Polyethylene water supply pipe rapid pressure testing device and pressure testing method

Abstract

The application discloses a kind of polyethylene water supply pipe rapid pressure testing device and pressure testing method, one end of the second sealing member is fixed end, the first sealing member is compensation end, when the internal pressure of the pipe to be measured reaches the preset pressure value, the pressure drives the pipe to be measured to move towards the first sealing member;The fixed assembly includes baffles respectively arranged at the end of the first sealing member and the second sealing member, and a water inlet pipe connected between the two baffles for injecting water into the pipe and limiting the distance between the first sealing member and the second sealing member;The test device of the application sets the first sealing member and the second sealing member as air bags, which can reliably block both ends of the pipe after inflation and quickly form a sealed pressure testing space;Compared with the traditional pressure testing method using metal sealing joints, this device does not need to be equipped with multiple adjustment joints for different pipe diameters, and does not need to repeatedly check the sealing tightness of the joint and the pipe end face, simplifying the operation process and improving the pressure testing efficiency.

Description

Technical Field

[0001] This invention relates to the technical field of water supply pipe pressure testing devices, specifically to a rapid pressure testing device and method for polyethylene water supply pipes. Background Technology

[0002] Polyethylene (PE) water supply pipes are widely used in urban water supply, gas transmission, and industrial pipelines due to their excellent corrosion resistance, flexibility, and long service life. Before leaving the factory or being installed in an engineering project, pressure testing is usually required to verify that their pressure-bearing capacity and sealing performance meet design requirements.

[0003] Currently, common pipe pressure testing methods mainly employ metal sealing joints or flange blind plates secured with bolts. For example, patent publication number CN103574214A discloses a "hydraulic testing device for plastic water supply pipe fittings," which uses a combination of plugs, clamps, and plugs to achieve sealing via rubber sealing rings, and is fixed to the pipe fitting by the counter-toothed engagement of the clamp's inner wall. While such devices can achieve a seal, their sealing structure is complex, requiring different clamps and plugs for different pipe diameters, resulting in poor versatility. Installation requires repeated tightening of multiple bolts, making operation cumbersome and pressure testing inefficient, especially for large-diameter pipes where installation time is even longer. More importantly, the seal often cannot be achieved in one attempt; sometimes, repeated disassembly and reassembly, along with adjustments to the clamps and sealing rings, are necessary to achieve an effective seal, further wasting time and manpower. Furthermore, the counter-toothed structure of the clamps can easily scratch or indent the pipe's outer wall, affecting surface quality. Metal materials are prone to rust and corrosion, and using stainless steel would increase manufacturing costs.

[0004] Existing technologies also employ flexible sealing methods using airbags as sealing elements. For example, patent publication number CN115791424A discloses a "Pressure Testing Device for Flange Pipe Welded Components," which uses an airbag encased outside the pipe fitting. Gas is injected into the airbag, causing it to expand and adhere to the inner wall of the pipe to form a seal. This method can adapt to pipes with different inner diameters, solving the problem of poor versatility of rigid sealing methods. However, the airbag in this device is only used to achieve pipe diameter adaptation, and the airbag relies solely on the frictional force generated by inflation to adhere to the pipe wall, without a limiting structure to prevent axial displacement of the airbag. Under high-pressure water, the airbag is easily affected by axial thrust, causing it to shift or be flushed out of the pipe, leading to seal failure. Therefore, this invention proposes a rapid pressure testing device and method for polyethylene water supply pipes. Summary of the Invention

[0005] The purpose of this invention is to solve the above problems by providing a rapid pressure testing device and method for polyethylene water supply pipes.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a rapid pressure testing device for polyethylene water supply pipes, comprising a first sealing element installed inside one end of the pipe to be tested; The second sealing element is installed inside the other end of the pipe to be tested; A fixing assembly for fixing a first seal and a second seal; characterized in that: one end of the second seal is a fixed end, the first seal is a compensating end, and when the internal pressure of the pipe under test gradually increases, the pipe expands or deforms radially under pressure, and elongates axially towards the first seal; The fixing assembly includes baffles respectively disposed at the ends of the first seal and the second seal, and a water inlet pipe connecting the two baffles for injecting water into the pipe and for limiting the distance between the first seal and the second seal. The second seal is fitted with a limiting ring to prevent relative movement between the second seal and the pipe.

[0007] More preferably, both the first and second sealing elements are airbags.

[0008] A further preferred embodiment includes a friction-reducing layer disposed between the first seal and the inner wall of the pipe to reduce the coefficient of friction between the two.

[0009] More preferably, the friction-reducing layer is a polytetrafluoroethylene film.

[0010] More preferably, the water inlet pipe is a hollow threaded pipe connected to the two baffles to limit the distance between the two baffles.

[0011] More preferably, one end of the hollow threaded pipe is provided with a water inlet valve, and the portion of the hollow threaded pipe located inside the pipe has at least one water inlet.

[0012] More preferably, both the first and second sealing elements are provided with air inlets, and the first and second sealing elements are provided with through holes for the water inlet pipe to pass through.

[0013] More preferably, a sealant is provided between the through hole and the water inlet pipe.

[0014] A pressure testing method for a rapid pressure testing device for polyethylene water supply pipes, characterized in that the pressure testing steps include: S1. Device installation: Insert the first sealing element into one end of the pipe, place the second sealing element inside the other end of the pipe, and fit a limiting ring on the exposed part of the second sealing element; install two baffles at the ends of the first and second sealing elements respectively, so that the water inlet pipe passes through the baffle, the first sealing element, the inside of the pipe, the second sealing element and the baffle in sequence, and tighten the baffles at both ends of the hollow threaded pipe with bolts; S2. Seal expansion: Inflate the first and second seals through the air inlet to expand them and seal them against the inner wall of the pipe. At the same time, before installation, a friction-reducing layer should be set between the first seal and the inner wall of the pipe to reduce the coefficient of friction between them. S3. Water injection and pressure test: Water is injected into the pipe through the inlet pipe to gradually increase the water pressure inside the pipe to the preset test pressure value; S4. Axial displacement compensation: Under the action of water pressure in step S3, the pipe is subjected to axial thrust. Since the friction coefficient between the first seal with the anti-friction layer and the inner wall of the pipe is lower than that of the second seal, and the limiting ring prevents the pipe from axially elongating towards the second seal, the pipe elongates axially towards the first seal. S5. Pressure Maintenance and Detection: Maintain the test pressure for the preset time, and monitor the pressure changes inside the pipe and whether there is any leakage or abnormal deformation in the pipe body during the period. S6. Pressure Relief and Disassembly: After the pressure test is completed, release the pressure inside the pipe, vent the first and second seals respectively, remove the baffle, limit ring and water inlet pipe, take out the first and second seals, and complete the pressure test operation.

[0015] In a further preferred embodiment, in step S1, the water inlet pipe is a hollow threaded pipe. By rotating the hollow threaded pipe, the distance between the two baffles is adjusted so that the first and second sealing elements maintain a predetermined distance from both ends of the pipe before inflation.

[0016] The beneficial effects of this invention are as follows: By setting the first and second sealing elements as airbags, this test device can reliably seal both ends of the pipe after inflation, quickly forming a closed test pressure space. Compared with the traditional test method using metal sealing joints, this device does not require multiple debugging joints for different pipe diameters, nor does it require repeated checks on the tightness of the seal between the joint and the pipe end face, simplifying the operation process and improving the test pressure efficiency.

[0017] With the fixed components in place, test water enters the pipe from the inlet pipe, causing the water pressure inside the pipe to rise continuously. At the same time, the inlet pipe is connected to two baffles. Under the action of water pressure, the first and second seals are subjected to an axial thrust that moves them outward from the pipe. The inlet pipe holds the two baffles, which can effectively resist the thrust and prevent the first and second seals from being pushed out of the pipe under pressure, ensuring that the seals always remain in the predetermined sealing position.

[0018] Furthermore, by fitting the limiting ring onto the limiting groove of the exposed portion of the second seal, the limiting ring is pressed and pressed against the end of the pipe when the airbag is inflated. This, in conjunction with the baffle, prevents relative movement between the second seal and the pipe, avoiding the second seal being pushed into the pipe during water injection. It also prevents the pipe from axially elongating towards the second seal. Thus, after the pipe expands radially under pressure, it can only axially elongate towards the first seal on the side away from the limiting ring.

[0019] By applying sealant, the sealing between the inlet pipe and the through hole can be effectively increased, preventing test water from leaking along the gap, thereby ensuring stable internal pressure of the pipe and improving the accuracy and reliability of the test results.

[0020] By setting the friction-reducing layer, the friction between the first seal and the inner wall of the pipe is reduced. Under the pressure test, the second seal is restricted from relative movement by the limiting ring, while the first seal is easier to slide relative to the first seal due to the reduced friction, thereby causing the pipe to elongate axially toward the first seal. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view of the overall structure of the present invention; Figure 2 This is a partially enlarged view of the present invention; Figure 3 This is a side view of the first or second sealing element of the present invention after it has been inflated.

[0022] Legend: 1. First seal; 11. Through hole; 12. Air inlet; 2. Second seal; 3. Baffle; 4. Limiting ring; 5. Water inlet pipe; 51. Water inlet; 6. Anti-friction layer; 7. Water inlet valve; 8. Pipe; 9. Sealant. Detailed Implementation

[0023] The following description, in conjunction with the accompanying drawings, further illustrates the rapid pressure testing device and method for polyethylene water supply pipes according to the present invention.

[0024] See Figures 1-3As shown, a rapid pressure testing device and method for polyethylene water supply pipes includes a first sealing element 1, installed inside one end of the pipe 8 to be tested; a second sealing element 2, installed inside the other end of the pipe 8 to be tested; and a fixing assembly for fixing the first sealing element 1 and the second sealing element 2. The device is characterized in that: one end of the second sealing element 2 is a fixed end, meaning the second sealing element 2 is fixed by a limiting ring 4 and a baffle 3, preventing axial displacement to the inside or outside of the pipe 8; the first sealing element 1 is a compensating end, meaning the first sealing element 1 side allows the pipe 8 to axially elongate in its direction under pressure, compensating for the axial deformation of the pipe 8. When the internal pressure of the pipe 8 under test gradually increases, the pipe 8 expands or deforms radially under pressure, and elongates axially towards the first seal 1; the fixing assembly includes baffles 3 respectively disposed at the ends of the first seal 1 and the second seal 2, and a water inlet pipe 5 connecting the two baffles 3 for injecting water into the pipe 8 and for limiting the distance between the first seal 1 and the second seal 2; the second seal 2 is fitted with a limiting ring 4 to prevent relative movement between the second seal 2 and the pipe 8; the first seal 1 and the second seal 2 are both airbags; the second seal 2 is provided with a limiting groove that matches the limiting ring 4.

[0025] This test device sets the first sealing element 1 and the second sealing element 2 as airbags. After inflation, they can reliably seal both ends of the pipe 8 and quickly form a closed test pressure space. Compared with the traditional test method using metal sealing joints, this device does not require multiple debugging joints for different pipe diameters, nor does it require repeated checks on the tightness of the seal between the joint and the end face of the pipe 8. This simplifies the operation process and improves the test pressure efficiency.

[0026] With the fixed components in place, test water enters the pipe 8 from the inlet pipe 5, causing the water pressure inside the pipe 8 to rise continuously. At the same time, the inlet pipe 5 is connected to two baffles 3. Under the action of water pressure, the first seal 1 and the second seal 2 are subjected to an axial thrust that moves outward from the pipe 8. The inlet pipe 5 holds the two baffles 3, which can effectively resist the thrust and prevent the first seal 1 and the second seal 2 from being pushed out of the pipe 8 under pressure, ensuring that the seals are always kept in the predetermined sealing position.

[0027] Furthermore, by fitting the limiting ring 4 onto the limiting groove of the exposed portion of the second seal 2, the limiting ring 4 is pressed and abuts against the end of the pipe 8 when the airbag is inflated, cooperating with the baffle 3 to prevent relative movement between the second seal 2 and the pipe 8, thus avoiding the second seal 2 being pushed into the pipe 8 during water injection, and also preventing the pipe 8 from axially elongating towards the second seal 2; thereby ensuring that after the pipe 8 expands radially under pressure, it can only axially elongate towards the first seal 1 on the side away from the limiting ring 4.

[0028] The water inlet pipe 5 is a hollow threaded pipe connected to the two baffles 3 to limit the distance between the two baffles 3; one end of the hollow threaded pipe is provided with a water inlet valve 7, and the portion of the hollow threaded pipe located inside the pipe 8 is provided with at least one water inlet 51; the hollow threaded pipe is provided with an external thread that is compatible with a nut; as a preferred embodiment, a pressure sensor is provided on the water inlet pipe 5 between the water inlet valve 7 and the pipe 8.

[0029] By setting the water inlet pipe 5 as a hollow threaded pipe, with two baffles 3 and the first seal 1 and the second seal 2 passing through its two ends, and nuts screwed into both ends of the hollow threaded pipe, it can serve as a water injection channel to uniformly inject test water into the pipe 8. At the same time, by rotating the nuts, the nuts can be moved axially along the water inlet pipe 5 and push the baffles 3, thereby changing the distance between the two baffles 3. This allows the device to quickly adapt to pipes 8 of different lengths to be tested. Simultaneously, when the high-pressure water generates axial thrust and attempts to push the first seal 1, the second seal 2 and the baffles 3 outward, the nuts at both ends press against the outer side of the baffles 3, converting the thrust into tensile stress inside the water inlet pipe 5, providing reliable axial support for the baffles 3, thereby effectively preventing the baffles 3 from shifting.

[0030] Both the first sealing element 1 and the second sealing element 2 are provided with air inlets 12, and the first sealing element 1 and the second sealing element 2 are provided with through holes 11 for the water inlet pipe 5 to pass through for sealing. A sealant 9 is provided between the through hole 11 and the water inlet pipe 5. The sealant 9 is a water-swellable sealant; when test water seeps in along the tiny gap between the through hole 11 and the water inlet pipe 5, the water-swellable sealant expands in volume after contact with water, automatically filling and sealing the leakage channel, forming a dynamic self-sealing effect.

[0031] By using sealant 9, the sealing between the inlet pipe 5 and the through hole 11 can be effectively increased, preventing the test water from leaking along the gap, thereby ensuring the stability of the internal pressure of the pipe 8 and improving the accuracy and reliability of the test results.

[0032] In one embodiment, a friction-reducing layer 6 is further provided between the first seal 1 and the inner wall of the pipe 8 to reduce the coefficient of friction between the two; the friction-reducing layer 6 is a polytetrafluoroethylene film.

[0033] By setting the friction-reducing layer 6, the friction between the first seal 1 and the inner wall of the pipe 8 is reduced; under the action of the test pressure, the second seal 2 side is restricted from relative movement by the limiting ring 4, while the first seal 1 side is easier to slide relative to each other due to the reduced friction, thereby causing the pipe 8 to axially elongate towards the first seal 1 side.

[0034] The pressure testing method of the present invention includes the following steps: First, with the first seal 1 in a state where it is not inflated or only partially inflated and has not yet adhered to the inner wall of the pipe 8, the friction-reducing layer 6 is wrapped around the outer surface of the first seal 1, and the first seal 1 covered with the friction-reducing layer 6 is inserted into one end of the pipe 8.

[0035] Next, the second seal 2 is partially inserted into the second end of the pipe 8, with one part inside the pipe 8 and the other part protruding outside the end of the pipe 8. When the second seal 2 is not inflated or only partially inflated and not yet in contact with the inner wall of the pipe 8, a limiting ring 4 is fitted onto the limiting groove of the protruding part of the second seal 2, positioning the limiting ring 4 outside the end of the second end of the pipe 8. When the second seal 2 is subsequently fully inflated, the limiting ring 4 is pressed against the end of the second end of the pipe 8 by the expansion force, forming an axial limit and preventing the second seal 2 from sliding into the pipe 8 under high pressure.

[0036] Then, place the two baffles 3 on the outer ends of the first seal 1 and the second seal 2 respectively; let the water inlet pipe 5 pass through the baffle 3, the through hole 11 on the first seal 1, the inside of the pipe 8, the through hole 11 on the second seal 2, and the baffle 3 in sequence, and screw nuts into both ends of the water inlet pipe 5 to initially tighten them.

[0037] Next, the inflation device is connected sequentially to the inflation port 12 on the first sealing member 1 and the inflation port 12 on the second sealing member 2 to inflate the first sealing member 1 and the second sealing member 2. The first sealing member 1 and the second sealing member 2 gradually expand until their outer walls are tightly fitted with the inner wall of the pipe 8 to form a seal. During the inflation process, the limiting ring 4 is pressed against the end of the second end of the pipe 8 by the expansion force of the second sealing member 2, forming an axial limit.

[0038] Then, after the seal is inflated, tighten the nuts at both ends of the water inlet pipe 5 again, so that the two baffles 3 press against the outer ends of the first seal 1 and the second seal 2 respectively, ensuring that the baffles 3 can effectively resist the axial thrust generated during the subsequent pressure test.

[0039] Next, the experiment begins: the test water source is connected to the inlet valve 7 at one end of the inlet pipe 5, the inlet valve 7 is opened, and the test water flows in through the inlet pipe 5 and is injected into the inside of the pipe 8 through the inlet 51 located inside the pipe. The water is continuously injected so that the water pressure inside the pipe 8 gradually increases. The pressure sensor 10 is set on the inlet pipe 5 between the inlet valve 7 and the pipe 8 to detect the water pressure inside the inlet pipe 5 in real time. Since the inlet pipe 5 is connected to the inside of the pipe 8, the detection value of the pressure sensor 10 is the real-time pressure inside the pipe 8. When the pressure sensor 10 detects that the pressure has risen to the preset test pressure value, the inlet valve 7 is closed and the water injection stops.

[0040] Under water pressure, the axial thrust generated by the water pressure inside the pipe 8 acts on the first seal 1 and the second seal 2, attempting to push the first seal 1 and the second seal 2 out of the pipe 8. At this time, the baffles 3 located at the ends of the first seal 1 and the second seal 2 are subjected to the thrust transmitted by the first seal 1 and the second seal 2, and the outer surface of the baffles 3 is tightened by the nuts at both ends of the water inlet pipe 5; this thrust is converted into tensile stress inside the water inlet pipe 5 through the nuts, causing mutual tension between the two baffles 3, thereby balancing the outward thrust of the high-pressure water, preventing the first seal 1 and the second seal 2 from being flushed out of the pipe 8, and ensuring that the first seal 1 and the second seal 2 always remain in the predetermined sealing position.

[0041] Meanwhile, since the second seal 2 is provided with a limiting ring 4 and the limiting ring 4 abuts against the second end of the pipe 8, it prevents the pipe 8 from axially elongating in the direction of the second seal 2; while the first seal 1 is provided with a friction-reducing layer 6 on the outside, which reduces the friction coefficient between the first seal 1 and the inner wall of the pipe 8, causing the pipe 8 to undergo axial elongation deformation in the direction of the first seal 1, thereby releasing the pressure inside the pipe 8.

[0042] At this time, the pressure value inside pipe 8 will drop briefly; after the axial elongation deformation of pipe 8 stabilizes, the pressure value will stabilize. This is a normal phenomenon and will not affect the judgment of the pressure test results.

[0043] Under this pressure, continuously monitor the changes in the pressure sensor readings; observe whether there is leakage or dripping on the surface of pipe 8 and at both ends of the seal; check whether pipe 8 has abnormal deformation such as bulges or cracks; record the pressure drop value and determine whether it is within the allowable range.

[0044] After the pressure test is completed, disconnect the water supply and slowly open the water inlet valve 7 to release the pressure inside the pipe 8; then open the air inlet 12 on the first seal 1 and the second seal 2 to allow the airbag to fully deflate and contract.

[0045] Finally, after the device is completely depressurized and removed, the wall thickness and length of pipe 8 after the test are measured and compared with the initial wall thickness and length before the test to determine whether the wall thickness and axial elongation of pipe 8 meet the requirements.

[0046] The scope of protection of this invention is not limited to the above embodiments and their variations. Conventional modifications and substitutions made by those skilled in the art based on the content of these embodiments are all within the scope of protection of this invention.

Claims

1. A rapid pressure testing device for polyethylene water supply pipes, comprising a first sealing element installed inside one end of the pipe to be tested; The second sealing element is installed inside the other end of the pipe to be tested; A fixing assembly for fixing a first seal and a second seal; characterized in that: One end of the second sealing element is a fixed end, and the first sealing element is a compensation end. When the internal pressure of the pipe under test gradually increases, the pipe expands or deforms radially under the pressure and elongates axially towards the first sealing element. The fixing component includes baffles respectively disposed at the ends of the first sealing element and the second sealing element, and a water inlet pipe connecting the two baffles for injecting water into the pipe and for limiting the distance between the first sealing element and the second sealing element. The second seal is fitted with a limiting ring to prevent relative movement between the second seal and the pipe.

2. The rapid pressure testing device for polyethylene water supply pipes according to claim 1, characterized in that: Both the first and second sealing elements are airbags.

3. The rapid pressure testing device for polyethylene water supply pipes according to claim 1, characterized in that: It also includes a friction-reducing layer disposed between the first seal and the inner wall of the pipe to reduce the coefficient of friction between the two.

4. The rapid pressure testing device for polyethylene water supply pipes according to claim 3, characterized in that: The friction-reducing layer is a polytetrafluoroethylene film.

5. The rapid pressure testing device for polyethylene water supply pipes according to claim 1, characterized in that: The water inlet pipe is a hollow threaded pipe that connects to the two baffles to limit the distance between the two baffles.

6. The rapid pressure testing device for polyethylene water supply pipes according to claim 5, characterized in that: One end of the hollow threaded pipe is provided with a water inlet valve, and the portion of the hollow threaded pipe located inside the pipe has at least one water inlet.

7. The rapid pressure testing device for polyethylene water supply pipes according to claim 5, characterized in that: Both the first and second sealing elements are provided with air inlets, and the first and second sealing elements are provided with through holes for the water inlet pipe to pass through.

8. The rapid pressure testing device for polyethylene water supply pipes according to claim 7, characterized in that: A sealant is provided between the through hole and the water inlet pipe.

9. A pressure testing method using the rapid pressure testing device for polyethylene water supply pipes as described in any one of claims 1-8, characterized in that, The pressure testing steps include: S1. Device installation: Insert the first sealing element into one end of the pipe, place the second sealing element inside the other end of the pipe, and fit a limiting ring on the exposed part of the second sealing element; install two baffles at the ends of the first and second sealing elements respectively, so that the water inlet pipe passes through the baffle, the first sealing element, the inside of the pipe, the second sealing element and the baffle in sequence, and tighten the baffles at both ends of the hollow threaded pipe with bolts; S2. Seal expansion: Inflate the first and second seals through the air inlet to expand them and seal them against the inner wall of the pipe. At the same time, before installation, a friction-reducing layer should be set between the first seal and the inner wall of the pipe to reduce the coefficient of friction between them. S3. Water injection and pressure test: Open the water inlet valve and inject water into the pipe through the water inlet pipe to gradually increase the water pressure in the pipe to the preset test pressure value; S4. Axial displacement compensation: Under the action of water pressure in step S3, the pipe is subjected to axial thrust. Since the friction coefficient between the first seal with the anti-friction layer and the inner wall of the pipe is lower than that of the second seal, and the limiting ring prevents the pipe from moving towards the second seal, the pipe elongates axially towards the first seal. S5. Pressure Maintenance and Detection: Maintain the test pressure for the preset time, and monitor the pressure changes inside the pipe and whether there is any leakage or abnormal deformation in the pipe body during the period. S6. Pressure Relief and Disassembly: After the pressure test is completed, release the pressure inside the pipe, vent the first and second seals respectively, remove the baffle, limit ring and water inlet pipe, take out the first and second seals, and complete the pressure test operation.

10. The pressure testing method of the polyethylene water supply pipe rapid pressure testing device according to claim 9, characterized in that: In step S1, the water inlet pipe 5 is a hollow threaded pipe. By rotating the hollow threaded pipe, the distance between the two baffles 3 is adjusted so that the first sealing element 1 and the second sealing element 2 maintain a predetermined distance from both ends of the pipe 8 before inflation.

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