A positive and negative pressure detection device for large-diameter rubber hoses

Abstract

This invention proposes a positive and negative pressure testing device for large-diameter hoses, comprising a housing with two vertically symmetrically arranged support plates inside. The support plates have mounting holes at their four corners for installing lead screws, and nuts threaded to the lead screws are located on both sides of the support plates. The two ends of the lead screws are fixedly connected to the interior of the housing. One support plate has a longitudinally arranged square-round hole in its center, through which a first stainless steel connector and a second stainless steel connector pass. A first plug is welded to one end of each connector, and the first plug has a through hole corresponding to the first and second connectors. A second plug is located opposite the first plug. The first and second plugs are fixed to the support plates by plug fixing clamps. The first and second stainless steel connectors are connected to a control and testing device.

Description

Technical Field

[0001] This invention relates to a positive and negative pressure testing device for large-diameter rubber hoses, belonging to the field of rubber hose pressure testing technology. Background Technology

[0002] Before being put into use, some important large-diameter hoses (with an inner diameter greater than 50mm) on heavy-duty trucks need to be tested for their resistance to positive and negative pressure. If the test is not carried out, there is a risk that the hoses will be flattened or burst during use, causing a major quality accident. Therefore, it is necessary to use a large-diameter positive and negative pressure tester to test the pressure resistance of large-diameter hoses.

[0003] When the negative pressure sealing tester is working, first close the positive pressure passage to measure the negative pressure. When the negative pressure reaches the specified value, maintain the pressure for the specified time, observe the changes in the hose, and record them. If it is necessary to observe the hose's ability to withstand negative pressure, continue to apply negative pressure until the hose is sucked flat, and record the pressure value.

[0004] After the negative pressure test is completed, close the negative pressure passage and perform the positive pressure test according to the operating procedure. When the positive pressure reaches the specified value, maintain the pressure for the specified time, observe the changes in the hose, and record the results. If it is necessary to test the burst pressure of the hose, continue to pressurize until the hose ruptures, and record the pressure value.

[0005] Currently, there are no dedicated "positive and negative pressure testing instruments" for large-diameter rubber hoses ranging from 50mm to 250mm on the market. This makes it impossible to test the pressure resistance of large-diameter rubber hoses, and the product technical requirements cannot be verified, thus posing potential quality risks. Summary of the Invention

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A large-diameter hose positive and negative pressure testing device includes a housing. Two vertically symmetrical support plates are provided inside the housing. Mounting holes for installing lead screws are located at the four corners of each support plate. Nuts threadedly connected to the lead screws are located on both sides of each support plate. The two ends of the lead screws are fixedly connected to the interior of the housing. A longitudinally arranged square-round hole is provided in the middle of one of the support plates. A first stainless steel connector and a second stainless steel connector pass through the square-round hole. A first plug is welded to one end of each of the first and second stainless steel connectors. A through hole corresponding to the first and second stainless steel connectors is provided on the first plug. A second plug is located opposite the first plug. The first and second plugs are fixed to the support plates by plug fixing clamps. The first and second stainless steel connectors are connected to a control and testing device.

[0008] Preferably, a sliding bearing is installed in the mounting hole, and a lead screw is slidably connected inside the sliding bearing.

[0009] Preferably, the control and detection device includes a first tower-type tee and a second tower-type tee. The first ports of the first tower-type tee and the second tower-type tee are respectively connected to a first stainless steel connector and a second stainless steel connector. The second port of the first tower-type tee is connected to a vacuum pressure gauge through a first ball valve. The third port of the first tower-type tee is connected to the first port of a third tower-type tee. The second port of the third tower-type tee is connected to a water tank through a second ball valve. The third port of the third tower-type tee is connected to a pressure gauge through a third ball valve. The second port of the second tower-type tee is connected to the first port of a fourth tower-type tee. The second port of the fourth tower-type tee is connected to a vacuum pump through a pressure regulating valve. The third port of the fourth tower-type tee is connected to a pressure pump through a pressure regulating valve. The pressure pump is connected to a water tank. The third port of the second tower-type tee is connected to the water tank through a fourth ball valve.

[0010] Preferably, the housing is equipped with a drain valve.

[0011] Preferably, the housing is made of steel plate or aluminum plate.

[0012] Preferably, the plug fixing clamp includes two semi-circular steel plates with a thickness of ≥8mm, and the plug fixing clamp is fixedly connected to the support plate through an ear plate provided on the support plate.

[0013] Preferably, the first and second plugs are made of stainless steel with a thickness of ≥1.2mm.

[0014] This invention can achieve positive and negative pressure resistance testing (sealing performance testing) and airtightness testing of hoses of different lengths and diameters by adjusting the distance of the support plate and making plugs of different outer diameters. (For small-diameter hoses with pressure less than 3MPa, sealing performance testing) can be performed. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a large-diameter hose positive and negative pressure detection device according to the present invention.

[0016] In the picture:

[0017] 1. Housing; 2. Support plate; 3. Screw rod; 4. First stainless steel connector; 5. Second stainless steel connector; 6. First plug; 7. Second plug; 8. Plug fixing clamp; 9. First tower-type tee; 10. Second tower-type tee; 11. Vacuum pressure gauge; 12. Third tower-type tee; 13. Pressure gauge; 14. Fourth tower-type tee; 15. Air pressure regulating valve; 16. Vacuum pump; 17. Pressure regulating valve; 18. Pressure pump; 19. Drain valve; 20. Rubber hose; Q1. First ball valve; Q2. Second ball valve; Q3. Third ball valve; Q4. Fourth ball valve; A. Water tank. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] During positive pressure testing of large-diameter hoses, the thrust exerted by the pressure on the plugs at both ends increases exponentially with the increase of the hose's inner diameter (e.g., if the hose's inner diameter increases from 50mm to 100mm, the thrust on the plug will increase fourfold under the same pressure). This can cause the plugs to come off, making it impossible to complete the testing process, or even leading to safety accidents. In addition, the large diameter of the plugs makes them difficult to process. These two problems are the main reasons why this equipment is not currently available on the market.

[0020] This testing device solves the problems of plug detachment under stress and the difficulties in plug manufacturing, and uses a housing as a safety protection measure to eliminate safety hazards. Specifically, as follows... Figure 1 As shown, a large-diameter hose positive and negative pressure testing device includes a housing 1 made of steel or aluminum plate. Two vertically symmetrical support plates 2 are provided inside the housing 1. Mounting holes for installing lead screws 3 are provided at the four corners of each support plate 2. Nuts threadedly connected to the lead screws 3 are provided on both sides of each support plate 2. The two ends of the lead screws 3 are fixedly connected to the interior of the housing 1. A longitudinally arranged square-round hole is provided in the middle of one of the support plates 2. A first stainless steel connector 4 and a second stainless steel connector 5 pass through the square-round hole. A first plug 6 is welded to one end of the first stainless steel connector 4 and the second stainless steel connector 5. The first plug 6 has an opening... The device includes through holes corresponding to the first stainless steel connector 4 and the second stainless steel connector 5. A second plug 7 is located opposite the first plug 6. The first plug 6 and the second plug 7 are respectively fixed to the support plate 2 by plug fixing clamps 8. The plug fixing clamp 8 comprises two semi-circular steel plates with a thickness ≥8mm. The two steel plates of the plug fixing clamp 8 abut against the outer walls of the first plug 6 and the second plug 7 to support them. The plug fixing clamp 8 is fixedly connected to the support plate 2 via ear plates provided on the support plate 2. The first stainless steel connector 4 and the second stainless steel connector 5 are connected to a control and detection device. A drain valve 19 is provided on the housing 1 to drain accumulated water from the housing 1.

[0021] The first plug 6 and the second plug 7 are cylindrical structures with one end closed and the other end open. The closed end of the first plug 6 has a through hole corresponding to the first stainless steel connector 4 and the second stainless steel connector 5. The first plug 6 and the second plug 7 are stainless steel parts with a thickness ≥1.2mm.

[0022] Specifically, a sliding bearing is installed in the mounting hole, and a lead screw 3 is slidably connected in the sliding bearing to facilitate the movement of the support plate 2 in the axial direction of the lead screw 3.

[0023] The control and detection device includes a first tower-type tee 9 and a second tower-type tee 10. The first ports of the first tower-type tee 9 and the second tower-type tee 10 are respectively connected to a first stainless steel connector 4 and a second stainless steel connector 5. The second port of the first tower-type tee 9 is connected to a vacuum pressure gauge 11 through a first ball valve Q1. The third port of the first tower-type tee 9 is connected to the first port of a third tower-type tee 12. The second port of the third tower-type tee 12 is connected to a water tank A through a second ball valve Q2. The third port of the tower-type tee 12 is connected to the pressure gauge 13 via the third ball valve Q3; the second port of the second tower-type tee 10 is connected to the first port of the fourth tower-type tee 14, the second port of the fourth tower-type tee 14 is connected to the vacuum pump 16 via the air pressure regulating valve 15, the third port of the fourth tower-type tee 14 is connected to the pressure pump 18 via the pressure regulating valve 17, the pressure pump 18 is connected to the water tank A, and the third port of the second tower-type tee 10 is connected to the water tank A via the fourth ball valve Q4.

[0024] The working principle of this invention is as follows:

[0025] 1. Install the hose to be tested

[0026] Based on the inner diameter of the hose being tested, select the corresponding first plug 6 and second plug 7 and install them at both ends of the hose 20, then tighten them with clamps. Place the hose 20 with the first plug 6 and second plug 7 installed in the middle of the support plate 2 inside the housing 1. Adjust the spacing of the support plates 2 so that the outer sides of the first plug 6 and second plug 7 are tightly against the support plates 2. Tighten the support plates 2 by adjusting the nuts on the screw 3, and use a suitable plug fixing clamp 8 to fix the first plug 6 and second plug 7. At the same time, fix the plug fixing clamp 8 to the ear plate on the support plate 2. The first stainless steel connector 4 and the second stainless steel connector 5 are connected to the first tower-type tee 9 and the second tower-type tee 10 through pipelines, respectively.

[0027] 2. Negative pressure detection

[0028] Close the fourth ball valve Q4, the second ball valve Q2, the third ball valve Q3, the pressure regulating valve 17, and the air pressure regulating valve 15. Open the first ball valve Q1, turn on the vacuum pump 16, and slowly open the air pressure regulating valve 15. Observe the vacuum pressure gauge 11 to slowly increase the negative pressure. When the negative pressure reaches the required value, close the air pressure regulating valve 15 and the vacuum pump 16. Observe and record the changes in the hose 20. If the negative pressure of the hose 20 does not change when it reaches the required value, continue to increase the pressure until the hose 20 flattens. Record the pressure value; this value is the negative pressure resistance of the hose 20. (If the vacuum pressure gauge value does not increase, it indicates a system leak; tighten the hose 20 and check other connections.)

[0029] 3. Air tightness and burst pressure testing

[0030] Close the fourth ball valve Q4, the third ball valve Q3, the first ball valve Q1, and the air pressure regulating valve 15. Open the second ball valve Q2, turn on the pressure pump 18 switch, and slowly open the pressure regulating valve 17 to add water to the system at a certain flow rate. When water flows out from the venting second ball valve Q2, close the second ball valve Q2 and observe the pressure gauge 13. Control the pressurization rate with the pressure regulating valve 17. When the pressure reaches the working pressure required by the technical specifications, stop pressurizing and maintain the pressure for 30 seconds (or the time specified in the test method standard). Observe whether the hose 20 leaks. If there is a leak, mark the leak point and end the test. If no leak occurs, continue pressurizing and measure the burst pressure of the hose 20.

[0031] Another embodiment of the present invention uses a manual booster pump instead of the pressure pump 18. The manual booster pump is filled with more than half its volume of tap water. The first ball valve Q1 is replaced with a three-way water valve connected to the tap water supply for adding water into the pipe and draining the water after the test. The outlet of the second ball valve Q2 is discharged into a container or drain, mainly for overflow water added into the pipe. The water tank A of the control and detection device can be omitted. Considering the low efficiency of the manual booster pump, and the increased difficulty due to the increased inner diameter and length of the hose, a large amount of water needs to be injected. Therefore, by connecting to the tap water supply, after the pipe is full, only a small amount of water is needed for manual pressurization; adding more than half its volume of water to the manual booster pump is sufficient.

[0032] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A positive and negative pressure testing device for large-diameter rubber hoses, characterized in that: The device includes a housing, inside which are two vertically symmetrically arranged support plates. Each support plate has mounting holes at its four corners for installing lead screws. Nuts, threaded to the lead screws, are located on both sides of the support plates. The two ends of the lead screws are fixedly connected to the interior of the housing. One support plate has a longitudinally arranged square-round hole in its center. A first stainless steel connector and a second stainless steel connector pass through this hole. A first plug is welded to one end of each connector. The first plug has a through hole corresponding to the first and second connectors. A second plug is located opposite the first plug. The first and second plugs are fixed to the support plates by plug fixing clamps. The first and second stainless steel connectors are connected to a control and detection device. A sliding bearing is installed in the mounting hole, and a lead screw is slidably connected inside the sliding bearing; The plug fixing clamp includes two semi-circular steel plates with a thickness of ≥8mm. The two steel plates of the plug fixing clamp are mated to the outer walls of the first plug and the second plug to support the first plug and the second plug. The plug fixing clamp is fixedly connected to the support plate through the ear plate provided on the support plate. The first plug and the second plug are cylindrical structures with one end closed and the other end open. The closed end of the first plug has a through hole corresponding to the first stainless steel connector and the second stainless steel connector. It also includes a control and detection device, which comprises a first tower-type tee and a second tower-type tee. The first ports of the first tower-type tee and the second tower-type tee are respectively connected to a first stainless steel connector and a second stainless steel connector. The second port of the first tower-type tee is connected to a vacuum pressure gauge through a first ball valve. The third port of the first tower-type tee is connected to the first port of a third tower-type tee. The second port of the third tower-type tee is connected to a water tank through a second ball valve. The third port of the third tower-type tee is connected to a pressure gauge through a third ball valve. The second port of the second tower-type tee is connected to the first port of a fourth tower-type tee. The second port of the fourth tower-type tee is connected to a vacuum pump through a pneumatic pressure regulating valve. The third port of the fourth tower-type tee is connected to a pressure pump through a pressure regulating valve. The pressure pump is connected to a water tank. The third port of the second tower-type tee is connected to the water tank through a fourth ball valve.

2. The positive and negative pressure testing device for a large-diameter hose according to claim 1, characterized in that: The box is equipped with a drain valve.

3. The positive and negative pressure testing device for a large-diameter hose according to claim 1, characterized in that: The enclosure is made of steel or aluminum plate.

4. The positive and negative pressure detection device for a large-diameter hose according to claim 1, characterized in that: The first and second plugs are made of stainless steel with a thickness of ≥1.2mm.

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