JP2014035233A - Pressure measuring device and leakage inspection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a leakage inspection device capable of suppressing influence of temperature change, and a pressure measuring device used for leakage inspection.SOLUTION: The leakage inspection device 100 includes a pressure measuring device 10 and a signal processor 80. The pressure measuring device 10 incorporates a pressure sensor 30 and a temperature sensor 40, and is connected to gas piping 90 so as to be capable of measuring pressure and temperature of a gas locked in the gas piping 90. The signal processor 80 obtains the measurement result of the pressure measuring device 10, corrects a change of pressure due to temperature change of the gas, and determines whether leakage exists in the gas piping 90 or not on the basis of the corrected pressure.

Description

  The present invention relates to a leak inspection apparatus for detecting a leak in a gas pipe and a pressure measurement apparatus used therefor.

  Conventionally, as this kind of leakage inspection device, the pressure when a predetermined inspection time (for example, 2 minutes) elapses when the pressure of the gas confined in the gas piping is measured by a pressure measuring device connected to the gas piping. It is known that the presence or absence of leakage in a gas pipe is determined from the amount of decrease in gas (for example, Patent Document 1).

JP 2001-255226 A (paragraphs [0003], [0004], FIGS. 6 and 7)

  However, in the conventional leakage inspection apparatus described above, the pressure also changes due to the temperature change of the gas during the pressure measurement, which affects the inspection.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a leakage inspection apparatus capable of suppressing the influence of temperature change and a pressure measurement apparatus used therefor.

  The pressure measuring device according to the invention of claim 1 made to achieve the above object is used for a leak test for detecting a leak in a gas pipe due to a pressure drop in the gas pipe, connected to the gas pipe, and the gas In a pressure measuring device that measures the pressure of gas confined in a pipe, it is characterized in that it is equipped with a temperature sensor for detecting the temperature of the gas and correcting the change in pressure accompanying the change in temperature of the gas. .

  The invention according to claim 2 is the pressure measuring device according to claim 1, wherein the pressure measuring device according to claim 1 is provided with an L-shaped communication chamber that is entirely L-shaped and has one end attached to the gas pipe and communicating with the inside of the gas pipe. A pressure sensor is provided at the other end of the L-shaped communication chamber so as to measure the pressure of the gas in the L-shaped communication chamber, and the temperature sensor has a rod shape and detects the temperature at its tip. The L-shaped communication room is characterized in that it penetrates through the wall facing the one-end opening communicating with the gas pipe in the L-shaped communication room toward the one-end opening, and the tip is disposed in the L-shaped communication room. .

  The invention of claim 3 is characterized in that, in the pressure measuring device according to claim 2, the tip of the temperature sensor is arranged at one end of the L-shaped communication room.

  According to a fourth aspect of the present invention, in the pressure measuring device according to the third aspect, a quick joint fitted to the gas pipe is provided at one end portion of the L-shaped communication chamber, and the gas pipe is formed at the center of the quick joint. A valve push rod for pushing and opening the valve body is provided, and the tip of the temperature sensor is characterized in that the tip of the temperature sensor is located slightly on the side of the valve push rod from the tip of the valve push rod.

  According to a fifth aspect of the present invention, there is provided a pressure measuring apparatus according to the fourth aspect, wherein a manifold having a quick joint, a pressure sensor and a temperature sensor and having an L-shaped communication chamber therein is formed of a heat insulating material from the outside. It is characterized by its covering.

  According to a sixth aspect of the present invention, in the pressure measuring device according to the fifth aspect, a cable group of a composite cable in which a plurality of cables are bundled with an insulating coating, and a cable group separately extending from the pressure sensor and the temperature sensor. It is characterized in that it is connected via a relay board provided in the case, and the composite cable is extended to the outside of the case so that it can be connected to a signal processing device for leakage inspection.

  According to a seventh aspect of the present invention, there is provided a leakage inspection apparatus that acquires the pressure measurement apparatus according to any one of the first to sixth aspects and the measurement result of the pressure measurement apparatus and accompanies a change in gas temperature. The present invention is characterized in that it includes a correction processing unit that corrects the amount of change in pressure and a leakage determination unit that determines whether there is a leak in the gas pipe based on the gas pressure corrected by the correction processing unit.

[Inventions of Claims 1 and 7]
According to the first and seventh aspects of the present invention, when the gas pipe is inspected for leaks, the temperature sensor measures the temperature of the gas confined in the gas pipe, so that the pressure change accompanying the gas temperature change can be measured. Therefore, the influence of the temperature change on the inspection can be suppressed. Moreover, since the pressure and temperature of the gas can be measured simply by connecting the pressure measuring device to the gas pipe, the workability of the inspection can be improved as compared with the case where the temperature sensor is attached to the gas pipe.

[Invention of claim 2]
According to the invention of claim 2, it is possible to use a bar-type temperature sensor. Moreover, the temperature sensor penetrates the wall facing the one end opening communicating with the gas pipe in the L-shaped communication room toward the one end, and the pressure sensor is provided at the other end of the L-shaped communication room. The bulkiness of the pressure measuring device in the direction of connection to the gas pipe can be reduced, and the workability when connecting the pressure measuring device to the gas pipe is improved.

[Invention of claim 3]
According to the invention of claim 3, since the temperature measured by the temperature sensor can be brought close to the temperature in the gas pipe, even if there is a temperature difference between the L-shaped communication room and the gas pipe, the gas pipe The pressure can be corrected based on the temperature inside.

[Invention of claim 4]
In the invention of claim 4, when the quick joint is fitted to the gas pipe, the valve push rod pushes open the valve body in the gas pipe, and the L-shaped communication chamber communicates with the inside of the gas pipe. Here, the tip of the temperature sensor is located slightly on the side of the valve push rod and more proximal than the tip of the valve push rod, so that the measured temperature of the temperature sensor is avoided while avoiding interference between the valve element and the temperature sensor. Can be brought close to the temperature in the gas pipe.

[Invention of claim 5]
In the invention of claim 5, since the manifold having the L-shaped communication chamber inside is held from the outside by holding the quick joint, the pressure sensor, and the temperature sensor, the worker can attach the manifold to the manifold. Direct contact is prevented. Thereby, the temperature difference between the L-shaped communication room and the gas pipe can be reduced, and the accuracy of the leakage inspection can be improved.

[Invention of claim 6]
In the invention of claim 6, there is provided a composite cable in which a group of cables extending separately from the pressure sensor and the temperature sensor are connected to a plurality of cables via a relay board in a case, and the plurality of cables are bundled with an insulating coating. Since it extends to the outside of the case and is connected to the signal processing device for leakage inspection, the cable can be easily routed during the leakage inspection, and workability can be improved.

The perspective view which looked at the pressure measuring device concerning one embodiment of the present invention from the upper part Front section of pressure measuring device Enlarged view around the manifold in Figure 2 Partially broken perspective view of pressure measuring device Enlarged view around the sensor mounting hole in FIG. Side view of pressure sensor and temperature sensor connected to relay board Front view of rear case component Sectional view conceptually showing the pressure measuring device in use (A) Front sectional view of the plug before the quick coupling is connected, (B) Front sectional view of the plug with the quick coupling connected Block diagram of leak test equipment

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the pressure measuring device 10 according to the present embodiment includes an L-shaped measuring body 11 having straight portions extending in the vertical direction and the horizontal direction, and is arranged on one end side in the horizontal direction of the measuring body 11. On the front side, a gas introduction part 13 for introducing a gas for inspection (hereinafter simply referred to as “gas”) into the measurement body 11 is provided. The gas introduction unit 13 includes a gas introduction port 13A connected to a pump (not shown) and a cock 13B for opening and closing the gas introduction port 13A.

  A quick joint 20 that can be fitted to a plug 91 provided at the end of the gas pipe 90 is provided on the upper end of the measurement body 11 in the lateral direction (see FIG. 9B). The quick joint 20 is provided with a valve push rod 21 that is fixed to the inner surface 20M and extends along the central axis of the quick joint 20, and is provided in the plug 91 when the quick joint 20 is fitted to the plug 91. The check valve 92 (see FIG. 9A) is opened.

  Specifically, as shown in FIG. 9A, the check valve 92 is normally closed by a valve body 93 urged toward the distal end side of the plug 91 by a compression coil spring 94 against the valve seat 95. It is in a state. 9B, when the quick coupling 20 is fitted to the plug 91, the valve push rod 21 pushes the valve body 93 toward the proximal end side of the plug 91 (the upper side in FIG. 9B). The check valve 92 is opened after being separated from the valve seat 95.

  As shown in FIG. 2, the measurement body 11 includes a pressure sensor 30. The pressure sensor 30 has a cylindrical shape with one end, measures the pressure of the gas introduced from the introduction port 33 with the pressure-sensitive member 31, and outputs the measurement result with the cable group 32 (see FIG. 6). It is like that. In the drawings other than FIGS. 6 and 10, the cable group 32 is omitted.

  As shown in FIG. 2, the pressure sensor 30 and the quick coupling 20 are held by a block-like manifold 23. Specifically, the quick joint 20 is fixed to the upper portion of the manifold 23, and the pressure sensor 30 is fixed to the side portion of the manifold 23.

  As shown in FIG. 3, the manifold 23 communicates with the inside of the quick joint 20 and extends in the axial direction of the quick joint 20, and with the inlet 33 of the pressure sensor 30. A second communication hole 24B extending in a direction orthogonal to the central axis 20 (lateral direction in FIG. 3) is provided. The first communication hole 24 </ b> A and the second communication hole 24 </ b> B communicate with each other at the center of the manifold 23, whereby the internal space of the pressure sensor 30 communicates with the space inside the quick coupling 20. The L-shaped communication chamber 14 is formed by the space inside the quick joint 20, the internal space of the pressure sensor 30, and the first communication hole 24 </ b> A and the second communication hole 24 </ b> B of the manifold 23. The connecting portion between the quick joint 20 and the manifold 23 and the connecting portion between the manifold 23 and the pressure sensor 30 are sealed with a seal member 25.

  Further, the above-described gas introduction portion 13 (see FIG. 1) is attached to the front end portion of the manifold 23 so that gas can be injected into the L-shaped communication chamber 14. Specifically, the manifold 23 is provided with a third communication hole (not shown) that extends forward from the L-shaped communication chamber 14 and opens on the front surface of the manifold 23, and the third communication hole is formed inside the gas introduction unit 13. I'm in touch.

  As shown in FIG. 3, the manifold 23 is provided with a sensor insertion hole 26 opened on the surface opposite to the quick joint 20, and a temperature sensor 40 is attached to the sensor insertion hole 26. The sensor insertion hole 26 extends in parallel with the first communication hole 24A and communicates with the L-shaped communication chamber 14. As shown in FIG. 4, the center axis of the sensor insertion hole 26 is disposed at a position shifted obliquely forward with respect to the center axis of the first connection hole 24 </ b> A (the center axis of the quick coupling 20). It penetrates through the hole 24A.

  As shown in FIG. 4, the temperature sensor 40 includes a temperature-sensitive member 41 that has a rod shape and can detect the temperature at the distal end portion, and a shaft support portion 42 that supports the temperature-sensitive member 41 from the proximal end side. The measurement result by the temperature sensitive member 41 can be output by the cable group 43 (see FIG. 6). In the drawings other than FIGS. 6 and 10, the cable group 43 is omitted.

  Specifically, the temperature sensor 40 is fixed to the manifold 23 as follows. That is, the temperature-sensitive member 41 is inserted from the outside of the manifold 23 into the sensor insertion hole 26 to enter the L-shaped communication chamber 14, and the shaft support portion 42 is fitted into the sensor insertion hole 26. And the temperature sensor 40 is being fixed to the manifold 23 by screwing the bracket 44 to the manifold 23 from the outer side of the shaft support part 42 (refer FIG. 5). The shaft support portion 42 and the sensor mounting hole 26 are sealed with the seal member 25.

  As shown in FIG. 4, the temperature sensing member 41 of the temperature sensor 40 is disposed on the center axis of the sensor mounting hole 26, passes through the first communication hole 24 </ b> A of the manifold 23, and is inserted into the quick coupling 20. Yes. And the front-end | tip of the temperature sensing member 41 is arrange | positioned at the upper end part of the quick coupling 20, ie, the edge part by the side connected to the gas piping 90. FIG. Thereby, when the quick joint 20 is connected to the gas pipe 90, the temperature measured by the temperature sensor 40 can be brought close to the temperature inside the gas pipe 90. More specifically, the tip of the temperature sensing member 41 is disposed below the tip of the valve push rod 21 of the quick joint 20, so that when the quick joint 20 is fitted to the plug 91 of the gas pipe 90, the temperature sensing is performed. Interference between the member 41 and the valve body 93 in the plug 91 can be avoided (see FIG. 9B). The upper end opening of the quick coupling 20 corresponds to the “one end opening” of the present invention, and the wall portion of the manifold 23 in which the sensor mounting hole 26 is formed corresponds to the “wall portion facing the one end opening” of the present invention. To do.

  As shown in FIGS. 2 and 4, the pressure sensor 30, the manifold 23, and the temperature sensor 40 are covered with a rubber case 15. The case 15 is configured by joining and combining the rear case structural body 15A and the front case structural body 15B.

  Here, the manifold 23 is made of metal. For example, when an operator touches the manifold 23, the temperature in the L-shaped communication room 14 is easily changed by the body temperature of the operator. However, in this embodiment, since the manifold 23 is accommodated in the case 15, an operator can be prevented from directly touching the manifold 23. In addition, since the case 15 is made of rubber, heat is hardly transmitted to the manifold 23 even when the operator touches the case 15. In the present embodiment, the quick joint 20 is made of synthetic resin, and even if the operator touches the quick joint 20, the temperature inside the quick joint 20 is difficult to change. Thereby, it is not necessary to cover the quick joint 20 with the case 15.

  As shown in FIGS. 2 and 6, a relay substrate 53 connected to a cable group 32 extending from the pressure sensor 30 and a cable group 43 extending from the temperature sensor 40 is provided inside the case 15. A composite cable in which a first cable group 51 connected to the pressure sensor 30 via the relay board 53 and a second cable group 52 connected to the temperature sensor 40 via the relay board 53 are combined with an insulating coating. 50 extends outside the case 15.

  As shown in FIG. 8, the composite cable 50 is connected to a signal processing device 80 that is separate from the pressure measurement device 10 during a leak test, and the measurement results of the pressure sensor 30 and the temperature sensor 40 are connected to the relay substrate 53, The signal is transmitted to the signal processing device 80 via the cable 50. Thus, in this embodiment, since the cable group connected to the signal processing device 80 is grouped, the cable can be easily routed at the time of inspection, and workability can be improved.

  As shown in FIG. 7, a relay board receiving groove 54 for receiving and positioning the relay board 53 is provided on the inner surface of the rear case structure 15A, and the cable group 43 of the temperature sensor 40 is provided. A guide groove 55 for receiving and guiding to the relay substrate 53 is formed. According to this configuration, the cable group 43 and the relay substrate 53 of the temperature sensor 40 can be accommodated in the case 15 in a compact manner. As a result, the case 15 can be reduced in size.

  Further, a retaining ring 57 (see FIG. 2) is attached to the end of the composite cable 50 on the relay board 53 side, and the retaining ring 57 is formed in the ring receiving groove formed in the front and rear case components 15A and 15B. The composite cable 50 is fixed to the case 15 by being received by 56 (in FIG. 7, only the ring receiving groove 56 of the rear case structure 15A is shown).

  As shown in FIG. 10, the signal processing device 80 acquires the measurement results of the pressure sensor 30 and the temperature sensor 40 and corrects the change in pressure due to the temperature change of the gas, and the correction processing unit 81. And a leakage determination unit 82 for determining whether or not the gas pipe 90 has leaked based on the gas pressure corrected by the above. That is, the pressure measuring device 10 and the signal processing device 80 constitute a leakage inspection device 100 of the present invention.

  The leak determination unit 82 indicates that there is a leak in the gas pipe 90 when the amount of decrease in the gas pressure when a predetermined inspection time (for example, 2 minutes) has passed since the start of the inspection is greater than or equal to a predetermined reference value. It is determined, and it is determined that there is no leakage when the amount of decrease in gas pressure is smaller than the reference value. Here, for the determination by the leakage determination unit 82, the gas pressure measured by the pressure sensor 30 is corrected by the correction processing unit 81.

  The correction processing unit 81 corrects the change in the gas pressure due to the temperature change using the measurement result of the temperature sensor 40 when the gas temperature changes while a predetermined inspection time has elapsed from the start of the inspection. This correction is performed by, for example, converting the gas pressure measured by the pressure sensor 30 when a predetermined inspection time has elapsed from the start of the inspection into the pressure at the gas temperature at the start of the inspection using Boyle-Charles' law. Is done. The correction processing unit 81 may convert the gas pressure measured by the pressure measuring device 10 into a pressure at a predetermined reference temperature.

  The description regarding the structure of the pressure measuring apparatus 10 and the leak test | inspection apparatus 100 is above. Next, the leakage inspection of the gas pipe 90 using the leakage inspection apparatus 100 will be described. In order to detect leakage of the gas pipe 90, first, the composite cable 50 of the pressure measuring device 10 is connected to the signal processing device 80, and the quick joint 20 is fitted to the plug 91 of the gas pipe 90. Then, the L-shaped communication chamber 14 in the measurement body 11 communicates with the inside of the gas pipe 90.

  Next, gas is introduced into the inside of the gas pipe 90 and the L-shaped communication room 14, and the gas is sealed in the inside of the gas pipe 90 and the L-shaped communication room 14. Here, as the gas, for example, city gas flowing through the gas pipe 90 can be used, or air can be used. When the gas flowing through the gas pipe 90 is used, after opening the main plug of the gas pipe 90 and introducing the gas into the L-shaped communication chamber 14, the cock 13B of the gas introduction unit 13 and the main plug of the gas pipe 90 may be closed. . When air is used, a pump (not shown) is connected to the gas inlet 13A of the gas inlet 13 with the main plug of the gas pipe 90 closed, and the cock 13B is opened to allow air to enter the L-shaped communication chamber 14. After the introduction, the cock 13B may be closed.

  When the gas is sealed in the inside of the gas pipe 90 and the L-shaped communication room 14, the leak inspection is started. That is, the pressure measuring device 10 measures the pressure and temperature of the gas at the start of the inspection and when a predetermined inspection time (for example, 2 minutes) has elapsed from the start of the inspection. Then, the presence or absence of leakage in the gas pipe 90 is determined.

  Here, when the gas temperature changes during the inspection, the correction processing unit 81 of the signal processing device 80 corrects the change in the gas pressure due to the temperature change using the measurement result of the temperature sensor 40. Then, the leakage determination unit 82 compares the gas pressure at the start of the inspection with the corrected pressure, and determines that there is a leak in the gas pipe 90 when the gas pressure drop is equal to or greater than the reference value. To do.

  As described above, according to the pressure measuring device 10 and the leakage inspection device 100 of the present embodiment, the temperature sensor 40 measures the gas temperature during the leakage inspection of the gas pipe 90, thereby accompanying the temperature change of the gas. Since the change in the gas pressure can be corrected, the influence of the temperature change on the inspection can be suppressed. Moreover, since the pressure and temperature of the gas can be measured simply by connecting the pressure measuring device 10 to the gas pipe 90, the workability of the leak inspection is improved compared with the case where the temperature sensor is attached to the gas pipe. Figured.

  Moreover, in this embodiment, the temperature sensor 40 measures the temperature which the temperature sensor 40 measures by arrange | positioning the front-end | tip part of the rod-shaped temperature sensor 40 in the edge part by the side of the connection part with the gas piping 90 among the quick couplings 20. The temperature of the gas inside can be approached. As a result, for example, when the operator touches the pressure measuring device 10 or is affected by the outside air temperature around the pressure measuring device 10, a temperature difference occurs in the L-shaped communication chamber 14 and the gas pipe 90. However, it is possible to prevent the pressure from being corrected under the influence of the temperature difference. Furthermore, since the manifold 23 is covered with the rubber case 15, the operator can be prevented from touching the manifold 23 directly. Thereby, the temperature difference between the L-shaped communication room 14 and the gas pipe 90 can be reduced, and the accuracy of the leakage inspection can be improved.

[Other Embodiments]
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.

  (1) In the above embodiment, the leakage inspection device 100 is configured by providing the correction processing unit 81 and the leakage determination unit 82 in the signal processing device 80 that is separate from the pressure measurement device 10, but the correction processing unit 81 and A leakage inspection device may be configured by providing the leakage determination unit 82 integrally with the pressure measurement device 10.

  (2) In the above embodiment, the guide groove 55 for guiding the cable group 43 of the temperature sensor 40 to the relay board 53 is formed in the rear case structure 15A. A guide groove for guiding to the relay board 53 may be formed, or a guide groove for guiding both the cable groups 32 and 43 to the relay board 53 may be formed.

  (3) A cable group formed by bundling the cable group 32 extending from the pressure sensor 30 and the cable group 43 extending from the temperature sensor 40 without connecting the relay board 53 can be connected to the signal processing device 80. It may be a simple configuration.

  (4) The case 15 is not limited to rubber, and may be made of foamed resin, for example, as long as it is made of a heat insulating material.

  (5) The connection portion with the gas pipe 90 may be a metal joint. In this case, if the case 15 is configured to cover the outside of the joint, the operator can be prevented from directly touching the joint, and the temperature difference between the L-shaped communication chamber 14 and the gas pipe 90 is reduced. be able to.

  (6) In the above embodiment, the connecting portion of the pressure measuring device 10 to the gas pipe 90 is the quick joint 20 that can be connected to the plug 91, but it is a hose that can be connected to a plug that does not include the check valve 92. There may be.

  (7) In the above-described embodiment, the L-shaped communication chamber 14 is formed along the shape of the measurement body 11 inside the L-shaped measurement body 11. For example, an L-shape is formed inside the rectangular parallelepiped measurement body. The structure in which the communication room 14 was formed may be sufficient.

  (8) The space that can communicate with the gas pipe 90 in the measurement body 11 only needs to include an L-shaped portion, and may be, for example, a T-shape or a cross shape.

  (9) In the above embodiment, the manifold 23 and the pressure sensor 30 are arranged side by side in the direction orthogonal to the central axis of the quick joint 20, but may be arranged side by side in the central axis direction of the quick joint 20. In addition, according to the said embodiment, the bulkiness of the pressure measuring device 10 in the connection direction to the gas piping 90 can be made small, and the workability | operativity at the time of connecting the pressure measuring device 10 to the gas piping 90 is improved. It is done.

  (10) In the above embodiment, the signal processing device 80 is configured to include the correction processing unit 81 and the leakage determination unit 82. However, if the signal processing device 80 is connected to the composite cable 50, the correction processing unit 81 and the leakage are provided. The configuration is not limited to the configuration provided with the determination unit 82, and for example, a monitor for displaying the gas pressure and temperature to the operator and a memory for storage may be provided. In this case, the correction processing unit 81 and the leakage determination unit 82 may be provided integrally with the pressure measurement device 10.

DESCRIPTION OF SYMBOLS 10 Pressure measuring device 14 L-shaped communication room 15 Case 20 Quick joint 21 Valve push rod 23 Manifold 30 Pressure sensor 40 Temperature sensor 50 Composite cable 53 Relay board 80 Signal processing device 81 Correction processing part 82 Leak determination part 90 Gas piping 93 Valve body 100 Leak inspection device

Claims (7)

In a pressure measuring device that is used for leak inspection to detect a leak in the gas pipe due to a pressure drop in the gas pipe and is connected to the gas pipe and measures the pressure of the gas confined in the gas pipe,
A pressure measuring apparatus comprising a temperature sensor for measuring a temperature of the gas and correcting a change in pressure caused by a change in temperature of the gas. The whole is L-shaped, and one end is attached to the gas pipe and includes an L-shaped communication chamber that communicates with the gas pipe, and a pressure sensor is provided at the other end of the L-shaped communication chamber. Configured to measure the pressure of the gas in the communication room,
The temperature sensor has a rod shape and is configured to detect a temperature at a tip portion thereof, and a wall portion facing one end opening communicating with the gas pipe in the L-shaped communication chamber is directed toward the one end opening side. The pressure measuring device according to claim 1, wherein the tip portion is disposed in the L-shaped communication chamber.   The pressure measuring device according to claim 2, wherein a tip portion of the temperature sensor is arranged at one end of the L-shaped communication room. A quick joint fitted to the gas pipe is provided at one end of the L-shaped communication chamber, and a valve push rod for pushing and opening the valve body in the gas pipe is provided at the center of the quick joint.
The pressure measuring device according to claim 3, wherein a distal end portion of the temperature sensor is disposed on a side of the valve push rod slightly closer to a proximal end side than the distal end of the valve push rod.   5. The manifold holding the quick joint, the pressure sensor and the temperature sensor and having the L-shaped communication chamber therein is covered from the outside with a case made of a heat insulating material. Pressure measuring device.   A cable group of a composite cable in which a plurality of cables are grouped with an insulation coating, and a cable group separately extended from the pressure sensor and the temperature sensor in the case are connected via a relay board provided in the case. The pressure measuring device according to claim 5, wherein the composite cable is extended to the outside of the case and can be connected to a signal processing device for leak inspection. A pressure measuring device according to any one of claims 1 to 6;
A correction processing unit that acquires a measurement result of the pressure measuring device and corrects a change in pressure due to a temperature change of the gas;
A leakage inspection apparatus comprising: a leakage determination unit configured to determine whether or not the gas pipe has leaked based on the pressure of the gas corrected by the correction processing unit.

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