CN114812978B - Valve leakage detection device with variable measuring range - Google Patents

Abstract

The invention discloses a valve leakage detection device with variable range, which includes a leakage detection pipeline 6, and the leakage detection pipeline 6 includes an expandable section 24, a variable diameter pipeline 23, an outer wall part and a supporting pipeline 19; the expandable section 24 includes The flexible cloth 242 and the movable metal plate 241; the flexible cloth 242 wraps the metal plate 241 inside to ensure that the gas enters the variable-diameter pipeline 23 without leakage; the variable-diameter pipeline 23 includes an upper support 32, a lower support 33, and movable blades 34 , a protruding round pin is arranged on the upper support 32 plate to drive the movable blade 34 to move, and the lower support 33 plate has a square groove to make the movable blade 34 rotate around it. The same detection equipment can realize the detection of large leakage changes and different gas leakage. The flow rate of the leakage medium is small and the flow rate is low. When it is lower than the lower limit of the measuring instrument, it is difficult to test the anemometer and other measuring devices. By reducing the flow area, the flow rate is increased, so as to accurately measure the small leakage.

Description

A variable range valve leak detection device

technical field

The invention relates to the field of leakage detection, in particular to a variable range valve leakage detection device.

Background technique

As a control component in the oil and gas transportation system, the valve has the functions of cut-off, regulation, flow diversion, pressure stabilization, flow diversion and overflow pressure relief. In the process of oil and gas transportation, the leakage of valves is very common, which will cause waste if it is light, and lead to serious consequences if it is serious. Among them, natural gas, as a necessity in residents' lives, has the characteristics of poisonous, flammable and explosive. When natural gas leaks, it will volatilize carbon monoxide, making people feel dizzy, nauseous, and in severe cases, people will be poisoned to death. Carbon monoxide itself is a flammable gas, and the more it leaks into the air, the higher the chance of a fire. When the amount of natural gas leakage reaches a certain level, there may be a huge explosion behavior. Therefore, the leak detection of this kind of gas is an indispensable link in the production.

For possible valve leakage, most of the methods used are pressure-holding tests. The general pressure test is to connect the pump or compressor at one end of the system, such as the flange of the valve, inject the medium into the system, and close the shut-off valve after reaching the preset pressure. Then after the time required by the specification, read the reading from the pressure gauge to see if there is a decrease and whether it is within a reasonable range. It takes a long time for the test process, the pressure measurement accuracy is not high, it is difficult to quantitatively determine the leakage rate of the valve, and the detection accuracy of the small leakage rate needs to be improved.

Contents of the invention

The invention proposes a variable-range valve leakage detection device, which includes a device that is simple to manufacture and can be infinitely changed in diameter so that the flow rate of leaked gas meets the anemometer range, and can perform leakage detection on different devices with a wide range of applications.

Technical scheme of the present invention is as follows:

A valve leakage detection device with variable range, comprising a leakage detection pipeline 6, the leakage detection pipeline 6 includes an expandable section 24, a variable diameter pipeline 23, an outer wall part and a support pipeline 19; the expandable section 24 includes a flexible cloth 242 and Movable metal plate 241; flexible cloth 242 wraps the metal plate 241 inside to ensure that the gas enters the variable-diameter pipeline 23 without leakage; the variable-diameter pipeline 23 includes an upper support 32, a lower support 33, and movable blades 34. There is a protruding round pin on the 32 plate to drive the movable blade 34 to move, and the lower support 33 plate has a square groove to make the movable blade 34 rotate around it; the movable blade 34 has an outer rib 38 in the middle, and its upper end surface has Groove, the round pin of the upper support 32 is inserted into the groove, used to drive the movable blade 34 to rotate as a whole, the lower end surface has a square protrusion, and the square protrusion is inserted into the square groove of the lower support 33, and the movable blade 34 is supported on the lower support 33 plate Move under the constraint of the upper square groove; the outer side of the upper end surface of the movable blade also has holes and notches of different sizes, which are used to place the movable block 36, pressing plate 35 and spring 37; wherein the spring 37 is fixed in the notch of the movable blade, and the movable block 36 Moveably placed on the spring 37 in the notch, the two pressing plates 35 are connected with the top of the blade by bolts to limit the movable block 36 in the notch; the supporting plate of the reducing layer in the middle of the reducing pipe is fixed with the large bevel gear 22 Connection, used to realize real-time variable diameter.

The valve leakage detection device with variable range also includes an air compressor 1, an air storage tank 2, a switch ball valve 3, a pressure stabilizing valve 4, a valve to be tested 5, a pressure regulating valve 7, a data acquisition board 8 and a computer 9. Use the air compressor 1 to send the test medium into the measuring device, and control the pressure of the medium sent in through the pressure regulating part of the air storage tank 2 to avoid excessive pressure during the test. At the same time, switch the ball valve 3 to control the input of the medium to stabilize The pressure valve 4 and the pressure regulating valve 7 control the inlet and outlet pressures of the valve to be tested respectively. Sensors 39 are respectively installed in the pipelines before and after the valve to be tested 5, and the leakage rate of the medium is collected through the data acquisition board 8, and the detected leakage value is passed Computer 9 shows, thereby confirms the accurate numerical value of the leakage of valve.

In the valve leakage detection device with variable range, the gas storage tank 2 includes a tank body and a control part for the output pressure of the air compressor 1, and a detection window is opened on the left side of the tank body to facilitate maintenance of the gas storage tank; the control part It includes piston upper stop plate 10, pressure relief valve 11, cylinder body 12, piston 13, piston lower stop plate 14, inspection window baffle plate 15 and gland head 16; piston upper stop plate 10 is an annular perforated plate, its The inner diameter is larger than the maximum size of the mass block, and there is a small hole on the upper surface to connect with the cylinder body 12 through bolts; the piston lower stop plate 14 is a porous plate, and the upper plate surface contains a micro switch 18 to control the wind compressor 1; Among them, the set pressure can be changed by changing the weight of the mass block; when the piston 13 moves down and touches the micro switch 18 on the lower stop plate 14, the wind compressor is controlled by the circuit to start working; when the piston 13 moves to the upper At the baffle position, the pressure in the gas storage tank is reduced through the pressure relief valve 11. At the same time, the electric contact on the pressure relief valve 11 moves to cut off the work of the wind compressor to control the pressure of the test medium, so as to avoid damage to the test device during the test.

In the variable range valve leakage detection device, the support pipe 19 includes support parts on both sides and a variable length hose 21 in the middle, and the support parts on both sides support the variable diameter part and the internal impeller anemometer ; The support pipe 19 has a circular hole for installing the small bevel gear 28 .

In the valve leakage detection device with variable range, the connection between the outer wall pipe 25 and the expandable section 24 is sealed with a sealing gasket 26 to ensure that no leakage occurs when the air flow enters the pipe.

In the variable-range valve leakage detection device, the variable-diameter pipe 23 is welded to the movable metal plate 241 of the expandable section 24, and the expandable section 24 and the variable-diameter pipe 23 at both ends form a Venturi tube structure, and the metal plate 241 The expandable section 24 can be changed simultaneously with the variable-diameter pipe 23; at the same time, the flexible cloth 242 constrains the range of motion of the metal plate 241 to ensure that the outer wall will not be affected when the pipe is in different diameters.

In the valve leakage detection device with variable range, the movable block 36 on the end surface of the blade passes between the multi-section variable-diameter pipes 23 and presses against the tail of the adjacent movable blade under the action of a spring to realize air-tightness.

The variable-range valve leakage detection device is provided with a gear transmission mechanism in the variable-diameter pipeline 23 in the middle section. When the diameter of the pipeline is changed through gear transmission, the power is transmitted through the friction between the head and tail of each movable blade. To other layers, the overall simultaneous diameter reduction of the multi-section diameter-reducing pipeline 23 is finally realized.

The valve leakage detection device with variable range, according to the valve leakage detection device with variable range according to claim 1, is characterized in that the spring 37 is directly welded to the blade 34 to ensure the movement of the movable block 36 in the axial direction Amount, a plurality of springs 37 guarantee the smooth operation of the movable block 36, to prevent jamming.

In the variable-range valve leakage detection device, a through hole is opened on the pressure plate 35, and a small hole is also opened on the end face of the notch of the blade 34, which are connected by bolts 10 to ensure that the movable block 36 does not occur in the radial direction. Movement while ensuring gas tightness.

In the valve leakage detection device with variable range, the upper support 32 is connected with the square groove on the blade rib 38 through the small round pin protruding from the end surface, so as to ensure the trajectory and synchronization of each blade when it rotates.

In the valve leakage detection device with variable range, the lower support 33 is connected with the raised small square on the blade rib 38 through the notch on the end face, so as to ensure the trajectory and synchronization of each blade rotation.

The present invention focuses on the field of valve leakage detection and solves the following problems:

1. The same detection equipment can realize the detection of large leakage changes and different gas leakage.

2. In view of the problem that when the valve has a small leakage, the flow rate of the leakage medium is small and the flow rate is lower than the lower limit of the measuring instrument, it is difficult to test the measurement device such as anemometer, and the flow rate is increased by reducing the flow area, so as to accurately measure Tiny leaks.

3. For different leakage magnitudes, the variation range is wide. By changing the diameter of the variable diameter part of the leakage detection pipeline, the detection of different leakage values of a wide range of gases is realized.

4. For the transition requirements of different tested valves, the length of the leak detection pipeline can be changed to meet the requirements of the transition section.

Description of drawings

Fig. 1 is an overall schematic diagram of a valve leakage detection device with variable range.

Figure 2 is a schematic diagram of the gas storage tank

Fig. 3 is a sectional view of the leak detection part and an enlarged schematic diagram of the anemometer.

Figure 4 is a schematic diagram of the leak detection part

Figure 5 is a schematic diagram of the supporting pipeline

Figure 6 is a schematic diagram of the variable diameter pipeline

Figure 7 is a schematic diagram of the upper and lower supports

Figure 8 is a schematic diagram of the blade

Figure 9 is a part of the parts of the gas storage tank

1——Air compressor, 2—Air storage tank, 3—Switch ball valve, 4—Pressure regulator valve, 5—Valve to be tested, 6—Leakage detection pipeline, 7—Pressure regulating valve, 8— — data acquisition board, 9 — computer, 10 — piston upper stop plate, 11 — pressure relief valve, 12 — barrel, 13 — piston, 14 — piston lower stop plate, 15 — Inspection window baffle, 16—gland head, 17—tank body, 18—micro switch, 19—support tube, 20—pipe seal, 21—variable length hose, 22— Large bevel gear, 23—reducing pipe, 231—the first layer of reducing pipe, 232—the middle layer of reducing pipe, 233—the tail layer of reducing pipe, 24—expandable section, 241—metal plate , 242—flexible cloth, 25—outer wall pipe, 26—gasket, 27—cylindrical support, 28—small bevel gear, 29—anemometer, 30—bolt, 31—nut, 32— - upper support, 33 - lower support, 34 - movable vane, 35 - pressure sheet, 36 - movable block, 37 - spring, 38 - outer rib, 39 - pressure sensor.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments.

As shown in Figure 1, the variable-range valve leakage detection device includes an air compressor 1, an air storage tank 2, an on-off ball valve 3, a pressure stabilizing valve 4, a valve to be tested 5, a leakage detection pipeline 6, a pressure regulating valve 7, data Acquisition board 8 and computer 9.

The air storage tank 2 includes a tank body and a control part for the output pressure of the air compressor 1, as shown in FIG. 2 . There is a detection window on the left side of the tank body, which is convenient for overhauling the gas storage tank. The control part includes a piston upper stop plate 10, a pressure relief valve 11, a cylinder body 12, a piston 13, a piston lower stop plate 14, an inspection window baffle plate 15 and a gland head 16. As shown in FIG. 9 , the piston upper stop plate 10 is an annular perforated plate with an inner diameter larger than the maximum size of the mass block, and a small hole is opened on the upper surface to connect with the cylinder body 12 through bolts. The piston lower stop plate 14 is a perforated plate, and the upper plate surface contains a micro switch 18 to control the wind compressor 1 . Wherein the set pressure can be changed by changing the weight of the mass block. When the piston 13 moves down and touches the microswitch 18 on the lower stop plate 14, the wind compressor is controlled by the circuit to start working. When the piston 13 moves to the position of the upper baffle plate, the pressure in the air storage tank is reduced through the pressure relief valve 11 . At the same time, the electric contact on the pressure relief valve 11 moves to cut off the work of the wind compressor to control the pressure of the test medium, so as to avoid damage to the test device during the test.

Wherein the leakage detection pipeline 6 includes an expandable section 24 , a diameter reducing pipeline 23 , an outer wall part and a supporting pipeline 19 .

The expandable section 24 includes a flexible cloth 242 and a movable metal plate 241 . The flexible cloth 242 wraps the metal plate 241 inside to ensure that the gas enters the reducing pipe 23 without leakage. The overall shrinkage section and the expansion section are welded to the left and right sections of the reducing pipe 23 respectively.

The variable-diameter pipe 23 includes an upper support 32, a lower support 33, and movable blades 34 (eight movable blades are shown in FIG. 6), as shown in FIGS. 4 and 6. As shown in Figure 7, a protruding round pin is arranged on the upper support 32 plate to drive the movable vane 34 to move, and the lower support 33 plate has a square groove to make the movable vane 34 rotate around it. Both the upper support 32 and the lower support 33 are provided with through holes in the center to accommodate and support the movable blades. There is an outer rib 38 in the middle of the movable blade 34, and a groove is formed on its upper end surface, and the round pin of the upper support 32 is inserted into the groove to drive the movable blade 34 to rotate as a whole. There is a square protrusion on the lower end surface, and the square protrusion Inserted into the square groove of the lower support 33, the movable vane 34 moves under the constraint of the square groove on the lower support 33 plate. There are also holes and notches of different sizes on the outside of the upper end surface of the movable vane, which are used to place the movable block 36, the pressing plate 35 and the spring 37. Wherein the spring 37 is welded in the notch of the movable blade, the movable block 36 is movably placed on the spring 37 in the notch, and the two pressing plates 35 use bolts to connect with the blade top to limit the movable block 36 in the notch. Wherein, the support plate of the middlemost diameter reducing layer of the reducing pipe is welded with the large bevel gear 22 to realize real-time diameter reducing, as shown in FIG. 6 .

The outer wall portion includes a sealing gasket 26 and an outer wall duct 25 . The outer wall pipe 25 is connected to the expandable sections at both ends through sealing gaskets 26 to ensure that the gas does not leak out.

The support pipe 19 includes support parts on both sides and a variable-length hose 21 in the middle, and the support parts on both sides support the variable-diameter part and the impeller-type anemometer inside. The support pipe 19 has a circular hole for installing the small bevel gear 28, and is equipped with sealing gaskets of the same diameter to ensure the sealing of the pipe. The length change of the variable diameter part can be achieved by opening the pipe seal 20 and adding one or more layers of variable diameter pipes inside. At the same time, the length of the hose 21 is changed to coincide with the newly added variable-diameter pipe to ensure that the anemometer is always located inside the variable-diameter part, and then the sealing member 20 is closed. The protruding support on the inner side of the pipe supports the entire variable diameter part to ensure that the position of the variable diameter part does not change.

The implementation points of the variable diameter part assembly method are as follows:

The connection between the outer wall pipe 25 and the expandable section 24 is sealed with a sealing gasket 26 to ensure that no leakage occurs when the airflow enters the pipe.

The variable diameter pipe 23 is welded to the movable metal plate 241 of the expandable section 24, as shown in Figure 3-4, the expandable section 24 at both ends and the variable diameter pipe 23 form a structure similar to a Venturi tube, and the metal plate 241 can be The expansion section 24 can be changed simultaneously with the reducing pipe 23 . At the same time, the flexible cloth 242 constrains the range of motion of the metal plate 241 to ensure that the outer wall will not be affected when the pipe is in different diameters. The movable blocks 36 passing through the end surfaces of the blades between the multi-section variable-diameter pipes 23 are pushed against the tails of the adjacent movable blades under the action of springs to realize air-tightness. The variable-diameter pipeline 23 in the middle section is provided with a gear transmission mechanism. When the diameter of the pipeline is changed through gear transmission, the power is transmitted to other layers through the friction between the head and tail of each section of movable blades, and finally the multi-section variable-diameter pipeline 23 is realized. The overall diameter change at the same time.

The spring 37 is directly welded to the blade 34 to ensure the amount of activity of the movable block 36 in the axial direction, and multiple springs 37 ensure the smooth operation of the movable block 36 to prevent jamming.

There are through holes on the pressure plate 35, and small holes are also opened on the end faces of the notches of the blades 34, which are connected by bolts 10 to ensure that the movable block 36 does not move in the radial direction, while ensuring gas tightness.

The upper support 32 is connected with the square groove on the blade rib plate 38 through the protruding small round pin on the end surface, so as to ensure the trajectory and synchronization of each blade when it rotates.

The lower support 33 is connected with the raised small square on the blade rib plate 38 through the notch opened on the end face, so as to ensure the track and synchronization of the rotation of each blade.

The support pipe 25 supports the overall reduced-diameter pipe through the internal cylindrical support 27 shown in FIG. 5 to ensure that the reduced-diameter pipe does not move in the circumferential direction during operation. At the same time, the supporting parts on both sides support the anemometer inside the variable diameter pipe, and transmit the flow velocity inside the pipe to the display end, so as to determine the leakage of the whole pipe.

The variable range detection device realized according to the above-mentioned assembly method has a variable range detection method as follows:

Connect the valve 5 to be tested to the measuring device, as shown in Figure 1, use the air compressor 1 to send the test medium into the measuring device, and control the pressure of the medium sent in through the pressure regulating part of the air storage tank 2, so as to avoid Too much pressure. At the same time, the switch ball valve 3 controls the input of the medium, and the pressure stabilizing valve 4 and the pressure regulating valve 7 respectively control the inlet and outlet pressures of the valve to be tested. Sensors 39 are respectively installed in the pipelines before and after the valve 5 to be tested, and the leakage rate of the medium is collected through the data acquisition board 8, and the detected leakage value is displayed by the computer 9, so as to determine the accurate value of the leakage value of the valve.

When the leakage of the pipeline under test is large, turn the knob connected with the small bevel gear 28 to drive the small bevel gear 28 to rotate, and the small bevel gear drives the large bevel gear, and the large bevel gear 22 drives the upper support 32 of the middle layer 232 to start rotating , the blade 34 is rotated and translated outward, the pipe diameter of the reducing pipe 23 begins to increase, and the internal flow area begins to increase. Through the measurement value of the internal anemometer and the size of the changed pipe diameter, the size of the leakage can be obtained, which meets the requirements of ordinary measurement.

The change in diameter of the variable-diameter pipeline 23 will be transmitted layer by layer through the friction between the movable blades in the two sections of pipelines, so as to ensure that the diameter of the entire variable-diameter pipeline 23 becomes larger to the same value.

As the blades of the tail layer 233 of the variable-diameter pipe move outward, the metal plate 241 of the expandable section also moves accordingly, stretching the flexible cloth 242 wrapped on it. Similarly, the expandable segment connected to the first layer 231 of the variable-diameter pipeline also expands thereupon. Reduce the impact of gas on the pipeline and avoid gas turbulence.

Simultaneously, the movable block 36 on the end face of the blade always pushes against the afterbody of the movable blade of the previous layer due to the elastic force of the spring 37 during the whole activity process, which ensures the sealing of the whole pipeline in the activity process.

When the internal leakage of the pipeline under test is small, reverse the knob connected to the small bevel gear 28 to drive the small bevel gear to rotate. Through the transmission of the bevel gear, the large bevel gear drives the upper support of the middle layer to start to rotate, so that the blades move inward. The internal flow area begins to become smaller, and the pipe diameter of the reducing pipe 23 begins to become smaller.

The diameter change of the variable diameter pipeline will be transmitted layer by layer through the friction between the two layers of pipeline blades, so as to ensure that the diameter of the entire variable diameter pipeline 23 is reduced to the same value. Through the measured value of the internal anemometer and the size of the changed pipe diameter, the size of the leakage can be obtained, which meets the measurement requirements of small leakage.

As the blades of the trailing layer reducing pipe 233 move inward, the metal strip 241 of the expandable section also moves accordingly, and the flexible cloth 242 wrapped thereon is retracted. Similarly, the expandable segment connected to the first layer 231 is also retracted thereupon. Simultaneously, the movable block 36 on the end surface of the blade is always supported by the blade of the previous layer during the whole activity process, which ensures the sealing of the whole pipeline during the activity process.

When the detected element requires different lengths of transitional straight pipes, it can be realized by opening the pipe seal 20 and adding or removing one or more layers of variable diameter pipes. At the same time, the length of the hose 21 is changed to coincide with the new one-stage variable-diameter pipeline to ensure that the length of the transitional straight pipeline in the measuring device meets the requirements. Meanwhile, the anemometer is always located inside the variable-diameter part, and then the seal 20 is closed. The protruding support on the inner side of the pipe supports the entire diameter-reducing part to ensure that the position of the diameter-reducing part does not change.

It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should belong to the protection scope of the appended claims of the present invention.

Claims (8)

1. A valve leak detection device with variable range, characterized in that it includes a leak detection pipeline (6), and the leak detection pipeline (6) includes an expandable section (24), a variable diameter pipeline (23), an outer wall part and a support Pipeline (19); described expandable section (24) comprises flexible cloth (242) and movable metal plate (241); Flexible cloth (242) wraps metal plate (241) inside, guarantees that gas enters reducing pipe ( 23) no leakage; the variable-diameter pipeline (23) includes an upper support (32), a lower support (33), and movable blades (34), and a protruding round pin is arranged on the upper support (32) plate to drive The movable blade (34) is movable, and the lower support (33) plate has a square groove to make the movable blade (34) rotate around it; there is an outer rib (38) in the middle of the movable blade (34), and its upper end surface has a groove, The round pin of the upper support (32) is inserted into the groove to drive the movable blade (34) to rotate as a whole. There is a square protrusion on the lower end surface, and the square protrusion is inserted into the square groove of the lower support (33). The movable blade ( 34) Move under the constraint of the square groove on the lower support (33) plate; there are also holes and notches of different sizes on the outer side of the upper end surface of the movable blade for placing the movable block (36), pressing plate (35) and spring (37); Wherein the spring (37) is fixed in the notch of the movable blade, and the movable block (36) is movably placed on the spring (37) in the notch, and the two pressing plates (35) are connected with the top of the blade using bolts to secure the movable block (36) Defined in the notch; Wherein the supporting plate of the variable diameter layer in the middle of the variable diameter pipeline is fixedly connected with the large bevel gear (22), used to realize real-time variable diameter; The left and right sections are welded, and the center of the upper support (32) and the lower support (33) are provided with through holes to accommodate and support the movable blades; the support pipe (19) includes support parts on both sides and the middle The variable length hose (21), the support parts on both sides support the variable diameter part and the internal impeller anemometer; the support pipe (19) has a circular hole for installing the small bevel gear (28), and at the same time Sealing gaskets of the same diameter are installed to ensure the tightness of the pipeline; the length change of the variable diameter part can be realized by opening the pipeline seal (20) and adding one or more layers of variable diameter pipelines; at the same time, the hose (21 ) to coincide with the newly added variable-diameter pipe, to ensure that the anemometer is always inside the variable-diameter part, and then close the seal (20); change; the variable diameter pipeline (23) is welded to the movable metal plate (241) of the expandable section (24), and the expandable section (24) and the variable diameter pipeline (23) at both ends form a Venturi tube structure, and the metal The expandable section (24) of the plate (241) can change simultaneously with the variable-diameter pipe (23); at the same time, the flexible cloth (242) constrains the range of motion of the metal plate (241) to ensure that there will be no damage to the outer wall when the pipe is in different diameters. Influence; the movable block (36) passing through the end face of the blade between the multi-section variable diameter pipelines (23) is pushed against the tail of the movable blade adjacent to it under the action of the spring to realize air sealing; the variable diameter pipeline (23) in the middle section is provided with The gear transmission mechanism, when changing the diameter of the pipeline through gear transmission, transmits the power to other layers through the friction between the head and tail of each section of movable blades, and finally realizes the overall simultaneous diameter reduction of the multi-section variable diameter pipeline (23). 2. The valve leakage detection device with variable range according to claim 1, characterized in that, it also includes an air compressor (1), an air storage tank (2), a switch ball valve (3), a pressure stabilizing valve (4) , the valve to be tested (5), the pressure regulating valve (7), the data acquisition board (8) and the computer (9); use the air compressor (1) to send the test medium into the detection device, and pass through the air storage tank (2 ) to control the pressure of the medium to avoid excessive pressure during the test. At the same time, the switch ball valve (3) controls the input of the medium, and the pressure stabilizing valve (4) and pressure regulating valve (7) respectively control the pressure of the valve to be tested. The inlet and outlet pressures are equipped with sensors (39) in the front and rear of the valve to be tested (5), and the leakage rate of the medium is collected through the data acquisition board (8), and the detected leakage value is displayed by the computer (9), thereby determining The exact value of the leakage of the valve. 3. The valve leakage detection device with variable range according to claim 2, characterized in that, the air storage tank (2) comprises a tank body and a control part for the output pressure of the air compressor (1), and the left side of the tank body is opened. There is a detection window, which is convenient for inspection and maintenance of the gas storage tank; the control part includes the piston upper stop plate (10), the pressure relief valve (11), the cylinder (12), the piston (13), and the piston lower stop plate (14) , the inspection window baffle (15) and the gland (16); the piston upper baffle (10) is an annular perforated plate, its inner diameter is larger than the maximum size of the mass block, and there are small holes on the upper surface to pass through the bolt and the cylinder (12) connection; the piston lower stop plate (14) is a porous plate, and the upper plate surface contains a micro switch (18) to control the wind compressor (1); wherein the setting can be changed by changing the weight of the mass block pressure; when the piston (13) moves downward and touches the microswitch (18) on the lower stop plate (14), the wind compressor is controlled by the circuit to start working; when the piston (13) moves to the position of the upper stop plate , reduce the pressure in the gas storage tank through the pressure relief valve (11); at the same time, the electric contact on the pressure relief valve (11) moves to cut off the work of the wind compressor to control the pressure of the test medium, so as to avoid damage to the test device during the detection process. 4. The valve leakage detection device with variable range according to claim 1, characterized in that the connection between the outer wall pipe (25) and the expandable section (24) is sealed with a sealing gasket (26) to ensure that the air flow enters the pipe No leakage occurs. 5. The valve leakage detection device with variable range according to claim 1, the spring (37) is directly welded to the blade (34) to ensure the amount of activity of the movable block (36) in the axial direction, and multiple springs (37) Guarantee the smooth operation of movable block (36), prevent from being stuck. 6. The valve leakage detection device with variable range according to claim 1, characterized in that, the pressure plate (35) is provided with a through hole, and the end face of the notch of the blade (34) is also provided with a small hole, through which the bolt (10 ) to connect it to ensure that the movable block (36) does not move in the radial direction, while ensuring gas tightness. 7. The valve leakage detection device with variable range according to claim 1, characterized in that the upper support (32) is connected with the square groove on the blade rib (38) through a small round pin protruding from the end surface, so as to ensure that each blade Trajectory and synchronicity when turning. 8. The valve leakage detection device with variable range according to claim 1, characterized in that, the lower support (33) is connected with the raised small square on the blade rib (38) through the notch opened on the end face to ensure The trajectory and synchronization of each blade rotation.

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