Gate valve sealing performance detection system and sealing performance detection method

Abstract

The embodiment of the invention provides a gate valve sealing performance detection system and a sealing performance detection method, and belongs to the technical field of gate valve sealing performance detection. The gate valve sealing performance detection system is applied to a gate valve, and comprises a connecting piece which is provided with a medium channel for conveying an experimental medium, and a medium inlet and a medium outlet which are communicated with the medium channel, is adaptively installed on a valve body of a balance valve, and enables the medium outlet to be communicated with one end, far away from a gate valve middle cavity, of a first connecting pipe; one end of the pressurizing pipe is communicated with the medium inlet, and the pressurizing pipe is used for conveying an experimental medium; the outlet end of the block valve is communicated with the end, away from the medium inlet, of the pressurizing pipe, the inlet end of the block valve is used for being connected with a medium source, the medium source is used for providing an experimental medium, and the block valve is used for controlling connection and disconnection between the pressurizing pipe and the medium source; and the pressure detection piece is connected to the pressurizing pipe and is used for detecting the pressure in the pressurizing pipe. According to the embodiment of the invention, the convenience of detecting the sealing performance of the gate valve can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of gate valve sealing detection, and in particular to a gate valve sealing detection system and a sealing detection method. Background Art

[0002] Sealing test is the process of measuring and evaluating the sealing performance of the object to be tested, and is mainly used to detect whether the object to be tested has leakage. Gate valves are mainly used to control the flow of fluids, and the sealing performance of gate valves is the key to ensuring their normal operation. The gate valve sealing test method in the related art usually involves sealing the valve body with a blind plate or a plug installed on the gate valve and then filling it with a test medium for sealing test, or filling the closed chamber formed between the valve disc of the gate valve and the upper part of the valve body and the valve cover with a test medium through the packing purge hole of the gate valve to perform a middle cavity sealing test. However, the former requires the gate valve to be removed from the pipeline and installed on the pressure test bench, which is difficult to disassemble and assemble; and the latter requires that the valve design include a packing purge hole, and the gate valve without a packing purge hole cannot perform a middle cavity sealing test. Therefore, how to improve the convenience of sealing test of gate valves has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] The main purpose of the embodiments of the present application is to propose a gate valve sealing detection system and a sealing detection method, aiming to improve the convenience of sealing detection of gate valves.

[0004] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a gate valve sealing detection system, which is applied to a gate valve, wherein the gate valve has a gate valve middle cavity, the gate valve middle cavity is connected to a balancing valve through a first connecting pipe, and the balancing valve is used to balance the pressure in the gate valve middle cavity. The gate valve sealing detection system includes:

[0005] A connecting piece, having a medium channel for conveying experimental medium, and a medium inlet and a medium outlet connected to the medium channel, wherein the connecting piece is adapted to be installed on the valve body of the balancing valve, and enables the medium outlet to be connected to an end of the first connecting pipe away from the middle cavity of the gate valve;

[0006] A pressure charging pipe, one end of which is connected to the medium inlet, and the pressure charging pipe is used to transport the experimental medium;

[0007] A cut-off valve, wherein the outlet end of the cut-off valve is connected to an end of the pressure-charging tube away from the medium inlet, the inlet end of the cut-off valve is used to connect to a medium source, the medium source is used to provide the experimental medium, and the cut-off valve is used to control the connection between the pressure-charging tube and the medium source;

[0008] The pressure detection component is connected to the pressure charging pipe and is used to detect the pressure in the pressure charging pipe.

[0009] In some embodiments, the medium inlet and the medium outlet are respectively arranged at two opposite ends of the connecting member;

[0010] Alternatively, the medium inlet is arranged at the end of the connecting member, and the medium outlet is arranged at the side of the connecting member;

[0011] Alternatively, the medium inlet is arranged at a side of the connecting member, and the medium outlet is arranged at an end of the connecting member.

[0012] In some embodiments, a mounting groove is recessed on one side of the valve body of the balancing valve, and an experimental flow channel and a non-experimental flow channel are provided inside the valve body of the balancing valve, both of which are connected to the mounting groove, and an end of the experimental flow channel away from the mounting groove is connected to an end of the first connecting pipe away from the middle cavity of the gate valve, and the mounting groove can be adapted for the connector to be installed therein;

[0013] When the connecting piece is installed in the installation groove, it can block the end of the non-experimental flow channel close to the installation groove, and make the medium outlet communicate with the end of the experimental flow channel close to the installation groove.

[0014] In some embodiments, the gate valve sealing detection system further comprises a sealing member, wherein the sealing member is sealingly abutted between the bottom of the installation groove and the connecting member;

[0015] Wherein, when the medium outlet is arranged on a side of the connecting member close to the bottom of the mounting groove, the sealing member is provided with a through hole, and the through hole is communicated with both the medium outlet and the experimental flow channel.

[0016] In some embodiments, the connecting member includes a first mounting portion and a second mounting portion connected in sequence, the cross-sectional size of the first mounting portion is larger than the cross-sectional size of the second mounting portion, the first mounting portion is provided with the medium inlet, the second mounting portion is provided with the medium outlet, the second mounting portion can be adapted to be installed in the mounting groove, and the first mounting portion can be fixedly connected to the valve body of the balancing valve by fasteners.

[0017] To achieve the above object, a second aspect of an embodiment of the present application provides a sealing detection method, which is performed by applying the gate valve sealing detection system described in the first aspect, and the method includes:

[0018] Disassemble the balancing valve, install the connecting piece on the valve body of the balancing valve, and make the medium outlet communicate with the first connecting pipe;

[0019] Open the cut-off valve, and inject the experimental medium into the middle cavity of the gate valve through the medium source, the pressure-charging pipe, the medium channel and the first connecting pipe in sequence, and make the pressure in the middle cavity of the gate valve reach the experimental pressure;

[0020] Close the cut-off valve and detect the pressure of the pressure-charging pipe within a preset time through the pressure detection component;

[0021] The detection value of the pressure detection component is compared with the theoretical pressure value to determine the sealing performance of the gate valve.

[0022] In some embodiments, after the step of closing the shutoff valve and detecting the pressure of the pressure-charging pipe within a preset time by the pressure detection component, and before the step of comparing the detection value of the pressure detection component with the theoretical pressure value to determine the sealing performance of the gate valve, the method further includes:

[0023] Obtaining a first volume corresponding to the gate valve cavity, a second volume corresponding to the first connecting pipe, a third volume corresponding to the gate valve sealing detection system, and an allowable leakage rate of the gate valve to the test medium under the test pressure;

[0024] superimposing the first volume, the second volume and the third volume to obtain a total experimental volume;

[0025] The theoretical pressure value is obtained based on the preset time, the experimental pressure, the total experimental volume and the allowable leakage rate.

[0026] In some embodiments, when the test medium is gas, the method further includes: obtaining the allowable leakage rate of the gate valve to the gas under the test pressure by the following expression:

[0027]

[0028] The theoretical pressure value is obtained by the following expression:

[0029]

[0030] Wherein, Q1 is the allowable leakage rate of the gate valve for the gas under the test pressure, DN is the nominal diameter of the gate valve, V is the total volume of the experiment, t is the preset time, k is the safety factor used to compensate for the error caused by the simplification of values ​​in the calculation process, 1.013 is the approximate value of the ground standard atmospheric pressure, P1 is the test pressure, and P2 is the theoretical pressure value when the test medium is gas.

[0031] In some embodiments, when the test medium is liquid, the method further includes: obtaining the allowable leakage rate of the gate valve for the liquid under the test pressure by the following expression:

[0032]

[0033] The theoretical pressure value is obtained by the following expression:

[0034]

[0035] Wherein, Q2 is the allowable leakage rate of the gate valve to the liquid under the test pressure, P s is the design pressure of the gate valve, Q s is the allowable leakage rate of the gate valve’s design volume, E v is the bulk elastic modulus of the liquid, V is the total experimental volume, t is the preset time, P1 is the experimental pressure, and P3 is the theoretical pressure value when the experimental medium is liquid.

[0036] In some embodiments, before the steps of disassembling the balancing valve, installing the connector on the valve body of the balancing valve, and connecting the medium outlet to the first connecting pipe, the method further includes:

[0037] The sealing performance of the gate valve sealing performance detection system is tested.

[0038] The present application proposes a gate valve sealing detection system and a sealing detection method. The gate valve sealing detection system is applied to a gate valve. The gate valve has a gate valve middle cavity, which is connected to a balancing valve through a first connecting pipe. The balancing valve is used to balance the pressure in the gate valve middle cavity. The system includes a connecting piece, a charging pipe, a shut-off valve and a pressure detection piece. The connecting piece has a medium channel for conveying an experimental medium, and a medium inlet and a medium outlet connected to the medium channel. The connecting piece is adapted to be installed on the valve body of the balancing valve, and the medium outlet is connected to an end of the first connecting pipe away from the gate valve middle cavity; one end of the charging pipe is connected to the medium inlet, and the charging pipe is used to convey the experimental medium; the outlet end of the shut-off valve is connected to an end of the charging pipe away from the medium inlet, the inlet end of the shut-off valve is used to connect to a medium source, the medium source is used to provide an experimental medium, and the shut-off valve is used to control the on-off between the charging pipe and the medium source; the pressure detection piece is connected to the charging pipe and is used to detect the pressure in the charging pipe. When the present application performs a sealing test on a gate valve equipped with a balancing valve for balancing the pressure in the gate valve cavity, the test medium can pass from the medium inlet of the connector to the gate valve cavity through the pressure-charging pipe, and the medium outlet of the connector is connected to the first connecting pipe to ensure that the test medium can enter the gate valve cavity, and the cut-off valve is used to open and close the pressure-charging pipe. In addition, the pressure detection component is connected to the pressure-charging pipe, and the pressure detection component can detect the pressure in the gate valve cavity. The gate valve sealing test system of the present application can directly utilize the design of the existing gate valve without the need for complex modification or adjustment, thereby improving the convenience of the gate valve sealing test. In addition, the gate valve sealing test system proposed in the present application avoids the cumbersome steps of removing the gate valve from the pipeline and installing it on the pressure test stand in the related art, and also solves the problem that the cavity sealing test cannot be performed due to the lack of a packing purge hole in the valve design, thereby improving the convenience of the gate valve sealing test. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a structural schematic diagram of a gate valve sealing detection system provided in an embodiment of the present application;

[0040] Figure 2 is a structural schematic diagram of a connector provided in an embodiment of the present application;

[0041] Figure 3 is another structural schematic diagram of a connector provided in an embodiment of the present application;

[0042] Figure 4 is a schematic diagram of a cross-sectional structure of a connector provided in an embodiment of the present application;

[0043] Figure 5 It is a flow chart of the sealing detection method provided in the embodiment of the present application.

[0044] Figure numerals: gate valve sealing detection system 100, connecting part 110, medium channel 111, medium inlet 112, medium outlet 113, first mounting part 114, second mounting part 115, charging tube 120, shut-off valve 130, pressure detection part 140, balancing valve 150, experimental flow channel 151, non-experimental flow channel 152, mounting groove 153, first valve body 160, gate valve middle cavity 161, first valve disc 162, first valve stem 163, upstream pipeline 164, downstream pipeline 165, first connecting pipe 170, second connecting pipe 180, sealing part 190. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] It should be noted that, although the functional modules are divided in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first", "second", etc. in the specification, claims and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0048] First, some nouns involved in this application are analyzed:

[0049] Sealing: refers to the ability of a system or component to prevent fluid (liquid or gas) from entering or escaping.

[0050] Valve: A device used to control flow in a fluid system. A valve can regulate, open or close the flow of liquid, gas, slurry or other media in pipelines, containers and other fluid delivery systems.

[0051] Valve cavity: also known as the valve body or the internal space of the valve, is the main part of the valve used to accommodate and guide the flow of fluid.

[0052] Globe valve: A common type of valve, mainly used to open or close the flow of fluid, and can regulate the flow to a certain extent. The globe valve controls the flow of fluid by driving the valve core (such as a valve disc) up and down through the valve stem. The valve disc is usually sealed with the valve body to block the flow of fluid.

[0053] Pressure balance: In some high-pressure applications, the pressure difference between the gate valve cavity and the upstream pipeline may cause operational difficulties. A balancing valve or pressure balancing device can be used to adjust the pressure between the cavity and the upstream pipeline to ensure that the valve can be opened and closed smoothly.

[0054] Balancing valve: Its main function is to adjust and balance the pressure difference between the valve cavity and the upstream pipeline. Balancing valve is usually integrated into the design of gate valve. Its structure is similar to a small stop valve. Its inlet end is connected to the upstream pipeline of the gate valve, and its outlet end is connected to the gate valve cavity. Balancing valve is mainly used to adjust the pressure of the upstream pipeline of the gate valve and the gate valve cavity, to ensure that the pressure of the gate valve cavity is balanced with the pressure of the upstream pipeline, and to prevent the valve from operating properly due to excessive pressure difference. In a high temperature and high pressure environment, if the pressure difference between the gate valve cavity and the upstream pipeline is too large, a boiler-like effect may occur, causing the valve to overheat and be difficult to open or close. Balancing valves can effectively avoid this phenomenon by adjusting the pressure.

[0055] Flange: A disc-shaped component used for the first connection of pipes, containers or equipment, mainly used to connect piping systems or install and fix equipment.

[0056] The nominal diameter of the valve (NB): is the diameter of the pipe that the valve can connect to. For example, NB 130 means that the valve is designed for pipes with a diameter of 130 mm.

[0057] Gate valves play a vital role in nuclear power plants, thermal power plants, and other types of process industrial plants. In the field of industrial production, judging whether the working condition of the gate valve is good is an indispensable part of the equipment management process. The gate valve is a shut-off valve, and the sealing test of the gate valve is the core link in the evaluation of the working condition of the gate valve. The sealing test is the process of measuring and evaluating the sealing performance of the gate valve, which is mainly used to detect whether the gate valve has leakage. By testing the sealing performance of the gate valve, not only can the sealing performance of the valve disc and the valve body be accurately judged, but also the sealing condition of the valve cover and the packing can be evaluated, thereby ensuring that the gate valve can play its original design sealing function in the next working cycle.

[0058] Testing the tightness of the gate valve helps determine whether the gate valve needs to be repaired during the current shutdown and maintenance phase, thereby rationally planning the gate valve maintenance plan and avoiding unnecessary cost waste caused by excessive maintenance. Conventional gate valve tightness testing mainly uses the following two methods:

[0059] Method 1: Before installing the gate valve into the pipeline system, the valve body is sealed by installing blind plates or plugs at the inlet and outlet of the gate valve, and then the test medium is filled into the valve body to complete the sealing test of the gate valve. However, this method requires the gate valve to be removed from the pipeline and installed on a pressure test bench, which is difficult to disassemble and assemble. If the gate valve is a large-diameter gate valve, the workload of removing it from the pipeline is very large; if the gate valve is a welded gate valve, when disassembling and assembling it, in addition to the large workload, there is also the risk of cutting and damaging the pipeline or the gate valve body, making it impossible to reinstall;

[0060] Method 2: Use a special pressure device to fill the closed chamber formed between the gate valve disc and the upper part of the valve body and the valve cover through the packing purge hole at the bottom of the gate valve stuffing box to test the sealing performance of the gate valve middle cavity. However, the implementation of this method for the gate valve middle cavity sealing test requires that the gate valve body is designed with a packing purge hole, that is, the gate valve without a packing purge hole cannot be tested for the middle cavity sealing performance.

[0061] Therefore, how to improve the convenience of sealing detection of gate valves has become a technical problem that needs to be solved urgently.

[0062] See also Figure 1 and Figure 2 , Figure 1 is a structural schematic diagram of a gate valve sealing detection system provided in an embodiment of the present application, Figure 2 1 is a schematic diagram of the structure of the connector provided in the embodiment of the present application. The gate valve sealing detection system 100 may specifically include: a connector 110, a pressure charging pipe 120, a cut-off valve 130 and a pressure detection component 140. The gate valve sealing detection system 100 is applied to a gate valve, which has a gate valve middle cavity 161, which is connected to a balancing valve 150 through a first connecting pipe 170, and the balancing valve 150 is used to balance the pressure in the gate valve middle cavity 161.

[0063] Combine the following Figure 1 , Figure 2 The specific structure of the gate valve sealing detection system 100 is introduced in detail.

[0064] The connecting piece 110 has a medium channel 111 for conveying experimental medium, and a medium inlet 112 and a medium outlet 113 connected to the medium channel 111. The connecting piece 110 is adapted to be installed on the valve body of the balancing valve 150, and the medium outlet 113 is connected to the end of the first connecting pipe 170 away from the gate valve cavity 161; one end of the charging tube 120 is connected to the medium inlet 112, and the charging tube 120 is used to convey the experimental medium; the outlet end of the shut-off valve 130 is connected to the end of the charging tube 120 away from the medium inlet 112, and the inlet end of the shut-off valve 130 is used to connect to the medium source, the medium source is used to provide the experimental medium, and the shut-off valve 130 is used to control the connection between the charging tube 120 and the medium source; the pressure detection component 140 is connected to the charging tube 120, and the pressure detection component 140 can be used to detect the pressure in the charging tube 120.

[0065] It should be noted that the object to be tested in the present application may be a gate valve, which is connected to a balancing valve 150 , and the pressure of the gate valve cavity 161 and the upstream pipeline 164 can be adjusted and balanced by the balancing valve 150 .

[0066] Specifically, see Figure 1 As shown, the gate valve may include a first valve body 160, a first valve flap 162 and a first valve stem 163. The first valve body 160 has a gate valve middle cavity 161, and is provided with a gate valve inlet end and a gate valve outlet end which are connected to each other and are both connected to the gate valve middle cavity 161. The gate valve inlet end is used to communicate with an upstream pipeline 164 of the gate valve, and the gate valve outlet end is used to communicate with a downstream pipeline 165 of the gate valve. The first valve flap 162 is provided in the first valve body 160, and the first valve stem 163 is connected to the first valve flap 162 and is movably mounted on the first valve body 160, wherein the opening or closing of the first valve flap 162 is controlled by controlling the movement of the first valve stem 163. When the first valve flap 162 is in the open position, the fluid can flow in from the gate valve inlet end, pass through the gate valve middle cavity 161, and then flow out from the gate valve outlet end, thereby allowing the fluid to flow in the pipeline system. When the first valve flap 162 is in the closed position, the first valve flap 162 contacts the first valve body 160 to form a sealing surface, preventing the fluid from passing through the gate valve cavity 161, thereby cutting off the flow of the fluid.

[0067] See also Figure 1 , Figure 2 , Figure 3As shown, the balancing valve 150 may include a second valve body, a second valve cover and a second valve flap, wherein the inlet end of the second valve body is connected to the upstream pipeline 164 of the gate valve through the second connecting pipe 180, and the outlet end of the second valve body is connected to the gate valve cavity 161 through the first connecting pipe 170 to balance the pressure of the gate valve cavity 161 and the upstream pipeline 164. The second valve flap is arranged in the second valve body, and the valve flow capacity of the valve can be adjusted by changing the gap (i.e., the opening) between the valve flap and the valve body, thereby changing the flow resistance flowing through the valve to achieve the purpose of regulating the flow. When disassembling the balancing valve 150, the external components of the balancing valve 150, such as the second valve cover, can be disassembled first; then the bleed screw on the valve can be loosened to release the internal pressure; and finally the second valve flap can be disassembled.

[0068] Specifically, the connector 110 is a workpiece that matches the valve body size of the balancing valve 150, and can be connected and fastened to the valve body flange of the balancing valve 150 using fastening components such as threads. In this way, by disassembling the balancing valve 150, taking out the valve cover and valve disc of the balancing valve 150, and installing the connector 110 on the valve body of the balancing valve 150, the connection between the gate valve sealing detection system 100 and the balancing valve 150 can be achieved, and the gate valve can be sealed by the gate valve sealing detection system 100.

[0069] The pressure-charging pipe 120 may be a pipe system for conveying and distributing a pressure medium (such as a gas or a liquid). In addition, the pressure-charging pipe 120 may withstand a certain pressure to ensure that the medium flows safely and effectively therein. The material and shape of the pressure-charging pipe 120 are not specifically limited in this application.

[0070] The shutoff valve 130 is a valve used to completely cut off or connect the flow of fluid, and common types include gate valves, ball valves, butterfly valves, etc., and the present application does not specifically limit the structure, material and shape of the shutoff valve 130. The shutoff valve 130 can be operated manually or by automated means such as electric, pneumatic or hydraulic.

[0071] Among them, the experimental medium can be a gas medium or a liquid medium. The inlet end of the shut-off valve 130 is connected to a medium source (such as a water pressure pump or a compressed air source) that provides the experimental medium. In this way, by controlling the opening of the shut-off valve 130, the medium source can be connected to the pressure-charging tube 120, the medium channel 111, the first connecting tube 170 and the gate valve cavity 161, and then the test medium can be injected toward the gate valve cavity 161 through the medium source; conversely, by controlling the closing of the shut-off valve 130, the connection between the medium source and the pressure-charging tube 120, the medium channel 111, the first connecting tube 170 and the gate valve cavity 161 can be interrupted, and the injection of the test medium toward the gate valve cavity 161 through the medium source can be stopped.

[0072] Of course, in other possible implementations, the medium source may also be designed as a part of the gate valve sealing detection system 100, and this embodiment does not impose any specific limitation on this.

[0073] Among them, the pressure detection component 140 refers to a device or instrument that can be used to measure pressure to monitor and control the pressure level in the system. The present application does not specifically limit the type of the pressure detection component 140. For example, the pressure detection component 140 can be a pressure gauge, or a pressure sensor, a pressure gauge, etc. The present application detects the pressure in the charging tube 120 through the pressure detection component 140, and indirectly achieves the purpose of detecting the pressure in the gate valve cavity 161, and the pressure detection component 140 is more convenient to install.

[0074] The working principle of the gate valve sealing detection system 100 of the present application is as follows: first disassemble the balancing valve 150 , install the connecting piece 110 on the valve body of the balancing valve 150 , and connect the medium outlet 113 with the first connecting pipe 170 . Subsequently, the shut-off valve 130 is opened, and the experimental medium is injected into the gate valve middle cavity 161 through the medium source through the pressure-charging tube 120, the medium channel 111 and the first connecting tube 170 in sequence to increase the pressure in the gate valve middle cavity 161, that is, to pressurize the gate valve middle cavity 161. At the same time, the pressure in the pressure-charging tube 120 can be monitored in real time through the pressure detection component 140, that is, the pressure in the gate valve middle cavity 161 can be monitored in real time, and the shut-off valve 130 is closed after the pressure in the gate valve middle cavity 161 reaches the experimental pressure; subsequently, the pressure is maintained for a preset time (for example, 1 hour), and at the same time, the pressure drop in the pressure-charging tube 120 is observed and recorded through the pressure detection component 140, that is, the pressure drop in the gate valve middle cavity 161 is observed and recorded, so as to determine whether the sealing between the gate valve and its first valve disc 162 and the first valve body 160 is qualified.

[0075] Based on this, the gate valve sealing detection system 100 of the present application can directly utilize the design of the existing gate valve without complicated modification or adjustment, thereby improving the convenience of the gate valve sealing detection. In addition, the gate valve sealing detection system 100 proposed in the present application avoids the cumbersome steps of removing the gate valve from the pipeline and installing it on the pressure test stand in the related art, and also solves the problem that the sealing detection of the middle cavity cannot be performed due to the lack of packing purge holes in the valve design, thereby improving the convenience of the gate valve sealing detection.

[0076] Specifically, in one possible embodiment, the medium inlet 112 and the medium outlet 113 may be disposed at opposite ends of the connector 110. In another possible embodiment, the medium inlet 112 is disposed at the end of the connector 110, and the medium outlet 113 is disposed at the side of the connector 110; of course, in other possible embodiments, the medium inlet 112 is disposed at the side of the connector 110, and the medium outlet 113 is disposed at the end of the connector 110. This embodiment does not limit this.

[0077] For details, please refer to Figure 2 , Figure 2 1 is a schematic diagram of the structure of the connector 110 provided in the embodiment of the present application. The connector 110 has a vertically arranged medium channel 111, and the medium inlet 112 and the medium outlet 113 of the connector 110 are respectively connected to the medium channel 111, and the medium inlet 112 and the medium outlet 113 are arranged at opposite ends of the connector 110.

[0078] For details, please refer to Figure 3 , Figure 3 FIG. 1 is another schematic diagram of the structure of the connector 110 provided in the embodiment of the present application. Figure 3 In the figure, the connecting member 110 has a folded “L”-shaped medium channel 111, and the medium inlet 112 and the medium outlet 113 of the connecting member 110 are respectively connected to the medium channel 111, the medium inlet 112 is arranged at the end of the connecting member 110, and the medium outlet 113 is arranged at the side of the connecting member 110.

[0079] Please refer to Figure 2 and Figure 3 , a mounting groove 153 is recessed on one side of the valve body of the balancing valve 150, and an experimental flow channel 151 and a non-experimental flow channel 152 are provided inside the valve body of the balancing valve 150, both of which are connected to the mounting groove 153. The end of the experimental flow channel 151 away from the mounting groove 153 is connected to the end of the first connecting pipe 170 away from the gate valve cavity 161, and the mounting groove 153 can be adapted for the connector 110 to be installed therein; one end of the non-experimental flow channel 152 is connected to the upstream pipeline 164 of the gate valve through the second connecting pipe 180; when the connector 110 is installed in the mounting groove 153, it can block the end of the non-experimental flow channel 152 close to the mounting groove 153, and make the medium outlet 113 connected to the end of the experimental flow channel 151 close to the mounting groove 153. For example Figure 2 When the medium inlet 112 and the medium outlet 113 are respectively arranged at opposite ends of the connector 110, the side of the connector 110 blocks the non-experimental flow channel 152 to ensure that the experimental medium enters the gate valve cavity 161 only through the medium channel 111. Figure 3When the medium inlet 112 is disposed at the end of the connecting member 110 and the medium outlet 113 is disposed at the side of the connecting member 110 , the bottom of the connecting member 110 blocks the non-experimental flow channel 152 .

[0080] Please refer to Figure 2 and Figure 3 The gate valve sealing detection system 100 also includes a sealing member 190, which is sealed and abutted between the bottom of the mounting groove 153 and the connecting member 110; wherein, when the medium outlet 113 is provided on the side of the groove bottom of the connecting member 110 close to the mounting groove 153, the sealing member 190 is provided with a through hole, and the through hole is connected with both the medium outlet 113 and the experimental flow channel 151. When the medium outlet 113 is provided on the side of the groove wall of the connecting member 110 close to the mounting groove 153, the sealing member 190 can be annular or sheet-shaped. The sealing member 190 can form a sealing area between the connecting member 110 and the mounting groove 153, thereby improving the sealing performance of the contact part between the connecting member 110 and the mounting groove 153, and can isolate the medium channel 111 of the connecting member 110 from the non-experimental flow channel 152 of the balancing valve 150, so as to ensure that the experimental medium only enters the gate valve cavity 161, and does not enter the non-experimental flow channel 152 of the balancing valve 150. In addition, the risk of leakage of experimental media in the system can be reduced, thereby improving the accuracy of sealing detection.

[0081] Specifically, the number of the sealing member 190 may be one or more, and the present application does not specifically limit the type, material and shape of the sealing member 190. For example, the sealing member 190 may be a sealing ring or the like.

[0082] Specifically, see Figure 3 In the embodiment, a gasket may be included between the connector 110 and the mounting groove 153 to further improve the sealing performance and further reduce the risk of leakage of the experimental medium. In one embodiment, a stepped countersunk hole is provided at the top of the mounting groove 153, a portion of the upper end of the connector 110 is inserted into the stepped countersunk hole, and the gasket is provided between the bottom wall of the countersunk hole and the connector 110.

[0083] In some embodiments, the connector 110 is threadedly connected to the mounting groove 153. Specifically, the connector 110 may be a rod-shaped component with external threads, and the inner wall of the mounting groove 153 may have internal threads corresponding to the external threads of the connector 110, so that the two fit tightly.

[0084] In other embodiments, the connecting member 110 includes a first mounting portion 114 and a second mounting portion 115 which are connected in sequence, the cross-sectional size of the first mounting portion 114 is larger than the cross-sectional size of the second mounting portion 115, the first mounting portion 114 is provided with a medium inlet 112, the second mounting portion 115 is provided with a medium outlet 113, the second mounting portion 115 can be adapted to be installed in the mounting groove 153, and the first mounting portion 114 can be fixedly connected to the valve body of the balancing valve 150 by fasteners.

[0085] It should be noted that the cross-sectional size usually refers to the specific size of a component at a certain cross section; the connector 110 can be T-shaped, wherein the cross section of the first mounting portion 114 is a circular shape with four symmetrical concave areas and a central through hole, each concave area being 90 degrees apart. The first mounting portion 114 is radially protruding compared to the second mounting portion 115, and the second mounting portion 115 is threadedly connected to the mounting groove 153. The first mounting portion 114 is locked to the top flange of the balancing valve 150. Please refer to Figure 4 , Figure 4 1 is a top view of the connector 110 provided in an embodiment of the present application. The middle through hole of the first mounting portion 114 is the medium inlet 112, and four holes are evenly distributed on the edge of the first mounting portion 114, which can be used to connect with the top flange of the balancing valve 150 through threaded fasteners or bolts. The top flange of the balancing valve 150 is located at the upper part of the balancing valve 150 and has a threaded hole for connecting with the first mounting portion 114. Furthermore, the first mounting portion 114 and the top flange of the balancing valve 150 can be connected and fastened by threaded fasteners or bolts.

[0086] Please refer to Figure 5 The embodiment of the present application also provides a sealing detection method, which is applied to the aforementioned gate valve sealing detection system 100, aiming to improve the convenience of sealing detection of the gate valve. Figure 5 is an optional flow chart of the sealing detection method provided in the embodiment of the present application. Figure 5 The method may include but is not limited to steps S1 to S4.

[0087] Step S1, disassembling the balancing valve 150, installing the connecting piece 110 on the valve body of the balancing valve 150, and connecting the medium outlet 113 with the first connecting pipe 170;

[0088] Step S2, opening the shut-off valve 130, injecting the experimental medium into the gate valve middle cavity 161 through the medium source through the pressure charging pipe 120, the medium channel 111 and the first connecting pipe 170 in sequence, and making the pressure in the gate valve middle cavity 161 reach the experimental pressure;

[0089] Step S3, closing the cut-off valve 130, and detecting the pressure of the charging pipe 120 within a preset time through the pressure detection member 140;

[0090] Step S4, comparing the detection value of the pressure detection component 140 with the theoretical pressure value to determine the sealing performance of the gate valve.

[0091] Steps S1 to S4 shown in the embodiment of the present application detect the sealing performance of the gate valve by testing the pressure holding capacity of the gate valve cavity 161 under a specific experimental pressure. Specifically, the experimental medium is first injected into the pressure charging tube 120 by opening the shutoff valve 130, with the purpose of gradually increasing the pressure of the gate valve cavity 161 to a predetermined experimental pressure, so as to ensure that the valve is tested under simulated working conditions. When the pressure of the gate valve cavity 161 reaches the required experimental pressure, the shutoff valve 130 is immediately closed to stop the further inflow of the experimental medium. At this time, the pressure detection component 140 can detect the pressure of the gate valve cavity 161 within a preset time. Finally, after the preset time is over, the detection value of the pressure detection component 140 is compared with the theoretical pressure value. If the detection value measured by the pressure detection component 140 is greater than or equal to the theoretical pressure value, this indicates that the gate valve cavity 161 maintains good sealing during the experiment and no significant pressure loss occurs; conversely, if the detection value measured by the pressure detection component 140 is less than the theoretical pressure value, that is, there is an obvious pressure drop in the gate valve cavity 161, then the gate valve has a leakage problem and requires further inspection and maintenance.

[0092] Before step S1 in some embodiments, the method further includes: testing the sealing performance of the gate valve sealing performance detection system 100. Specifically, the experimental medium is input into the gate valve sealing performance detection system 100 to test the sealing performance of the gate valve sealing performance detection system 100; it should be noted that only when the sealing performance of the gate valve sealing performance detection system 100 is qualified, the valve cover and valve disc assembly of the balancing valve 150 installed on the gate valve can be disassembled, and then the valve body of the balancing valve 150 is connected to the connector 110. When the sealing performance of the gate valve sealing performance detection system 100 is unqualified, the faulty components should be checked and replaced in time until the sealing performance is qualified.

[0093] In step S2 of some embodiments, the experimental medium may be a gas or a liquid. When the experimental medium may be a gas, the experimental pressure is greater than the standard atmospheric pressure and less than the preset pressure to ensure the safe operation of the system. For example, in order to ensure the safe operation of the system, when compressed air is used as the experimental medium, the preset pressure refers to the pressure of the compressed gas used, and the pressure of the compressed gas used may be 10 bar, that is, the experimental pressure is less than 10 bar. The embodiment of the present application only performs low-pressure sealing detection on the gate valve cavity 161.

[0094] In steps S2 and S3 of some embodiments, the present application regards the gate valve sealing detection system 100, the gate valve middle cavity 161, and the first connecting pipe 170 between the gate valve middle cavity 161 and the balancing valve 150 as a whole. Because the sealing of the gate valve sealing detection system 100 is qualified, it can be assumed that the pressure inside the three is consistent, and the value of the pressure detection component 140 is the gate valve middle cavity pressure. After the value of the pressure detection component 140 (i.e., the pressure of the gate valve middle cavity 161) rises to the test pressure, the shut-off valve 130 is closed and the pressure maintenance is started to detect the sealing of the gate valve.

[0095] In step S4 of some embodiments, a theoretical pressure value is calculated by the inherent properties of the gate valve, and compared with the detection value of the pressure detection component 140 after a preset time to determine whether the sealing of the gate valve is qualified. When the detection value measured by the pressure detection component 140 is greater than or equal to the theoretical pressure value, the sealing of the gate valve is qualified.

[0096] In step S4, the method for calculating the theoretical pressure value includes: first, obtaining the first volume V corresponding to the gate valve cavity 161 value , the second volume V corresponding to the first connecting pipe 170 pipe The third volume V corresponding to the gate valve sealing detection system 100 tool ; Further, for the first volume V value , the second volume V pipe and the third volume V tool Superposition is performed to obtain the total experimental volume V = V value +V pipe +V tool ; Finally, the theoretical pressure value is obtained based on the preset time, test pressure, total test volume and the allowable leakage rate of the gate valve to the test medium under the test pressure.

[0097] It should be noted that the first volume V value is the volume of the gate valve cavity 161. The first volume can be obtained by calculating the size of the valve drawing, or it can be actually obtained and recorded by calculating the water injection volume through historical dismantling work; the second volume V pipe The second volume V is the internal volume of the first connecting pipe 170 between the balancing valve 150 and the gate valve cavity 161. The second volume can be obtained by calculating the pipe size, or can be actually obtained and recorded by calculating the water injection volume through historical dismantling work; the third volume V tool The third volume V is the total volume of the downstream portion of the cut-off valve 130 in the gate valve sealing detection system 100. The third volume can be obtained by actually measuring the gate valve sealing detection system 100. value , the second volume V pipe and the third volume V tool The unit can be cubic centimeters (cm 3). Specifically, when the experimental medium is gas, for the convenience of calculation, the first volume V value , the second volume V pipe and the third volume V tool The unit can be cm 3 ; When the experimental medium is liquid, for the convenience of calculation, the first volume V value , the second volume V pipe and the third volume V tool The unit can be milliliter (mL).

[0098] In some embodiments, when the experimental medium is gas, the gate valve and the balancing valve 150 need to be emptied to make them free of water. For example, when the experimental medium is compressed air, the upstream of the shut-off valve 130 is connected to the compressed air source, and compressed air is introduced into the charging pipe 120 to make the pressure in the gate valve cavity reach the experimental pressure. To ensure safety, the pressure of the compressed air is not higher than 10 bar, that is, only a low-pressure sealing test is performed on the gate valve cavity 161. In GB / T13927 "Industrial Valve Pressure Test", the gas leakage rate of the gate valve that meets the AA-level sealing standard is ≤0.18*DN (mm 2 / s). In the embodiment of the present application, if the gate valve meets the AA-level sealing standard, the gas leakage rate of the gate valve needs to be converted into the leakage rate under 1 standard atmospheric pressure, that is, the allowable leakage rate of the gate valve to compressed air under the test pressure can be expressed by the following formula (1):

[0099]

[0100] Among them, Q1 is the allowable leakage rate of the gate valve to compressed air under the test pressure, in cm 3 / h; DN is the nominal diameter of the gate valve, in millimeters (mm). It can be seen that when the test medium is gas, the allowable leakage rate of the gate valve to the gas under the test pressure is only related to the nominal diameter of the gate valve.

[0101] After determining the allowable leakage rate of the gate valve to compressed air under the test pressure, the theoretical pressure value is obtained based on the preset time, test pressure, total test volume and the allowable leakage rate of the gate valve to compressed air under the test pressure. Specifically, for the convenience of expression, the test system is the general term for the gate valve cavity 161, the first connecting pipe 170 and the gate valve sealing detection system 100. Because the sealing detection process lasts for a short time and the test system has heat exchange with the outside world, it is assumed that the temperature of the test system remains unchanged during the sealing detection process. At the beginning of the sealing detection process, the test medium is introduced into the charging pipe 120, and the pressure in the gate valve cavity reaches the test pressure P1. P1 can be determined by the indication of the pressure detection component 140. At this time, according to the definition of the allowable leakage rate of the gas, the standard volume of compressed air is P1×V. After the preset time t, the theoretical pressure value of the gate valve cavity 161 is P2. At this time, the standard volume of compressed air is P2×V. Then the standard volume of compressed air leaked within the preset time t is Q1×t=(P1-P2)×V. When the allowable leakage rate Q1 of the gate valve for compressed air under the test pressure, the preset time t, and the test pressure P1 are known, the theoretical pressure value P2 can be expressed by the following formula (2):

[0102]

[0103] Where V is the total experimental volume in cm 3 ; t is the preset time, in h; k is the safety factor, dimensionless, and the value range can be (0, 1]. k can be used to compensate for the error caused by the simplification of the value in the calculation process, such as the error caused by the simplified calculation of the volume of the gate valve cavity 161. 1.013 is the approximate value of the ground standard atmospheric pressure, in bar; P1 is the experimental pressure, in bar; P2 is the theoretical pressure value when the experimental medium is compressed air, in bar.

[0104] After the preset time t, the detection value (i.e., the actual pressure value of the gate valve cavity 161) read from the pressure detection element 140 is P t , then the acceptance criteria for gate valve sealing is: P t ≥P2. That is, when the detection value measured by the pressure detection member 140 is greater than or equal to the theoretical pressure value, it indicates that the gate valve cavity 161 maintains good sealing performance during the experiment, and no significant pressure loss occurs, and the gate valve sealing performance is qualified.

[0105] In other embodiments, when the test medium is liquid, the gate valve cavity 161, the first connecting pipe 170 and the internal state of the gate valve sealing detection system 100 are all liquid, that is, there is no gas cavity. For example, when the test medium is water, the upstream of the cut-off valve 130 is connected to a hydraulic pump, and water is introduced into the pressure-charging pipe 120 to make the gate valve cavity pressure reach the test pressure. The allowable leakage rate of the gate valve to water under the test pressure can be expressed by the following formula (3):

[0106]

[0107] Where Q2 is the allowable leakage rate of the gate valve to water under the test pressure, in mL / s; P1 is the test pressure, in bar; P s P is the design pressure of the gate valve, that is, the pressure that the valve withstands under the design conditions. s The unit can be bar; Q s Q is the allowable leakage rate of the gate valve’s design volume, i.e. the allowable leakage rate of the water volume in the valve under the design conditions. s The unit can be mL / s.

[0108] Compared with gas, liquid has lower compressibility, but liquid will still deform under pressure. If the pressure inside the valve is not constant, that is, the pressure difference will change over time, resulting in changes in the allowable leakage rate. Specifically, the process of deriving the theoretical pressure value P3 when the experimental medium is liquid according to formula (3) is as follows:

[0109] When water is used for sealing test, the volume of the test system remains unchanged because the leakage is generally small and the temperature change of the test system is generally small within the preset time. Therefore, the relationship between the pressure difference of the test system and the leakage of water can be expressed by the following formula (4):

[0110]

[0111] Wherein, ΔP is the pressure difference of the test system, ΔP is a negative value, and the unit is bar; ΔV is the volume leakage of water within the preset time, and the unit is mL; V is the volume of the test system. Since the test system is the general term for the gate valve cavity 161, the first connecting pipe 170 and the gate valve sealing detection system 100, V=V valve +V pipe +V tool , unit is mL; E v is the bulk elastic modulus of water, in megapascals (MPa). In this application, the temperature range is 20-50°C, the pressure range is 0-50 MPa, and E v The value can be 2200MPa.

[0112] In equation (4), ΔV can be calculated using equation (5):

[0113]

[0114] Among them, Q T is the allowable leakage rate of water volume at any time T, in mL / s; Q T It is related to the pressure in the test system at any time T, Q T It can be expressed by the following formula (6):

[0115]

[0116] Among them, P T is the pressure of the test system at any time T. When T = 0, P T =P1;P s P is the design pressure of the gate valve, that is, the pressure that the valve withstands under the design conditions. s is a fixed value, P s The unit can be bar; Q s Q is the allowable leakage rate of the gate valve’s design volume, i.e. the allowable leakage rate of the water volume in the valve under the design conditions. s is a fixed value, Q s The unit can be mL / s.

[0117] In formula (6), the pressure P of the test system at any time T is T It can be expressed by the following formula (7):

[0118] P T =P1+ΔP (7)

[0119] From the above formula (7), it can be obtained that ΔP is a function that changes with T. ΔP can be expressed by the following formula (8):

[0120]

[0121] in, It is the real-time rate of change of pressure of the test system, and its sign is negative.

[0122] Combining the above formulas (4), (5), (6), (7) and (8), we can obtain the following formula (9):

[0123]

[0124] Let y = f(T), equation (7) can be transformed into (y ′ ) 2+ My = N form of differential equation. Because the above equation is a first-order nonlinear differential equation, it is difficult to find a general solution, and can only be solved by numerical methods, which is not convenient for calculation. Therefore, in the embodiment of the present application, the volume of water at the start time TT of the preset time is allowed to leak at a rate Q TT The pressure P of the test system T The relationship between is approximated as a linear relationship, and the following formula (10) can be obtained conservatively based on the above formula (6):

[0125]

[0126] Using Q in formula (10) TT Substituting Q in the above formula (6) T Substituting into formula (4), formula (5), formula (7), and formula (8), the calculated pressure drop at any time is less than Q T Substituting the calculated pressure drop, the theoretically allowable pressure drop at any time during the test is less than the actual pressure drop. After substitution, the obtained differential equation can be expressed by the following formula (11):

[0127]

[0128] Since the above formula (11) is a homogeneous first-order linear differential equation, its general solution can be expressed by the following formula (12):

[0129]

[0130] Because the test duration is the preset time t, the theoretical pressure value P3 of the test system at the end of the test can be expressed by the following formula (13):

[0131]

[0132] Among them, E v is the bulk elastic modulus of the liquid, V is the total experimental volume, t is the preset time, P1 is the experimental pressure, and P3 is the theoretical pressure value when the experimental medium is liquid.

[0133] When the detection value of the pressure detection element 140 (i.e. the actual pressure value read after the preset time t) is Pt after the preset time t, the standard for the gate valve sealing test to be qualified is: P t ≥P3. That is, when the detection value measured by the pressure detection member 140 is greater than or equal to the theoretical pressure value, it indicates that the gate valve cavity 161 maintains good sealing performance during the experiment, and no significant pressure loss occurs, and the gate valve sealing performance is qualified.

[0134] The gate valve sealing detection system and sealing detection method provided in the embodiment of the present application can perform a middle cavity sealing test on a gate valve without a packing purge hole through the gate valve sealing detection system 100, which makes up for the defect that the gate valve without a packing purge hole cannot perform an online middle cavity sealing test. The embodiment of the present application can directly perform an online sealing test on a gate valve with a balancing valve 150 structure without removing the gate valve from the pipeline, reducing the workload of disassembly or cutting, and eliminating the risks brought by the disassembly or cutting work; the present application uses a gate valve sealing detection system to perform an online sealing test on a gate valve with a balancing valve 150 structure, which can effectively evaluate the sealing performance between the gate valve disc and the valve body, avoid excessive disassembly and maintenance of the gate valve, and reduce the maintenance workload and maintenance labor costs.

[0135] The embodiments described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0136] Those skilled in the art will appreciate that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0137] The device embodiments described above are merely illustrative, and the units described as separate components may or may not be physically separated, that is, they may be located in one place or distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0138] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0139] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0140] It should be understood that in the present application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0141] In several embodiments provided in this application, it should be understood that the disclosed methods can be implemented in other ways.

[0142] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but the scope of the rights of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by a person skilled in the art without departing from the scope and essence of the present invention should be within the scope of the rights of the present invention.

Claims

1. A gate valve sealing detection system, applied to a gate valve, wherein the gate valve has a gate valve middle cavity, the gate valve middle cavity is connected to a balancing valve through a first connecting pipe, and the balancing valve is used to balance the pressure in the gate valve middle cavity, characterized in that: The gate valve sealing detection system comprises: A connecting piece, having a medium channel for conveying experimental medium, and a medium inlet and a medium outlet connected to the medium channel, wherein the connecting piece is adapted to be installed on the valve body of the balancing valve, and enables the medium outlet to be connected to an end of the first connecting pipe away from the middle cavity of the gate valve; A pressure charging pipe, one end of which is connected to the medium inlet, and the pressure charging pipe is used to transport the experimental medium; A cut-off valve, wherein the outlet end of the cut-off valve is connected to an end of the pressure-charging tube away from the medium inlet, the inlet end of the cut-off valve is used to connect to a medium source, the medium source is used to provide the experimental medium, and the cut-off valve is used to control the connection between the pressure-charging tube and the medium source; The pressure detection component is connected to the pressure charging pipe and is used to detect the pressure in the pressure charging pipe.

2. The gate valve sealing detection system according to claim 1, characterized in that: The medium inlet and the medium outlet are respectively arranged at two opposite ends of the connecting piece; Alternatively, the medium inlet is arranged at the end of the connecting member, and the medium outlet is arranged at the side of the connecting member; Alternatively, the medium inlet is arranged at a side of the connecting member, and the medium outlet is arranged at an end of the connecting member.

3. The gate valve sealing detection system according to claim 1, characterized in that: A mounting groove is recessed on one side of the valve body of the balancing valve, and an experimental flow channel and a non-experimental flow channel are provided inside the valve body of the balancing valve, both of which are connected to the mounting groove. An end of the experimental flow channel away from the mounting groove is connected to an end of the first connecting pipe away from the middle cavity of the gate valve, and the mounting groove can be adapted for the connector to be installed therein; When the connecting piece is installed in the installation groove, it can block the end of the non-experimental flow channel close to the installation groove, and make the medium outlet communicate with the end of the experimental flow channel close to the installation groove.

4. The gate valve sealing detection system according to claim 3 is characterized in that: The gate valve sealing detection system further comprises a sealing member, wherein the sealing member is sealingly abutted between the bottom of the installation groove and the connecting member; Wherein, when the medium outlet is arranged on a side of the connecting member close to the bottom of the mounting groove, the sealing member is provided with a through hole, and the through hole is communicated with both the medium outlet and the experimental flow channel.

5. The gate valve sealing detection system according to claim 3, characterized in that: The connecting member includes a first mounting portion and a second mounting portion which are connected in sequence, the cross-sectional size of the first mounting portion is larger than the cross-sectional size of the second mounting portion, the first mounting portion is provided with the medium inlet, the second mounting portion is provided with the medium outlet, the second mounting portion can be adapted to be installed in the mounting groove, and the first mounting portion can be fixedly connected to the valve body of the balancing valve by a fastener.

6. A sealing detection method, characterized in that: The method is performed by using the gate valve sealing detection system described in any one of claims 1 to 5, and comprises: Disassemble the balancing valve, install the connecting piece on the valve body of the balancing valve, and make the medium outlet communicate with the first connecting pipe; Open the cut-off valve, and inject the experimental medium into the middle cavity of the gate valve through the medium source, the pressure-charging pipe, the medium channel and the first connecting pipe in sequence, and make the pressure in the middle cavity of the gate valve reach the experimental pressure; Close the cut-off valve and detect the pressure of the pressure-charging pipe within a preset time through the pressure detection component; The detection value of the pressure detection component is compared with the theoretical pressure value to determine the sealing performance of the gate valve.

7. The method according to claim 6, characterized in that After the step of closing the cut-off valve and detecting the pressure of the pressure-charging pipe within a preset time by the pressure detection component, and before the step of comparing the detection value of the pressure detection component with the theoretical pressure value to determine the sealing performance of the gate valve, the method further includes: Obtaining a first volume corresponding to the gate valve cavity, a second volume corresponding to the first connecting pipe, a third volume corresponding to the gate valve sealing detection system, and an allowable leakage rate of the gate valve to the test medium under the test pressure; superimposing the first volume, the second volume and the third volume to obtain a total experimental volume; The theoretical pressure value is obtained based on the preset time, the experimental pressure, the total experimental volume and the allowable leakage rate.

8. The method according to claim 7, characterized in that When the experimental medium is gas, the method further includes: obtaining the allowable leakage rate of the gate valve to the gas under the experimental pressure by the following expression: The theoretical pressure value is obtained by the following expression: Wherein, Q1 is the allowable leakage rate of the gate valve for the gas under the test pressure, DN is the nominal diameter of the gate valve, V is the total volume of the experiment, t is the preset time, k is the safety factor used to compensate for the error caused by the simplification of values ​​in the calculation process, 1.013 is the approximate value of the ground standard atmospheric pressure, P1 is the test pressure, and P2 is the theoretical pressure value when the test medium is gas.

9. The method according to claim 7, characterized in that: When the experimental medium is liquid, the method further includes: obtaining the allowable leakage rate of the gate valve for the liquid under the experimental pressure by the following expression: The theoretical pressure value is obtained by the following expression: Wherein, Q2 is the allowable leakage rate of the gate valve to the liquid under the test pressure, P s is the design pressure of the gate valve, Q s is the allowable leakage rate of the gate valve’s design volume, E v is the bulk elastic modulus of the liquid, V is the total experimental volume, t is the preset time, P1 is the experimental pressure, and P3 is the theoretical pressure value when the experimental medium is liquid.

10. The method according to claim 6, characterized in that Before the steps of disassembling the balancing valve, installing the connecting piece on the valve body of the balancing valve, and connecting the medium outlet with the first connecting pipe, the method further includes: The sealing performance of the gate valve sealing performance detection system is tested.

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