Partial pressure test jig and partial pressure test method

Abstract

To efficiently perform a pressure test on a welding part between an additional member and a casing.SOLUTION: A partial pressure test jig comprises a supply pipe capable of supplying liquid, a discharge pipe capable of discharging the liquid, a supply valve capable of adjusting a supply rate of the liquid, a discharge valve capable of adjusting a discharge rate of the liquid, an insertion pipe capable of being inserted into a through hole and a casing hole, an attachable / detachable holding part attachably / detachably fixed to an additional member while the through hole is closed, a closing part for closing the casing hole at a tip of the insertion pipe, a seal part for sealing a gap between the closing part and the casing hole, and a pressure measurement part capable of measuring an internal pressure. The insertion pipe is formed in such a manner that its diameter is smaller than that of the through hole, and comprises a supply hole opened in the through hole, and capable of communicating with a space between the through hole and the insertion pipe.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a partial pressure resistance test jig and a partial pressure resistance test method. [Background technology]

[0002] Compressors are known as devices for compressing gas to generate high-pressure gas. A compressor comprises a rotor that rotates around an axis, an impeller attached to the outer periphery of the rotor, and a casing that forms a flow path by surrounding the rotor and impeller from the outer periphery. The gas flowing through the flow path is compressed as the impeller rotates integrally with the rotor. The compressed gas is in a state where its temperature and pressure are higher than before compression.

[0003] Depending on the type of gas being circulated, compounds contained in the gas may polymerize inside the compressor as the gas temperature rises, forming polymers known as fouling. If such fouling adheres to the walls that form the flow paths, it can lead to a decrease in compressor efficiency. Furthermore, if fouling adheres to the rotor, it can lead to vibrations caused by rotor imbalance.

[0004] As a technique for removing fouling in a compressor, for example, Patent Document 1 describes a cleaning liquid injection device that inserts a nozzle into a flow path in a casing and supplies a cleaning liquid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-177905 Summary of the Invention [Problem to be solved by the invention]

[0006] When cleaning with such a cleaning device, the nozzle is inserted into the casing through a cylindrical pipe with a flange fixed near the middle of the casing. Such a pipe may be added to an already constructed casing after the fact. In this case, the cylindrical pipe is fixed to the outer surface of the casing by welding.

[0007] In pressure vessels such as compressor casings, pressure tests must be performed on the welds connecting additional components such as connecting pipes to the existing casing. However, when the additional components are small compared to a large casing such as a compressor, performing a pressure test on the entire casing, including the casing, is extremely wasteful in terms of cost and work. Therefore, it is desirable to efficiently perform pressure tests on the welds connecting the additional components to the casing.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a partial pressure test jig and a partial pressure test method that can efficiently perform a pressure test on the weld between the additional member and the casing. [Means for solving the problem]

[0009] In order to solve the above problems, the partial pressure test jig according to the present disclosure is a partial pressure test jig used when supplying liquid to a cylindrical additional member fixed to a casing of a rotary machine by a welded portion in a state in which a through hole inside the additional member is in communication with a casing hole formed in the casing, thereby conducting a partial pressure test on the welded portion, and includes a supply pipe capable of supplying liquid toward the through hole, a discharge pipe capable of discharging the liquid from the through hole, a supply valve disposed on the supply pipe and capable of adjusting the amount of liquid supplied from the supply pipe to the through hole, and a discharge valve disposed on the discharge pipe and capable of adjusting the amount of liquid discharged from the through hole to the discharge pipe, The device comprises an insertion tube connected to the supply pipe and the discharge pipe and insertable into the through hole and the casing hole, a detachable holding section that is detachably fixed to the additional member while blocking the through hole and is capable of holding the insertion tube to the additional member, a blocking section that is arranged at the tip of the insertion tube and blocks the casing hole, a sealing section that is arranged at the blocking section and seals between the blocking section and the casing hole, and a pressure measuring section that can measure the pressure inside the supply pipe, the discharge pipe or the insertion tube, wherein the insertion tube is formed with a smaller diameter than the through hole, has a supply hole that opens within the through hole and is capable of communicating with the space between the through hole and the insertion tube.

[0010] Furthermore, the partial pressure test method according to the present disclosure is a partial pressure test method using the partial pressure test jig, and includes the steps of fixing the detachable holding portion to the additional member and attaching the partial pressure test jig to the additional member; opening the supply valve and the discharge valve to supply the liquid from the supply pipe; closing the discharge valve after the through hole is filled with the liquid; determining whether the pressure measured by the pressure measurement unit after closing the discharge valve exceeds a predetermined test pressure; closing the supply valve when it is determined that the pressure measured by the pressure measurement unit exceeds the test pressure; performing a water pressure test on the welded portion after closing the supply valve; and opening the supply valve and the discharge valve after performing the water pressure test. [Effects of the Invention]

[0011] According to the partial pressure test jig and partial pressure test method disclosed herein, a pressure test can be efficiently performed on the welded portion between the additional member and the casing. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing a compressor that is a target of a pressure resistance test according to an embodiment of the present invention; [Figure 2] FIG. 2 is an enlarged view of a main portion showing an intermediate flange according to the embodiment. [Figure 3] FIG. 2 is a flowchart showing a partial withstand voltage test method according to the present embodiment. [Figure 4] FIG. 2 is a schematic diagram showing a partial pressure resistance test jig according to the present embodiment. [Figure 5] FIG. 2 is a schematic diagram showing a state in which the partial pressure resistance test jig according to the present embodiment is attached to an intermediate flange. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments for carrying out a partial pressure test jig and a partial pressure test method according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to these embodiments.

[0014] (Configuration of rotating machines) As shown in FIG. 1, in this embodiment, the rotary machine to which the additional member that is the subject of the partial pressure test method S1 (see FIG. 3) is fixed is, for example, a centrifugal compressor 1. The centrifugal compressor 1 is capable of compressing a supplied gas. The centrifugal compressor 1 is capable of compressing, for example, a gas containing an organic chemical substance such as ethylene or propylene, or air as a working fluid. The centrifugal compressor 1 is a single-shaft multi-stage centrifugal compressor having a plurality of impellers (not shown). The centrifugal compressor 1 includes a casing 2 that houses a rotor 25 having an impeller therein, and an intermediate flange 3.

[0015] The casing 2 has a flow path formed therein where gas is compressed. The casing 2 is the outer shell of the centrifugal compressor 1 and is a compression vessel. As shown in FIG. 2, the casing 2 has a casing hole 21 formed therein that communicates with the internal flow path. The casing hole 21 communicates between the outside of the casing 2 and the internal flow path. The casing hole 21 extends straight in the vertical direction Dv.

[0016] The intermediate flange 3 is an additional component that is manufactured in a separate process from the casing 2 and subsequently fixed to the casing 2. A plurality of intermediate flanges 3 are provided for each casing 2 (see FIG. 1). The intermediate flange 3 is used as a supply port for supplying oil (cleaning oil) and water (cleaning water, or cooling water) to the flow passages inside the casing 2 during operation, for example, when cleaning the flow passages. A borescope (not shown) or an injection device (not shown) may be detachably attached to the intermediate flange 3. The intermediate flange 3 is formed in a cylindrical shape. As shown in FIG. 2, the intermediate flange 3 has a through hole 31 formed therein. The through hole 31 is formed to have the same diameter as the casing hole 21. The intermediate flange 3 of this embodiment has a cylindrical tube main body 35 and an annular flange portion 36 located at the upper end of the tube main body 35.

[0017] The intermediate flange 3 is fixed to the casing 2 by welding. The intermediate flange 3 is fixed to the casing 2 by a weld 4 with the internal through-hole 31 communicating with the casing hole 21. The lower end of the intermediate flange 3 in the vertical direction Dv is welded to the outer peripheral surface of the casing 2.

[0018] (Configuration of partial pressure resistance test method) The partial pressure test method S1 (see Figure 3) is a method in which a liquid is supplied to the intermediate flange (additional member) 3 to check whether the pressure resistance state of the welded portion 4 meets the standard. The partial pressure test method S1 is performed on the intermediate flange 3 and the welded portion 4, but is not performed on the entire casing 2. In the partial pressure test method S1, water (liquid) is filled while air is removed from the through hole 31 and the casing hole 21, and the pressure is increased to a predetermined pressure, which is left as is for a certain period of time to check that the pressure does not drop. In this way, the partial pressure test method S1 checks for water leakage and durability from the inside of the intermediate flange 3 and the welded portion 4. The partial pressure test method S1 is performed using a partial pressure test jig 7.

[0019] (Partial pressure test fixture) Here, the partial pressure test jig 7 will be described in detail. The partial pressure test jig 7 is used when conducting a partial pressure test. The partial pressure test jig 7 is capable of evacuating air from the interior of the intermediate flange 3 and supplying water thereto while the intermediate flange 3 is sealed. As shown in FIGS. 4 and 5 , the partial pressure test jig 7 of this embodiment includes a supply pipe 71, a discharge pipe 72, a supply valve 73, a discharge valve 74, an insertion pipe 75, a detachable holding portion 76, a blocking portion 77, a sealing portion 78, and a pressure measurement portion 79. In the partial pressure test jig 7, all of the components, including the supply pipe 71, the discharge pipe 72, the supply valve 73, the discharge valve 74, the insertion pipe 75, the detachable holding portion 76, the blocking portion 77, the sealing portion 78, and the pressure measurement portion 79, are integrally formed and configured as a single movable device.

[0020] The supply pipe 71 is capable of supplying water toward the through-hole 31. The supply pipe 71 is a pipe connected to a pump (not shown). The supply pipe 71 is disposed outside the intermediate flange 3.

[0021] The discharge pipe 72 is capable of discharging water from the through hole 31. The discharge pipe 72 is also capable of discharging air from the through hole 31. The discharge pipe 72 is a pipe connected to the outside of the partial pressure test jig 7 (the outside of the centrifugal compressor 1). The discharge pipe 72 is a pipe with the same diameter as the supply pipe 71. The discharge pipe 72 is arranged outside the intermediate flange 3.

[0022] The supply valve 73 is capable of adjusting the amount of water supplied from the supply pipe 71 to the through-hole 31. The supply valve 73 is disposed in the supply pipe 71. When the supply valve 73 is switched to an open state, the supply pipe 71 is able to supply water toward the through-hole 31. When the supply valve 73 is switched to a closed state, the supply pipe 71 is unable to supply water to the through-hole 31.

[0023] The discharge valve 74 is capable of adjusting the amount of water and air supplied from the through hole 31 to the discharge pipe 72. The discharge valve 74 is disposed in the discharge pipe 72. When the discharge valve 74 is switched to an open state, the discharge pipe 72 is able to discharge the water and air from the through hole 31 to the outside. When the discharge valve 74 is switched to a closed state, the discharge pipe 72 is unable to discharge the water and air from the through hole 31 to the outside.

[0024] The insertion pipe 75 is connected to the supply pipe 71 and the discharge pipe 72. The insertion pipe 75 is insertable into the through hole 31 and the casing hole 21. The insertion pipe 75 is insertable into the intermediate flange 3 from above in the vertical direction Dv. The insertion pipe 75 is formed to have a smaller diameter than the through hole 31. Specifically, the insertion pipe 75 is formed to have an outer diameter that allows a gap to be formed with the inner circumferential surfaces of the through hole 31 and the casing hole 21 when the insertion pipe 75 is inserted into the inner circumferential surfaces of the through hole 31 and the casing hole 21. The insertion pipe 75 of this embodiment is formed in a T-shape that is integrated with the supply pipe 71 and the discharge pipe 72. The insertion pipe 75 of this embodiment has a piping portion 751 and a solid portion 753.

[0025] The piping portion 751 is connected to the supply pipe 71 and the discharge pipe 72. The piping portion 751 in this embodiment is in communication with the interiors of the supply pipe 71 and the discharge pipe 72. The discharge pipe 72 is a pipe having the same diameter as the supply pipe 71 and the discharge pipe 72. The lower end of the piping portion 751 is inserted into the through hole 31. The upper end of the piping portion 751 is disposed outside the intermediate flange 3. In other words, when the insertion pipe 75 is inserted into the through hole 31 and the casing hole 21, only a partial lower region of the piping portion 751 is inserted into the through hole 31.

[0026] A supply hole 752 is formed at the lower end of the piping portion 751. The supply hole 752 opens into the through hole 31. The supply hole 752 is capable of communicating with the space between the through hole 31 and the insertion pipe 75. The supply hole 752 penetrates from the interior of the piping portion 751 to the outer peripheral surface of the piping portion 751. The supply hole 752 is formed near the boundary between the piping portion 751 and the solid portion 753. When the insertion pipe 75 is inserted into the through hole 31, the supply hole 752 is positioned near the upper end surface 37 of the intermediate flange 3, which faces upward in the vertical direction Dv, relative to the center of the through hole 31 in the vertical direction Dv. When the insertion pipe 75 is inserted into the through hole 31, the supply hole 752 is positioned below the upper end surface 37 of the intermediate flange 3 in the vertical direction Dv. A plurality of supply holes 752 are formed in the circumferential direction of the piping portion 751.

[0027] The solid portion 753 is connected to the piping portion 751 below in the vertical direction Dv. The solid portion 753 is connected to the piping portion 751 below in the vertical direction Dv where the supply hole 752 is formed. The solid portion 753 is formed in a solid cylindrical shape with no internal space. The solid portion 753 is formed integrally with the piping portion 751 and has the same outer diameter as the piping portion 751. The lower end of the solid portion 753 is inserted into the casing hole 21. The upper end of the solid portion 753 is disposed within the through hole 31. In other words, when the insertion tube 75 is inserted into the through hole 31 and the casing hole 21, only a partial lower region of the solid portion 753 is inserted into the casing hole 21, and the remaining region is disposed within the through hole 31.

[0028] The detachable holding portion 76 is detachably fixed to the intermediate flange 3 while closing the through hole 31. The detachable holding portion 76 is capable of holding the insertion pipe 75 to the intermediate flange 3. In this embodiment, the detachable holding portion 76 protrudes outward in an annular shape from the outer circumferential surface of the piping portion 751. The detachable holding portion 76 is disposed on the opposite side of the solid portion 753 with the supply hole 752 sandwiched therebetween. The detachable holding portion 76 is fixed to the flange portion 36 with detachable bolts while in close contact with the upper end surface 37 of the flange portion 36. In this way, the detachable holding portion 76 attaches the partial pressure proof test jig 7 to the intermediate flange 3 while sealing the intermediate flange 3.

[0029] The blocking portion 77 blocks the casing hole 21. The blocking portion 77 is arranged at the tip of the insertion tube 75. The blocking portion 77 is connected to the solid portion 753. The blocking portion 77 is arranged on the opposite side of the detachable holding portion 76 across the supply hole 752. The blocking portion 77 is insertable into the through hole 31 and the casing hole 21. The blocking portion 77 is formed to have approximately the same diameter as the casing hole 21. The blocking portion 77 is formed to have a larger diameter than the insertion tube 75. Specifically, the blocking portion 77 is formed to have an outer diameter that prevents the formation of a gap with the inner surface of the casing hole 21 when inserted into the inner surface of the casing hole 21.

[0030] The seal portion 78 provides a seal between the closing portion 77 and the casing hole 21. The seal portion 78 provides a seal between the outer peripheral surface of the closing portion 77 and the inner peripheral surface of the casing hole 21. The seal portion 78 is disposed in the closing portion 77. The seal portion 78 is an O-ring fixed to the outer peripheral surface of the closing portion 77, or a combination of an O-ring and a backup ring.

[0031] The pressure measuring unit 79 is capable of measuring the pressure inside the supply pipe 71, the discharge pipe 72, or the insertion pipe 75. The pressure measuring unit 79 in this embodiment is a pressure gauge attached to the discharge pipe 72. The pressure measuring unit 79 measures the pressure inside the through hole 31 and the casing hole 21 by measuring the pressure inside the discharge pipe 72.

[0032] The detailed steps of the partial pressure test method S1 using such a partial pressure test jig 7 will be described. As shown in FIG. 3 , in the partial pressure test method S1, first, the partial pressure test jig 7 is attached to the intermediate flange 3 (step S10). Specifically, with the insertion tube 75 inserted into the intermediate flange 3 fixed to the casing 2, the detachable holding part 76 is fixed to the intermediate flange 3. The detachable holding part 76 is fixed to the flange part 36 with bolts while being in close contact with the upper end surface 37 of the flange part 36. As a result, the upper part of the through hole 31 is blocked by the detachable holding part 76, and the lower part of the casing hole 21 is blocked by the blocking part 77 and the sealing part 78. As a result, the through hole 31 and the casing hole 21 are sealed by the partial pressure test jig 7.

[0033] After the partial pressure test jig 7 is attached to the intermediate flange 3, the supply valve 73 and the discharge valve 74 are opened and water is supplied from the supply pipe 71 (step S20). This opens the supply pipe 71 and the discharge pipe 72, allowing water to flow through. In addition, water is supplied to the supply pipe 71 by driving the pump. The water supplied from the supply pipe 71 to the intermediate flange 3 accumulates in the through hole 31 and the casing hole 21.

[0034] Thereafter, after the through-hole 31 is filled with water, the discharge valve 74 is closed (step S30). Specifically, first, water is supplied from the supply pipe 71, and then the water is discharged from the discharge pipe 72, which is then closed (step S31). As water begins to be supplied from the supply pipe 71 and accumulates in the through-hole 31 and the casing hole 21, the air that was originally retained in the through-hole 31 and the casing hole 21 is pushed out by the water. As a result, the air in the through-hole 31 and the casing hole 21 flows backward through the supply hole 752, which continues to discharge water, and is discharged from the open discharge pipe 72. Thereafter, when the air in the through-hole 31 and the casing hole 21 is removed and filled with water, water is discharged from the discharge pipe 72 instead of the air. In this state, the discharge valve 74 is closed, and the discharge pipe 72 is closed. In other words, the discharge pipe 72 is in a state where water and air cannot flow through.

[0035] After the discharge pipe 72 is blocked, the supply of water from the supply pipe 71 is stopped, and after a predetermined specified time has elapsed, the supply of water from the supply pipe 71 is resumed (step S32). Specifically, after the water has been discharged from the discharge pipe 72, the discharge valve 74 is closed to block the discharge pipe 72, and the pump is stopped. This interrupts the supply of water from the supply pipe 71. After a specified time of several minutes has elapsed, the pump is driven and the supply of water is resumed. Note that while waiting for the specified time of several minutes, pressure fluctuations may be checked by the pressure measuring unit 79 to monitor whether the through hole 31 and the casing hole 21, which are sealed pressure-resistant spaces, have been completely filled with water.

[0036] Thereafter, after the discharge valve 74 is closed, it is determined whether or not the pressure measured by the pressure measuring unit 79 exceeds a predetermined test pressure (step S40). Specifically, after the discharge valve 74 is closed and the supply of water from the supply pipe 71 is resumed, it is confirmed whether or not the pressure measured by the pressure measuring unit 79 reaches the test pressure. The test pressure is set to, for example, a value greater than the pressure value applied to the intermediate flange 3 when the rotary machine is in operation. The test pressure is set to, for example, a value approximately 1.5 to 2.0 times the pressure value applied to the intermediate flange 3 when the centrifugal compressor 1 is in operation.

[0037] When it is determined that the pressure measured by the pressure measuring unit 79 exceeds the test pressure, the supply valve 73 is closed (step S50). Specifically, the supply valve 73 is closed and the supply pipe 71 is blocked. Therefore, the supply pipe 71 is placed in a state where water cannot flow. In addition, the pump is stopped.

[0038] After the supply valve 73 is closed, a water pressure test is performed on the welded portion 4 (step S60). Specifically, a water pressure test is performed on the intermediate flange 3, which requires the passage of a predetermined time and pressure fluctuations such as pressurization and depressurization.

[0039] After the hydraulic pressure test is performed, the supply valve 73 and the discharge valve 74 are opened (step S70). This opens the supply pipe 71 and the discharge pipe 72, and releases the pressure inside the through hole 31 and the casing hole 21. Thereafter, the detachable holding part 76 is removed from the intermediate flange 3, and the partial pressure test jig 7 is removed.

[0040] (Action and effect) In the partial pressure test jig 7 and partial pressure test method S1 configured as described above, the upper portion of the through hole 31 is blocked by the detachable holding portion 76, and the lower portion of the casing hole 21 is blocked by the blocking portion 77 and the sealing portion 78. As a result, the through hole 31 and the casing hole 21 are sealed by the partial pressure test jig 7. Water is supplied to the sealed through hole 31 and the casing hole 21 from the supply pipe 71, and internal air is discharged from the discharge pipe 72. This allows the sealed through hole 31 and the casing hole 21 to be filled with water for a hydraulic test. In other words, the hydraulic test can be performed on the intermediate flange 3 and the welded portion 4 without supplying water to the entire interior of the casing 2. Therefore, a partial pressure test can be performed only on the intermediate flange 3, without testing the entire centrifugal compressor 1 including the intermediate flange 3. Therefore, the test can be completed on site where the centrifugal compressor 1 is already installed, without sending the centrifugal compressor 1 including the casing 2 to a facility capable of large-scale testing, such as a factory. In this way, a pressure test can be efficiently carried out on the welded portion 4 between the additional member and the casing 2.

[0041] Furthermore, when the insertion pipe 75 is inserted into the through hole 31, the supply hole 752 is positioned close to the upper end surface 37 of the intermediate flange 3. Therefore, water is supplied from above into the through hole 31 and the casing hole 21. The air originally remaining in the through hole 31 and the casing hole 21 is pushed out by the water and rises upward in the vertical direction Dv. As a result, the air in the through hole 31 and the casing hole 21 reaches the supply hole 752 and is discharged from the discharge pipe 72 via the supply hole 752. In this way, even if water is continuously supplied through the supply hole 752, the air in the through hole 31 and the casing hole 21 can be discharged from the supply hole 752 with high accuracy. Therefore, the air in the through hole 31 and the casing hole 21 can be efficiently discharged, and the through hole 31 and the casing hole 21 can be filled with water. This allows water to be efficiently supplied and air to be discharged, enabling a hydrostatic test to be performed quickly.

[0042] Furthermore, the sealing portion 78 is an O-ring fixed to the outer peripheral surface of the blocking portion 77, or a combination of an O-ring and a backup ring. Therefore, the casing hole 21 can be airtightly closed by the simple operation of simply inserting the blocking portion 77 into the casing hole 21.

[0043] Furthermore, the detachable holding portion 76 is detachably attached to the flange portion 36 while being in close contact with the upper end surface 37 of the intermediate flange 3 that faces upward in the vertical direction Dv. Therefore, the upper portion of the through-hole 31 can be airtightly sealed by the simple operation of simply fixing the detachable holding portion 76 to the flange portion 36.

[0044] Furthermore, when the discharge valve 74 is closed after the through-hole 31 is filled with water, the supply of liquid from the supply pipe 71 is stopped after the discharge pipe 72 is closed. Then, after a specified time has elapsed, the supply of water from the supply pipe 71 is resumed. Therefore, when the water supply is stopped, the flow of water in the through-hole 31 and the casing hole 21 ceases. As a result, while the water supply continues, the small amount of air remaining in the through-hole 31 gradually rises through the water accumulated in the through-hole 31 and is discharged. This allows the air remaining in the through-hole 31 to be discharged with high accuracy.

[0045] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0046] The rotary machine is not limited to the centrifugal compressor 1 of this embodiment. The rotary machine may be an axial flow compressor, a turbine, a pump, or a motor, as long as the cylindrical additional member can be fixed thereto.

[0047] Furthermore, the liquid used in the partial pressure test jig 7 and the partial pressure test method S1 is not limited to water. For example, a solution suited to the material of the additional member to be tested may be used as the liquid.

[0048] The supply valve 73 and the discharge valve 74 may be on-off valves that can adjust the water supply state between fully open and fully closed states, or may be flow control valves that can supply water at any flow rate by adjusting the opening degree. The supply valve 73 and the discharge valve 74 may be electromagnetic valves that can be opened and closed automatically, or may be valve devices that can be opened and closed manually.

[0049] Furthermore, the insertion pipe 75 is not limited to a structure having only a solid portion 753. The entire insertion pipe 75 may be configured as the piping portion 751, as long as it has enough strength to not be deformed by the pressure of the liquid inside the through-hole 31.

[0050] Furthermore, the pressure measuring unit 79 is not limited to being attached to the discharge pipe 72 as in this embodiment. The pressure measuring unit 79 only needs to be able to measure the pressure inside the supply pipe 71, the discharge pipe 72, or the insertion pipe 75. Therefore, the pressure measuring unit 79 may be disposed in the discharge pipe 72 or the insertion pipe 75.

[0051] <Additional Notes> The partial pressure resistance test jig 7 and the partial pressure resistance test method S1 described in the embodiment can be understood, for example, as follows.

[0052] (1) A partial pressure test jig 7 according to a first aspect is a partial pressure test jig 7 used when supplying liquid to a cylindrical additional member fixed to a casing 2 of a rotary machine by a welded portion 4 in a state in which a through hole 31 inside the additional member communicates with a casing hole 21 formed in the casing 2, thereby conducting a partial pressure test on the welded portion 4, and includes a supply pipe 71 capable of supplying liquid toward the through hole 31, a discharge pipe 72 capable of discharging the liquid from the through hole 31, a supply valve 73 disposed on the supply pipe 71 and capable of adjusting the amount of liquid supplied from the supply pipe 71 to the through hole 31, a discharge valve 74 disposed on the discharge pipe 72 and capable of adjusting the amount of liquid discharged from the through hole 31 to the discharge pipe 72, and a valve for connecting the supply pipe 71 and the discharge pipe 72. The additional member includes an insertion tube 75 connected to the outlet tube 72 and insertable into the through hole 31 and the casing hole 21; a detachable holding portion 76 that is detachably fixed to the additional member while blocking the through hole 31 and can hold the insertion tube 75 to the additional member; a blocking portion 77 that is arranged at the tip of the insertion tube 75 and blocks the casing hole 21; a sealing portion 78 that is arranged at the blocking portion 77 and seals between the blocking portion 77 and the casing hole 21; and a pressure measuring portion 79 that can measure the pressure inside the supply tube 71, the discharge tube 72 or the insertion tube 75. The insertion tube 75 is formed with a smaller diameter than the through hole 31, has a supply hole 752 that opens within the through hole 31 and can communicate with the space between the through hole 31 and the insertion tube 75.

[0053] As a result, the upper portion of the through hole 31 is blocked by the detachable holding portion 76, and the lower portion of the casing hole 21 is blocked by the blocking portion 77 and the sealing portion 78. As a result, the through hole 31 and the casing hole 21 are sealed by the partial pressure test jig 7. Liquid is supplied to the sealed through hole 31 and the casing hole 21 through the supply pipe 71, and internal air is discharged through the discharge pipe 72. This allows the sealed through hole 31 and the casing hole 21 to be filled with liquid and subjected to a hydraulic pressure test. In other words, a hydraulic pressure test can be performed on the additional member and the welded portion 4 without supplying liquid to the entire interior of the casing 2. Therefore, a partial pressure test can be performed only on the additional member, without testing the entire centrifugal compressor 1 including the additional member. Therefore, the test can be completed on site where the centrifugal compressor 1 is already installed, without sending the centrifugal compressor 1 including the casing 2 to a facility capable of large-scale testing, such as a factory. In this way, a pressure test can be efficiently performed on the welded portion 4 between the additional member and the casing 2.

[0054] (2) The partial pressure test jig 7 according to the second aspect is the partial pressure test jig 7 of (1), in which the supply hole 752 is positioned near the upper end surface 37 of the additional member facing upward in the vertical direction Dv, relative to the center of the through hole 31 in the vertical direction Dv, when the insertion tube 75 is inserted into the through hole 31.

[0055] As a result, liquid is supplied from above into the through hole 31 and the casing hole 21. The air originally remaining in the through hole 31 and the casing hole 21 is pushed out by the liquid and rises upward in the vertical direction Dv. As a result, the air in the through hole 31 and the casing hole 21 reaches the supply hole 752 and is discharged from the discharge pipe 72 via the supply hole 752. In this way, even if liquid continues to be supplied from the supply hole 752, the air in the through hole 31 and the casing hole 21 can be discharged from the supply hole 752 with high accuracy. Therefore, the air in the through hole 31 and the casing hole 21 can be efficiently discharged, and the through hole 31 and the casing hole 21 can be filled with liquid. As a result, liquid can be efficiently supplied and air can be efficiently discharged, allowing the hydrostatic test to be performed promptly.

[0056] (3) The partial pressure test jig 7 according to the third aspect is the partial pressure test jig 7 of (1) or (2), wherein the sealing portion 78 is an O-ring fixed to the outer peripheral surface of the blocking portion 77, or a combination of an O-ring and a backup ring.

[0057] As a result, the casing hole 21 can be airtightly closed by the simple operation of simply inserting the blocking portion 77 into the casing hole 21.

[0058] (4) The partial pressure resistance test jig 7 according to the fourth aspect is any one of the partial pressure resistance test jig 7 of (1) to (3), and the detachable holding portion 76 is detachably attached to the additional member while being in close contact with the upper end surface 37 of the additional member facing upward in the vertical direction Dv.

[0059] As a result, the upper portion of the through-hole 31 can be airtightly closed by the simple operation of simply fixing the detachable holding portion 76 to the flange portion 36.

[0060] (5) A partial pressure test method S1 according to a fifth aspect is a partial pressure test method S1 using a partial pressure test jig 7 of any one of (1) to (4), and includes the steps of fixing the detachable holding portion 76 to the additional member and attaching the partial pressure test jig 7 to the additional member; opening the supply valve 73 and the discharge valve 74 to supply the liquid from the supply pipe 71; closing the discharge valve 74 after the through hole 31 is filled with the liquid; determining whether the pressure measured by the pressure measurement unit 79 after closing the discharge valve 74 exceeds a predetermined test pressure; closing the supply valve 73 if it is determined that the pressure measured by the pressure measurement unit 79 exceeds the test pressure; performing a water pressure test on the welded portion 4 after closing the supply valve 73; and opening the supply valve 73 and the discharge valve 74 after performing the water pressure test.

[0061] As a result, the upper portion of the through hole 31 is blocked by the detachable holding portion 76, and the lower portion of the casing hole 21 is blocked by the blocking portion 77 and the sealing portion 78. As a result, the through hole 31 and the casing hole 21 are sealed by the partial pressure test jig 7. Liquid is supplied to the sealed through hole 31 and the casing hole 21 through the supply pipe 71, and internal air is discharged through the discharge pipe 72. This allows the sealed through hole 31 and the casing hole 21 to be filled with liquid and subjected to a hydraulic pressure test. In other words, a hydraulic pressure test can be performed on the additional member and the welded portion 4 without supplying liquid to the entire interior of the casing 2. Therefore, a partial pressure test can be performed only on the additional member, without testing the entire centrifugal compressor 1 including the additional member. Therefore, the test can be completed on site where the centrifugal compressor 1 is already installed, without sending the centrifugal compressor 1 including the casing 2 to a facility capable of large-scale testing, such as a factory. In this way, a pressure test can be efficiently performed on the welded portion 4 between the additional member and the casing 2.

[0062] (6) A partial pressure test method S1 according to a sixth aspect is any one of the partial pressure test methods S1 of (1) to (5), wherein the step of closing the discharge valve 74 includes the steps of: supplying the liquid from the supply pipe 71, and then closing the discharge pipe 72 when the liquid is discharged from the discharge pipe 72; and, after closing the discharge pipe 72, stopping the supply of the liquid from the supply pipe 71 and resuming the supply of the liquid from the supply pipe 71 after a predetermined specified time has elapsed.

[0063] This stops the supply of liquid, and the liquid stops flowing through the through-hole 31 and the casing hole 21. As a result, the small amount of air remaining in the through-hole 31 while the liquid continues to be supplied gradually rises through the liquid accumulated in the through-hole 31 and is discharged. This allows the air remaining in the through-hole 31 to be discharged with high precision. [Explanation of symbols]

[0064] 1...Centrifugal compressor (rotating machine) 2...Casing 21...Casing hole 25...Rotor 3...Intermediate flange (additional part) 31...Through hole 35...Cylinder body 36...Flange 37…Top end surface 4...Welded section Dv: vertical direction S1...Partial pressure test method 7...Partial pressure test fixture 71…Supply pipe 72...Discharge pipe 73...Supply valve 74...Discharge valve 75...insertion tube 751...Piping section 752…Supply hole 753…Solid part 76...Detachable holding part 77…Occluded part 78...Seal part 79...Pressure measurement section

Claims

1. A partial pressure test jig used to conduct a partial pressure test on a welded portion by supplying a liquid to a cylindrical additional member fixed to a casing of a rotary machine by a welded portion in a state in which a through hole inside the additional member is in communication with a casing hole formed in the casing, a supply pipe capable of supplying a liquid toward the through hole; a discharge pipe capable of discharging the liquid in the through hole; a supply valve disposed on the supply pipe and capable of adjusting the amount of the liquid supplied from the supply pipe to the through hole; a discharge valve disposed in the discharge pipe and capable of adjusting the amount of the liquid discharged from the through hole to the discharge pipe; an insertion pipe connected to the supply pipe and the discharge pipe and insertable into the through hole and the casing hole; a detachable holding portion that is detachably fixed to the additional member while closing the through hole and that can hold the insertion tube to the additional member; a closing portion disposed at a tip of the insertion tube and closing the casing hole; a seal portion disposed in the closing portion and sealing between the closing portion and the casing hole; a pressure measuring unit capable of measuring the pressure inside the supply pipe, the discharge pipe, or the insertion pipe; The insertion pipe is formed to have a smaller diameter than the through hole, and has a supply hole that opens within the through hole and can communicate with the space between the through hole and the insertion pipe.

2. 2. The partial pressure test fixture according to claim 1, wherein the supply hole is arranged at a position close to an upper end surface of the additional member facing upward in the vertical direction, relative to a center of the through hole in the vertical direction when the insertion tube is inserted into the through hole.

3. 3. The partial pressure test fixture according to claim 1, wherein the sealing portion is an O-ring fixed to the outer peripheral surface of the closing portion, or a combination of an O-ring and a backup ring.

4. 3. The partial pressure test fixture according to claim 1, wherein the detachable holding portion is detachably attached to the additional member while being in close contact with an upper end surface of the additional member facing upward in the vertical direction.

5. A partial pressure test method using the partial pressure test jig according to claim 1 or 2, a step of fixing the detachable holding portion to the additional member and attaching the partial pressure resistance test jig to the additional member; opening the supply valve and the discharge valve to supply the liquid from the supply pipe; closing the drain valve after the through-hole is filled with the liquid; a step of determining whether or not the pressure measured by the pressure measuring unit exceeds a predetermined test pressure after closing the discharge valve; closing the supply valve when it is determined that the pressure measured by the pressure measuring unit exceeds the test pressure; performing a hydrostatic test on the weld after closing the supply valve; and opening the supply valve and the discharge valve after performing the water pressure test.

6. The step of closing the discharge valve comprises: after supplying the liquid from the supply pipe, closing the discharge pipe when the liquid is discharged from the discharge pipe; 6. The partial pressure test method according to claim 5, further comprising the steps of: after blocking the discharge pipe, stopping the supply of the liquid from the supply pipe; and resuming the supply of the liquid from the supply pipe after a predetermined specified time has elapsed.

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