Pipe external pressure test tool

Abstract

The utility model belongs to the technical field of detection equipment, and particularly relates to a tubular product external pressure test tool. Comprising an outer box body which surrounds the sample pipe and is provided with a spacing part between the outer box body and the sample pipe; the supporting part comprises a first end connected with the outer surface of the sample pipe and a second end connected with the outer box body; the supporting part is used for positioning the sample pipe so as to maintain the spacing distance between the outer surface of the sample pipe and the outer box body; the packaging part, the outer box body and the outer surface of the sample pipe are matched to form at least part of the inner contour of the spacing part; and the guide pipe is arranged on the outer box body or the packaging part, and the spacing part is communicated to the voltage withstanding test equipment through the guide pipe. The device is a pipe external pressure test tool which can be matched with internal pressure test equipment, is good in compatibility with the internal pressure test equipment, is easy to obtain materials, is simple in installation mode, and has relatively low price cost and operation learning cost.

Description

Technical Field

[0001] This utility model belongs to the field of testing equipment technology, specifically relating to a pipe external pressure testing fixture. Background Technology

[0002] Hydrostatic testing is a crucial inspection process in pipe manufacturing. Its main purpose is to verify the strength and sealing performance of the pipe, ensuring that it can withstand the design pressure and operate long-term after use. The advantage of hydrostatic testing is that the force exerted by water pressure on the pipe is always radially directed towards the pipe's axis and is evenly distributed across the pipe's surface.

[0003] In pipeline-related product and operational standards, hydrostatic testing typically only requires internal pressure testing, with external pressure testing being less common. However, from a research and development perspective, pipe bursting due to internal pressure (internal pressure failure) and pipe collapse due to external pressure (external pressure failure) are attributed to different material mechanical properties, and the results of internal and external pressure tests are not interchangeable. For pipe internal pressure withstand capability, calculations are performed using the mean diameter formula during design; internal pressure failure indicates insufficient pipe strength or toughness. For pipe external pressure withstand capability, calculations are performed using the external pressure circumferential instability formula; external pressure failure indicates insufficient pipe stiffness. Conventional hydrostatic testing equipment can only perform internal pressure tests. If researchers need to perform external pressure tests on pipes under development, they need to use hydrostatic testing equipment specifically designed for external pressure testing. However, the frequency of testing for research samples is not high, and equipping dedicated testing equipment would incur significant procurement and long-term maintenance costs. Utility Model Content

[0004] In view of this, the present invention aims to provide an external pressure testing fixture adapted to conventional hydrostatic testing equipment. Furthermore, since the external pressure test object is a research and development sample and the testing frequency is low, this external pressure testing fixture has lower material costs and lower learning costs.

[0005] Therefore, this external pressure testing fixture should have a low price and low learning cost.

[0006] This utility model is achieved through the following technical solution:

[0007] A pipe external pressure testing fixture, characterized in that it comprises:

[0008] The outer casing surrounds the outside of the sample tube and has a spacer between it and the sample tube;

[0009] The support includes a first end connected to the outer surface of the sample tube and a second end connected to the outer box body; the support positions the sample tube and thus maintains the distance between the outer surface of the sample tube and the outer box body.

[0010] The encapsulation part, the outer box body, and the outer surface of the sample tube cooperate to form at least a portion of the inner contour of the spacer;

[0011] A conduit is disposed on the outer casing or the encapsulation part, and the spacer part is connected to the pressure resistance test equipment through the conduit.

[0012] This solution proposes a pipe external pressure testing fixture that enables the use of hydraulic testing equipment originally designed for internal pressure testing to perform external pressure tests on sample pipes. The working principle of the internal pressure testing equipment is as follows: the hydraulic testing equipment is connected to the inner surface of the sample pipe, forming a closed container; pressure is applied to a portion of the stagnant fluid within the closed container, and this pressure is transmitted in all directions of the stagnant fluid without change. This solution uses a support section to fix the distance between the sample pipe and the outer casing, forming a stable gap, and includes an encapsulation section to ensure that the gap forms the closed container required for the experiment, allowing the outer surface of the sample pipe to fully contact the pressure resistance test medium. When the outer surface of the sample pipe is within the closed container filled with the hydraulic testing medium, the hydraulic testing equipment can test the external pressure resistance of the sample pipe.

[0013] Compared to sample testing by the product quality control department, R&D samples are typically prototypes and do not require batch testing. Therefore, in this solution, components such as the outer casing, encapsulation, and conduits can be connected to the sample pipeline via non-removable methods such as welding, eliminating the need to consider the reusability of tooling. If the external pressure test sample needs to be replaced, R&D personnel can replace the matching external pressure test tooling simultaneously with the sample. This solution is simple to install and has low cost and low learning curve.

[0014] Preferably, the sample tube has a horizontal, fixed orientation.

[0015] The pressure test medium is dispersed in the cavity formed by the spacer, and the depth of the sample tube in the pressure test medium affects the distribution of static pressure. Therefore, the sample tube has a fixed horizontal orientation, and when the shape of the spacer is adjusted, the sample tube can be positioned at the same depth in the pressure test medium.

[0016] Preferably, the encapsulation part has a sample hole that passes through the encapsulation part, and the shape of the sample hole is adapted to the cross-sectional profile of the sample tube.

[0017] During installation, the sample tube passes directly through the sample hole, which simplifies the device setup process and allows the sample tube to pass fully over both sides of the encapsulation part. Both sides of the encapsulation part can connect with the outer surface of the sample tube, resulting in a better sealing effect of the cavity formed by the spacer.

[0018] Preferably, the sample hole is provided with the first end, and the encapsulation part is provided with the second end at a position away from the sample hole.

[0019] By using the encapsulation part as a support part, the number of points on the outer surface of the sample tube that are blocked is reduced, allowing the outer surface of the sample tube to fully contact the pressure resistance test medium and the test pressure distribution to be more uniform.

[0020] Preferably, the sample tube has both ends exposed at the ends of the spacer.

[0021] The exposed portions at both ends of the sample tube can be used to independently connect to other testing equipment to simulate the external pressure resistance when the sample tube is filled with or contains other media.

[0022] Preferably, the conduit is disposed on the encapsulation portion.

[0023] In this design, the encapsulation section is a flexible structure that combines the outer casing and the sample tubing. By mounting the conduit on the encapsulation section, the installation position of the conduit can be adjusted to accommodate different models of withstand voltage testing equipment.

[0024] Preferably, multiple sets of the encapsulation section are arranged; the conduits on the multiple sets of the encapsulation section are arranged coaxially.

[0025] In the pressure resistance test fixture with dual conduits, the encapsulation sections are symmetrically arranged at both ends of the sample tube, and the conduits on both sides of the encapsulation section are coaxially arranged. In this case, for the water pressure testing equipment, the entire fixture is equivalent to a pipe with narrow diameters at both ends and widening diameters in the middle, which meets the working requirements of the water pressure testing equipment.

[0026] Preferably, the outer casing is a pipe that is axially aligned with the sample tubing and has a larger diameter.

[0027] To reduce the cost of assembling the testing fixtures, the outer casing in this solution can be made from prefabricated pipes.

[0028] Preferably, the encapsulation part and the sample tube are sealed together, and the encapsulation part and the outer box are sealed together.

[0029] Preferably, the outer casing is a tubular component made of stainless steel.

[0030] To further reduce the manufacturing difficulty and material cost of the tooling, the outer box and the encapsulation part can be made of common stainless steel, and the outer box and the encapsulation part can be quickly and sealed by welding.

[0031] This invention features readily available materials, easy assembly, and low cost, enabling external pressure testing of sample pipes even with only internal pressure testing equipment. The outer casing can be made from common pipe materials. Due to its low cost, this invention eliminates the need for device recycling, directly employing non-removable methods such as welding to achieve cavity sealing, further simplifying the installation process. This device can perform external pressure tests on small-diameter pipes of different sizes by changing the size of the sample hole on the encapsulation section, making it widely applicable. Attached Figure Description

[0032] Figure 1 This is a front view of the pipe external pressure testing fixture described in Example 1;

[0033] Figure 2 This is a side view of the external pressure testing fixture for pipes described in Example 1.

[0034] Legend:

[0035] 1 Outer box, 2 Encapsulation part, 210 Pressure port, 220 Sample hole, 3 Sample tube, 4 Conduit, 5 Support part, 510 First end, 520 Second end. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, and not all of the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0037] Example 1

[0038] This embodiment proposes a pipe external pressure testing fixture.

[0039] Hydrostatic testing is a crucial inspection process in pipe manufacturing, primarily aimed at verifying pipe strength and sealing performance to ensure its ability to withstand design pressures and operate long-term after use. The advantage of hydrostatic testing is that the force exerted by water pressure on the pipe is always radially directed towards the pipe's axis and is evenly distributed across the pipe surface. Since external pressure testing is rarely required in pipe-related product and operational standards, general hydrostatic testing equipment can only perform internal pressure tests. If R&D or quality control personnel require external pressure testing of sample pipes, additional equipment must be purchased, resulting in higher economic costs.

[0040] In view of this, this embodiment aims to improve the pressure resistance testing fixture so as to test the external pressure resistance performance of the sample pipe material when only internal pressure testing equipment is available.

[0041] In this device, the outer surface of the sample tube 3 is used as the test surface, so a cavity for containing the pressure resistance test medium is set on the outside of the sample tube 3.

[0042] Please see Figure 1 The sample tube 3 is nested inside an outer casing 1. A support portion 5 is provided between the outer casing 1 and the sample tube 3. The first end 510 of the support portion 5 is connected to the outer surface of the sample tube 3, and the second end 520 is connected to the outer casing 1. A defined interval is provided between the first end 510 and the second end 520, and the outer surface of the sample tube 3 and the outer casing 1 maintain an interval for containing the pressure resistance test medium.

[0043] To form the sealed container required for the pressure resistance test, a sealing section 2 is provided on the device. The inner surface of the sealing section 2, the inner surface of the outer box 1, and the outer surface of the sample tube 3 are connected to each other to form the outline of the spacer section. The spacer section forms a cavity for containing the pressure resistance test medium. The cavity is connected to the pressure resistance test equipment through a conduit 4.

[0044] Since the outer casing 1 also needs to withstand the pressure of the pressure test, in order to ensure the normal operation of this device, the burst pressure of the outer casing 1 should exceed the pressure range of the sample tube 3 pressure test.

[0045] This device is a pipe external pressure testing fixture adapted to internal pressure testing equipment. The working principle of the internal pressure testing equipment is as follows: the hydraulic testing equipment is connected to the inner surface of the sample pipe 3, forming a closed container; pressure is applied to a portion of the stagnant fluid within the closed container, and this pressure is transmitted in all directions of the stagnant fluid without change. This design uses a support part 5 to fix the distance between the sample pipe 3 and the outer casing 1, forming a stable interval, and provides an encapsulation part 2 to ensure that the interval forms the closed container required for the experiment, allowing the outer surface of the sample pipe 3 to fully contact the pressure resistance test medium. When the outer surface of the sample pipe 3 is in the closed container filled with the hydraulic test medium, the hydraulic testing equipment can test the external pressure resistance of the sample pipe 3.

[0046] Compared to sample testing by the product quality control department, R&D samples are typically prototypes and do not require batch testing. Therefore, in this solution, components such as the outer casing, encapsulation, and conduit can be connected to the sample pipeline via non-removable methods such as welding, eliminating the need to consider the reusability of the tooling. If the external pressure test sample needs to be replaced, the R&D personnel can replace the matching external pressure test tooling simultaneously with the sample.

[0047] Since the pressure resistance test medium is a fluid, the fluid has different hydrostatic pressures at different depths. To ensure the most uniform distribution of hydrostatic pressure on the surface of the sample tube 3, the sample tube 3 has a fixed horizontal orientation. When the shape of the spacer is adjusted according to the shape of the outer casing 1 or the shape of the encapsulation part 2, the sample tube 3 can be positioned at the same depth in the pressure resistance test medium.

[0048] Further expand the application scenarios of external pressure testing fixtures. Please see [link / reference]. Figure 1 The sample tube 3 has two ends exposed at the interval. The exposed portion can be used to independently connect to other test equipment to simulate the external pressure resistance of the test fixture when the sample tube 3 is filled with or has other media flowing in it.

[0049] Further improve the compatibility of pressure testing fixtures with different pressure testing equipment.

[0050] In this pressure resistance testing fixture, the outer casing 1 is a finished pipe, while the encapsulation part 2 has a shape that matches both the outer casing 1 and the sample pipe 3. Therefore, this design places the connection between the conduit 4 and the spacer cavity on the encapsulation part 2. Users can adjust the single or double conduit 4 according to the encapsulation part 2 to adapt to different models of pressure resistance testing equipment. Please refer to... Figure 2 The encapsulation part 2 has a pressure port 210, and the conduit 4 is connected to the pressure port 210. In the pressure resistance test fixture with double conduits 4, the encapsulation part 2 is symmetrically arranged at both ends of the sample tube 3, and the conduits 4 on both sides of the encapsulation part 2 are coaxially arranged. At this time, for the water pressure test equipment, the fixture as a whole is equivalent to a pipe with narrow diameter at both ends and wide diameter in the middle section, which meets the working requirements of the water pressure test equipment.

[0051] For ease of material sourcing, the outer casing 1 can be made from a finished circular pipe with a diameter larger than the sample pipe. Please refer to [link / reference]. Figure 2 At this time, the encapsulation part 2 has a circular outer contour that fits it and is sealed to the inner wall of the outer box 1. A sample hole 220 is provided through the encapsulation part 2, which has a circular contour that fits the cross-section of the sample tube 3 and is sealed to the outer surface of the sample tube 3. The encapsulation part 2 is annular, with its inner ring also functioning as the first end 510 of the support part 5, and its outer ring also functioning as the second end 520 of the support part 5. The encapsulation part 2 fulfills the function of the support part 5, providing support for the sample tube 3 and separating it from the outer box 1, avoiding obstruction of the outer surface of the sample tube 3 by a separate support part 5, resulting in a more uniform test pressure distribution.

[0052] To further reduce the manufacturing difficulty and material cost of the tooling, the outer box 1 and the encapsulation part 2 can be made of common 304 stainless steel. The outer box 1 and the encapsulation part 2 are sealed together by welding. The encapsulation part 2 and the sample tube 3 can also be sealed together by welding or other methods. This solution uses readily available materials, is easy to install, and has low cost and low learning curve.

[0053] Example 2

[0054] This embodiment provides a method for fabricating and applying an external pressure withstand test fixture.

[0055] A sample pipe with an outer diameter of φ18×1.2mm needs to undergo a hydrostatic test. The pressure should be gradually increased from 10MPa in 1MPa increments, with a holding time of at least 5 seconds. The hydrostatic test is performed using the external pressure resistance testing fixture described in Example 1, including the following steps:

[0056] S1. Sample tube 3 is 1200mm long. Select a stainless steel pipe with specifications of φ73×10mm and a length of 1000mm as the outer box 1. Chamfer the two ends of the outer box 1.

[0057] S2. Processing and packaging part 2, the outer diameter of packaging part 2 is φ73mm, a φ18.1mm through hole is processed at the center as the first end 510 of support part 5, and a φ11.1mm through hole is processed at half the radius as the pressure port 210.

[0058] S3. Select a conduit 4 with a specification of φ11×3mm and a length of 350mm, and weld the conduit 4 to the pressure port 210 of the encapsulation part 2.

[0059] S4. Adjust the conduits 4 on the two end packaging parts 2 to be coaxial, and then weld the packaging parts 2 to the outer box 1 to seal.

[0060] S5. Pass the sample tube 3 through the first end 510 at the center of the two side encapsulation parts 2, and weld and seal the sample tube 3 and the encapsulation part 2.

[0061] S5, the conduit 4 is connected to the water pressure quick clamp, and the pressure resistance test equipment applies pressure to the interval inside the outer box 1 through the conduit 4.

Claims

1. A pipe external pressure testing fixture, used for performing external pressure tests on sample pipes (3), characterized in that, include: The outer casing (1) surrounds the outside of the sample tube (3) and has a spacer between it and the sample tube (3); The support part (5) includes a first end (510) connected to the outer surface of the sample tube (3) and a second end (520) connected to the outer box (1); the support part (5) positions the sample tube (3) and thus maintains the distance between the outer surface of the sample tube (3) and the outer box (1); The encapsulation part (2), the outer box body (1), and the outer surface of the sample tube (3) cooperate to form at least a portion of the inner contour of the spacer part; A conduit (4) is disposed on the outer box (1) or the encapsulation part (2), and the spacer part is connected to the pressure test equipment through the conduit (4).

2. The pipe external pressure testing fixture according to claim 1, characterized in that, The sample tube (3) has a horizontal fixed posture.

3. The pipe external pressure testing fixture according to claim 1, characterized in that, The encapsulation part (2) has a sample hole (220) that passes through the encapsulation part (2), and the shape of the sample hole (220) is adapted to the cross-sectional profile of the sample tube (3).

4. The pipe external pressure testing fixture according to claim 3, characterized in that, The sample hole (220) is provided with the first end (510), and the encapsulation part (2) is provided with the second end (520) at a position away from the sample hole (220).

5. The pipe external pressure testing fixture according to claim 1, characterized in that, The sample tube (3) has two ends exposed at the two ends of the spacer.

6. The pipe external pressure testing fixture according to claim 1, characterized in that, The conduit (4) is disposed on the encapsulation part (2).

7. The pipe external pressure testing fixture according to claim 6, characterized in that, The encapsulation part (2) is arranged in multiple sets; the conduits (4) on the multiple sets of encapsulation parts (2) are arranged coaxially.

8. The pipe external pressure testing fixture according to claim 1, characterized in that, The outer casing (1) is a pipe that is axially aligned with the sample tubing (3) and has a larger diameter.

9. The pipe external pressure testing fixture according to claim 1, characterized in that, The encapsulation part (2) and the sample tube (3) are sealed together, and the encapsulation part (2) and the outer box (1) are sealed together.

10. The pipe external pressure testing fixture according to claim 1, characterized in that, The outer box (1) is a tubular component made of stainless steel.

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