JP7535041B2 - Valve pressure test equipment - Google Patents

Description

The present invention relates to a pressure resistance testing device for valves, and in particular to a pressure resistance testing device for valves that reduces the impact on the space to be tested for pressure resistance testing by isolating the space to be tested from the outside.

Conventionally, as a device for pressure-resistance testing of an object to be tested, for example, a leak detection device is disclosed in Patent Document 1. This device performs pressure-resistance testing by leaking from a vehicle body, and a sampler moves on the surface of the vehicle body while a search gas is injected into the vehicle body, and a gas sensor detects leakage from a leakage flow path that occurs in the vehicle body. In this case, since hydrogen gas and helium gas, which are generally used as search gases, have high diffusibility, air flowing out from the sampler is directed at the vehicle surface to create a ring-shaped air curtain between them, and the search gas from the leakage flow path is detected in a sample collection space provided inside this air curtain. In this way, by separating the sample collection space from the outside atmosphere with an air curtain, the sample collection space is set small to facilitate detection of the highly diffusible search gas, while preventing the intrusion of outside air into the inspection space, thereby accurately detecting leakage of the search gas in the sample collection space.

The leak detector in Patent Document 2 is a pressure-resistance test device that detects leakage of signal gas from the body surface of a motor vehicle. In this device, a detection head that detects the signal gas (helium gas) is provided so as to be scannable, and in addition to an annular opening that forms a barrier gas curtain (air curtain), this detection head has multiple orifices formed on the outer periphery of this annular opening. This allows air to flow in an annular pattern at an equal mass flow rate through the orifices, providing an even air curtain while preventing localized air discharge, and this air curtain forms a test space to prevent the effects of outside air.

On the other hand, the gas leak detection device in Patent Document 3 is used to detect leaking gas from a pneumatic valve installed in a semiconductor manufacturing facility and perform a pressure resistance test, and is configured to prevent gas leakage to the outside using a collection unit made of a cylindrical case. The collection unit is attached so that the valve is inserted from the opening at the lower end and covers the valve from above, and a lid member is attached to the opening. The lid member is formed in a roughly semicircular shape, and a groove that can abut against the outer circumferential surface of the valve is formed on its inner periphery. An adhesive is applied to this groove and one outer edge of the lid member, and the groove is joined to the outer circumferential surface of the valve and the one outer edge is joined to the opening of the collection unit, respectively, so that the opening is closed by the lid member. In this way, gas leaking from the valve within a collection unit of a specified volume is detected while preventing gas leakage to the outside, and damage to the valve is detected.

Special Publication No. 58-500672 Japanese Unexamined Patent Publication No. 60-73329 Special Publication No. 2016-536623

In Patent Documents 1 and 2, air is discharged from the detection side and hits the vehicle surface, providing an air curtain between the detection side and the vehicle surface, and is used when the vehicle surface to be inspected is a substantially flat surface and leakage from a portion of the substantially flat surface is to be inspected. With these devices, it is difficult to provide an air curtain that separates the inspection area from the uneven valve, making it difficult to inspect the valve for pressure resistance.
In these devices, the detection part moves over the surface of the vehicle body to detect leaks, so it is not possible to perform pressure resistance testing of part or all of the vehicle at once, and it takes a significant amount of time to test the entire vehicle.

On the other hand, the gas leak detection device in Patent Document 3 is fixedly attached to each valve connected to the flow path of a semiconductor manufacturing facility, and detects leaks from each valve in a stationary state. Therefore, it is difficult to use this inspection device to continuously perform pressure resistance tests on different test valves. This device detects gas leaks from the entire valve inserted in the collection section, and cannot test for leaks from parts of the valve.

The present invention was developed to solve the problems of the past, and its purpose is to provide a valve pressure testing device that can accurately test for leaks from some or all of the test valves in one go in a short amount of time by making the space for testing for leaks small to facilitate detection of search gas while preventing outside air from entering this space, and that can perform pressure testing of different test valves in succession.

In order to achieve the above object, the invention according to claim 1 provides a method for testing a test valve by a method comprising the steps of: providing a chamber in an upper portion of an inspection space for carrying out a pressure test of a test valve ; providing a cover body surrounding an inspection portion of the test valve; and providing a hanging portion for moving the cover body at least vertically within the inspection space; the cover body has an inspection space in which a gas sensor is mounted; an opening formed as a semi-open type with an open lower portion and surrounding the inspection portion; and an opening edge formed at the opening that is capable of blowing air inward; and a test valve in a semi-completed state with a stem inserted into the axial cylinder portion of the body is fixed to the lower portion of the inspection space by a clamping jig; and the hanging portion is lowered to move the cover body to the inspection portion. The stem shaft seal portion is covered with a cover body having an opening, surrounding it in an unsealed state, and an air curtain is provided to define a communication area through which air from the edge of the opening connects the external environment area of the cover body to the inspected space of the cover body.By blocking the opening with this air curtain, the outside is isolated from the inspected space, preventing it from being affected by the atmospheric gas in the external environment area, while being capable of detecting the presence or absence of search gas leakage from the inspection area of the test valve in which search gas is sealed, this is a valve pressure inspection device that makes it possible to perform continuous preliminary pressure inspections of the stem shaft seal portion, which is the area to be inspected, even for test valves of different classes and sizes .

The invention of claim 2 is a pressure resistance testing device for a valve having an air purge flow path for purging the space to be tested in the cover body with air.

According to the invention of claim 1, the cover body covers a part of the test valve installed in the inspection space. Semi-open type with an open bottomBy surrounding the opening in a non-sealed state, the volume of the space to be inspected is set small, and the search gas leaking from the test valve can be easily detected by allowing an air flow in the cover body that allows the search gas leaking from the test valve to reach the gas sensor within the inspection time, while the communication space between the external environment area of the cover body and the space to be inspected is partitioned with an air curtain, which surrounds the space to be inspected and separates the inspection part of the test valve from the outside, preventing the atmospheric gas in the external environment area from entering and suppressing its influence. This allows the search gas from the test valve to be diffused and then retained in the small volume of the space to be inspected separated by the air curtain, and the leak from the test valve can be detected at once by the gas sensor, allowing a highly accurate pressure test to be performed in a short time even if the leak is very small. Moreover, the search gas is prevented from leaking from the space to be inspected to the external environment area, and there is no risk of adverse effects on external equipment, etc.The semi-finished test valve with the stem inserted into the axial tube of the body is fixed to the bottom of the inspection space with a clamping jig, and the hanging part is lowered to cover the stem seal part to be inspected with a cover body having an opening, surrounding it in an unsealed state.After that, the air curtain is used to block the atmospheric gas in the external environment area and make it pressure-resistant.spareSince this is a structure to be inspected, when conducting a pressure test on the valve,thisThe preliminary pressure inspection is to be carried out separately from the main pressure inspection which is carried out after the preliminary pressure inspection.Even for test valves of different classes and sizes, by continuously testing the stem shaft seal area, which is the area to be tested,By reducing the volume of the space to be inspected, even the slightest leak of search gas can be detected, and the search gas can be detected with high accuracy in a short time, enabling accurate pressure inspections to be performed. Furthermore, by carrying out the above-mentioned preliminary pressure inspection before the main pressure inspection, which is performed on the fully assembled test valve, it becomes possible to detect defects and processing defects in each test valve at an early stage, without having to assemble the entire test valve.spareAfter the inspection, the test valve can be removed by lifting the cover body from the test valve and unclamping it. Next, the test valve is fixed in place with a clamping tool in the same manner, and the cover body is used to detect leaks, allowing the test valve to be continuously and automatically pressure-resistant.spareIt will also be possible to inspect it.
Furthermore, it is now possible to partially pressure test the pressure test area of the test valve, and to pressure test a part of the test valve during assembly.spareMoreover, by surrounding the test valve with a space to be inspected of a predetermined size, the time required for the pressure resistance inspection can be made substantially constant, and by making the volume of the space to be inspected small, the inspection time can be shortened.

Even when pressure testing the protruding parts of the test valve, the opening can be securely blocked by an air curtain, reliably preventing atmospheric gas from the external environment from entering the space being tested, thereby enabling the search gas to be detected with high accuracy.

Even when pressure testing protruding parts such as the stem shaft seal of the test valve, the air curtain emerging from the edge of the opening reliably isolates the outside from the space being tested, reliably preventing atmospheric gas from the external environment from entering the space being tested, thereby enabling the search gas to be detected with high accuracy.

The air blown inward from the opening edge of the cover body collides with each other and surrounds the opening, blocking it, creating an air curtain to block the atmospheric gas in the external environment area and prevent it from entering the cover body, making it possible to reliably detect leakage from the entire test valve into the cover body. This makes it possible to perform high-precision pressure testing while suppressing the effects of external atmospheric gases while the test valve is stored in the cover body, even if the type, class, or size of the test valve is different.

According to the invention of claim 2, by providing an air purge flow path for purging the space to be inspected with air, the search gas in the space to be inspected can be quickly discharged through this air purge flow path, and the next test valve can be pressure-tested in a short time after the pressure-resistance test. Furthermore, if an air curtain is used to prevent the intrusion of atmospheric gas from the outside into the space to be inspected, the search gas can be discharged even more quickly.

1 is a schematic cross-sectional view showing an embodiment of a pressure resistance inspection device for a valve of the present invention. FIG. 2 is an enlarged cross-sectional view showing the pressure resistance test state of a test valve. FIG. FIG. 4 is a vertical central cross-sectional view of the cover body. This is a cross-sectional view taken along line AA in FIG. FIG. FIG. 11 is a front view showing another embodiment of a pressure resistance testing device of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressure resistance inspection device for a valve according to the present invention will be described in detail based on an embodiment.
FIG. 1 shows an embodiment of a pressure resistance testing device (hereinafter referred to as device body 1) of the present invention, FIG. 2 shows an enlarged cross-sectional view of the pressure resistance testing device, and FIG. 3 shows a cover body.

The device main body 1 shown in Figure 1 is configured to supply search gas to the test valve 2 to be inspected, thereby enabling the test valve 2 to be pressure-tested, and has a frame 10, a chamber 11, a gas sensor 12, a support jig 13, and a clamp jig 14.

The frame 10 is formed in a frame shape that allows the test valve 2 to be mounted inside, and an inspection space R is provided inside for performing a pressure test of the test valve 2. An open section 20 is provided in a part of the frame 10, and the test valve 2 can be attached and detached from the right side or front side of the frame 10 in Figure 1 through this open section 20. In the figure, two exhaust fans 21 shown by dashed lines are attached to the back side of the frame 10 via a plate material or the like not shown, and the rotation of these exhaust fans 21 allows the exhaust of the inside of the inspection space R. A chamber 11, a support jig 13, and a clamp jig 14 are attached inside the frame 10.

The chamber 11 is provided for carrying out a pressure test of the test valve 2, and has a cover body 30 and a hanging part 31. In Figs. 2 to 6, the cover body 30 is formed in a substantially rectangular shape, and an opening 32 is provided at the bottom. Thus, the cover body 30 is provided as a semi-open type with an open bottom, and its interior is provided so as to be able to surround a part or the whole of the test valve 2. In this example, the stem seal part 33, which is a part of the test valve 2, is set as the test target part (pressure test part), and an inspection space S is provided inside the cover body 30, which is large enough to surround the pressure test part 33 and perform the pressure test. As shown in Fig. 1, the hanging part 31 in the chamber 11 is attached to the upper part of the cover body 30, and the chamber 11 is provided so as to be able to move forward and backward and up and down within the inspection space R via the hanging part 31.
In this embodiment, the cover body 30 has a compact structure with dimensions of 50 mm in height, 70 mm in length, and 40 mm in depth.

2, the inspection space S of the cover body 30 is a space in which the search gas supplied to the test valve 2 can diffuse, and is isolated from the outside. In this embodiment, "isolated from the outside" means that the inside of the cover body 30 is not sealed, but is in a so-called non-sealed state. In other words, when the cover body 30 surrounds the pressure test portion 33 of the test valve 2 in a non-sealed state, it prevents the test valve 2 in the inspection space S from being affected by external wind, and allows gas flow to the extent that the search gas leaking from the test valve 2 within the cover body 30 can reach the gas sensor 12 within the inspection time.

The cover body 30 is provided with the gas sensor 12 and an air purge passage 34 .
The gas sensors 12 are attached to sensor mounting holes 35 formed in a number of predetermined locations in the inspected space S within the cover body 30 where the search gas is likely to accumulate, in this example, three locations on the inside surface of the cover body 30 and one location on the inside top surface of the cover body 30, and these four gas sensors 12 make it possible to reliably detect leakage of the search gas supplied into the test valve 2 from the pressure resistance inspection portion 33 within the inspected space S. The number of gas sensors 12 can be set arbitrarily, and increasing the number improves the detection capability and enables the detection time to be shortened and the detection to be automated.

The gas sensor 12 in this embodiment is a hydrogen sensor that can detect hydrogen gas (search gas) (described later) supplied into the test valve 2. By using the hydrogen sensor, it is possible to reliably detect hydrogen leakage from a mixture of hydrogen and nitrogen, which are diffusible gases. The gas sensor 12 may be movably attached so that its position can be adjusted relative to the cover body 30. Helium gas can also be used as the search gas, in which case a gas thermal conduction sensor can be used as the gas sensor.

The gas sensor 12 is made up of a module that outputs a voltage according to the concentration of leaked hydrogen when a certain voltage is applied. Before testing, the output voltage must be changed using a resistor adjustment volume to precisely adjust the sensitivity according to the warm-up state of the gas sensor 12 and changes in the hydrogen concentration in the atmosphere.

The gas sensor 12 may be a commercially available semiconductor sensor capable of outputting an analog signal (0-5V), such as a hot-wire semiconductor hydrogen sensor. This gas sensor 12 utilizes the change in electrical conductivity caused by the adsorption of hydrogen gas on the surface of a metal oxide semiconductor such as stannic oxide (SnO ₂ ). In this case, the output voltage is logarithmic with respect to the gas concentration, making it possible to provide a highly sensitive output even at low concentrations.

The air purge flow path 34 is provided so as to communicate from the inspection space S in the cover body 30 to the outside, and a purge air supply pipe 36 is connected to this air purge flow path 34. When purging air is supplied from the purge air supply pipe 36 by a compressor (not shown), this air is supplied through the air purge flow path 34 into the inspection space S, and the inspection space S is air purged. The air purge flow path 34 may be provided as an air flow path separate from the air flow path 41 for the air curtain 40 described later, or as a flow path that can be switched to the air flow path 41 for the air curtain.

3, 4, and 6, outside the inspection space S of the cover body 30, an air flow path 41 shown by a dashed line for forming an air curtain 40 is formed in a hollow state in a state not communicating with the inspection space S, and this air flow path 41 has an air supply port 42 and a branch flow path 43. The air supply port 42 is formed on the upper surface side of the cover body 30, and in FIG. 5, the branch flow paths 43 are formed so as to branch to the left and right from the air supply port 42. The branch flow paths 43 are each formed in a thin slit shape (planar shape) along the side of the cover body 30, and the opening edge 45, which is an air discharge port formed at the lower part, is formed on the left and right sides along the opening 32. As a result, the air discharged from each opening edge 45 faces or crosses each other to form an air curtain.

5 are provided so as to incline inwardly at a predetermined angle θ with respect to the vertical direction of the cover body 30. When air is supplied from the air supply port 42, the air flows into each branch flow path 43 at the branch position, and after passing through these slit-shaped branch flow paths 43, is blown out from the opening edge 45. As the air flows inward from the opening edge 45, the air from the left and right interferes with each other and collides with each other, forming an air curtain 40, shown by the dashed line, on the outer periphery of the opening 32 so as to surround the inspection space S.

Here, a desired angle θ of the opening edge 45 will be described in detail when the pressure of the air supplied to the speed controller (throttle valve: not shown) in the upstream stage of the air supply port 42 is set to about 0.6 MPa. Note that an air pressure of 0.6 MPa is a pressure generally used for air drive applications.
The flow rate of the air supplied to the speed controller is adjusted by the speed controller to about 100 mL/min to about 300 mL/min.

At the above air flow rate, when the angle θ of the opening edge 45 from the vertical direction is set to approximately 50° or more, the volume of the approximately triangular area in side view surrounded by the air curtain 40 and the bottom side of the cover body 30 is reduced, while the air blown out from the opening edge 45 is caused to strongly collide with each other, thereby making it possible to suppress the outflow of search gas leaking from the test valve 2 into the inspected space S to the outside.

On the other hand, when the angle θ is set to approximately 75° or less, the air blown out from the opening edge 45 collides with itself and flows downward, preventing the air from diffusing upward toward the inspection space S and preventing air from flowing into the inspection space S.

As described above, it has been confirmed that by setting the angle θ to a predetermined value or more (approximately 50° or more), the search gas is maintained in the inspection space S and leakage is prevented, while by setting the angle θ to a predetermined value or less (approximately 75° or less), it is possible to reliably prevent the external atmosphere from entering the inspection space S. For these reasons, in this example, the opening edge 45 is formed so as to be in the range of 50°≦angle θ≦75°, thereby avoiding the adverse effect of air on the inspection space and further improving the accuracy of the pressure resistance test.
In this example, the angle θ is set within the above range based on the conditions described above, but it is desirable to set this angle θ to an optimal value depending on various conditions such as the size and shape of the cover body 30 and the state of the test valve.

The air pressure should be sufficient to close the opening 32 of the cover body 30 and isolate the outside from the space to be inspected S, and even better, it should be sufficient to maintain a downward flow through the cover body 30 and thereby move the atmospheric gas in the external environment area T away from the space to be inspected S.

The width dimension of the opening edge 45 can be set to an appropriate size, and by changing this width, the air volume can be changed.

The device body 1 is provided with an air curtain 40, which defines a communication area near the opening 32 that connects the external environment area T of the cover body 30 and the inspection space S of the cover body 30, thereby isolating the outside (outside air) from the inspection space S. Therefore, within the inspection space S of the cover body 30, it is possible to suppress the effect of the atmospheric gas in the external environment area T on the search gas.

1 and 2, the support jig 13 is provided on the frame 10 at a predetermined interval so that the vicinity of both sides of the test valve 2 can be placed on it, and can support the test valve 2 from below. A mounting surface 46 is provided on the upper surface of the support jig 13, and this mounting surface 46 is provided in an appropriate shape, such as a tapered shape that can hold the side of the test valve, which is a polygonal shape such as a hexagon or octagon, or an arc shape that can hold the side of the test valve, which is a cylindrical shape.

The clamp jig 14 has a fixed clamp jig 50 and a movable clamp jig 51 .
The fixed clamp jig 50 is placed via a fixing holder 52 at a position that will be the primary side of the test valve 2, and a primary side flow passage 53 for supplying search gas into the test valve 2 is formed near the center of the fixed clamp jig 50. A seal member 54 consisting of a ring-shaped gasket is attached to the surface of the fixed clamp jig 50 facing the primary side of the test valve 2, and this seal member 54 prevents leakage from the pressure contact portion with the test valve 2 when the test valve 2 is fixed.

The movable clamp jig 51 is arranged on the secondary side of the test valve 2 and is attached so as to be able to move freely back and forth in the clamping direction to hold the test valve 2 together with the fixed clamp jig 50.
The cover body 30 described above is arranged so that the direction of advance and retreat is the same as the direction of advance and retreat of the movable clamping jig 51 which is the clamping jig for the test valve 2. A secondary flow passage 55 which serves as a purge flow passage is provided inside the movable clamping member 51, and after the pressure resistance inspection of the test valve 2, the search gas in the test valve is purged by air pressure through this secondary flow passage 55.

A seal member 54 consisting of a ring-shaped gasket is attached to the surface of the movable clamp jig 51 facing the secondary side of the test valve 2, similar to the fixed clamp jig 50. This seal member 54 prevents leakage from the pressure contact area with the movable clamp jig 51 when the test valve 2 is fixed.

The test valve 2 is a ball valve, and a pressure test is performed by the device main body 1 with some of the components of this ball valve 2 assembled. The test valve 2 has a body 60, which is a cast part, and a stem 62 for rotation is inserted into an axial tube portion 61 formed in this body 60, and a packing retainer 63 is attached from above by screwing, so that the stem 62 is rotatably positioned. O-rings 65 are attached to the outer periphery of the stem 62 in two places, and these O-rings 65 form a pressure test area 33, which is the stem axial seal portion, and the pressure test is performed by surrounding this pressure test area 33 with the cover main body 30 to detect leaks.

As a search gas for the pressure test of the above-mentioned test valve 2, for example, a gas containing hydrogen is used, and among these, a hydrogen gas mixture containing 5% hydrogen and 95% nitrogen, an inert gas, is used as a gas having diffusibility. This mixed gas has the property of leaking from the vicinity of the screwed portion of the packing retainer 63 of the stem shaft seal portion 33 of the body 60 if there is an external leak during the pressure test.

The search gas, a mixture of 5% hydrogen and 95% nitrogen, is a non-flammable high-pressure gas and can be used safely. The search gas can be a gas other than hydrogen-containing gas, for example, various gases such as helium gas and methane gas can be used. When hydrogen gas is used as the search gas, it is less expensive than the above gases. On the other hand, when helium gas is used, the diffusibility is high, similar to that of a hydrogen-containing mixed gas.

In the above embodiment, the device main body 1 is used for preliminary pressure resistance testing before the main pressure resistance testing, but its use is not limited to preliminary pressure resistance testing.

In this example, since the test valve 2 is a small-diameter screw-in type ball valve, the cover body 30 is shaped to surround the stem shaft seal portion 33 of the test valve 2, and the branch flow paths 43 of the air flow path 42 are provided only on both sides of the length of the cover body 30, but the cover body 30 may be provided in other forms. For example, slit-shaped branch flow paths may be provided on both sides of the width direction in addition to the length direction of the cover body 30, and air may be discharged from the opening edge of the branch flow path in the width direction (not shown). In this case, when air is discharged from each opening edge, an air curtain is formed that surrounds the opening 32 by facing or intersecting in the length direction and width direction, respectively. In addition, slit-shaped branch flow paths may be provided only on both sides of the width direction of the cover body 30, not in the length direction, and air may be discharged from the opening edge of the branch flow path in the width direction (not shown).

For example, when a large-diameter ball valve is used as the test valve, the cover body can be formed into a rectangular or cylindrical shape capable of surrounding the stem shaft seal portion of the ball valve, and an opening edge can be provided around the entire circumference of the opening of the cover body (not shown). In this case, an air curtain is formed so that the air blown out from the opening edge surrounds the test space from the entire circumference, further improving the insulation of the test space from the external environment. Therefore, the accuracy of the pressure resistance test can be maintained even if the test valve is large.

The areas to be inspected using the cover body are not limited to the stem shaft seal area of the test valve, but can be various areas of the test valve. This makes it possible to inspect the entire test valve and detect leaks occurring throughout the entire test valve. Furthermore, the test valve is not limited to a ball valve, but can be various valves such as globe valves and gate valves, and pressure testing can be performed on parts or the entirety of these valves.

In this case, the cover body is not limited to a rectangular shape, and its external shape and size, as well as the volume of the test space S, can be set arbitrarily according to the size and shape of the part to be tested, and the pressure test can be performed by surrounding the part to be tested of the test valve within this test space S. The part to be tested (test object) can be something other than the test valve (valve), and examples of the part to be tested include equipment such as various actuators, pressure vessels, and pumps, or parts for transporting fluids such as pipes, and it is possible to pressure test the shaft seal parts of these equipment and parts, or parts that may leak (parts that require pressure testing) within the test space S formed to the required volume.

The opening edge 45 of the opening 32 does not necessarily need to be formed so as to be inclined with respect to the vertical direction of the cover body 30, and may be provided in the vertical direction from the opening 32 (not shown). In this case, air flows directly downward from the opening edge of the branch flow path 43, and this air can be used to form an air curtain surrounding the inspection space S, making it possible to block the outside (external air) in the same way as when an inclined opening edge 45 is provided.

Next, the procedure and operation of the pressure test using the device main body 1 of the above embodiment will be described. The pressure test of the valve in this example is carried out in accordance with each air pressure test of the valve body pressure test specified in JIS B 2003 (General rules for inspection of valves). In this case, the pressure test is divided into a preliminary pressure test and a main pressure test for the test valve 2, and in the preliminary pressure test, a partial pressure test of the components of the test valve 2 is carried out using the device main body 1 described above. The main pressure test is carried out following the preliminary pressure test to perform a general inspection of the entire test valve 2 and each seal part.

When a preliminary pressure test is performed, the test subject is the semi-finished test valve 2, with the body 60, stem 62, O-ring 65, and packing retainer 63 assembled together. The test valve 2 is placed on the support jig 13 while the primary side of the test valve 2 is in contact with the seal member 54 of the fixed clamp jig 50, and in this state the movable clamp jig 51 is moved in the holding direction from the secondary side of the test valve 2 to clamp it. At this time, the seal members 54, 54 seal the primary and secondary ends of the test valve 2, respectively, preventing leakage from the primary and secondary openings of the test valve 2, and the primary flow path 53 of the fixed clamp jig 50 and the secondary flow path 55 of the movable clamp jig 51 are in communication with each other.

In this case, as shown in Figure 1, the chamber 11 is in a position retracted from the clamping position of the test valve 2, and by supplying purge air from the purge air supply pipe 36 through the air purge flow path 34 into the inspection space S in this retracted position, the inspection space S is air purged by the air flow indicated by the two-dot chain line as shown in Figure 4. At this time, a weak amount of air may be supplied from the air supply port 42 to provide an air curtain 40.

By moving the chamber 11 forward and downward so that the stem shaft seal portion 33 of the test valve 2 is covered by the cover body 30, the stem shaft seal portion 33, which is the pressure resistance test portion, is surrounded by the test space S in an unsealed state, as shown in Figure 2.

Next, search gas (hydrogen gas) is supplied from the primary flow path 53 into the test valve 2 to pressurize it while it is sealed in the body 60, and air is supplied from the air supply port 42. This air flows from the air supply port 42 into the branch flow paths 43, passes through each branch flow path 43, and is blown out from the opening edge 45. These air particles collide with the opening edge 45 inclined toward the inside, and an air curtain 40 is provided along the opening edge 45. This air curtain 40 partitions and forms a communication area between the external environment area T of the cover body 30 and the space to be inspected S, thereby isolating the outside from the space to be inspected S. Therefore, the influence of the atmospheric gas in the external environment area T on the search gas leaking from the test valve 2 is suppressed, and in this state, the presence or absence of leakage of hydrogen gas in the space to be inspected S and the amount of leakage can be detected with high accuracy, making it possible to accurately perform a pressure resistance test.

At this time, since the air supply port 42 is provided at approximately the center of the left and right branch flow paths 43, the air supplied from the air supply port 42 flows approximately evenly into the left and right branch flow paths 43, and the air that has traveled through each of these slit-shaped branch flow paths 43 is blown out evenly from the opening edge 45. As a result, an air curtain 40 with an approximately uniform volume of air throughout is provided below the inspection space S.

As described above, the stem shaft seal portion 33 of the test valve 2 is surrounded by the cover body 30 in an unsealed state to reduce the volume of the test space S, and the search gas leaking from the stem shaft seal portion 33 diffuses and accumulates in this test space S, making it possible for the gas sensor 12 to detect even a very small amount of search gas leakage. Moreover, by locating the gas detection portion of the gas sensor 12 in close proximity to the test valve 2, more accurate detection is possible.

At this time, the communication area between the external environment area T of the cover body 30 and the inspection space S is partitioned and formed by the air curtain 40, which surrounds and closes the opening 32 of the cover body 30, preventing atmospheric gas in the external environment area T, such as residual gas after the pressure test and exhaust gas, from penetrating into the inspection area S through the opening 32. The air curtain 40 also makes it possible to prevent the search gas remaining in the inspection area S from leaking to the outside.

As a result, it is possible to detect search gas leaking from the pressure test portion 33 of the test valve 2 into the test space S with high accuracy in a short time, and perform an accurate pressure test. At that time, by supplying weak air from the air supply port 42 to provide an air curtain 40, this weak air curtain 40 can suppress the diffusion of the search gas within the test space S while preventing leakage to the outside, thereby minimizing the impact on the test accuracy.

After the pressure test is performed, purge air is supplied from the air purge flow path 34 to discharge the search gas in the test space S from the opening 32 into the test space R. In this case, if the air purge flow path 34 is provided as a flow path separate from the air flow path 41 for the air curtain 40, the test space S can be purged while surrounded by the air curtain 40, making it possible to discharge the search gas more quickly. The search gas discharged into the test space R is discharged to the outside by the exhaust fan 21, preventing the search gas from remaining in the test space S and the test space R.

After the search gas has been discharged, the cover body 30 is raised and retracted from the inspection target portion 33 of the test valve 2, and the movable clamping jig 51 is moved in a direction away from the test valve 2 to unclamp it, and the test valve 2 is removed from the device main body 1.
Subsequently, when a preliminary pressure test is to be carried out on a different test valve 2, the test procedure may be carried out in the same manner as that described above.

When different test valves 2 are subjected to successive pressure-resistance preliminary tests, air may be continuously supplied from the air supply port to constantly generate the air curtain 40. In this case, after the test of the test valve 2 is completed, the air curtain 40 diffuses the search gas that may remain in the frame 10, which is the external environment area T, and promotes the exhaust fan 21 to exhaust the search gas to the outside, thereby more reliably preventing the search gas from remaining in the test space R.

As described above, if the test space S is air purged even when not being subjected to a pressure test, residual gas after the pressure test can be reliably removed, and the pressure test of the next test valve 2 can be accurately performed.
Furthermore, by constantly supplying a small amount of air from the air supply port 42, a weak air curtain 40 can be used to separate the outside (external environment area T) from the space to be inspected S, thereby constantly preventing, for example, exhaust gases from equipment such as a forklift installed at the inspection site or residual gas from the test valve 2 that was previously inspected from entering through the opening 32, thereby preventing erroneous judgments during pressure resistance testing and obtaining accurate detection results.

After the preliminary pressure test, all components such as the valve body, ball seat, and cap (not shown) are assembled and integrated into the partially assembled test valve 2. Furthermore, a handle is fixed to the top of the stem 62 via a washer and nut (not shown) to provide a fully assembled test valve, which is then subjected to the main pressure test.

In this pressure test, the test valve is held by a clamping jig in a large test space in a large test device (not shown) and the test is performed while it is completely covered. In this case, the test valve is half-opened and a search gas is sealed in, and a gas sensor is used to detect whether or not the search gas is leaking.

A test valve that passes both the preliminary pressure test and this main pressure test is deemed to have passed the test. If the main pressure test is deemed to have failed, the cause can be quickly identified by checking areas other than the sealed areas that passed the preliminary pressure test. After the pressure test, the inside of the test valve is purged to remove any remaining gas, and then the clamping jig is loosened to remove the test valve.

As described above, by conducting a preliminary pressure inspection before the main pressure inspection, it becomes possible to detect defects or processing defects in each test valve at an early stage without having to assemble the entire test valve.

7 shows another embodiment of the pressure resistance testing device of the present invention. In this embodiment, the same parts as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted.
The device body 70 of this embodiment is capable of pressure testing the entire test valve 71, and can also be used for the main pressure test after the preliminary pressure test described above.

The device body 70 has a cylindrical cover body 72, which is formed to a size capable of housing the entire test valve 71. A disk 74 is attached to the opening 72a at the bottom of the cover body 72, and a fixed clamp jig 75 for clamping the test valve 71 is attached to the center of the top surface of the disk 74.

On the other hand, an annular plate 76 is attached to an opening 72b in the upper part of the cover body 72, and a movable clamp jig 77 can be attached to the upper surface of this annular plate 76.
The movable clamp jig 77 has a mounting plate 80, an operating rod 81, and a movable clamp plate 82, and is provided so as to be fixed to the annular plate 76 via the mounting plate 80. A plurality of communication holes (not shown) are formed in the mounting plate 80, and an operating rod 81 is inserted into each of these communication holes. A movable clamp plate 82 that clamps the test valve 71 is attached to the tip side of the operating rod 81, and this movable clamp plate 82 is provided so as to be movable up and down by the operating rod 81.

The disk 74 and annular plate 76 of the cover body 72 are formed with a larger diameter than the cover body 72, and the disk 74 is provided with a plurality of air supply ports 84 at predetermined intervals that can blow air supplied from the outside downward. Meanwhile, a plurality of gas sensors 85 are attached to predetermined positions on the outer periphery of the cover body 72 so as to communicate with the inspection space S1 provided within the cover body 72, and these gas sensors 85 detect leakage of the search gas supplied into the test valve 71.

When conducting a pressure test on the test valve 71, the assembled test valve 71 is stored in the cover body 72 while the lower flange surface is placed on the fixed clamp jig 75, and the movable clamp jig 77 is attached to the cover body 72 so that the mounting plate 80 is placed on the upper surface of the annular plate 76.

Next, the movable clamp plate 82 is lowered by the operating rod 81, and the movable clamp plate 82 presses against the flange surface on the upper side of the test valve 71, thereby placing the test valve 71 in a predetermined position within the cover body 72. At this time, because a gap is provided between the communication hole of the mounting plate 80 and the operating rod 81, the entire test valve 71 is enclosed within the cover body 72 in a non-sealed state.

With the test valve 71 clamped by the fixed clamp jig 75 and the movable clamp jig 77, search gas is supplied into the test valve 71 and air is supplied from each air supply port 84. At this time, air is blown out from the discharge side of the air supply port 84 in the direction indicated by the two-dot chain arrow, and this air collides with the vicinity of the outer periphery of the disk 74, forming an annular air curtain 90 indicated by the dashed line between the upper annular plate 76 and the lower disk 74, and this air curtain 90 can surround the outer periphery of the cover body 72. This prevents the test space S1 inside the cover body 72 from being affected by the atmospheric gas in the external environment area T1 outside the cover body 72.

In this device main body 70, the air curtain 90 reliably prevents exhaust gases and the like generated in the external environment area T1 from entering the inspection space S1 through the gaps in the movable clamp jig 77, thereby preventing erroneous judgments during inspection. This makes it possible to suppress the effect on the search gas without eliminating the gaps on the movable clamp jig 77 side and sealing the inspection space S. As a result, the structure of the movable clamp jig 77 and fixed clamp jig 75 does not become complicated, making it possible to perform pressure resistance inspection of part or all of the test valve 71 while keeping costs down.

In the illustrated arrows, air is blown out linearly from the air supply port 84, but this arrow indicates the air blowing direction, and in reality, the air should be blown out radially from the air supply port 84 as it moves in the blowing direction. In this case, the air blown out from adjacent air supply ports 84 collides with each other, forming a circumferential air curtain 90 between the disk 74 and the annular plate 76 (mounting plate 80). This improves the insulation of the inspected space S1 from the external environment region T1, more reliably preventing leakage of the search gas from the inspected space S1 to the external environment region T1, while at the same time minimizing the influence of the external environment region T1.

Although not shown, an air purge flow path may be provided in the device body 70, as in the above embodiment. In this case, the air purge flow path can be used to supply purge air to the inspection space S1, thereby efficiently purging the inspection space S1.

Although not shown, an air supply port 84 may be provided on the outer periphery of the annular plate 76 or the mounting plate 80. In this case, the distance from the inspection space S1 to the external environment area T1 becomes longer, so that the influence of the external environment area T1 can be minimized.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention described in the claims of the present invention. For example, the present invention can be applied to various piping equipment other than valves, and can also be used for pressure testing of various pressure equipment such as pneumatic actuators. When conducting a pressure test, it is also possible to measure the amount of leakage instead of the presence or absence of a search gas leak.

1, 70 Device body 2, 71 Test valve 12, 85 Gas sensor 30, 72 Cover body 32 Opening 33 Pressure test part (stem shaft seal part)
34 Air purge flow path 40, 90 Air curtain 45 Opening edge S, S1 Inspected space T, T1 External environment area

Claims (2)

A chamber for carrying out a pressure test of the test valve is provided at the upper part of the inspection space, and the chamber includes a cover body surrounding the inspection part of the test valve, and a hanging part for moving the cover body at least in the vertical direction within the inspection space, and the cover body has an inspection space in which a gas sensor is mounted, an opening formed as a semi-open type with an open lower part and surrounding the inspection part, and an opening edge formed at the opening that can blow air inward, and the test valve in a semi-finished state with a stem inserted into the axial cylinder part of the body is fixed to the lower part of the inspection space with a clamping tool, and the hanging part is lowered to inspect the stem shaft seal part, which is the part to be inspected, by moving the cover body at least in the vertical direction within the inspection space. a cover body that covers the test valve in a non-sealed state, and an air curtain is configured to define a communication area through which air from the opening edge connects the external environment area of the cover body to the test space of the cover body, and by blocking the opening with this air curtain, the outside and the test space are isolated from each other to prevent them from being affected by the atmospheric gas in the external environment area, while being capable of detecting the presence or absence of search gas leaking from the test portion of the test valve in which search gas is sealed, thereby making it possible to perform continuous preliminary pressure testing of the stem shaft seal portion, which is the area to be tested, even for test valves of different classes or sizes . The pressure resistance inspection device for a valve according to claim 1, which is provided with an air purge flow path for purging the space to be inspected in the cover body with air.

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