Welded universal cryogenic valve body testing tool

Abstract

The utility model discloses a kind of welding general cryogenic valve body test tool, including base, first locating plate and second locating plate are provided on base, two first guide blocks are provided in the bottom of first locating plate, two second guide blocks are fixedly provided in the bottom of second locating plate, two guide grooves are provided on base, two first guide blocks and two second guide blocks are respectively slidably arranged in two guide grooves;Fixed positioning stud is on the side wall of first locating plate, first cryogenic flange is connected on positioning stud;Positioning threaded hole is provided on the side wall of second locating plate, transmission screw is threadedly connected in positioning threaded hole, second cryogenic flange is connected in the one end of transmission screw, hand wheel disc is fixedly arranged in the other end;Sealing structure is provided on the end face opposite to first cryogenic flange and second cryogenic flange;Two supports are provided on base.The utility model is compact in structure, easy to operate, can quickly clamp valve body and carry out sealing test, greatly improve detection efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of valve testing equipment, and in particular to a welded universal cryogenic valve body testing fixture. Background Technology

[0002] In industries such as petrochemicals and liquefied natural gas (LNG), cryogenic valves are key equipment for transporting cryogenic liquid media, and their sealing performance directly affects the safety and reliability of the system. After welding, the valve body must undergo rigorous pressure sealing tests. Cryogenic valves are suitable for operation in low-temperature environments (typically below -40°C) and are widely used in liquefied natural gas, air separation, cryogenic liquid storage and transportation. They are crucial devices that use a valve stem to move the valve core within the valve body to achieve control functions such as fluid cutoff and flow regulation. Welded valve bodies better ensure the valve's sealing and cryogenic performance, preventing leakage of cryogenic media. After assembly, the valve body needs to undergo pressure and leakage tests to verify its strength and sealing performance.

[0003] The connection between the low-temperature welded valve body and the pipeline is welded. After the weld bevel is machined, the operability during the pressure test after the entire assembly is poor. Due to the special structure of the valve body, it is difficult to directly and effectively clamp and pressurize it. Testing can only be carried out by using a test flange. However, the tooling flanges adapted to different diameters and pressure ratings are different in size and specifications. This means that special tooling is required for each different combination of diameter and pressure rating, which undoubtedly increases production costs significantly and makes the operation process extremely complicated. Frequent changes of different tooling also seriously restrict the improvement of work efficiency, resulting in problems such as poor adaptability, inconvenient adjustment, and poor sealing effect. Especially for valve bodies of different sizes, it is necessary to change the entire set of fixtures, resulting in low testing efficiency and cumbersome operation. Utility Model Content

[0004] This utility model provides a welded universal cryogenic valve body testing fixture to solve the problems of poor compatibility with testing valve bodies of different specifications, unreliable sealing, and cumbersome operation in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A welding-type universal cryogenic valve body testing fixture includes a base. The base has a first positioning plate and a second positioning plate that can slide relative to each other. Multiple guide blocks are provided at the bottom of both the first and second positioning plates, and each guide block slides in a guide groove on the base. A horizontally suspended positioning stud is fixedly connected to the side wall of the first positioning plate, and a first cryogenic flange is threaded onto the positioning stud. A positioning threaded hole is provided on the side wall of the second positioning plate, and a transmission screw is threaded into the positioning threaded hole. One end of the transmission screw is fixedly connected to the second cryogenic flange, and the other end is fixedly equipped with a handwheel. Sealing structures are provided on the opposite end faces of the first and second cryogenic flanges. Two supports for supporting the cryogenic welded valve body are provided on the base between the first and second positioning plates.

[0006] Furthermore, the sealing structure includes a plurality of concentric annular grooves formed on the end faces of the first cryogenic flange and the second cryogenic flange, and a sealing gasket embedded in each of the annular grooves.

[0007] Furthermore, a wrench is provided on the outer wall of the first cryogenic flange.

[0008] Furthermore, the upper end of the support is provided with a V-shaped groove for accommodating and positioning the valve body pipeline.

[0009] Furthermore, the first positioning plate and the second positioning plate are connected and fixed by a plurality of detachable positioning bolts.

[0010] Furthermore, a central medium channel is provided axially in the middle of the first cryogenic flange, and a lateral medium channel communicating with the central medium channel is provided radially on the side wall of the first cryogenic flange. The outer end interface of the lateral medium channel is used to connect to an external gas source.

[0011] Furthermore, the base is equipped with four shock-absorbing feet at its bottom.

[0012] The beneficial effects of this utility model are: 1. This utility model, by setting a slidingly adjustable first positioning plate and a second positioning plate, and in conjunction with a guide block and guide groove structure, can adapt to cryogenic valve bodies of different lengths and dimensions, and has strong versatility; the positioning stud and transmission screw connected by threads drive the two cryogenic flanges to move towards each other, so as to achieve tight contact with the inlet and outlet end faces of the valve body, which is labor-saving and has reliable sealing.

[0013] 2. By providing multiple concentric annular grooves and sealing gaskets on the end faces of both low-temperature flanges, multiple specifications of sealing rings are formed to adapt to valve bodies of different diameters and form a seal, which significantly improves the sealing performance during high-pressure gas testing and avoids leakage.

[0014] 3. This utility model can stably support valve bodies of different pipe diameters through the V-shaped groove at the upper end of the support, ensuring accurate positioning and convenient installation.

[0015] 4. This utility model has a compact overall structure and is easy to operate. It can quickly clamp low-temperature welded valve bodies and perform sealing tests, greatly improving testing efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this utility model, the drawings used in the implementation examples will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a schematic front view of the overall structure of Embodiment 1 of this utility model; Figure 3 This is a schematic diagram of the overall structure of Embodiment 1 of this utility model from the left side; Figure 4 This is a schematic diagram of the overall structure on the right side of Embodiment 1 of this utility model; Figure 5 This is a top view of the overall structure of Embodiment 1 of this utility model; Figure 6 Appendix to this utility model Figure 5 AA sectional view; Figure 7 Appendix to this utility model Figure 6 A magnified schematic diagram of the structure at position I; Figure 8 This is a schematic diagram of the support installation structure of Embodiment 1 of this utility model.

[0018] In the diagram: 1. Base; 2. First positioning plate; 3. Second positioning plate; 4. First guide block; 5. Second guide block; 6. Guide groove; 7. Positioning stud; 8. First cryogenic flange; 9. Transmission screw; 10. Second cryogenic flange; 11. Handwheel; 12. Support; 13. Circular groove; 14. Sealing gasket; 15. Wrench; 16. Cryogenic welded valve body; 17. Positioning bolt; 18. Central medium channel; 19. Lateral medium channel; 20. Vibration damping foot. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0020] Example 1: See Figure 1-8 ,like Figures 1 to 4 As shown, this utility model provides a welded universal cryogenic valve body testing fixture, including a rectangular base 1. Four shock-absorbing feet 20 are fixedly installed at the bottom of the base 1 to stably support the entire fixture and reduce vibration. Two parallel T-shaped guide grooves 6 are machined on the upper surface of the base 1. A first positioning plate 2 and a second positioning plate 3 are slidably installed in the T-shaped guide grooves 6 of the base 1 via first guide blocks 4 and second guide blocks 5 fixedly installed at their bottoms, allowing the first positioning plate 2 and the second positioning plate 3 to slide along the guide grooves 6, thereby adjusting the distance between them. The first positioning plate 2 and the second positioning plate 3 can also be connected and fixed by multiple positioning bolts 17. After the distance is adjusted appropriately, tightening the positioning bolts 17 can prevent the two positioning plates from moving during testing. A horizontally extending positioning stud 7 is welded to the side wall of the first positioning plate 2. A first cryogenic flange 8 is screwed onto the positioning stud 7 through its central threaded hole. The extension position of the first cryogenic flange 8 can be finely adjusted by rotating it. A wrench 15 is fixedly installed on the outer circumference of the first cryogenic flange 8 for easy rotation. The side wall of the second positioning plate 3 is machined with a positioning threaded hole, through which a transmission screw 9 passes and is threadedly engaged. A second cryogenic flange 10 is fixedly mounted at the end of the transmission screw 9, so that when the transmission screw 9 rotates, it can push the second cryogenic flange 10 to move horizontally, while the second cryogenic flange 10 itself does not rotate. A handwheel 11 is fixedly mounted on the outer end of the transmission screw 9 for convenient manual rotation operation.

[0021] In some embodiments, preferably, see Figure 6 Multiple concentric annular grooves 13 are machined on the two opposite end faces of the first cryogenic flange 8 and the second cryogenic flange 10. Each groove 13 is fitted with a sealing gasket 14. The sealing gasket 14 is made of polytetrafluoroethylene and is used to form a high-pressure seal with the inlet and outlet end faces of the cryogenic welded valve body 16.

[0022] In some embodiments, preferably, two supports 12 are fixedly installed on the base 1 between the first positioning plate 2 and the second positioning plate 3. Each support 12 has a V-shaped groove machined at its upper end; see attached diagram for details. Figure 8 The V-shaped groove is used to support and position the pipes at both ends of the cryogenic welded valve body 16 to be tested.

[0023] In some embodiments, the first cryogenic flange 8 has an axial central medium channel 18 machined at its center, and a radial lateral medium channel 19 machined on its sidewall communicating with the central medium channel 18. The outer port of the lateral medium channel 19 is machined with internal threads or a quick-connect coupling for connecting the air pipe of an external air pump.

[0024] The working principle of this utility model is as follows: During testing, firstly, based on the length of the cryogenic welded valve body 16 to be tested, loosen the positioning bolts 17, slide the first positioning plate 2 and the second positioning plate 3, and initially adjust the spacing. Hoist the cryogenic welded valve body 16 onto the V-grooves of the two supports 12. Rotate the handwheel 11 to drive the transmission screw 9, thereby pushing the second cryogenic flange 10 towards the cryogenic welded valve body 16, so that its end face is initially aligned with the inlet / outlet end face of one end of the cryogenic welded valve body 16. Then, use the wrench 15 to rotate the first cryogenic flange 8, so that its end face is tightly abutted against the inlet / outlet end face of the other end of the cryogenic welded valve body 16. Continue rotating the handwheel 11 to press the end face of the second cryogenic flange 10 against the corresponding end face of the cryogenic welded valve body 16. At this time, the multiple sealing gaskets 14 are compressed, forming a reliable seal. Finally, tighten the positioning bolts 17 to fix the relative positions of the two positioning plates. Normal temperature environment simulation: Connect the outlet pipe of the external air pump to the lateral medium channel 19 on the first cryogenic flange 8, and fill the cryogenic welded valve body 16 with test gas (such as nitrogen) at a specified pressure. Then immerse the entire cryogenic welded valve body 16 in a water tank or apply soapy water to the weld and seal, and observe whether bubbles are generated, thereby verifying the sealing performance of the cryogenic welded valve body 16; Low temperature environment simulation: Place the test fixture into the low temperature test chamber, connect the medium input pipe to the side medium channel 19 on the first low temperature flange 8, set the target test temperature (e.g. -196℃) on the control panel, start the cooler, and the temperature sensor monitors the valve body temperature in real time. When the set temperature is reached and stabilized, the test phase begins. Pressure test: Introduce test medium (such as nitrogen or gas) into the valve body, observe the readings of the pressure sensor and pressure gauge, and close the medium valve after the pressure rises to the set value. Hold the pressure for a specified time. If the pressure drop is less than the specified parameter, the airtightness is qualified. At the same time, observe the status of the safety valve to ensure that the pressure does not exceed the safety threshold. Test completed: After turning off the cooler and waiting for the valve body temperature to rise back to room temperature, remove the test fixture, loosen the handwheel, and remove the valve body to complete the test.

[0025] Other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of the invention is indicated by the claims.

[0026] It should be understood that this utility model is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model.

Claims

1. A welded universal cryogenic valve body testing fixture, comprising a base (1), characterized in that: The base (1) is provided with a first positioning plate (2) and a second positioning plate (3) that can slide closer to or further away from each other. The bottom of the first positioning plate (2) and the second positioning plate (3) are provided with multiple guide blocks. Each guide block is guided and slidably engaged with the guide groove provided on the base (1). A horizontally suspended positioning stud (7) is fixedly connected to the side wall of the first positioning plate (2). A first low-temperature flange (8) is threadedly connected to the positioning stud (7). A positioning threaded hole is provided on the side wall of the second positioning plate (3). A transmission screw (9) is threadedly connected to the positioning threaded hole. A second low-temperature flange (10) is fixedly connected to one end of the transmission screw (9), and a handwheel (11) is fixedly provided at the other end. A sealing structure is provided on the opposite end faces of the first low-temperature flange (8) and the second low-temperature flange (10). Two supports (12) for supporting the low-temperature welded valve body (16) are provided on the base (1).

2. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that: The sealing structure includes a plurality of concentric annular grooves (13) opened on the end faces of the first cryogenic flange (8) and the second cryogenic flange (10), and a sealing gasket (14) embedded in each of the annular grooves (13).

3. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that: A wrench (15) is provided on the outer wall of the first low-temperature flange (8).

4. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that: The upper end of the support (12) is provided with a V-shaped groove.

5. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that: The first positioning plate (2) and the second positioning plate (3) are connected and fixed by a plurality of detachable positioning bolts (17).

6. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that: The first low-temperature flange (8) has a central medium channel (18) arranged axially in the middle part, and a lateral medium channel (19) communicating with the central medium channel (18) is arranged radially on the side wall of the first low-temperature flange (8). The outer end interface of the lateral medium channel (19) is used to connect to an external gas source.

7. The welded universal cryogenic valve body testing fixture according to claim 1, characterized in that, The base (1) is provided with four shock-absorbing feet (20) at the bottom.

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