Large pressure cylinder water pressure test tool

Abstract

The application discloses a large pressure-bearing cylinder water pressure test tool which is composed of a water outlet pipe assembly, a front support frame welding assembly, a water inlet pipe assembly, a sleeve, a front end face cover, a pull rod, an arc-shaped seat, a rear end face cover, a rear support frame welding assembly and an M42 nut. The cylinder is horizontally placed on the arc-shaped seat, and the front end and the rear end of the cylinder are both large openings, so that sealing measures are needed during water pressure test. If a traditional cover bolt connection compression sealing mode is adopted, the local stress of the connecting bolt during water pressure test is high, and the cylinder can be damaged. The front opening and the rear opening are changed into a piston type sealing structure, and a 'cylindrical surface sealing + end surface sealing + sealing glue' mode is adopted for sealing, most of the test pressure can be transferred, the bearing stress of the bolt is reduced, and irreversible damage to the cylinder caused by the deformation of the cylinder during water pressure can be avoided.

Description

Technical Field

[0001] This invention relates to the field of pressure-bearing cylinder testing technology, and specifically to a large pressure-bearing cylinder hydrostatic testing fixture. Background Technology

[0002] Hydraulic pressure testing is a crucial method for verifying the structural integrity, pressure-bearing capacity, and sealing effect of pressure-bearing products. The pressure-bearing capacity and sealing performance of large pressure-bearing cylinders are core indicators of their safe and reliable operation; therefore, rigorous hydraulic pressure testing is essential. This invention designs a novel hydraulic pressure testing fixture. A piston-type sealing structure is used at the large openings at the front and rear ends of the cylinder, allowing free deformation of the sealing devices at the front and rear ends of the cylinder during hydraulic pressure testing. Utilizing the principle of communicating vessels, air inside the cylinder is automatically expelled during water injection, eliminating the need for traditional venting copper pipes. The entire cylinder is connected to the hydraulic pressure fixture using a tie-rod integrated structure, transferring excess force during hydraulic pressure testing to the tie rod, better conforming to actual working conditions and preventing damage to the cylinder structure, surface quality, and end bolt holes caused by external forces.

[0003] In the hydrostatic testing of large pressure-bearing cylinders, traditional hydrostatic fixtures often rely on the enormous axial bolt preload to tighten the sealing rings. This is not only labor-intensive to assemble and disassemble, but also prone to failure under high pressure due to the reliance on a single sealing method. Furthermore, ensuring complete air evacuation from the test chamber is crucial for accurate and safe testing. Therefore, there is an urgent need to design a hydrostatic testing fixture with excellent sealing performance, requiring no additional venting components, and exhibiting stable structure to address the shortcomings of existing technologies and meet the hydrostatic testing requirements of large pressure-bearing cylinders.

[0004] Traditional hydrostatic testing employs a sealed plug structure, sealing the end faces of the test product by using a plug in conjunction with an axially compressed sealing ring to open the cylinder. This method has the following drawbacks: (1) Sealing depends on huge axial force: In order to resist the axial thrust generated by high pressure water, it is necessary to apply a huge bolt preload or external clamping force, which makes the tooling bulky, difficult to load and unload, and easy to cause deformation of the cylinder port.

[0005] (2) Unstable sealing reliability: A single end face seal is prone to leakage when pressure fluctuates or the cylinder is slightly deformed, resulting in failure of water pressure test.

[0006] (3) The support and positioning structure of the tooling is unstable, and the cylinder is prone to displacement or deformation during the test, which cannot meet the test requirements of large pressure cylinders.

[0007] Furthermore, during hydrostatic testing, traditional testing fixtures typically employ either a separate venting copper pipe or a complex internal venting channel to remove air from the cylinder. Both venting methods not only increase the structural complexity of the fixture but also raise processing and assembly costs. Incomplete venting can also negatively impact the hydrostatic test results. Summary of the Invention

[0008] Based on the above-mentioned technical problems, this invention proposes a large pressure-bearing cylindrical hydrostatic testing fixture to solve the problems of traditional hydrostatic testing using complex sealing structures, difficult loading and unloading, and unreliable sealing, thereby meeting the hydrostatic testing requirements of large pressure-bearing cylindrical cylinders.

[0009] To address the aforementioned technical problems, one objective of this invention is to provide a large-scale pressure-bearing cylindrical hydrostatic testing fixture. This fixture includes an outlet pipe assembly 1, a front support frame welding assembly 2, an inlet pipe assembly 3, a front end cap 5, a pull rod 6, an arc-shaped seat 7, a rear end cap 9, a rear support frame welding assembly 10, and an M42 nut 11. The test piece, cylindrical 8, is placed horizontally on the arc-shaped seat 7 to reduce the vertical deflection of the tie rod caused by its own weight and prevent overload deformation of the cylinder. The front end cap 5 and the rear end cap 9 are used to seal the left and right ends of the cylinder 8; The front end cap 5 and the rear end cap 9 are respectively equipped with a front support frame welding assembly 2 and a rear support frame welding assembly 10. The front support frame welding assembly and the rear support frame welding assembly are connected and fixed by a tie rod 6 with an M42 nut 11 to ensure that the excess pressure of the water pressure test is transferred to the tie rod. The inlet pipe assembly 3 and the outlet pipe assembly 1 are mounted on the front end cover 5, and the inlet pipe assembly 3 is positioned above the outlet pipe assembly 1.

[0010] Furthermore, the inlet pipe assembly 3 and the outlet pipe assembly 1 are respectively inserted into the holes opened on the front support frame welding assembly 2 and the front end cover 5, and fixed by welding to ensure that the weld is firm and leak-free.

[0011] Furthermore, the front and rear openings of the cylinder 8 to be tested are sealed using a piston-type sealing structure.

[0012] Furthermore, the use of "end face sealing + cylindrical surface sealing + sealant" transfers most of the test pressure, reduces the load stress on the bolts, and avoids irreversible damage to the cylinder due to deformation of the cylinder under water pressure.

[0013] Furthermore, the tie rod 6 and the M42 nut 11 are connected by a sleeve 4, and the assembly and testing of cylinders of different specifications can be achieved by adjusting the size of the sleeve.

[0014] The above-described one or more technical solutions of the present invention have at least one or more of the following technical effects: (1) The front and rear openings of the cylinder adopt a radial and end face piston-type sealing structure, which utilizes water pressure to self-tighten. The sealing performance increases with the increase of test pressure, which greatly improves the sealing performance of the tooling and effectively avoids the leakage problem during water pressure test. (2) The design utilizes the principle of communicating vessels to automatically discharge air from the cylinder during the water injection process, eliminating the need for traditional exhaust copper pipes, simplifying the tooling structure, and reducing processing and assembly costs.

[0015] (3) The combined structure of the arc-shaped seat and the front and rear support welding components can stably support and position the large pressure cylinder. During the test, the cylinder does not shift or deform, which is suitable for the testing needs of large pressure cylinders of different specifications.

[0016] (4) The tooling has a compact overall structure, is easy to operate, and can be reused. Attached Figure Description

[0017] Figure 1 : Schematic diagram of the structure of the large pressure-bearing cylindrical hydrostatic testing fixture of the present invention; Figure 2 : Schematic diagram of the front end face of the piston-type sealing structure of the present invention; Figure 3 : Schematic diagram of the rear end face of the piston-type sealing structure of the present invention; The components are: 1-outlet pipe assembly, 2-front support frame welding assembly, 3-inlet pipe assembly, 4-sleeve, 5-front end cap, 6-pull rod, 7-arc seat, 8-cylinder, 9-rear end cap, 10-rear support frame welding assembly, 11-M42 nut. Detailed Implementation

[0018] The structure, sealing method, assembly and fixing method, and water injection method of a large pressure-bearing cylindrical hydrostatic testing fixture. It includes inlet / outlet pipe assemblies, a front support frame welding assembly, sleeves, a front end cap, tie rods, an arc-shaped seat, a rear end cap, and a rear support frame welding assembly.

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments obtained. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0020] The water pressure testing fixture designed in this invention is shown in the attached figure. Figure 1As shown, it mainly consists of an outlet pipe assembly 1, a front support frame welding assembly 2, an inlet pipe assembly 3, a sleeve 4, a front end cap 5, a tie rod 6, an arc-shaped seat 7, a rear end cap 9, a rear support frame welding assembly 10, and an M42 nut 11. The cylinder 8 is placed horizontally on the arc-shaped seat 7. Since both the front and rear ends of the cylinder are large openings, sealing measures are required during the water pressure test. If a traditional bolt-connected sealing method is used, the local stress on the connecting bolts during the water pressure test will be high, potentially damaging the cylinder. Therefore, the front and rear openings are changed to a piston-type sealing structure, using a "cylindrical surface seal + end face seal + sealant" method. This transfers most of the test pressure, reduces the load-bearing stress on the bolts, and avoids irreversible damage to the cylinder due to deformation during water pressure testing. The piston-type sealing method is shown in the attached figure. Figure 2 and attached Figure 3 As shown.

[0021] As attached Figure 1 As shown, the inlet pipe assembly 3 and the outlet pipe assembly 1 are respectively inserted into the holes opened on the front support frame welding assembly 2 and the front end cap, and fixed by welding to ensure that the weld is firm and leak-free. During the water pressure test, the inlet pipe assembly 3 is located at the top of the end face of the cylinder 8, and the outlet pipe assembly 1 is located at the bottom of the end face of the cylinder 8, with the three connected to form a "communicating vessel". When filling with water, after blocking the outlet of the outlet pipe assembly 1, water is injected into the inner cavity of the cylinder through the inlet of the inlet pipe assembly 3. At this time, the gas at the bottom of the inner cavity is compressed by the liquid and will gather upwards near the inlet. Maintaining the water inlet state, the outlet is slightly opened, and the water pressure pushes the liquid to drive the gathered gas to be discharged in the opposite direction from the outlet. At this time, the outlet temporarily acts as an exhaust channel. Water is continuously injected until a stable flow of water without bubbles flows out of the outlet, indicating that the gas in the inner cavity of the cylinder has been completely discharged. After the gas is discharged, the outlet is blocked, and water is injected to increase the pressure to the test pressure. During testing, the communicating vessel structure ensures uniform internal pressure and prevents pressure fluctuations caused by residual gas.

[0022] As attached Figure 2 and attached Figure 3 As shown, the front and rear end faces and the transition rings of the cylinder under test are bolted together. End face sealing grooves are formed on the surfaces where the transition rings connect to the front and rear end faces of the cylinder under test to accommodate sealing rings and form end face seals. Cylindrical sealing grooves are formed on the sides of the piston rings on the front and rear end faces, forming cylindrical seals together with the transition rings. The end caps on the front and rear end faces are then fastened onto the piston rings, together forming a piston-type sealing structure. The piston rings, transition rings, and end caps are not fixedly connected; during the hydrostatic test, the cylinder under test, piston rings, transition rings, and end caps can all move freely axially.

[0023] During the hydrostatic test, the front end cap 5 and the rear end cap 9 move outwards at both ends under the test pressure, requiring constraints on their movement. Therefore, a front support frame welding assembly 2 and a rear support frame welding assembly 10 are installed on the outside of the front and rear end caps. These assemblies are connected and fixed by 22 tie rods 6 using M42 nuts 11. The piston's stroke is thus limited by these assemblies. The tie rods connect the front and rear support frame welding assemblies, ensuring that excess pressure from the hydrostatic test is transferred to the tie rods. The arc-shaped seat 7 reduces the vertical deflection of the tie rod due to its own weight, preventing overload deformation of the cylinder. Furthermore, a sleeve 4 is used to connect the tie rod and the nut, allowing for the assembly and testing of cylinders of different specifications by adjusting the sleeve's size.

[0024] This invention has been successfully applied to the hydrostatic testing of a large pressure-bearing cylinder. The hydrostatic test successfully passed the entire process of pressurization, pressure holding, and pressure release. Furthermore, no damage was found to the structure or surface quality of the large pressure-bearing cylinder after the hydrostatic test, indicating that no irreversible deformation or damage to the cylinder occurred due to excessive axial load during the test. This fully demonstrates that the hydrostatic testing fixture is safe, reliable, and has good sealing performance.

[0025] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A large pressure-bearing cylindrical hydraulic pressure testing fixture, characterized in that: The tooling includes an outlet pipe assembly (1), a front support frame welding assembly (2), an inlet pipe assembly (3), a front end cap (5), a tie rod (6), an arc-shaped seat (7), a rear end cap (9), a rear support frame welding assembly (10), and an M42 nut (11). The test piece, cylindrical (8), is placed horizontally on the arc-shaped seat (7) to reduce the vertical deflection of the tie rod caused by its own weight and prevent the cylinder from being overloaded and deformed. The front end cap (5) and the rear end cap (9) are sealed at the left and right ends of the cylinder (8); The front end cap (5) and the rear end cap (9) are respectively equipped with a front support frame welding assembly (2) and a rear support frame welding assembly (10), and the front support frame welding assembly and the rear support frame welding assembly are connected and fixed by a tie rod (6) and an M42 nut (11). The inlet pipe assembly (3) and the outlet pipe assembly (1) are mounted on the front end cover (5), and the inlet pipe assembly (3) is mounted above the outlet pipe assembly (1).

2. The large pressure-bearing cylindrical hydrostatic testing fixture according to claim 1, characterized in that: The inlet pipe assembly (3) and outlet pipe assembly (1) are respectively inserted into the holes opened on the front support frame welding assembly (2) and the front end cover (5), and are fixed by welding to ensure that the weld is firm and leak-free.

3. The large pressure-bearing cylindrical hydrostatic testing fixture according to claim 1, characterized in that: The front and rear openings of the cylinder (8) to be tested are sealed with a piston-type sealing structure.

4. The large pressure-bearing cylindrical hydrostatic testing fixture according to claim 3, characterized in that: The sealing method of "end face sealing + cylindrical surface sealing + sealant" transfers most of the test pressure, reduces the load stress on the bolts, and avoids irreversible damage to the cylinder due to cylinder deformation under water pressure.

5. The large pressure-bearing cylindrical hydrostatic testing fixture according to claim 1, characterized in that: The tie rod (6) and the M42 nut (11) are connected by a sleeve (4), and the assembly and testing of cylinders of different specifications can be achieved by adjusting the size of the sleeve.

6. The large pressure-bearing cylindrical hydrostatic testing fixture according to claim 5, characterized in that: The front support frame welding assembly (2) and the rear support frame welding assembly (10) are connected and fixed by 22 tie rods (6) with M42 nuts (11) to ensure that excess pressure from the water pressure test is transferred to the tie rods.

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