Piping structure and airtightness test method for piping structure

Abstract

To provide a piping structure capable of easily performing an airtightness test.SOLUTION: A piping structure comprises: an inner pipe; an outer pipe arranged outside the inner pipe, and defining a flow path between itself and the inner pipe; a partition member that partitions the flow path into a first flow path and a second flow path; and a desorption member removably attached to the outer pipe. The desorption member has a communication path communicating between the first flow path and the second flow path.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a piping structure and a method for testing airtightness of the piping structure. [Background technology]

[0002] Patent Document 1 discloses a piping configuration for introducing gas fuel from a gas fuel tank to an engine. As an example of this piping configuration, a gas manifold is configured as a double pipe, and one end of the gas manifold is connected to another pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-188688 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the piping configuration of Patent Document 1, when performing an airtightness test on the gas manifold, it is necessary to remove other piping from one end of the gas manifold and connect an apparatus for airtightness testing to one end of the gas manifold.

[0005] An object of the present invention is to provide a piping structure that allows easy airtightness testing and a method for testing the airtightness of the piping structure. [Means for solving the problem]

[0006] One aspect of the present invention is An inner tube; an outer tube disposed outside the inner tube and defining a flow path between the outer tube and the inner tube; a partition member that divides the flow path into a first flow path and a second flow path; A detachable member removably attached to the outer tube; Equipped with The detachable member provides a piping structure having a communication passage that connects the first flow path and the second flow path.

[0007] According to this configuration, when the detachable member is attached to the outer pipe, the first flow path and the second flow path can be connected by the communication path. On the other hand, when the detachable member is removed from the outer pipe, the first flow path can be connected to a device used in an airtightness test, for example. Therefore, by removing the detachable member from the outer pipe, it is not necessary to remove other pipes from the piping structure, and the first flow path can be connected to a device used in an airtightness test. This makes it easy to perform an airtightness test. In other words, the connection destination of the first flow path can be changed by attaching and detaching the detachable member to and from the outer pipe.

[0008] In one embodiment, the outer tube has a first opening formed on the outer tube on the first flow path side and communicating with the first flow path, and one end of the communication passage is connected to the first opening.

[0009] According to this configuration, the first flow path and one end of the communication path are connected via the first opening. This allows the fluid in the first flow path blocked by the partition member to be guided to the communication path. On the other hand, the fluid guided from the second flow path blocked by the partition member to the communication path can be guided to the first flow path.

[0010] In one embodiment, the first opening is a hole penetrating a first attachment portion rising from the outer tube on the first flow path side.

[0011] According to this configuration, the detachable member is attached to the outer pipe via the first attachment part in order to connect one end of the communication passage to the hole penetrating the first attachment part. As a result, the first attachment part forms a part of the flow passage by the first opening and can support the detachable member attached to the outer pipe. Furthermore, when the detachable member is removed from the outer pipe and the first flow passage is connected to a device used for airtightness testing, for example, the first attachment part can be used as a connection base.

[0012] In one embodiment, the outer tube has a second opening formed on the outer tube on the second flow path side and communicating with the second flow path, and the other end of the communicating passage is connected to the second opening.

[0013] According to this configuration, the second flow path and the other end of the communication path are connected via the second opening. This allows the fluid guided from the first flow path blocked by the partition member to the communication path to be guided to the second flow path. On the other hand, the fluid in the second flow path blocked by the partition member can be guided to the communication path.

[0014] In one embodiment, the second opening is a hole penetrating a second attachment portion rising from the outer tube on the second flow path side.

[0015] According to this configuration, the detachable member is attached to the outer pipe via the second attachment part to connect the other end of the communication passage to the hole penetrating the second attachment part. As a result, the second attachment part forms a part of the passage by the second opening, and can support the detachable member attached to the outer pipe. Furthermore, in order to prevent foreign matter from entering the second passage opened by removing the detachable member from the outer pipe, the second attachment part can be used as a covering part to be covered with a cover.

[0016] In one embodiment, the communicating passage has a through hole formed at one end on the first flow path side connected to the first opening, and a through hole formed at the other end on the second flow path side connected to the second opening.

[0017] According to this configuration, the communication passage can be formed only by the through hole on the first flow path side, the through hole on the second flow path side, and the flow path connecting these two through holes. This simplifies the structure of the detachable member and increases the degree of freedom in design. Furthermore, when attaching the removed detachable member to the outer pipe, it can be easily attached by simply positioning the through hole on the first flow path side to the first opening and the through hole on the second flow path side to the second opening.

[0018] In one embodiment, the outer pipe has a first opening formed in the outer pipe on the first flow path side and communicating with the first flow path, and a second opening formed in the outer pipe on the second flow path side and communicating with the second flow path, one end of the communicating passage is connected to the first opening and the other end of the communicating passage is connected to the second opening, the first opening is a hole that penetrates a first mounting portion that rises from the outer pipe on the first flow path side, and the second opening is a hole that penetrates a second mounting portion that rises from the outer pipe on the second flow path side, and the detachable member is removably attached to the outer pipe via the first mounting portion and the second mounting portion.

[0019] According to this configuration, the detachable member is supported at two points relative to the outer pipe by the first attachment portion and the second attachment portion, so that the strength of the detachable member when attached to the outer pipe can be ensured.

[0020] In one embodiment, an external device is connected to the first opening in a state in which the detachable member is detached from the outer tube.

[0021] When the detachable member is attached to the outer pipe, the first flow path and the second flow path are connected via the communication passage. On the other hand, when the detachable member is removed from the outer pipe, the connection between the first flow path and the second flow path is released, and the first flow path is connected to an external device via the first opening. In this way, by attaching and detaching the detachable member to the outer pipe, the connection destination of the first flow path can be changed. Also, when the detachable member is removed from the outer pipe, the second flow path is released from the communication passage, so it can be used for any purpose.

[0022] In one embodiment, with the detachable member detached from the outer pipe, a device for performing an airtight test on the first flow path is connected to the first opening.

[0023] When the detachable member is attached to the outer pipe, the first flow path and the second flow path are connected via a communication passage. On the other hand, when the detachable member is removed from the outer pipe, the first flow path is connected to a device used in an airtightness test. Therefore, by removing the detachable member from the outer pipe, it is not necessary to remove other pipes from the piping structure, and the first flow path can be connected to the device used in the airtightness test. This makes it easy to perform an airtightness test. In this way, by attaching and detaching the detachable member to and from the outer pipe, the connection destination of the first flow path can be changed. Also, when the detachable member is removed from the outer pipe, the second flow path is disconnected from the communication passage, and therefore can be used for any purpose.

[0024] Another aspect of the present invention is A method for airtightness testing of a piping structure comprising: an inner pipe; an outer pipe disposed outside the inner pipe and defining a flow path between the inner pipe and the outer pipe; a partition member dividing the flow path into a first flow path and a second flow path; and a detachable member removably attached to the outer pipe, the detachable member having a communication path connecting the first flow path and the second flow path, After the detachable member is removed from the outer tube, supplying a gas to the first flow passage through a connection point between the first flow passage and the communication passage to apply a predetermined pressure to the first flow passage; A change in pressure in the first flow path is measured. The present invention provides an air tightness test method, comprising:

[0025] According to this method, by removing the detachable member from the outer pipe, it is possible to connect the first flow path to a device used in the airtightness test without having to remove other pipes from the piping structure. This makes it possible to easily perform the airtightness test. In other words, by attaching and detaching the detachable member to and from the outer pipe, it is possible to change the connection destination of the first flow path. Effect of the Invention

[0026] According to the present invention, it is possible to provide a piping structure that allows easy airtightness testing and a method for testing an airtightness of a piping structure. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic diagram of a piping structure according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a piping structure around the detachable member in FIG. [Diagram 3] FIG. 3 is a perspective view showing the piping structure in FIG. 2 in a cutaway state. [Figure 4] FIG. 4 is a vertical cross-sectional view of a piping structure around the detachable member in FIG. [Diagram 5] FIG. 5 is a schematic diagram of the piping structure of FIG. 1 during an airtight test. [Figure 6] FIG. 6 is a vertical cross-sectional view of the piping structure around the partition member during an airtightness test. [Figure 7] FIG. 7 is a schematic diagram of a piping structure according to a modified example of the above embodiment. [Figure 8] FIG. 8 is a schematic diagram of the piping structure of FIG. 7 during an airtightness test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, a piping structure and an airtightness test method for the piping structure according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0029] [Piping structure] FIG. 1 is a schematic diagram of a piping structure 1 according to one embodiment of the present invention.

[0030] Referring to FIG. 1, a piping structure 1 of this embodiment is a piping structure for supplying gas fuel to an engine 2.

[0031] The piping structure 1 is a double pipe. The piping structure 1 includes an inner pipe 10 and an outer pipe 20. In the following description, the direction in which the inner pipe 10 and the outer pipe 20 extend may be referred to as the axial direction. Also, the circumferential direction of a virtual circle centered on the axial direction may be simply referred to as the circumferential direction, and the radial direction of a virtual circle centered on the axial direction may be simply referred to as the radial direction.

[0032] The inner pipe 10 has a cylindrical shape. Gaseous fuel is supplied to the inner pipe 10 from a gaseous fuel supply source (not shown). The gaseous fuel supplied to the inner pipe 10 is supplied to the engine 2 via a plurality of branch pipes 10a communicating with the inner pipe 10.

[0033] The outer pipe 20 is a circular pipe having an inner diameter larger than the outer diameter of the inner pipe 10, and is disposed coaxially with the inner pipe 10. This defines a flow path 30 between the outer pipe 20 and the inner pipe 10. In the unlikely event that gaseous fuel leaks from the inner pipe 10, the gaseous fuel flows through the flow path 30 and is prevented from leaking out of the outer pipe 20. In addition, ventilation air flows through the flow path 30, and the gaseous fuel that leaks into the flow path 30 from inside the inner pipe 10 is carried by the ventilation air and discharged to the outside of the piping structure 1.

[0034] The piping structure 1 has a first end 1a and a second end 1b located on the opposite side to the first end 1a in the axial direction.

[0035] An air pipe 40 is disposed at a first end 1a of the piping structure 1. Air for ventilation is supplied to the air pipe 40 from an air supply source (not shown). The inside of the air pipe 40 communicates with a flow path 30 (more specifically, a first flow path 31 described later). The air supplied to the air pipe 40 and then to the flow path 30 flows through the flow path 30 and is discharged from a second end 1b of the piping structure 1 to the outside of the piping structure 1 (more specifically, a second external pipe 4 described later).

[0036] The first external pipe 3 is mechanically connected to the air pipe 40. The first external pipe 3 is removable from the air pipe 40. The first external pipe 3 fluidly connects an air supply source (not shown) and the air pipe 40. In this embodiment, the first external pipe 3 is a single pipe.

[0037] A second external pipe 4 is mechanically connected to the second end 1b of the piping structure 1. The second external pipe 4 is a double pipe. The gas fuel is supplied to the inner pipe of the second external pipe 4 from a gas fuel supply source (not shown). The gas fuel supplied to the inner pipe of the second external pipe 4 is supplied to the engine 2 via the inner pipe 10.

[0038] The piping structure 1 of this embodiment includes two expansion joints 50. The piping structure 1 has three sections each connected by each expansion joint 50. In other words, the piping structure 1 has three sections divided by two expansion joints 50. When the expansion joint 50 is removed from the piping structure 1 for maintenance or the like and then reinstalled, an airtightness test of the piping structure 1 needs to be performed.

[0039] The piping structure 1 includes a partition member 60 and a detachable member 70. Fig. 2 is a perspective view of the piping structure 1 around the detachable member 70. Fig. 3 is a perspective view showing a cutaway view of the piping structure 1 in Fig. 2. Fig. 4 is a vertical cross-sectional view of the piping structure 1 around the detachable member 70.

[0040] The partition member 60 divides the flow path 30 into a first flow path 31 and a second flow path 32. Specifically, the partition member 60 divides the flow path 30 into the first flow path 31 located on the first end 1a side with respect to the partition member 60, and the second flow path 32 located on the second end 1b side with respect to the partition member 60. The partition member 60 of this embodiment is disposed at a position closer to the second end 1b than to the first end 1a. In other words, the first flow path 31 is longer than the second flow path 32.

[0041] 2 to 4, the partition member 60 is ring-shaped and is disposed coaxially with the inner pipe 10. In addition, as shown in Figs. 3 and 4, the partition member 60 is disposed between the inner pipe 10 and the outer pipe 20.

[0042] The outer pipe 20 includes a first attachment portion 21 and a second attachment portion 22 to which the detachable member 70 is attached. The first attachment portion 21 and the second attachment portion 22 are provided so as to rise radially outward from the tubular main body of the outer pipe 20. The first attachment portion 21 and the second attachment portion 22 are arranged in the axial direction with the partition member 60 sandwiched therebetween. Specifically, the first attachment portion 21 is arranged on the first end portion 1a side of the partition member 60 in the axial direction, and the second attachment portion 22 is arranged on the second end portion 1b side of the partition member 60 in the axial direction.

[0043] The outer tube 20 includes a first opening 20a communicating with the first flow passage 31 and a second opening 20b communicating with the second flow passage 32. The first opening 20a and the second opening 20b are arranged with the partition member 60 in between in the axial direction. Specifically, the first opening 20a is arranged on the first end 1a side of the partition member 60 in the axial direction, and the second opening 20b is arranged on the second end 1b side of the partition member 60 in the axial direction. In other words, the first opening 20a is formed on the first flow passage 31 side of the partition member 60 in the axial direction, and the second opening 20b is formed on the second flow passage 32 side of the partition member 60 in the axial direction. The first opening 20a in this embodiment is a hole that radially penetrates the tubular main body and the first attachment portion 21 of the outer tube 20, and the second opening 20b in this embodiment is a hole that radially penetrates the tubular main body and the second attachment portion 22 of the outer tube 20.

[0044] The detachable member 70 has a substantially rectangular block shape. The detachable member 70 is removably attached to the outer pipe 20. The detachable member 70 is fastened to the first attachment portion 21 and the second attachment portion 22 with bolts 71. The detachable member 70 has a communication passage 72 that communicates between the first opening 20a and the second opening 20b. One end of the communication passage 72 is connected to the first opening 20a. The other end of the communication passage 72 is connected to the second opening 20b.

[0045] The communication passage 72 has two through holes 72a, 72b. The two through holes 72a, 72b include a through hole 72a on the first flow passage 31 side that is formed at one end of the communication passage 72 and connected to the first opening 20a, and a through hole 72b on the second flow passage 32 side that is formed at the other end of the communication passage 72 and connected to the second opening 20b. The communication passage 72 has the through hole 72a on the first flow passage 31 side, the through hole 72b on the second flow passage 32 side, and a portion that extends along the axial direction to connect the through hole 72a on the first flow passage 31 side to the through hole 72a on the first flow passage 31 side.

[0046] As shown in FIG. 4, a seal member 80 is disposed between the first mounting portion 21 and the detachable member 70. The seal member 80 in this embodiment is an O-ring. The seal member 80 is recessed from a seat surface 21a facing the detachable member 70 in the first mounting portion 21 and disposed in a housing portion 21b disposed so as to surround the first opening 20a. In this embodiment, the seat surface 21a of the first mounting portion 21 is flat. A female thread (not shown) used for attaching the detachable member 70 to the first mounting portion 21 is disposed on the seat surface 21a of the first mounting portion 21. The female thread fits with a male thread (not shown) of a bolt 71 (shown in FIG. 2) used for fastening the detachable member 70 to the first mounting portion 21.

[0047] A seal member 81 is disposed between the second mounting portion 22 and the detachable member 70. The seal member 81 is recessed from a seating surface 22a of the second mounting portion 22 that faces the detachable member 70, and is disposed in a storage portion 22b disposed so as to surround the second opening 20b. The seating surface 22a of the second mounting portion 22 is flat.

[0048] [Airtightness test method for piping structure] Hereinafter, a method for testing airtightness of the piping structure 1 according to the present embodiment will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a schematic diagram of the piping structure 1 during airtightness testing according to the present embodiment. Fig. 6 is a vertical cross-sectional view of the piping structure 1 around a partition member during airtightness testing.

[0049] First, as shown in FIG. 5, the detachable member 70 (shown in FIG. 1) is removed from the outer tube 20.

[0050] Next, a cock 90 for airtightness testing is attached to the first attachment part 21. A pressure gauge 91 is attached to the cock 90. ​​The cock 90 is fluidly connected to a gas supply source 5 for airtightness testing. Compressed air is supplied to the cock 90 from the gas supply source 5. The second attachment part 22 is protected with tape or the like to prevent foreign matter from entering the second flow path 32. In other words, the second opening 20b is covered with tape or the like. The gas supply source 5 according to this embodiment is an example of an external device according to the present invention, and is an example of a device for performing an airtightness test according to the present invention.

[0051] 6, the cock 90 is attached to the first attachment portion 21 via a closing flange 92. The cock 90 is fitted into an opening provided in the closing flange 92.

[0052] The closing flange 92 is fastened to the first mounting portion 21 by using a bolt (not shown). The female thread provided on the seat surface 21a for fastening the detachable member 70 to the first mounting portion 21 can also be used to fasten the closing flange 92 to the first mounting portion 21. That is, the closing flange 92 is fastened to the first mounting portion 21 by, for example, fastening a bolt (not shown) to the female thread provided on the seat surface 21a in a state where the closing flange 92 is placed on the seat surface 21a. In other words, the female thread provided on the first mounting portion 21 can be used both to attach the detachable member 70 and to attach the closing flange 92. In this embodiment, the detachable member 70 or the closing flange 92 is attached to the first mounting portion 21 by using a bolt. However, the detachable member 70 or the closing flange 92 may be attached to the first mounting portion 21 by using a method other than bolt fastening while maintaining the sealed state of the first flow path 31 and the first opening 20a.

[0053] Next, as shown in Fig. 5, the first external piping 3 (shown in Fig. 1) is removed from the air pipe 40. After that, a closing flange 93 is attached to the air pipe 40. As a result, the opening of the air pipe 40 is closed by the closing flange 93, and the first flow path 31 is sealed so that gas does not leak.

[0054] Next, gas is supplied to the first flow passage 31 through a connection point between the first flow passage 31 and the communication passage 72 (shown in FIG. 4), and a predetermined pressure is applied to the first flow passage 31. Specifically, compressed air is supplied to the first flow passage 31 through the first opening 20a, and thus a predetermined pressure is applied to the first flow passage 31.

[0055] Next, a change in pressure in the first flow path 31 is measured. Specifically, after the fluid connection between the cock 90 and the gas supply source 5 is cut off, the change in pressure in the first flow path 31 is measured by the pressure gauge 91. In this embodiment, the airtightness of the piping structure 1 is confirmed by measuring the pressure drop in the first flow path 31 for 10 minutes after the fluid connection between the cock 90 and the gas supply source 5 is cut off.

[0056] [effect] According to the piping structure 1 of the present embodiment, when the detachable member 70 is attached to the outer pipe 20, the first flow path 31 and the second flow path 32 can be connected by the communication passage 72. On the other hand, when the detachable member 70 is removed from the outer pipe 20, the first flow path 31 can be connected to, for example, an apparatus used in an airtightness test (in this embodiment, the gas supply source 5). Therefore, by removing the detachable member 70 from the outer pipe 20, it is not necessary to remove the second external pipe 4 from the piping structure 1, and the first flow path 31 can be connected to an apparatus used in an airtightness test. This makes it easy to perform an airtightness test. In other words, by attaching and detaching the detachable member 70 to and from the outer pipe 20, the connection destination of the first flow path 31 can be changed. In addition, by removing the detachable member 70 from the outer pipe 20, the connection between the second flow path 32 and the communication passage 72 is released, so that the second flow path 32 can be used for any purpose.

[0057] Furthermore, in this embodiment, the seat surface 21a of the first mounting portion 21 can be shared for mounting the detachable member 70 and for mounting the closing flange 92. As a result, the structure of the first mounting portion 21 can be simplified compared to a case in which the first mounting portion 21 is provided with a structure for mounting the detachable member 70 and a structure for mounting the closing flange 92 separately.

[0058] In this embodiment, the outer pipe 20 has a first opening 20a formed on the outer pipe 20 on the first flow path 31 side and communicating with the first flow path 31, and one end of the communication passage 72 is connected to the first opening 20a. According to this configuration, the first flow path 31 and one end of the communication passage 72 are connected via the first opening 20a. This makes it possible to guide the fluid in the first flow path 31 blocked by the partition member 60 to the communication passage 72. On the other hand, the fluid guided to the communication passage 72 from the second flow path 32 blocked by the partition member 60 can be guided to the first flow path 31.

[0059] In this embodiment, the first opening 20a is a hole penetrating the first attachment portion 21 rising from the outer pipe 20 on the first flow path 31 side. According to this configuration, the detachable member 70 is attached to the outer pipe 20 via the first attachment portion 21 in order to connect one end of the communication passage 72 to the hole penetrating the first attachment portion 21. As a result, the first attachment portion 21 forms a part of the flow path by the first opening portion 20a and can support the detachable member 70 attached to the outer pipe 20. Furthermore, when the detachable member 70 is removed from the outer pipe 20 and the first flow path 31 is connected to, for example, an apparatus used in an airtight test (in this embodiment, the gas supply source 5), the first attachment portion 21 can be used as a connection base.

[0060] In this embodiment, the outer pipe 20 has a second opening 20b formed on the outer pipe 20 on the second flow path 32 side and communicating with the second flow path 32, and the other end of the communication passage 72 is connected to the second opening 20b. According to this configuration, the second flow path 32 and the other end of the communication passage 72 are connected via the second opening 20b. This makes it possible to guide the fluid led from the first flow path 31 blocked by the partition member 60 to the communication passage 72 to the second flow path 32. On the other hand, the fluid in the second flow path 32 blocked by the partition member 60 can be guided to the communication passage 72.

[0061] In this embodiment, the second opening 20b is a hole penetrating the second attachment portion 22 rising from the outer pipe 20 on the second flow path 32 side. According to this configuration, in order to connect the other end of the communication passage 72 to the hole penetrating the second attachment portion 22, the detachable member 70 is attached to the outer pipe 20 via the second attachment portion 22. As a result, the second attachment portion 22 forms a part of the flow path by the second opening 20b, and can support the detachable member 70 attached to the outer pipe 20. Furthermore, in order to prevent foreign matter from entering the second flow path 32 opened by removing the detachable member 70 from the outer pipe 20, the second attachment portion 22 can be used as a covering portion to be covered with a cover (tape in this embodiment).

[0062] In this embodiment, the communication passage 72 has a through hole 72a on the first flow path 31 side formed at one end and connected to the first opening 20a, and a through hole 72b on the second flow path 32 side formed at the other end and connected to the second opening 20b. With this configuration, the communication passage 72 can be configured only by the through hole 72a on the first flow path 31 side, the through hole 72b on the second flow path 32 side, and a flow path connecting these two through holes 72a, 72b. This simplifies the structure of the detachable member 70 and increases the degree of freedom in design. In addition, when attaching the detachable member 70 to the outer tube 20, it can be easily attached by simply positioning the through hole on the first flow path 31 side to the first opening 20a and the through hole on the second flow path 32 side to the second opening 20b.

[0063] In this embodiment, the detachable member 70 is supported at two points relative to the outer pipe 20 by the first mounting portion 21 and the second mounting portion 22, thereby ensuring the strength of the detachable member 70 when attached to the outer pipe 20.

[0064] According to the airtightness test method for the piping structure 1 of the present embodiment, by removing the detachable member 70 from the outer pipe 20, it is not necessary to remove the second external pipe 4 from the piping structure 1, and the first flow path 31 can be connected to a device used in the airtightness test. This makes it possible to easily perform the airtightness test. In other words, by attaching and detaching the detachable member 70 to and from the outer pipe 20, the connection destination of the first flow path 31 can be changed.

[0065] Second embodiment Hereinafter, a piping structure 101 according to a second embodiment of the present invention and an airtightness test method for the piping structure 101 will be described with reference to Figs. 7 and 8. The piping structure 101 according to the second embodiment has substantially the same configuration as the piping structure 1 according to the first embodiment, except that it has a second partition member 160 and a second detachable member 170. In the second embodiment, the same or similar configurations as those in the first embodiment are denoted by the same reference symbols, and detailed descriptions thereof will be omitted. Fig. 7 is a schematic diagram of the piping structure 101 of this embodiment. Fig. 8 is a schematic diagram of the piping structure 101 of Fig. 7 during an airtightness test.

[0066] 7, the piping structure 101 has a second partition member 160 and a second detachable member 170. The second partition member 160 is disposed on the first end portion 1a side with respect to the partition member 60. The flow path 130 is partitioned in the axial direction by the partition member 60 and the second partition member 160 into a first flow path 131, a second flow path 132, and a third flow path 133. In this modification, the air pipe 40 communicates with the third flow path 133.

[0067] In this modification, the outer tube 120 includes a third attachment portion 123 and a fourth attachment portion 124. The third attachment portion 123 has the same configuration as the first attachment portion 21, and a detailed description thereof will be omitted. The fourth attachment portion 124 has the same configuration as the second attachment portion 22, and a detailed description thereof will be omitted.

[0068] The third attachment portion 123 and the fourth attachment portion 124 are arranged in the axial direction with the second partition member 160 sandwiched therebetween. Specifically, the third attachment portion 123 is arranged on the second end portion 101b side of the second partition member 160 in the axial direction, and the fourth attachment portion 124 is arranged on the first end portion 101a side of the second partition member 160 in the axial direction.

[0069] The outer tube 120 has a third opening 120c which is a hole that communicates with the first flow path 131 and radially penetrates the third mounting portion 123, and a fourth opening 120d which is a hole that communicates with the third flow path 133 and radially penetrates the fourth mounting portion 124.

[0070] The second detachable member 170 has the same configuration as the detachable member 70. The second detachable member 170 is attached to the third attachment portion 123 and the fourth attachment portion 124. The second detachable member 170 includes a second communication passage 172 that communicates between the third opening 120c and the fourth opening 120d.

[0071] 8, in the airtightness test method for the piping structure 101 of this embodiment, instead of removing the first external piping 3 from the air pipe 40, the second detachable member 170 (shown in FIG. 7) is removed from the outer pipe 120. Then, the closing flange 194 is attached to the third mounting part 123. As a result, the third opening 120c provided in the third mounting part 123 is closed by the closing flange 194, and the first flow path 131 is sealed so that gas does not leak. The fourth mounting part 124 is protected with tape or the like so that foreign matter does not enter the third flow path 133. In other words, the fourth opening 120d is covered with tape or the like.

[0072] The piping structure 101 according to the second embodiment provides the same effects as those of the piping structure 1 according to the first embodiment.

[0073] According to the piping structure 101 of this embodiment, in a state where the second detachable member 170 is attached to the outer pipe 120, the first flow path 131 and the third flow path 133 can be connected by the second communication passage 172. On the other hand, by removing the second detachable member 170 from the outer pipe 120 and closing the third opening 120c with the closing flange 194, the first flow path 131 is sealed so that gas does not leak from it. Therefore, by removing the second detachable member 170 from the outer pipe 120, it is not necessary to remove the first external pipe 3 from the piping structure 101, and the first flow path 131 can be sealed for an airtightness test. This makes it possible to easily perform an airtightness test.

[0074] Although the present invention has been fully described in connection with the preferred embodiments with reference to the accompanying drawings, various changes and modifications will be apparent to those skilled in the art, and such changes and modifications should be understood to be included within the scope of the present disclosure as defined by the appended claims unless they depart therefrom.

[0075] In the above embodiment, the piping structure 1 is a double pipe, but the piping structure according to the present invention is not limited to this and may be another piping structure including an inner pipe 10 and an outer pipe 20. The inner pipe and the outer pipe according to the present invention are not limited to a cylindrical shape and may be a tubular or tubular shape having a polygonal cross section.

[0076] In the above embodiment, the partition member 60 is ring-shaped and arranged coaxially with the inner pipe 10, but the partition member according to the present invention is not limited to this. The shape, material, arranged position, and posture of the partition member according to the present invention are not limited. The partition member according to the present invention may be another member that divides the flow path 30 into a first flow path 31 located on the first end 1a side with respect to the partition member and a second flow path 32 located on the second end 1b side with respect to the partition member.

[0077] In the above embodiment, the detachable member 70 is in the shape of a substantially rectangular parallelepiped block, but the detachable member according to the present invention is not limited to this and may have another shape. Also, in the above embodiment, the detachable member 70 is fastened to the first mounting portion 21 and the second mounting portion 22 by the bolts 71, but another mechanism for removably mounting the detachable member 70 to the outer pipe 20 may be adopted.

[0078] In the above embodiment, the communication passage 72 is formed by the two through holes 72a, 72b and the portion connecting them, but the communication passage according to the present invention is not limited to this and may be formed in other shapes.

[0079] In the above embodiment, an apparatus for performing an airtightness test has been described as an example of the external device according to the present invention, but the external device according to the present invention is not limited to this. The external device according to the present invention may be an apparatus for cleaning and purging a piping structure, an apparatus for supplying and exhausting air to and from an engine, or other apparatus.

[0080] In the above embodiment, O-rings are used as the seal members 80 and 81, but the present invention is not limited to this and, for example, paper packing or the like may be used. [Explanation of symbols]

[0081] 1 Piping structure 1a 1st end 1b Second end 2 Engine 3. First external piping 4. Second external piping 5 Gas supply source 10 Inner tube 10a Branch pipe 20 outer tube 20a 1st opening 20b 2nd opening 21 First mounting part 21a Seat 21b Storage section 22 Second mounting part 22b Storage section 30 Flow Path 31 First Channel 32 Second flow path 40 Air Pipe 50 Expansion joint 60 Partitioning material 70 Detachable parts 71 Volts 72 Communication path 80 Sealing material 81 Sealing material 90 Cook 91 Pressure Gauge 92 Blind flange 93 Blind flange 101 Piping structure 101a First end 101b Second end 120 Outer tube 120c 3rd opening 120d 4th opening 123 Third mounting part 124 4th mounting part 130 Flow Path 131 First Channel 132 Second Channel 133 Third Stream 160 Second partition member 170 Second detachable member 172 Second Passage

Claims

1. A piping structure having a first end to which a first external piping is removably connected, and a second end located axially opposite the first end to which a second external piping is removably connected, An inner tube; an outer tube disposed outside the inner tube and defining a flow path between the outer tube and the inner tube; a partition member that divides the flow path into a first flow path located on the first end side and a second flow path located on the second end side; a first attachment portion that rises radially outward from the outer pipe on the first flow path side of the partition member and has a first opening that communicates with the first flow path; a second attachment portion that rises radially outward from the outer pipe on the second flow path side of the partition member and has a second opening that communicates with the second flow path; a detachable member that is detachably attached to the first attachment portion and the second attachment portion and has a communication passage that connects the first flow path and the second flow path; a test device for performing an airtightness test on the first flow path, the test device being attached to the first mounting portion with the detachable member removed from the first mounting portion and the second mounting portion; Equipped with the first attachment portion has a seat surface to which the detachable member is attached, The piping structure, wherein the test device can be attached to the seat surface with the detachable member removed from the seat surface.

2. A piping structure as described in claim 1, wherein the testing device supplies gas to the first flow path through the first opening, applies a predetermined pressure to the first flow path, and measures the change in pressure in the first flow path.

3. The test device comprises: a closing flange that is removably attached to the first mounting portion when the detachable member is removed from the first mounting portion and the second mounting portion, and that closes the first opening when attached to the first mounting portion; a cock attached to the first attachment portion via the closing flange and fluidly connected to a gas supply source for airtightness testing; Equipped with The piping structure according to claim 1 , wherein the closing flange is attachable to the seating surface in a state where the detachable member is detached from the seating surface.

4. A threaded portion is formed on the seating surface, 4. The piping structure of claim 3, wherein the detachable member is fastened to the first mounting portion using the threaded portion while positioned on the seat surface, and the closing flange is fastened to the first mounting portion using the threaded portion while the detachable member is removed from the seat surface and the closing flange is positioned on the seat surface.

5. The first opening is disposed on the seat surface of the first mounting portion, a receiving portion is formed in the seat surface of the first attachment portion, the receiving portion being recessed from the seat surface and arranged to surround the first opening, 5. The piping structure according to claim 3, wherein an O-ring is disposed in the housing portion to seal between the seat surface and the detachable member and between the seat surface and the closure flange.

6. A second partition member is arranged on the first end side of the partition member and defines a third flow path separated from the first flow path on the first end side of the first flow path; a third attachment portion that rises radially outward from the outer pipe on the first flow path side with respect to the second partition member and has a third opening that communicates with the first flow path; a fourth attachment portion that rises radially outward from the outer pipe on the third flow path side with respect to the second partition member and has a fourth opening portion that communicates with the third flow path; a second detachable member that is detachably attached to the third attachment portion and the fourth attachment portion and has a communication passage that communicates the first flow path and the third flow path; a second closing flange that is removably attached to the third mounting portion in a state in which the second detachable member is removed from the third mounting portion and the fourth mounting portion, and that closes the third opening when attached to the third mounting portion; The piping structure according to claim 3 or 4, further comprising:

7. A piping structure as described in claim 1 or 2, comprising an expansion joint arranged between the first end and the second end and forming part of the first flow path.

8. A method for testing airtightness of a piping structure according to claim 1 or 2, comprising: Remove the detachable member from the outer tube; the test device is attached to the seat surface of the first attachment portion; removing the first external pipe from the first end; a connection point between the first end and the first external pipe is closed by a closing flange; supplying a gas to the first flow path through the first opening using the testing device to apply a predetermined pressure to the first flow path; A change in pressure in the first flow path is measured. An airtightness test method, including:

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