A high-pressure pulsating liquid seal failure test device

Abstract

The present invention discloses a high-pressure pulsating liquid seal failure test device, which belongs to the field of metal-metal hard seal technology. The seal failure test device is arranged in the original high-pressure hydraulic circulation system, and the seal failure test device outputs the hydraulic working condition in the form of a tee. The seal failure test device can measure the sealing compression force, and at the same time can reduce the verticality processing requirements of the sealing base surface of the tee structure and the base surface connecting thread; the seal failure test device is arranged downstream of the high-pressure boosting equipment, which is the highest point of the entire circulating liquid pressure. The present invention can monitor the pressure load of the sealing surface in real time, judge whether the seal is reliable according to the amount of leakage, and at the same time can significantly reduce the processing difficulty of the test piece, and eliminate the influence of unnecessary processing deviations on the experimental force.

Description

Technical Field

[0001] The invention belongs to the technical field of metal-metal hard sealing, and in particular relates to a high-pressure pulsating liquid sealing failure test device. Background Art

[0002] In equipment with high-pressure liquids, seal failure of high-pressure liquids is a very important issue. Most existing seal test devices are designed for testing under static pressure, and lack seal test devices for testing under pressure fluctuation or pulsation conditions. Among the seal test devices under static pressure, the most classic one is the ConST 137S test bench, as shown in the attached figure. Figure 1 As shown, the ConST 137S test bench uses a preload pump, preload shutoff valve, and a boost fine-tuning handwheel to control and adjust the system pressure. By machining the test surface onto a gasket and bolting the test gasket into the system piping, metal seal failure under static sealing conditions can be studied. However, in reality, high-pressure liquid operating conditions often occur in the form of pulsating pressure. The impact of pulsating liquid pressure loads on seal fatigue failure is crucial, making it difficult for existing seal test equipment to fully simulate the hydraulic conditions of the equipment during operation.

[0003] Furthermore, seals are crucial components of sealing test equipment. The flatness and parallelism of the seal's sides determine the test equipment's sealing performance and the accuracy of the test. Therefore, these seals have stringent requirements for flatness and parallelism, making them difficult to machine. For example, in the ConST 137S test equipment, the test piece is a gasket. The test places extremely high demands on the flatness and parallelism of both sides of the gasket. Even the slightest deviation in machining can significantly impact the force applied to the test piece. Summary of the Invention

[0004] In view of this, the present invention provides a high-pressure pulsating liquid seal failure test device, which can monitor the pressure load on the sealing surface in real time and judge whether the seal is reliable based on the amount of leakage. At the same time, it can significantly reduce the processing difficulty of the test piece and eliminate the influence of unnecessary processing deviations on the experimental force.

[0005] A high-pressure pulsating liquid seal failure test device is arranged in an original high-pressure hydraulic circulation system. The seal failure test device outputs the hydraulic working condition in the form of a tee. The seal failure test device can measure the sealing compression force and at the same time reduce the verticality processing requirements of the sealing base surface of the tee structure and the base surface connecting thread; the seal failure test device is arranged downstream of the high-pressure boosting equipment, which is the highest point of the entire circulating liquid pressure.

[0006] Furthermore, the sealing failure test device includes a three-way structure, a sealing test piece, a test piece adapter, a pressure sensor and a pressure sleeve;

[0007] The upper and lower ends of the three-way structure are respectively installed in the high-pressure hydraulic pipeline through interface bolts, and the pressure sleeve presses the pressure sensor, the test piece adapter, and the test piece at the side interface of the three-way structure through the tightening force of the bolts. The sealing test piece and the test piece adapter are matched with each other in a spherical and conical manner; a hole is opened at the center of the pressure sleeve, and the hole is used for the signal transmission line of the pressure sensor to pass through. The signal line transmits the extrusion pressure of the sleeve to the external display device through the signal measured by the pressure sensor.

[0008] Furthermore, the surface of the sealing test piece in contact with the sealing base surface of the tee structure is a plane, and the surface of the sealing test piece in contact with the test piece adapter is a spherical surface; the outer shape of the test piece adapter is a cylindrical structure, and a groove with a conical surface is machined on the surface of one end of the cylindrical structure.

[0009] Furthermore, the cone angle of the conical surface groove on the test piece adapter is 45° to 70°.

[0010] Furthermore, the interface thread of the tee structure has the same specifications as the pipeline interface thread, but has an opposite rotation direction.

[0011] Furthermore, a guide section is provided on the outer circumferential surface of the middle section of the pressure sleeve, a leakage hole is opened on the guide section, the position of the leakage hole corresponds to the sealing surface, and a measuring cylinder is provided directly below the guide section.

[0012] Furthermore, the flatness of the sealing base surface of the three-way structure is greater than 0.01, and the roughness Ra is greater than 0.4; the test surface of the sealing test piece is processed with test patterns.

[0013] Furthermore, when the sealing test piece and the adapter are installed, grease is applied to the contact surface of the sealing test piece and the adapter, or positioning pins are installed in the sealing test piece and the tee structure to ensure the positioning and correspondence of the contact points during the test.

[0014] Beneficial effects:

[0015] 1. The seal failure test device of the present invention is installed in a high-pressure flow pipeline by setting a three-way structure, so as to almost completely simulate the hydraulic working conditions under working conditions. The actual working conditions are the test conditions, and the impact on the original equipment and working conditions is minimal.

[0016] 2. The sealing failure test device of the present invention consists of a three-way structure, a sealing test piece, a test piece adapter, a pressure sensor and a pressure sleeve. An adapter is arranged outside the sealing test piece. The cooperation of the spherical structure and the conical structure can reduce the parallelism of the surfaces on both sides of the sensor, the flatness and verticality of the inner surface of the pressure sleeve, and the verticality of the three-way sealing base surface (the surface where the three-way structure contacts the test piece) and the base surface thread. In addition, this structure can make the sealing surface of the test piece more evenly stressed, and can eliminate the errors caused by processing defects as much as possible in the experiment.

[0017] 3. The present invention provides a guide section on the outer circumferential surface of the middle section of the pressure sleeve. The guide section is provided with a leakage hole. The position of the leakage hole corresponds to the sealing surface. A measuring cylinder is provided directly below the guide section. After the seal fails and leakage occurs, the liquid flows out along the guide section and drips into the measuring cylinder. The sealing leakage is determined by measuring the volume of the liquid in the measuring cylinder.

[0018] 4. The interface thread of the tee structure of the present invention has the same specifications as the pipeline interface thread, but the rotation direction is opposite. During the installation process, the joint between the tee and the pipeline interface is only pressed without sliding, ensuring more efficient sealing. After fixing the direction of the pipeline interface and the tee, the interface nut is rotated to achieve contact, compression and sealing between the tee and the pipeline interface.

[0019] 5. The pressure sleeve of the present invention has a hole at the center, and the extrusion pressure of the sleeve is transmitted to the external display device through the signal transmission line of the pressure sensor through the signal measured by the pressure sensor, so that the accurate real-time measurement of the sealing compression force can be achieved. The tightening force can be adjusted according to the measured value to achieve the effect of controlling the sealing pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a piping diagram of the ConST 137S test bench in the prior art.

[0021] Figure 2 Schematic diagram of the sealing failure test device of the present invention located in a high-pressure hydraulic circulation system;

[0022] Figure 3 is a cross-sectional view of a sealing failure test device according to the present invention;

[0023] Figure 4 This is a structural diagram of the sealing failure test device of the present invention;

[0024] Figure 5 is the three-dimensional structure diagram of the test piece;

[0025] Figure 6 This is the pressure load diagram of the test piece.

[0026] Among them, 1- three-way structure, 2- sealing test piece, 3- test piece adapter, 4- pressure sensor, 5- pressure sleeve, 6- interface nut, 7- pipeline interface, 8- signal transmission line, 9- flow guide section, 10- measuring cylinder, 11- sealing failure test device, 12- high-pressure boosting equipment, 13- high-pressure hydraulic circulation system. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0028] The present invention provides a high-pressure pulsating liquid seal failure test device, which is parasitic outside the real working condition equipment and can monitor and control the seal extrusion pressure in real time, monitor whether leakage occurs in real time, and replace the test piece. Figure 2 As shown, in the existing high-pressure hydraulic cycle, the seal failure test device 11 of the present invention outputs hydraulic conditions from the sealing device in the form of a tee, thereby nearly completely simulating the hydraulic conditions under working conditions. The placement of the seal failure test device 11 is related to the seal location to be studied. Generally, the seal condition under high pressure is studied. Therefore, in this embodiment, the seal failure test device 11 is placed downstream of the high-pressure boosting device 12, at the highest point of the entire high-pressure hydraulic circulation system 13.

[0029] As attached Figure 3 As shown, the high-pressure pulsating liquid seal failure test device includes a tee structure 1, a sealing test piece 2, a test piece adapter 3, a pressure sensor 4, a pressure sleeve 5, an interface nut 6, and a signal transmission line 8. The tee structure 1 is installed in the high-pressure hydraulic pipeline via an interface bolt 6. The tee interface thread has the same specifications as the pipeline interface thread, but the rotation direction is opposite. The figure only shows the lower end interface of the tee structure 1. The upper end interface of the tee structure 1 is the same as the lower end interface. The pressure sleeve 5 presses the pressure sensor 4, the test piece adapter 3, and the test piece 2 to the side interface of the tee through the tightening force of the bolts. The pressure sleeve 5 has a hole at the center, through which the signal transmission line 8 of the pressure sensor 4 passes. The signal transmission line 8 transmits the extrusion pressure of the pressure sleeve 5 measured by the pressure sensor 4 to an external display device, which can realize accurate real-time measurement of the sealing compression force. The tightening force can be adjusted according to the measured value to achieve the purpose of controlling the sealing pressure.

[0030] The pressure load of the sealing test piece 2 and the test piece adapter 3 is as follows Figure 6As shown. The back of the sealed test piece 2 utilizes a spherical surface. A 45° to 70° tapered opening is formed on the inside of the test piece adapter 4. The combination of the spherical and tapered surfaces reduces machining requirements for the parallelism of the sensor surfaces, the flatness and perpendicularity of the inner surface of the pressure sleeve 5, and the perpendicularity of the tee sealing base (the surface where the tee contacts the test piece 2) and the base thread. Furthermore, this structure ensures more uniform force on the test piece sealing surface, minimizing errors caused by machining defects during experiments.

[0031] As attached Figure 4 As shown, a guide section 9 is provided in the middle of the pressure sleeve 5, with a drainage hole formed in it. The drainage hole is aligned with the sealing surface. If the seal fails and leaks, liquid will flow out along the guide section 9 and drip into the graduated cylinder 10. The leakage of the seal can be determined by measuring the volume of liquid in the graduated cylinder 10.

[0032] The right side of the tee structure 1 in contact with the test piece is the sealing base surface, which has a high flatness requirement of 0.01 or above and a roughness Ra requirement of 0.4 or above. The plane of the sealing test piece 2 is the test surface, and the test surface can be processed with the test pattern, as shown in the attached figure. Figure 5 shown.

[0033] To prevent the sealing test piece 2 from slipping during installation and rotation, grease can be applied to the contact surfaces between the sealing test piece 2 and the test piece adapter 3 during installation. Furthermore, locating pins can be installed between the sealing test piece 2 and the tee structure 1 to ensure the correct positioning and alignment of the contact points during the experiment.

[0034] In this embodiment, the tee is used to connect the upper and lower ends of the pipeline, and the bypass end is used as the test end. The bypass connection pipeline can also be used with one of the upper and lower ends as the test end.

[0035] The three-way structure in this embodiment can also be replaced by a cross interface or other forms of interfaces parasitic on the actual pipeline.

[0036] This test plan does not add a hydraulic switch because it can be opened and closed at any time under actual working conditions. If it is difficult to start and stop at any time under actual working conditions, a switch valve can be installed on the three-way test end pipeline for use when replacing the test piece.

[0037] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-pressure pulsating liquid seal failure test device, characterized in that: The sealing failure test device is installed in the existing high-pressure hydraulic circulation system. The sealing failure test device outputs the hydraulic working condition in the form of a tee. The sealing failure test device can measure the sealing compression force and can also reduce the verticality processing requirements of the sealing base surface of the tee structure and the connecting thread of the base surface. The sealing failure test device is arranged downstream of the high-pressure boosting equipment, which is the highest point of the entire circulating liquid pressure. The sealing failure test device includes a three-way structure, a sealing test piece, a test piece adapter, a pressure sensor and a pressure sleeve; The upper and lower ends of the three-way structure are respectively installed in the high-pressure hydraulic pipeline through interface bolts, and the pressure sleeve presses the pressure sensor, the test piece adapter, and the test piece at the side interface of the three-way structure through the tightening force of the bolts. The sealing test piece and the test piece adapter are matched with each other in a spherical and conical manner; a hole is opened at the center of the pressure sleeve, and the hole is used for the signal transmission line of the pressure sensor to pass through. The signal line transmits the extrusion pressure of the sleeve to the external display device through the signal measured by the pressure sensor.

2. The high-pressure pulsating liquid seal failure test device according to claim 1, characterized in that: The surface of the sealing test piece in contact with the sealing base surface of the tee structure is a plane, and the surface of the sealing test piece in contact with the test piece adapter is a spherical surface; the outer shape of the test piece adapter is a cylindrical structure, and a groove with a conical surface is machined on the surface of one end of the cylindrical structure.

3. The high-pressure pulsating liquid seal failure test device according to claim 2, characterized in that: The cone angle of the conical surface groove on the test piece adapter is 45°~70°.

4. The high-pressure pulsating liquid seal failure test device according to claim 3, characterized in that: The interface thread of the tee structure has the same specifications as the pipeline interface thread, but the rotation direction is opposite.

5. The high-pressure pulsating liquid seal failure test device according to claim 4, characterized in that: A flow guide section is provided on the outer circumferential surface of the middle section of the pressure sleeve. A leakage hole is opened on the flow guide section. The position of the leakage hole corresponds to the sealing surface. A measuring cylinder is provided just below the flow guide section.

6. The high-pressure pulsating liquid seal failure test device according to claim 4 or 5, characterized in that: The flatness of the sealing base surface of the three-way structure is greater than 0.01, and the roughness Ra is greater than 0.4; the test surface of the sealing test piece is processed with test lines.

7. The high-pressure pulsating liquid seal failure test device according to claim 6, characterized in that: When the sealing test piece and the adapter are installed, grease is applied to the contact surfaces of the sealing test piece and the adapter, or positioning pins are installed in the sealing test piece and the tee structure to ensure the positioning and correspondence of the contact points during the test.

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