Rapid connection method for pressure test of conduit

Abstract

The invention belongs to the technical field of machining, and relates to a quick connection method for pressure test of conduits. After the rapid connection device for the pressure test of the conduit is used for rapid connection pressure test, the production efficiency is remarkably improved, test failure caused by medium leakage in the pressure test process due to conduit process flaring can be effectively avoided, and meanwhile the problems that some high-strength pipes are large in flaring difficulty and low in flaring efficiency are solved. And the technical standard component falls off in the pressure test process.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing and relates to a catheter pressure test quick connection method. Background Art

[0002] Strength and airtightness test is an important means to verify the bending quality and end forming quality of conduits. For conduits without forming requirements at the end, the strength and airtightness test method is to reserve process expansion margin and cut off the process expansion margin after the test is qualified. However, process expansion has high requirements on tube end finishing and expansion quality, and the process flow is cumbersome and the test efficiency is low. At the same time, the process standard parts used for process expansion need to be stored separately, resulting in high management costs. The quick connection device is applied to the strength and airtightness test of conduits. The conduit can be connected to the test bench without reserving process expansion margin and without forming, which improves the test efficiency and saves material costs. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a new method for connecting a pressure test conduit and a test bench, which is used to solve the quality and efficiency problems of the expansion connection in the traditional pressure test process.

[0004] In order to achieve the above object, the technical solution of the present invention is:

[0005] A catheter pressure test quick connection method, the steps are as follows:

[0006] Step 1, develop a catheter pressure test quick connection device, the device includes a shaft, a spring, a gasket, a retaining ring, a rear cylinder cover, an O-ring A, a handle, a support ring, an O-ring B, a support ring, an O-ring C, an O-ring D, a clamping block, a shell, and a sealant.

[0007] The shaft is made of metal and is hollow to form a cylindrical cavity. A hole is opened on the shaft to facilitate the flow of the test medium. It can be inserted into the housing and sealed by an O-ring. The pressure F from the working medium on the shaft (1) in the sealed cavity formed by the shaft, the rear cylinder head and the housing is 介质 , F 轴合 =F 轴 +F 介质 ; F 轴合 The clamping block acts on the clamping block, and the clamping block and the inner conical surface of the shell work together to clamp the conduit. The sealant is wrapped and fixed on the threaded surface on the right side of the shaft to improve the sealing performance.

[0008] The rear cylinder cover is made of metal, is hollow to form a cylindrical cavity, has a stepped cross-section, has an external thread at one end and can enter the housing and be threadedly connected to it, and an O-ring seal is installed at the end of the thread to fix the spring and the shaft during operation.

[0009] The handle is made of metal, one end of which is in the shape of a circular ring, which is sleeved on the shaft and fixed by a gasket and a retaining spring. The hand-held tool applies a gripping force to the handle, and the compression spring pushes the clamping block.

[0010] The clamping block is made of metal and consists of three identical clamping blocks. The surface of each clamping block that contacts the outer surface of the catheter is rough and has a fine-grained ring shape. The spring force and the pressure of the medium push the clamping block to move, and the reaction force of the inner cone of the shell on the clamping block is used to tighten the catheter.

[0011] The sealant is made of non-metallic material. In order to ensure that there is no leakage at the joint during the pressure test after the joint of the catheter pressure test quick connection device is connected to the joint of the pressure test bench, the joint surface must be connected with sealant. The application of sealant should follow the following rules. First, clean the surface of the joint, without burrs, sharp corners, and sharp corners. In particular, the joint surface should be clean, dry, and oil-free. Use grease-free cotton dipped in acetone to remove grease and dry it. When applying the sealant, cut the glue nozzle according to the width of the sealing surface, squeeze the glue out, continuously along the center line of the joint surface, and around each bolt hole to form a closed sealant line; or use a glue knife to evenly apply it on the two joint surfaces with a thickness of 0.10mm to 0.15mm. The coating amount should be slightly squeezed out after the combination, and too much coating should be avoided to block the pipeline. Immediately overlap the sealing joint surface after coating, and tighten the joint surface fastening bolts to the torque specified by the design with a force-limiting wrench. The parts assembled after the application of liquid gaskets should be vulcanized for 24 hours at 23±2℃ and 60-70% humidity. After the assembled parts have been vulcanized for 24 hours, they can enter the next process, and the pressure test of the parts should be carried out after 48 hours. The liquid gaskets remaining on the joint surface can be removed by scraping them off with a bamboo or hardwood knife, or by using a special cleaning agent.

[0012] Step 2, when the connecting device is in a non-working state, the clamping block is at the maximum limit of tight clamping, and the spring is within its elastic range.

[0013] Step 3. Select the corresponding clamping block according to the specifications of the end of the pressure test catheter. The inner diameter of the clamping block after closing should match the outer diameter of the catheter. Different specifications should not be mixed to avoid clamping the outer surface of the catheter. Check the O-ring D before connecting the pressure test quick connection device. It must not be broken or damaged. The end of the pressure test catheter should be deburred in advance. To prevent leakage at the clamping part of the workpiece, the inner hole of the shaft is made into a step at the contact point between the end of the catheter and the shaft, and the contact part between the workpiece and the shaft is sealed with an O-ring D.

[0014] Step 4: When the connection device needs to work, press the handle evenly and apply force. At the same time, the shell is subjected to the axial force from the handle. The spring continues to be in a compressed state. The clamping part moves with the shaft and retracts along the conical surface of the shell. At the same time, the clamping block gradually relaxes and then opens. Insert the pressure test tube into the clamping block and ensure that the pressure test tube is inserted straight to the bottom and that the tube passes through the O-ring D.

[0015] Step 5. After inserting the catheter, slowly loosen the handle. Through the rebound of the spring, the clamping block slowly returns to the original clamping state along the conical surface of the shell. When the test medium fills the chamber where the spring is located, when the pressure in the chamber increases, the shaft pushes the clamping block axially to move, and acts on the inclined surface in the shell to tighten the catheter. When the pressure test is over, the test medium in the chamber flows out of the pressure test device, and then the clamping force of the clamping block on the catheter is reduced. Press the handle, loosen the clamping block, take out the catheter, and the test is over.

[0016] Beneficial effects of the present invention:

[0017] Using the catheter pressure test quick connection device for quick connection pressure testing can not only significantly improve production efficiency, but also effectively avoid medium leakage during the pressure test caused by catheter process expansion, which may lead to test failure. At the same time, it can solve the difficulties in expanding certain higher-strength pipes and the risk of standard process parts falling off during the pressure test. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of the catheter pressure test quick connection device;

[0019] Figure 2 Cutaway view of quick-connect device for catheter pressure testing Figure 1 ;

[0020] Figure 3 Cutaway view of quick-connect device for catheter pressure testing Figure 2 .

[0021] In the figure: 1 shaft; 2 spring; 3 gasket; 4 retaining ring; 5 rear cylinder head; 6 "O" ring A, 9 "O" ring B; 11 "O" ring C; 12 "O" ring D; 7 handle; 8 support ring; 10 support ring; 13 clamping block; 14 housing; 15 sealant. DETAILED DESCRIPTION

[0022] Embodiment 1:

[0023] Before using the device to connect the catheter, the end surface of the tube should be cleaned, without burrs, sharp corners, and sharp corners. In particular, the joint surface of the two tube ends should be clean, dry, and oil-free. Use cotton wool dipped in acetone to remove grease and other grease, and dry it.

[0024] Press one end of the catheter to the predetermined stop position and release it. At this time, the three clamping blocks are in mesh with the catheter, and filling and pressurization can be carried out. When the catheter is pressed, ensure that the catheter is fully inserted into the bottom of the clamping block until the catheter can no longer be inserted and is pressed to the stop position.

[0025] The other end of the device is pre-coated with sealant and connected to the test bench through the external thread on the shaft. Apply the required pressure to the inside of the catheter, and do not exceed the maximum working pressure of the device design. When the required pressure is reached, maintain the pressure as required. During the pressure maintenance process, the device and the catheter should be placed on a horizontal operating table, do not move, and avoid vibration. The pressure should be applied evenly during the pressure test.

[0026] When the pressure test is completed, make sure that the pressure is completely removed from the tested catheter, then release the clamping block by pressing the handle and remove the catheter from the device. Gently press the clamping block forward to facilitate the removal of the catheter.

[0027] In order to maintain the maximum sealing ability of the pipe seal O-ring, the burrs should be removed from the end of the catheter in advance. When doing the pressure test, clean water should be used if conditions permit, and the chloride ion content should be less than 25PPM to extend the sealing of the O-ring. When the pipe seal O-ring fails or is damaged, it should be replaced in time. The shaft and shaft seal ring should be cleaned and lubricated regularly, and a thin layer of specified lubricating grease should be applied on the surface.

[0028] Embodiment 2:

[0029] A catheter pressure test quick connection method, the steps are as follows:

[0030] Step 1, develop a catheter pressure test quick connection device, the device includes a shaft 1, a spring 2, a gasket 3, a retaining ring 4, a rear cylinder cover 5, an O-ring A6, a handle 7, a support ring 8, an O-ring B9, a support ring 10, an O-ring C11, an O-ring D12, a clamping block 13, a shell 14, and a sealant 15.

[0031] The shaft 1 is made of metal and is hollow to form a cylindrical cavity. A hole is opened on the shaft to facilitate the flow of the test medium. It can be inserted into the housing 14 and sealed by an O-ring. The pressure F from the working medium on the shaft (1) in the sealed cavity formed by the shaft 1, the rear cylinder cover 5 and the housing 14 is 介质 , F 轴合 =F 轴 +F 介质 ; F 轴合 The clamping block 13 is acted on, and the clamping block 13 and the inner conical surface of the housing 14 work together to clamp the conduit, and the sealant 15 is wound and fixed on the right side thread surface of the shaft 1 to improve the sealing performance.

[0032] The rear cylinder cover 5 is made of metal, is hollow to form a cylindrical cavity, has a stepped cross-section, has an external thread at one end and can enter the housing 14 and be threadedly connected thereto, and an O-ring seal is installed at the end of the thread to fix the spring 2 and the shaft 1 during operation.

[0033] The handle 7 is made of metal, one end of which is in a circular ring shape, which is sleeved on the shaft 1 and fixed by a gasket 3 and a retaining spring 4. The hand-held tool applies a gripping force to the handle 7, and the compression spring 2 pushes the clamping block 13.

[0034] The clamping block 13 is made of metal and consists of three identical clamping blocks. The surface of each clamping block that contacts the outer surface of the catheter is rough and has a fine-grained ring shape. The spring force and the pressure of the medium push the clamping block to move, and the reaction force of the inner cone of the shell 14 on the clamping block is used to tighten the catheter.

[0035] The sealant 15 is made of non-metallic material. In order to ensure that there is no leakage at the joint during the pressure test after the joint of the catheter pressure test quick connection device is connected to the joint of the pressure test bench, the joint surface must be connected with sealant. The application of sealant should follow the following rules. First, clean the surface of the joint, without burrs, sharp corners, and sharp corners. In particular, the joint surface should be clean, dry, and oil-free. Remove grease and other substances with acetone-stripped cotton and dry it. When applying the sealant, cut the glue nozzle according to the width of the sealing surface, squeeze the glue out, continuously along the center line of the joint surface, and around each bolt hole to form a closed sealant line; or use a glue knife to evenly apply it on the two joint surfaces with a thickness of 0.10mm to 0.15mm. The coating amount should be slightly squeezed out after the combination, and too much coating should be avoided to block the pipeline. Immediately overlap the sealing joint surface after coating, and tighten the joint surface fastening bolts to the torque specified by the design with a force-limiting wrench. The parts assembled after the application of liquid gaskets should be vulcanized for 24 hours at 23±2℃ and 60-70% humidity. After the assembled parts have been vulcanized for 24 hours, they can enter the next process, and the pressure test of the parts should be carried out after 48 hours. The liquid gaskets remaining on the joint surface can be removed by scraping them off with a bamboo or hardwood knife, or by using a special cleaning agent.

[0036] Step 2, when the connecting device is in a non-working state, the clamping block 13 is at the maximum limit of tight clamping, and the spring 2 is within its elastic range.

[0037] Step 3, select the corresponding clamping block 13 according to the specifications of the end of the catheter to be pressure tested. The inner diameter of the clamping block 13 after closing should match the outer diameter of the catheter. Different specifications should not be mixed to avoid clamping the outer surface of the catheter. Check the O-ring D12 before connecting the pressure test quick connection device. It must not be broken or damaged. The end burrs of the catheter to be pressure tested should be removed in advance. To prevent leakage at the clamping part of the workpiece, the inner hole of the shaft 1 is made into a step at the contact point between the end of the catheter and the shaft 1, and the contact part between the workpiece and the shaft is sealed with an O-ring D12.

[0038] Step 4, when the connection device needs to work, press the handle 7 evenly according to the working requirements, and at the same time, the housing 14 is subjected to the axial force of the handle 7, the spring 2 continues to be in a compressed state, the clamping part moves with the shaft 1, and retracts along the conical surface of the housing 14, and at the same time, the clamping block 13 gradually relaxes and then opens. The pressure test catheter is inserted into the clamping block 13, and the pressure test catheter is ensured to be inserted straight to the bottom, and the catheter is ensured to pass through the O-ring D12.

[0039] Step 5, after the catheter is inserted, slowly loosen the handle 7, and through the rebound of the spring 2, the clamping block 13 slowly returns to the original clamping state along the conical surface of the shell 14. When the test medium fills the chamber where the spring 2 is located, when the pressure in the chamber increases, the shaft 1 pushes the clamping block 13 to move axially, and acts on the inclined surface in the shell 14 to tighten the catheter. When the pressure test is over, the test medium in the chamber flows out of the pressure test device, and then the clamping force of the clamping block 13 on the catheter is reduced. Press the handle 7, loosen the clamping block 13, take out the catheter, and the test is over.

Claims

1. A catheter pressure test quick connection method, characterized in that: Here are the steps: Step 1, developing a catheter pressure test quick connection device, the device comprising a shaft (1), a spring (2), a gasket (3), a retaining ring (4), a rear cylinder cover (5), an O-ring A (6), a handle (7), a support ring (8), an O-ring B (9), a support ring (10), an O-ring C (11), an O-ring D (12), a clamping block (13), a housing (14), and a sealant (15); The shaft (1) is hollow to form a cylindrical cavity, and a hole is opened on the shaft to facilitate the flow of the test medium; it can be inserted into the housing (14) and sealed by an O-ring; The pressure F from the working medium on the shaft (1) in the sealed cavity formed by the shaft (1), the rear cylinder cover (5) and the housing (14) 介质 , F 轴合 =F 轴 +F 介质 ; F 轴合 The clamping block (13) acts on the clamping block (13) and the inner conical surface of the housing 14 to clamp the conduit, and the sealant (15) is wound around and fixed on the right thread surface of the shaft (1) to improve the sealing performance; One end of the handle (7) is in the shape of a circular ring, which is sleeved on the shaft (1) and fixed by a gasket (3) and a retaining spring (4); a hand-held tool applies a gripping force to the handle (7), compressing the spring (2) to push the clamping block (13); Step 2, when the connecting device is in a non-working state, the clamping block (13) is at the maximum limit of tight clamping, and the spring (2) is within its elastic range; Step 3, select a corresponding clamping block (13) according to the specifications of the end of the pressure test conduit, and the inner diameter of the clamping block (13) after closing is consistent with the outer diameter of the conduit; check the O-ring D (12) before connecting the pressure test quick connection device, and the end of the pressure test conduit should be deburred in advance; Step 4, when the connection device needs to work, the handle (7) is pressed evenly, and the housing (14) is subjected to the axial force given by the handle (7), the spring (2) continues to be in a compressed state, the clamping part moves with the shaft (1), and retracts along the conical surface of the housing (14), and the clamping block (13) is gradually relaxed and then opened; the pressure test tube is inserted into the clamping block (13), and the pressure test tube is ensured to be inserted straight to the bottom, and the tube is ensured to pass through the O-ring D (12); Step 5, after the catheter is inserted, slowly loosen the handle (7), and the clamping block (13) slowly returns to the original clamping state along the conical surface of the shell (14) through the rebound of the spring (2); when the test medium fills the chamber where the spring (2) is located, when the pressure in the chamber increases, the shaft (1) pushes the clamping block (13) to move in the axial direction, and acts with the inclined surface inside the shell (14) to tighten the catheter; when the pressure test is completed, the test medium in the chamber flows out of the pressure test device, and then the clamping force of the clamping block (13) on the catheter is reduced, and the handle (7) is pressed to loosen the clamping block (13), and the catheter is taken out, and the test is completed.

2. A catheter pressure test quick connection method as claimed in claim 1, characterized in that: The application of the sealant (15) should be handled according to the following rules: First, clean the joint surface to make sure there are no burrs, sharp corners or sharp corners. Remove grease with cotton wool dipped in acetone and let it dry. When applying the sealant, cut the glue nozzle according to the width of the sealing surface, squeeze the glue out continuously along the center line of the joint surface and around each bolt hole to form a closed sealant line. Alternatively, use a glue knife to evenly apply it on the two joint surfaces with a thickness of 0.10mm to 0.15mm.

3. A catheter pressure test quick connection method as claimed in claim 1 or 2, characterized in that: The clamping block (13) is composed of three identical clamping blocks. The surface of each clamping block contacting the outer surface of the catheter is rough and has a fine-grained ring shape. The spring force and the pressure of the medium push the clamping block to move, and the reaction force of the inner cone of the shell (14) on the clamping block is used to tighten the catheter.

4. A catheter pressure test quick connection method as claimed in claim 1 or 2, characterized in that: In the step 3, at the point where the end of the conduit contacts the shaft (1), the inner hole of the shaft (1) is formed into a step, and an O-ring D (12) is provided to seal the contact portion between the workpiece and the shaft.

5. A catheter pressure test quick connection method as claimed in claim 3, characterized in that: In the step 3, at the point where the end of the conduit contacts the shaft (1), the inner hole of the shaft (1) is formed into a step, and an O-ring D (12) is provided to seal the contact portion between the workpiece and the shaft.

6. A catheter pressure test quick connection method as claimed in claim 1, 2 or 5, characterized in that: The rear cylinder cover (5) is hollow to form a cylindrical cavity with a stepped cross section. One end has an external thread and can enter the housing (14) and be threadedly connected thereto. An O-ring seal is installed at the end of the thread to fix the spring (2) and the shaft (1) during operation.

7. A catheter pressure test quick connection method as claimed in claim 3, characterized in that: The rear cylinder cover (5) is hollow to form a cylindrical cavity with a stepped cross section. One end has an external thread and can enter the housing (14) and be threadedly connected thereto. An O-ring seal is installed at the end of the thread to fix the spring (2) and the shaft (1) during operation.

8. A catheter pressure test quick connection method as claimed in claim 4, characterized in that: The rear cylinder cover (5) is hollow to form a cylindrical cavity with a stepped cross section. One end has an external thread and can enter the housing (14) and be threadedly connected thereto. An O-ring seal is installed at the end of the thread to fix the spring (2) and the shaft (1) during operation.

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