32c and the end face of the insulated pipe 40c. This allows the packings to deform and absorb variations in the shapes of the end faces of the insulated pipes 40a, 40b, and 40c, thereby improving the airtightness.

[0076] Furthermore, when the joint body 20 and the receiving members 30a, 30b, 30c are made of a crystalline resin such as polypropylene or polyethylene that cannot be bonded with adhesive, their joining surfaces can be fused together by butt welding or ultrasonic welding. In this case, the receiving side inner joints 332a, 332b, 332c, the receiving side outer joints 342a, 342b, 342c, the body inner joints 212a, 212b, 212c, and the body outer joints 222a, 222b, 222c can have flat joining surfaces.

[0077] The above-described pipe joint 10 and piping system 50 can be applied to, for example, a drain piping system of an air conditioning system 60 as shown in FIG. The air conditioning system 60 shown in Fig. 6 is a multi-air conditioning system for a building that is installed in a building 70 such as an office building. An outdoor unit 71 is installed on the roof of the building 70, and a plurality of indoor units 72 are connected to the outdoor unit 71 by refrigerant piping 73. The indoor units 72 are ceiling-mounted air conditioners that are embedded in a ceiling 74. The refrigerant piping 73 that connects the indoor and outdoor areas runs from each indoor unit 72 through the attic, gathers in a shaft 75 of the building 70, and is led to the outdoor unit 71 from a dovecote 76 installed on the roof of the building 70.

[0078] Drainage generated in the indoor units 72 is discharged by a drain pump installed in each indoor unit 72. A discharge pipe 77 (corresponding to the insulated pipe 40c) that discharges drainage from each indoor unit 72 is connected to a horizontal pipe 78 (corresponding to the insulated pipes 40a and 40b) arranged in the ceiling by a pipe fitting 10, which is a T-shaped joint according to the first embodiment, and is connected to a vertically running collective pipe 79 arranged in the shaft 75 by the pipe fitting 10, a pipe fitting 10A, which is an elbow joint according to the second embodiment described below, and the like. Drainage discharged from each room is discharged outdoors by this vertically running collective pipe 79. As shown in this example, the drainage pipes in an air conditioning system installed in a typical office building consist of the discharge pipe 77, the horizontal pipe 78, the vertically running collective pipe 79, and the like, and these drainage pipes are connected to each other by a T-shaped pipe fitting 10 and an elbow-shaped pipe fitting 10A. When used in the drain piping system of such an air conditioning system 60, the pipe fitting 10 allows drainage water to flow through the inlet-side flow paths 331a, 331b, 331c and the main body flow paths 211ab, 211c while being insulated from the outside air by the inlet-side insulating air layers 341a, 341b, 341c and the main body insulating air layers 221ab, 221c. This effectively prevents condensation from forming around the pipe fitting 10.

[0079] [Second embodiment] {Pipe fitting 10A} A pipe fitting 10A according to a second embodiment will be described mainly with reference to FIGS. 7 and 8, focusing on differences from the pipe fitting 10 according to the first embodiment. As shown in FIG. 7, the pipe fitting 10A has a fitting main body 20A that is partially different from the fitting main body 20, and a receiving member 30a and a receiving member 30c that are similar to those of the pipe fitting 10, and as shown in FIG. 7, the fitting main body 20A, receiving member 30a, and receiving member 30c are joined together to form an integrated unit.

[0080] <Joint body 20A> As shown in FIG. 7, the joint body 20A has a main flow passage forming portion 21Aac, a main heat insulating layer forming portion 22Aac, and a support portion (not shown). The main flow path forming portion 21Aac is cylindrical with a 90° curve in the axial center, and the radially inner side forms the main flow path 211Aac. The main flow path forming portion 21Aac has a main body inner joint portion 212a similar to the joint body 20 at one axial end, and a main body inner joint portion 212c similar to the joint body 20 at the other axial end. The main body flow path forming portion 21Aac has a central axis of the main body inner joint portion 212a and a central axis of the main body inner joint portion 212c that are perpendicular to each other.

[0081] The main insulation layer forming portion 22Aac is cylindrical with a 90° curve in the axial center. Its inner diameter is larger than the outer diameter of the main flow path forming portion 21Aac. Its central axis is aligned with that of the main flow path forming portion 21Aac so as to cover the main flow path forming portion 21Aac radially outward. The main insulation layer forming portion 22Aac has the same axial length as the main flow path forming portion 21Aac, and the space between the main insulation layer forming portion 22Aac and the main flow path forming portion 21Aac on the radially inner side forms a main insulating air layer 221Aac. The main insulating air layer 221Aac is disposed around the main flow path 211Aac, overlapping the main flow path 211Aac in the axial direction so as to surround the main flow path 211Aac radially outward. The main insulation layer forming portion 22Aac has a main outer joint portion 222a similar to that of the fitting body 20 at one axial end and a main outer joint portion 222c similar to that of the fitting body 20 at the other axial end. The position of the body outer joint 222a in the axial direction of the joint body 20A coincides with the position of the body inner joint 212a. The position of the body outer joint 222c in the axial direction of the joint body 20A coincides with the position of the body inner joint 212c. In the body insulating layer forming portion 22Aac, the central axis of the body outer joint 222a and the central axis of the body outer joint 222c are perpendicular to each other.

[0082] The support portion (not shown) connects the main flow path forming portion 21Aac and the main insulation layer forming portion 22Aac so that their central axes are aligned. In other words, the support portion (not shown) supports the main flow path forming portion 21Aac on the main insulation layer forming portion 22Aac.

[0083] The joint body 20A is integrally formed by injection molding of synthetic resin. The joint body 20A is injection molded separately from the receiving member 30a and the receiving member 30c using a mold different from that used for the receiving member 30a and the receiving member 30c. The joint body 20A can be formed from the same resin material as the joint body 20, and can be made of a transparent material overall so that the main body flow path 211Aac can be seen from the outside.

[0084] The convex body outer joint 222a of the body insulation layer forming portion 22Aac of the joint body 20A is fitted and bonded to the concave socket side outer joint 342a (see FIG. 3) of the socket side insulation layer forming portion 34a of the socket member 30a with adhesive applied therebetween over the entire circumference, and the concave body inner joint 212a of the body flow path forming portion 21Aac of the joint body 20A is fitted and bonded to the convex socket side inner joint 332a (see FIG. 3) of the socket member 30a with adhesive applied therebetween over the entire circumference, thereby integrating the joint body 20A and the socket member 30a.

[0085] When the fitting body 20A and the receiving member 30a are integrated, the outer peripheral surface of one end of the main body insulating layer forming portion 22Aac of the fitting body 20A and the outer peripheral surface of the receiving-port-side insulating layer forming portion 34a of the receiving member 30a are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of one end of the main body insulating layer forming portion 22Aac of the fitting body 20A and the inner peripheral surface of the receiving-port-side insulating layer forming portion 34a of the receiving member 30a are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the outer peripheral surface of one end of the main body flow path forming portion 21Aac of the fitting body 20A and the outer peripheral surface of the receiving-port-side flow path forming portion 33a (see FIG. 3) of the receiving member 30a are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner circumferential surface of one end of the main body flow passage forming portion 21Aac of the joint main body 20A and the inner circumferential surface of the receiving port side flow passage forming portion 33a (see FIG. 3) of the receiving member 30a are arranged on the same cylindrical surface and are continuous in the axial direction.

[0086] The convex body outer joint 222c of the body insulation layer forming section 22c of the joint body 20A is fitted and bonded to the concave socket side outer joint 342c (see FIG. 3) of the socket side insulation layer forming section 34c of the socket member 30c with adhesive applied therebetween over the entire circumference, and the concave body inner joint 212c of the body flow path forming section 21Aac of the joint body 20A is fitted and bonded to the convex socket side inner joint 332c (see FIG. 3) of the socket member 30c with adhesive applied therebetween over the entire circumference. This integrates the joint body 20A and the socket member 30c.

[0087] When the fitting body 20A and the receiving member 30c are integrated, the outer peripheral surface of the other end of the main body insulating layer forming portion 22Aac of the fitting body 20A and the outer peripheral surface of the receiving-port-side insulating layer forming portion 34c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the other end of the main body insulating layer forming portion 22Aac of the fitting body 20A and the inner peripheral surface of the receiving-port-side insulating layer forming portion 34c of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the outer peripheral surface of the other end of the main body flow path forming portion 21Aac of the fitting body 20A and the outer peripheral surface of the receiving-port-side flow path forming portion 33c (see FIG. 3) of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the other end side of the main body flow passage forming portion 21Aac of the joint main body 20A and the inner peripheral surface of the receiving port side flow passage forming portion 33c (see FIG. 3) of the receiving member 30c are arranged on the same cylindrical surface and are continuous in the axial direction.

[0088] When the joint body 20A and the socket members 30a, 30c are integrated to form the pipe joint 10A, the central axis of the socket member 30a and the central axis of the socket member 30c are perpendicular to each other.

[0089] In the pipe fitting 10A formed by bonding and integrating the socket members 30a and 30c to the fitting body 20A as described above, the socket-side flow path 331a (see FIG. 3) of the socket member 30a, the main body flow path 211Aac of the fitting body 20A, and the socket-side flow path 331c (see FIG. 3) of the socket member 30c are connected to each other. In other words, the fitting body 20A has a plurality of socket members 30a and 30c joined together, and has a main body flow path 211Aac that connects these plurality of socket-side flow paths 331a, 331c.

[0090] In addition, in the pipe fitting 10A, the receiving port side insulating air space 341a (see FIG. 3) of the receiving member 30a, the main body insulating air space 221Aac of the fitting main body 20A, and the receiving port side insulating air space 341c (see FIG. 3) of the receiving member 30c are in communication with each other.

[0091] Furthermore, pipe fitting 10A is arranged such that main body insulating air layer 221Aac, inlet-side insulating air layer 341a (see FIG. 3), and inlet-side insulating air layer 341c (see FIG. 3) radially surround main body flow path 211Aac, inlet-side flow path 331a (see FIG. 3), and inlet-side flow path 331c (see FIG. 3) on the outside. In pipe fitting 10A, main body insulating air layer 221Aac, inlet-side insulating air layer 341a, and inlet-side insulating air layer 341c are partitioned by main body flow path forming portion 21Aac, inlet-side flow path forming portion 33a (see FIG. 3), and inlet-side flow path forming portion 33c (see FIG. 3) so as not to communicate with main body flow path 211Aac, inlet-side flow path 331a, and inlet-side flow path 331c. In the pipe fitting 10A, the main body insulating air layer 221Aac, the inlet side insulating air layer 341a, and the inlet side insulating air layer 341c are sealed.

[0092] The pipe joint 10A is an elbow-type pipe joint.

[0093] {Piping System} The piping system according to the second embodiment has the above-mentioned pipe joint 10A and a plurality of insulated pipes 40a (see FIG. 4) and insulated pipes 40c (see FIG. 4) similar to those of the piping system 50, which are connected by the pipe joint 10A.

[0094] As with the piping system 50, one end of the insulated piping 40a to be connected to the pipe fitting 10A is inserted into and bonded to the socket 32a of the socket member 30a, so that the socket-side flow path 331a of the socket member 30a communicates with the internal pipe flow path 401a in the insulated piping 40a.

[0095] As with the piping system 50, one end of the insulated piping 40c to be connected to the pipe fitting 10A is inserted into and bonded to the socket 32c of the socket member 30c, so that the socket-side flow path 331c of the socket member 30c communicates with the internal pipe flow path 401c within the insulated piping 40c.

[0096] In this way, the pipe joint 10A is a component for connecting the heat-insulated pipe 40a and the heat-insulated pipe 40c and for communicating the internal pipe flow path 401a and the internal pipe flow path 401c.

[0097] Here, in the pipe fitting 10A, when the insulated pipe 40a and the insulated pipe 40c have the same outer diameter, the receiving member 30a and the receiving member 30c can be common parts having the same shape.

[0098] In the pipe fitting 10A, when the outer diameters of the insulated pipes 40a and 40c are different, the shapes of the base portion 31a and the socket 32a of the socket member 30a are different from the shapes of the base portion 31c and the socket 32c of the socket member 30c, as in the pipe fitting 10.

[0099] In the pipe fitting 10A, depending on the outer diameter of the insulated pipe 40a to be fitted, the inner diameter of the receiving body 321a may be equal to or greater than the inner diameter of the inlet side insulation layer forming portion 34a, and in the receiving member 30c, depending on the outer diameter of the insulated pipe 40c to be fitted, the inner diameter of the receiving body 321c may be equal to or greater than the inner diameter of the inlet side insulation layer forming portion 34c.

[0100] The pipe fitting 10A according to the second embodiment described above is configured such that multiple receiving members 30a, 30c, including receiving member 30a having receiving port 32a into which one end of insulated pipe 40a to be connected is inserted and joined, and receiving member 30c having receiving port 32c into which one end of insulated pipe 40c to be connected is inserted and joined, are joined to a fitting main body 20A having a main flow path 211Aac that connects receiving port-side flow paths 331a, 331c of these multiple receiving members 30a, 30c. Therefore, even when connecting insulated pipes 40a, 40c of various outer diameters, it is sufficient to change receiving members 30a, 30c, and there is no need to change fitting main body 20A. This prevents increases in costs. In addition, since the receiving member 30a has a receiving port side insulating air layer 341a around the receiving port side flow path 331a, the receiving member 30c has a receiving port side insulating air layer 341c around the receiving port side flow path 331c, and the fitting body 20A has a main body insulating air layer 221Aac around the main body flow path 211Aac, insulation properties can be improved.

[0101] In the pipe joint 10A according to the second embodiment, the receiving members 30a, 30c and the joint body 20A are integrated by bonding, which facilitates integration and further improves heat insulation.

[0102] In the pipe fitting 10A according to the second embodiment, the receiving members 30a, 30c and the fitting body 20A are formed from a resin material that allows the receiving port-side flow paths 331a, 331c and the main body flow path 211Aac to be visible from the outside, and therefore the receiving port-side flow paths 331a, 331c and the main body flow path 211Aac can be seen from the outside of the pipe fitting 10A. This allows visual confirmation of the communication state between the receiving port-side flow paths 331a, 331c and the main body flow path 211Aac—in other words, the joint state between the main body flow path-forming portion 21Aac, the receiving port-side flow path-forming portion 33a, and the receiving port-side flow path-forming portion 33c—and the state of fluid flow in the receiving port-side flow paths 331a, 331c and the main body flow path 211Aac.

[0103] The piping system of the second embodiment has the above-mentioned pipe fitting 10A and a plurality of insulated pipes 40a, 40c similar to those of the piping system 50, which are connected by the pipe fitting 10A. Therefore, by virtue of the above-mentioned effects of the pipe fitting 10A, even when connecting insulated pipes 40a, 40c of various outer diameters, it is possible to suppress increases in costs and improve insulation properties.

[0104] As in the piping system 50, perforated disc-shaped packings made of foam resin may be provided between the abutment portion 322a of the socket 32a of the pipe fitting 10A and the end face of the insulated pipe 40a, and between the abutment portion 322c of the socket 32c and the end face of the insulated pipe 40c. This allows the packings to deform and absorb variations in the shapes of the end faces of the insulated pipes 40a and 40c, thereby improving the airtightness.

[0105] Furthermore, as with pipe fitting 10, when fitting body 20A and receiving members 30a, 30c are made of a crystalline resin that cannot be bonded with an adhesive, their joining surfaces are fused together by butt welding or ultrasonic welding. In this case, it is possible to form flat joining surfaces for receiving side inner joints 332a, 332c, receiving side outer joints 342a, 342c, body inner joints 212a, 212c, and body outer joints 222a, 222c.

[0106] When used in the above-described air conditioning system 60, the pipe fitting 10A can constitute a drain piping system, in which case the drainage water can flow into the inlet-side flow paths 331a, 331c and the main body flow path 211ac while being insulated from the outside air by the inlet-side insulating air layers 341a, 341c and the main body insulating air layer 221Aac. This effectively prevents condensation from forming around the pipe fitting 10A.

[0107] [Third embodiment] {Pipe fitting 10B} A pipe fitting 10B according to a third embodiment will be described, mainly with reference to FIGS. 9 and 10, focusing on differences from the pipe fitting 10 according to the first embodiment. As shown in Figure 9, the pipe fitting 10B has a fitting body 20B that is partially different from the fitting body 20, a receiving member 30Ba that is partially different from the receiving member 30a, and a receiving member 30Bb that is partially different from the receiving member 30b, and as shown in Figure 10, the fitting body 20B, receiving member 30Ba, and receiving member 30Bb are joined together to form an integrated unit.

[0108] <Joint body 20B> As shown in FIG. 9, the joint body 20B has a main body flow passage forming portion 21Bab, a main body heat insulating layer forming portion 22Bab, and a support portion 24B. The main flow path forming portion 21Bab is cylindrical, and its radially inner side forms the main flow path 211Bab. The main flow path forming portion 21Bab has a main body inner joining portion 212a similar to the joint body 20 at one axial end, and a main body inner joining portion 212b similar to the joint body 20 at the other axial end.

[0109] The main body insulating layer forming portion 22Bab is cylindrical with an inner diameter larger than the outer diameter of the main body flow path forming portion 21Bab, and is arranged coaxially with the main body flow path forming portion 21Bab so as to cover the main body flow path forming portion 21Bab from the radially outer side. The main body insulating layer forming portion 22Bab has the same axial length as the main body flow path forming portion 21Bab, and the space between the main body insulating layer forming portion 22Bab and the main body flow path forming portion 21Bab on the radially inner side forms a main body insulating air layer 221Bab. The main body insulating air layer 221Bab is provided around the main body flow path 211Bab, overlapping in the axial direction with the main body flow path 211Bab so as to surround the main body flow path 211Bab from the radially outer side. The main body insulating layer forming portion 22Bab has a main body outer joint portion 222a similar to the joint body 20 at one axial end and a main body outer joint portion 222b similar to the joint body 20 at the other axial end. The position of the body outer joining portion 222a in the axial direction of the body thermal insulating layer forming portion 22Bab coincides with the position of the body inner joining portion 212a. The position of the body outer joining portion 222b in the axial direction of the body thermal insulating layer forming portion 22Bab coincides with the position of the body inner joining portion 212b.

[0110] The support portion 24B is flat and extends radially from the main flow path forming portion 21Bab and the main insulation layer forming portion 22Bab at an intermediate position in the axial direction of the main flow path forming portion 21Bab and the main insulation layer forming portion 22Bab, specifically at the center position, to connect the main flow path forming portion 21Bab and the main insulation layer forming portion 22Bab. The support portion 24B crosses the radial direction across the center of the main insulation air layer 221Bab in the axial direction, dividing the main insulation air layer 221Bab into two. The support portion 24B supports the main flow path forming portion 21Bab on the main insulation layer forming portion 22Bab.

[0111] The joint body 20B is integrally formed by injection molding of synthetic resin. The joint body 20B is injection molded separately from the receiving member 30a and the receiving member 30b using a mold different from that used for the receiving member 30a and the receiving member 30b. The joint body 20B can be formed from the same resin material as the joint body 20, and can be made of a transparent material overall so that the main body flow path 211Bab can be seen from the outside.

[0112] <Receptacle member 30Ba> The receiver member 30Ba has a receiver-side flow-path forming portion 33Ba that is partially different from the receiver-side flow-path forming portion 33a of the receiver member 30a. The receiver-side flow-path forming portion 33Ba is cylindrical and coaxial with the receiver body 321a. The receiver-side flow-path forming portion 33Ba has a receiver-side inner joint portion 332a similar to the receiver-side flow-path forming portion 33a at the end opposite the receiver body 321a in the axial direction. The receiver-side flow-path forming portion 33Ba has an inner diameter that is the same as the inner diameter of the receiver body 321a, and an outer diameter, excluding the receiver-side inner joint portion 332a, that is the same as the outer diameter of the receiver body 321a. Therefore, the inner diameter of the abutment portion 322a is smaller than the inner diameter of the receiver-side flow-path forming portion 33Ba.

[0113] <Receptacle member 30Bb> The receiving member 30Bb has a receiving-port-side flow-path forming portion 33Bb that is partially different from the receiving-port-side flow-path forming portion 33b of the receiving member 30b. The receiving-port-side flow-path forming portion 33Bb is cylindrical and coaxial with the receiving body 321b. The receiving-port-side flow-path forming portion 33Bb has a receiving-port-side inner joint portion 332b similar to the receiving-port-side flow-path forming portion 33b at the end opposite the receiving body 321b in the axial direction. The receiving-port-side flow-path forming portion 33Bb has an inner diameter equal to that of the receiving body 321b, and an outer diameter excluding the receiving-port-side inner joint portion 332b equal to that of the receiving body 321b. Therefore, the inner diameter of the abutting portion 322b is smaller than the inner diameter of the receiving-port-side flow-path forming portion 33Bb.

[0114] The convex body outer joint 222a of the body insulation layer forming portion 22Bab of the joint body 20B is fitted and bonded to the concave socket side outer joint 342a of the socket side insulation layer forming portion 34a of the socket member 30Ba with adhesive applied over the entire circumference, and the concave body inner joint 212a of the body flow path forming portion 21Bab of the joint body 20B is fitted and bonded to the convex socket side inner joint 332a of the socket side flow path forming portion 33Ba of the socket member 30Ba with adhesive applied over the entire circumference, thereby integrating the joint body 20B and the socket member 30Ba.

[0115] The convex body outer joining portion 222b of the body insulation layer forming portion 22Bab of the joint body 20B is fitted and bonded to the concave reception side outer joining portion 342b of the reception side insulation layer forming portion 34b of the reception member 30Bb with adhesive applied over the entire circumference, and the concave body inner joining portion 212b of the body flow path forming portion 21Bab of the joint body 20B is fitted and bonded to the convex reception side inner joining portion 332b of the reception side flow path forming portion 33Bb of the reception member 30Bb with adhesive applied over the entire circumference, thereby integrating the joint body 20B and the reception member 30Bb.

[0116] When the fitting body 20B and the receiving members 30Ba, 30Bb are integrated to form the pipe fitting 10B, the outer peripheral surface of the main body insulating layer forming portion 22Bab of the fitting body 20B and the outer peripheral surfaces of the inlet-side insulating layer forming portions 34a, 34b of the receiving members 30Ba, 30Bb are arranged on the same cylindrical surface and are continuous in the axial direction. The inner peripheral surface of the main body insulating layer forming portion 22Bab of the fitting body 20B and the inner peripheral surfaces of the inlet-side insulating layer forming portions 34a, 34b of the receiving members 30Ba, 30Bb are arranged on the same cylindrical surface and are continuous in the axial direction. The outer peripheral surface of the main body flow path forming portion 21Bab of the fitting body 20B and the outer peripheral surfaces of the inlet-side flow path forming portions 33Ba, 33Bb of the receiving members 30Ba, 30Bb are arranged on the same cylindrical surface and are continuous in the axial direction. Furthermore, the inner peripheral surface of the main body flow passage forming portion 21Bab of the joint main body 20B and the inner peripheral surfaces of the receiving port side flow passage forming portions 33Ba, 33Bb of the receiving members 30Ba, 30Bb are arranged on the same cylindrical surface and are continuous in the axial direction.

[0117] When the joint body 20B and the receiving members 30Ba, 30Bb are integrated to form the pipe joint 10B, the central axis of the receiving member 30Ba, the central axis of the joint body 20B, and the central axis of the receiving member 30Bb are aligned on the same straight line.

[0118] In the pipe fitting 10B formed by bonding and integrating the receiving member 30Ba and the receiving member 30Bb to the fitting body 20B as described above, the receiving port-side flow path 331a of the receiving member 30Ba, the main body flow path 211Bab of the fitting body 20B, and the receiving port-side flow path 331b of the receiving member 30Bb are linearly connected. In other words, the fitting body 20B is formed by joining a plurality of receiving members 30Ba and 30Bb, and has a main body flow path 211Bab that connects these plurality of receiving port-side flow paths 331a, 331b.

[0119] In addition, in the pipe fitting 10B, the inlet side insulating air layer 341a of the inlet member 30Ba is in communication with the main body insulating air layer 221Bab of the fitting main body 20B, and the main body insulating air layer 221Bab of the fitting main body 20B is in communication with the inlet side insulating air layer 341b of the inlet member 30Bb.

[0120] In addition, in pipe fitting 10B, main body insulating air layer 221Bab, inlet-side insulating air layer 341a, and inlet-side insulating air layer 341b are arranged to radially surround main flow path 211Bab, inlet-side flow path 331a, and inlet-side flow path 331b on the outside. In pipe fitting 10B, main body insulating air layer 221Bab, inlet-side insulating air layer 341a, and inlet-side insulating air layer 341b are partitioned by main flow path forming portion 21Bab, inlet 32a, inlet-side flow path forming portion 33Ba, inlet 32b, and inlet-side flow path forming portion 33Bb so as not to communicate with main flow path 211Bab, inlet-side flow path 331a, and inlet-side flow path 331b. In pipe fitting 10B, main body insulating air layer 221ab, inlet-side insulating air layer 341a, and inlet-side insulating air layer 341b are sealed.

[0121] The pipe fitting 10B is an I-shaped socket fitting. Note that by forming a step at the axial middle position of the fitting body 20B, it is possible to make the central axis of the receiving member 30Ba and the central axis of the receiving member 30Bb parallel to each other.

[0122] {Piping System} The piping system according to the third embodiment has the above-mentioned pipe fitting 10B and a plurality of insulated pipes 40a (see FIG. 4) and insulated pipes 40b (see FIG. 4) similar to those of the piping system 50, which are connected by the pipe fitting 10B.

[0123] One end of the insulated pipe 40a to be connected to the pipe fitting 10B is inserted into and bonded to the socket 32a of the socket member 30Ba, as in the piping system 50. Then, the socket-side flow path 331a of the socket member 30Ba communicates with the internal pipe flow path 401a in the insulated pipe 40a.

[0124] One end of the insulated pipe 40b to be connected to the pipe fitting 10B is inserted into and bonded to the socket 32b of the socket member 30Bb, as in the piping system 50. Then, the socket-side flow path 331b of the socket member 30Bb communicates with the internal pipe flow path 401b in the insulated pipe 40b.

[0125] In this way, the pipe joint 10B is a component for connecting the heat-insulated pipe 40a and the heat-insulated pipe 40b and for communicating the internal pipe flow path 401a and the internal pipe flow path 401b.

[0126] Here, when the heat-insulating pipe 40a and the heat-insulating pipe 40b have the same outer diameter, the receiving member 30Ba and the receiving member 30Bb can be common parts having the same shape.

[0127] In the pipe fitting 10B, when the outer diameters of the insulated pipes 40a and 40b are different, the shapes of the base portion 31a and the socket 32a of the receiving member 30a are different from the shapes of the base portion 31b and the socket 32b of the receiving member 30b, as in the pipe fitting 10.

[0128] In the pipe fitting 10B, depending on the outer diameter of the insulated pipe 40a to be fitted, the inner diameter of the receiving body 321a may be equal to or greater than the inner diameter of the inlet side insulation layer forming portion 34a, and in the receiving member 30Bb, depending on the outer diameter of the insulated pipe 40b to be fitted, the inner diameter of the receiving body 321b may be equal to or greater than the inner diameter of the inlet side insulation layer forming portion 34b.

[0129] The pipe fitting 10B according to the third embodiment described above has a configuration in which multiple receiving members 30Ba, 30Bb, including a receiving member 30Ba having a receiving port 32a into which one end of a thermally insulated pipe 40a to be connected is inserted and joined, and a receiving member 30Bb having a receiving port 32b into which one end of a thermally insulated pipe 40b to be connected, are joined to a fitting main body 20B having a main flow path 211Bab that connects the receiving port-side flow paths 331a, 331b of the multiple receiving members 30Ba, 30Bb. Therefore, even when connecting thermally insulated pipes 40a, 40b of various outer diameters, it is sufficient to change the receiving members 30Ba, 30Bb, and there is no need to change the fitting main body 20B. This prevents increases in costs. In addition, the receiving member 30Ba has a receiving port side insulating air layer 341a around the receiving port side flow path 331a, the receiving member 30Bb has a receiving port side insulating air layer 341b around the receiving port side flow path 331b, and the fitting body 20B has a main body insulating air layer 221Bab around the main body flow path 211Bab, thereby improving insulation properties.

[0130] In the pipe fitting 10B according to the third embodiment, the receiving members 30Ba, 30Bb and the fitting body 20B are integrated by bonding, which facilitates integration and further improves heat insulation.

[0131] In the pipe fitting 10B according to the third embodiment, the receiving members 30Ba, 30Bb and the fitting body 20B are formed from a resin material that allows the receiving port-side flow paths 331a, 331b and the main body flow path 211Bab to be visible from the outside, and therefore the receiving port-side flow paths 331a, 331b and the main body flow path 211Bab can be seen from the outside of the pipe fitting 10B. This allows visual confirmation of the communication state between the receiving port-side flow paths 331a, 331b and the main body flow path 211Bab, in other words, the joining state of the main body flow path-forming portion 21Bab, the receiving port-side flow path-forming portion 33Ba and the receiving port-side flow path-forming portion 33Bb, and the state of fluid flow in the receiving port-side flow paths 331a, 331b and the main body flow path 211Bab.

[0132] The piping system according to the third embodiment has the above-mentioned pipe fitting 10B and a plurality of insulated pipes 40a, 40b similar to those of the piping system 50, which are connected by the pipe fitting 10B. Therefore, by virtue of the above-mentioned effects of the pipe fitting 10B, even when connecting insulated pipes 40a, 40b of various outer diameters, it is possible to suppress increases in costs and improve insulation properties.

[0133] Note that perforated disc-shaped packings made of foam resin may be provided between the abutment portion 322a of the socket 32a of the pipe fitting 10B and the end face of the insulated pipe 40a, and between the abutment portion 322b of the socket 32b and the end face of the insulated pipe 40b. This allows the packings to deform and absorb variations in the shapes of the end faces of the insulated pipes 40a, 40b, thereby improving the sealing performance.

[0134] In addition, if the pipe fitting 10B and the receiving members 30Ba, 30Bb are made of a crystalline resin that cannot be bonded with an adhesive, their joining surfaces can be fused together by butt welding or ultrasonic welding. In this case, the receiving side inner joining portions 332a, 332b, the receiving side outer joining portions 342a, 342b, the main body inner joining portions 212a, 212b, and the main body outer joining portions 222a, 222b can be made into flat joining surfaces.

[0135] When used in an air conditioning system, pipe fitting 10B can form a drain piping system, in which case drain water can flow through inlet-side flow paths 331a, 331b and main flow path 211ab while being insulated from the outside air by inlet-side insulating air layers 341a, 341b and main body insulating air layer 221ab, thereby effectively suppressing condensation around pipe fitting 10B.

[0136] Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and the present invention also includes modifications, combinations, deletions, etc. of the configurations within the scope of the gist of the present invention. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combinations. [Explanation of symbols]

[0137] 10, 10A, 10B pipe fittings 20, 20A, 20B fitting body 30a, 30b, 30Ba, 30Bb, 30c Receiver members 32a,32b,32c socket 40a, 40b, 40c Insulated piping 50 Piping System 211ab, 211Aac, 211Bab Main flow channel 221ab, 221c, 221Aac, 221Bab Main body insulating air layer 331a, 331b, 331c Inlet side channel 341a, 341b, 341c Inlet side insulating air layer 401a, 401b, 401c Pipe flow path

Claims

1. A pipe joint for connecting a plurality of insulated pipes, a plurality of receiving members, each having a receiving port into which one end of a thermally insulated pipe to be connected is inserted and joined, and a receiving port-side flow path communicating with an internal flow path in the thermally insulated pipe; a joint body to which the plurality of receiving members are joined and having a body flow path that connects the plurality of receiving-side flow paths, the receiving member has a receiving-port-side insulating air layer around the receiving-port-side flow path, The joint body is a pipe joint having a body insulating air layer around the body flow path.

2. The receiving member and the joint body are integrated by adhesive.

2. The pipe fitting according to claim 1.

3. The receiving member and the joint body are formed of a resin material that allows the receiving port side flow path and the main body flow path to be seen from the outside.

2. The pipe fitting according to claim 1.

4. A piping system comprising the pipe joint according to any one of claims 1 to 3 and a plurality of insulated pipes connected by the pipe joint.

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