Corrugated pipe stop valve with backflow preventing structure and using method

Abstract

The invention discloses a corrugated pipe stop valve with a backflow preventing structure and a using method, and relates to the technical field of stop valves. The flanges are mounted at the two ends of the valve body and used for connecting the valve body with an external pipeline; the transmission mechanism is installed at the top of the valve body and used for controlling the valve body internal assembly and controlling the medium circulation channel to be opened and closed by being matched with the valve body internal assembly; when the valve needs to be closed, an operator rotates the hand wheel, the pressing block moves downwards and then makes contact with the top of the upper valve seat, the upper valve seat is pressed tightly, and therefore fixed closing of the upper valve seat is achieved. Meanwhile, the first threaded rod moves upwards in the pressing block to drive the lower valve seat to move upwards, and the bottom of the communicating groove is sealed; through the linkage mechanism, simultaneous sealing of the bottom and the top of the communicating groove is achieved, double-sealing guarantee is provided for the valve, and the sealing performance and reliability of the valve are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of stop valves, and in particular to a bellows stop valve with a backflow resistance structure and a use method thereof. Background Art

[0002] Globe valves, as a common fluid control device, are widely used in various industrial piping systems. Their core function is to control the flow of fluids by opening and closing the valve. Valve sealing performance is a key indicator of its performance, directly affecting the safety, stability, and operational efficiency of the system.

[0003] Existing globe valve designs mostly utilize a single seat-to-body sealing method. While this design is simple in structure, it has significant practical limitations. First, the limited contact area of ​​a single sealing point makes it difficult to maintain a stable seal under high-pressure or high-flow conditions.

[0004] Furthermore, the single seat-to-body sealing design lacks redundancy. If the sealing point fails, the entire valve's sealing function is completely lost, providing no additional safeguard. This design struggles to meet the high reliability and safety requirements of complex industrial environments and frequent operations.

[0005] To this end, the present invention proposes a bellows stop valve with dual sealing functions and its use method. This solution, through an innovative structural design, achieves simultaneous sealing of both the bottom and top of the connecting groove, providing dual protection for valve sealing and significantly improving the valve's sealing performance and reliability. Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the present invention provides a bellows stop valve with a backflow prevention structure and a method of use, which solves the problem in the background technology that the sealing method of the existing valve with a single valve seat in contact with the valve body is difficult to maintain a stable sealing effect under high pressure or high flow conditions.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a bellows stop valve with a backflow resistance structure and a method of use, comprising: A valve body, wherein a medium flow channel is provided inside the valve body; Flanges are installed at both ends of the valve body and are used to connect the valve body to external pipelines; A transmission mechanism, which is installed on the top of the valve body and is used to control the internal components of the valve body and control the opening and closing of the medium flow channel by cooperating with the internal components of the valve body; An indicator assembly is installed on one side of the transmission mechanism and is in communication with internal components of the transmission mechanism; A handwheel is installed on the top of the transmission mechanism and is connected to the internal components of the transmission mechanism for controlling the transmission mechanism.

[0008] Preferably, a water inlet is provided at one end of the valve body, and a water outlet is provided at the other end of the valve body, one end of the water outlet is located above the water inlet, the water inlet and the water outlet are connected to each other through a connecting groove, a lower valve seat is provided below the connecting groove, the lower valve seat is welded to one end of the first threaded rod, and the first threaded rod is connected to the internal thread of the pressure block; by arranging the water inlet and the water outlet at both ends of the valve body and communicating with each other through the connecting groove, and arranging the lower valve seat welded to the first threaded rod below the connecting groove, and the pressure block threadably connected to the first threaded rod, the medium can flow along a specific path, so that the internal pressure of the transmission mechanism is relatively small when the valve is closed.

[0009] Preferably, the outer wall of the pressure block is slidably connected to the upper valve seat, the contact surface of the upper valve seat and the pressure block is provided with a rubber coating, the bottom of the upper valve seat is fitted with the surface of the communicating groove by lifting and matching, and the top of the upper valve seat is provided with a first spring, which is sleeved on the outside of one end of the bottom of the pressure block; the sliding connection between the pressure block and the upper valve seat and the setting of the rubber coating ensures a tight fit and reliable sealing performance between the two; at the same time, the lifting and matching of the bottom of the upper valve seat and the surface of the communicating groove can realize flexible sealing control of the top of the communicating groove, and the first spring on the top provides elastic support for the upper valve seat, so that it can automatically respond under the joint action of the medium pressure and the spring elastic force, realize opening when the medium flows and closing when the medium refluxes, thereby effectively preventing the medium from reflux, and further improving the sealing effect and reliability of the valve.

[0010] Preferably, the transmission mechanism includes a sealing component and a connecting component, the sealing component is sleeved on the outside of the connecting component and is used to seal the connecting component, and the connecting component is used to drive the pressure block and the lower valve seat to move up and down in the vertical direction; the transmission mechanism sets the sealing component and the connecting component, sleeves the sealing component on the outside of the connecting component to achieve the sealing function, and uses the connecting component to drive the pressure block and the lower valve seat to move up and down in the vertical direction. This structural design not only effectively prevents medium leakage and ensures the sealing of the transmission process, but also realizes precise control of the lower valve seat, so that it can move up and down accurately, thereby realizing the sealing and opening operation of the bottom of the connecting groove, providing reliable transmission guarantee for the double sealing mechanism of the valve, and significantly improving the overall performance and reliability of the valve.

[0011] Preferably, the connecting assembly includes a limit block, the interior of the limit block is welded to the outer wall of the connecting rod, and the connecting rod passes through the interior of the limit block, one end of the bottom of the connecting rod is welded to the top of the pressure block, and a protrusion is provided at both ends of the limit block. The protrusions on both sides of the limit block are slidably connected to the grooves on the inner wall of the shell, and the grooves on the inner wall of the shell are symmetrically distributed. One end of the top of the limit block is welded to the bottom of the bellows, and one end of the top of the bellows is connected to a sealing plate. The sealing plate is located between the top of the shell and the top cover, and the top cover is connected to the shell by bolts. One end of the top of the top cover is threadedly connected to the second threaded rod; the connecting assembly is fixed by welding the limit block to the connecting rod and slidingly cooperates with the limit block and the groove on the inner wall of the shell, thereby achieving stable up and down movement of the connecting rod. At the same time, the vertical symmetry of the protrusion of the limit block and the groove of the shell ensures precise guidance of the movement. The connection between the connecting rod and the pressure block transmits power, enabling the pressure block to drive the upper valve seat to perform a sealing operation. The connection between the bellows and the limit block, sealing plate and the threaded connection of the top cover not only provides good sealing for the connection components, but also realizes adaptive adjustment to the internal pressure changes of the valve through the elastic deformation of the bellows, ensuring the reliability and sealing of the valve under different working conditions. At the same time, it provides stable mechanical support and precise motion control for the double sealing mechanism of the valve, in which multiple sealing rings are arranged between the connecting rod and the second threaded rod.

[0012] Preferably, the second threaded rod is threadedly connected to the top end of the connecting rod via a bearing. The interior of the connecting rod is hollow, and the bottom end of the second threaded rod is inserted into the interior of the connecting rod. The bottom end of the second threaded rod is sleeved onto the exterior of the square rod. The square rod has a rectangular cross-section, and the outer wall of the square rod is slidably connected to the second threaded rod. The bottom end of the square rod is welded to the top of the first threaded rod, and the threads of the first and second threaded rods are in opposite directions. The top end of the second threaded rod is fixedly mounted to the handwheel. The thread pitch of the first threaded rod is twice that of the second threaded rod, thereby achieving a movement speed twice as fast as that of the pressure block, ensuring that the top and bottom of the connecting groove are simultaneously compressed and sealed. The thread pitch of the first threaded rod is twice that of the second threaded rod. The top end of the second threaded rod is fixedly mounted to the handwheel. This structural design ensures that when the handwheel is turned, the second threaded rod drives the square rod and the first threaded rod to rotate synchronously. Due to the difference in thread pitch, the first threaded rod rises twice as fast as the second threaded rod within the pressure block, thereby driving the lower valve seat to rise twice as fast as the pressure block. When the pressure block moves downward to press the upper valve seat, the lower valve seat can rise synchronously and quickly and seal the bottom of the connecting groove, ensuring that the top and bottom of the connecting groove are compressed and sealed at the same time, achieving a double sealing effect and significantly improving the sealing performance and reliability of the valve.

[0013] Preferably, the indicator assembly includes a pressure tank, which is mounted on one side of the housing. One end of the bottom of the pressure tank is connected to the interior of the gas tank, and the other end of the gas tank is connected to the interior of the bellows. A one-way valve is provided at the bottom of the pressure tank to connect to the interior. A piston is provided inside the pressure tank, and the top of the piston is connected to an indicator rod. One end of the top of the indicator rod extends out of the top of the pressure tank, and a second spring is provided on the top of the piston. The indicator assembly is connected to the interior of the bellows through the pressure tank, and high-pressure gas is injected into the pressure tank using the one-way valve, so that the piston compresses the spring under the action of the gas pressure and maintains a stable state. When the bellows' sealing performance decreases due to fatigue cracking, the pressure in the pressure tank decreases, and the spring pushes the piston downward, causing the indicator rod to contract, thereby intuitively reminding the staff that there may be a sealing problem with the bellows, so that timely inspection and maintenance can be carried out, effectively improving the safety and reliability of the valve.

[0014] Preferably, the bottom and top ends of the piston are both made of rubber, an annular groove is provided in the middle of the piston, one side of the pressure tank is threadedly connected to a set screw, a third spring is provided at one end of the set screw, and a spring pin is provided at one end of the third spring. One end of the spring pin is hemispherical and engages with the annular groove on the outer wall of the piston. The upper and lower ends of the piston are made of rubber, which ensures its sealing performance and elastic contact within the pressure tank. The annular groove in the middle is designed to engage with the spring pin. The pressure tank is connected to the third spring and the spring pin by a set screw, and the hemispherical end of the spring pin fits tightly with the annular groove of the piston. This structural design allows the piston to stably maintain the set position under pressure. When the sealing performance of the bellows decreases, resulting in a decrease in pressure, the spring pushes the piston out of the spring pin engagement, thereby triggering the action of the indicator rod, realizing real-time monitoring and early warning of the bellows sealing status, and enhancing the safety and reliability of the valve.

[0015] Preferably, the steps are as follows: S01. Preparation for valve opening: Install the stop valve in the piping system, ensuring that the water inlet and outlet of the valve body are properly connected to the upstream and downstream pipes respectively. Also, check that the handwheel is in the loosened state and the bellows is in the naturally contracted state. S02. Valve opening operation: Turn the handwheel clockwise. The handwheel drives the connecting rod upward through the second threaded rod. The connecting rod causes the bellows to contract. Simultaneously, the pressure block moves upward and away from the top of the upper valve seat. The medium enters the valve body through the water inlet, pushes the upper valve seat upward, and is discharged from the outlet. S03. Valve Closing Operation: Turn the handwheel counterclockwise, which drives the second threaded rod to rotate and move downward. The connecting rod also moves downward, stretching the bellows. The pressure block moves downward and contacts the top of the upper valve seat, tightening it. Simultaneously, the second threaded rod rotates the first threaded rod via the square rod. The first threaded rod moves upward within the pressure block, driving the lower valve seat upward and sealing the bottom of the connecting groove, achieving simultaneous sealing of both the bottom and top of the connecting groove. S04. Bellows Leakage Test: High-pressure air is injected into the pressure tank through a one-way valve, causing the piston inside the pressure tank to move upward and compress the second spring. The annular groove on the piston's outer surface engages the spring pin. When the bellows is subjected to long-term reciprocating tension, causing metal fatigue cracking, the pressure inside the pressure tank and the bellows decreases. When the pressure drops to a specified threshold, the second spring pushes the piston out of the spring pin, causing it to move downward, causing the indicator rod to retract downward, alerting personnel to the risk of a bellows leak. S05. Valve maintenance and inspection: Regularly observe the status of the indicator stem. If the indicator stem shrinks downward, it indicates that the bellows may be at risk of reduced sealing performance. The stop valve should be promptly shut down for inspection and repair, and damaged bellows or other sealing components should be replaced to ensure the sealing performance and reliability of the stop valve.

[0016] The present invention provides a bellows stop valve with a backflow prevention structure and a method of use. It has the following beneficial effects: When the valve needs to be closed, the operator turns the handwheel, which drives the second threaded rod to rotate and move downward; since the second threaded rod and the connecting rod are rotationally connected, the connecting rod moves downward synchronously, thereby driving the bellows to stretch and pushing the pressure block to move downward; after moving downward, the pressure block contacts the top of the upper valve seat, pressing the upper valve seat tightly, thereby achieving fixed closure of the upper valve seat; at the same time, the rotation of the second threaded rod is transmitted to the first threaded rod through the square rod, causing it to rotate inside the pressure block; since the pressure block is restricted by the limit block and cannot rotate with the first threaded rod, the first threaded rod moves upward inside the pressure block, driving the lower valve seat to move upward, and sealing the bottom of the connecting groove; through the above-mentioned linkage mechanism, the bottom and top of the connecting groove are sealed simultaneously, providing double sealing protection for the valve, and significantly improving the sealing performance and reliability of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 Schematic diagram of the internal structure of the present invention; Figure 3 It is a schematic diagram of the cross-sectional structure of the present invention; Figure 4 For the present invention Figure 3A in the middle is an enlarged structural diagram; Figure 5 This is a schematic diagram of the bellows structure of the present invention; Figure 6 This is a schematic diagram of the connection between the second threaded rod and the connecting rod of the present invention; Figure 7 It is a schematic diagram of the structure of the present invention; Figure 8 This is a schematic diagram of the structure of the limit block of the present invention; Figure 9 This is a schematic diagram of the square rod housing structure of the present invention; Figure 10 Schematic diagram of the piston structure of the present invention.

[0018] In the figure, 1. valve body; 101. connecting groove; 102. water outlet; 103. water inlet; 104. lower valve seat; 105. first threaded rod; 106. upper valve seat; 107. pressure block; 108. first spring; 2. flange; 3. transmission mechanism; 301. limit block; 302. connecting rod; 303. bellows; 304. sealing plate; 305. second threaded rod; 306. outer shell; 307. top cover; 308. square rod; 4. indicator assembly; 401. pressure tank; 402. one-way valve; 403. air tank; 404. second spring; 405. piston; 406. spring pin; 407. third spring; 408. set screw; 409. indicator rod; 5. handwheel. DETAILED DESCRIPTION

[0019] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1: Please refer to Figure 1-10 The embodiment of the present invention provides a technical solution: a bellows stop valve with a backflow resistance structure, comprising: a valve body 1, wherein a medium flow channel is provided inside; flanges 2, mounted at both ends of the valve body 1, used to connect the valve body 1 to an external pipeline; a transmission mechanism 3, mounted on the top of the valve body 1, used to control the internal components of the valve body 1 and to control the opening and closing of the medium flow channel by cooperating with the internal components of the valve body 1; an indicator component 4, mounted on one side of the transmission mechanism 3, communicated with the internal components of the transmission mechanism 3; a handwheel 5, mounted on the top of the transmission mechanism 3, connected to the internal components of the transmission mechanism 3, used to control the transmission mechanism 3; The embodiment provides a bellows 303 stop valve with a backflow prevention structure. Through the coordinated action of the valve body 1, flange 2, transmission mechanism 3, indicator assembly 4 and handwheel 5, precise control of the medium flow channel is achieved. The design of the stop valve effectively solves the problem of unstable sealing performance of existing valves under high pressure or high flow conditions. At the same time, through the double sealing mechanism and bellows 303 structure, the reliability and safety of the valve are significantly improved, meeting the requirements for high sealing and high reliability in complex industrial environments.

[0021] Example 2: Please refer to Figure 1-10, the embodiment of the present invention provides a technical solution: a bellows stop valve with a backflow resistance structure, wherein a water inlet 103 is provided at one end of the valve body 1, and a water outlet 102 is provided at the other end of the valve body 1, one end of the water outlet 102 is located above the water inlet 103, and the water inlet 103 and the water outlet 102 are connected to each other through a connecting groove 101, and a lower valve seat 104 is provided below the connecting groove 101, and the lower valve seat 104 is welded to one end of a first threaded rod 105. The first threaded rod 105 is connected to the internal thread of a pressure block 107; the outer wall of the pressure block 107 is slidably connected to the upper valve seat 106, and the upper valve seat 10 6 is provided with a rubber coating on the contact surface with the pressure block 107. The bottom of the upper valve seat 106 is fitted with the surface of the connecting groove 101 by lifting and lowering. A first spring 108 is provided on the top of the upper valve seat 106. The first spring 108 is sleeved on the outside of one end of the bottom of the pressure block 107. The transmission mechanism 3 includes a sealing component and a connecting component. The sealing component is sleeved on the outside of the connecting component for sealing the connecting component. The connecting component is used to drive the pressure block and the lower valve seat 104 to move up and down in the vertical direction. The connecting component includes a limit block 301. The inside of the limit block 301 is welded to the outer wall of the connecting rod 302, and the connecting rod 302 passes through Inside the limit block 301, one end of the bottom of the connecting rod 302 is welded to the top of the pressure block 107, and protruding structures are provided at both ends of the limit block 301. The protruding structures on both sides of the limit block 301 are slidably connected to the grooves on the inner wall of the shell 306. The grooves on the inner wall of the shell 306 are symmetrically distributed. One end of the top of the limit block 301 is welded to the bottom of the bellows 303, and one end of the top of the bellows 303 is connected to the sealing plate 304. The sealing plate 304 is located between the top of the shell 306 and the top cover 307. The top cover 307 is connected to the shell 306 by bolts, and one end of the top of the top cover 307 is threadedly connected to the second threaded rod 305; The second threaded rod 305 is threadedly connected to the top end of the connecting rod 302 through a bearing. The interior of the connecting rod 302 is a hollow structure, and the bottom end of the second threaded rod 305 is inserted into the interior of the connecting rod 302. The bottom end of the second threaded rod 305 is sleeved on the outside of the square rod 308. The cross-section of the square rod 308 is a rectangular structure. The outer wall of the square rod 308 is slidably connected to the second threaded rod 305. The bottom end of the square rod 308 is welded to the top of the first threaded rod 105, and the thread directions of the first threaded rod 105 and the second threaded rod 305 are opposite. The top end of the second threaded rod 305 is fixedly installed with the handwheel 5; In this embodiment, when the device is in use, when the pressure block 107 is at the top, the lower valve seat 104 is at the bottom, and the pressure medium enters the valve body 1 through the water inlet 103. The medium pushes the upper valve seat 106 upward, so that the communication groove 101 can be opened, and then the medium can be discharged through the water outlet 102. When the medium flows back, the upper valve seat 106 can be pushed downward by the action of the first spring 108, so that the upper valve seat 106 can close the communication groove 101, so that the medium cannot flow back, thereby achieving the effect of preventing backflow; When the valve needs to be closed, the handwheel 5 is rotated, and the handwheel 5 can drive the second threaded rod 305 to rotate and move downward. When the second threaded rod 305 moves downward, due to the rotational connection with the connecting rod 302, the connecting rod 302 can move downward synchronously. When the connecting rod 302 moves downward, it can drive the bellows 303 to stretch and drive the pressure block 107 to move downward. After moving downward, the pressure block 107 contacts the top of the upper valve seat 106, so that the upper valve seat 106 can be pressed, and the upper valve seat 106 can be fixed and closed. When the second threaded rod 305 rotates, it can drive the first threaded rod 105 to rotate through the square rod 308. The first threaded rod 105 is connected to the internal thread of the pressure block 107, and the pressure block 107 cannot rotate with the first threaded rod 105 under the action of the limit block 301, so that the first threaded rod 105 can move upward inside the pressure block 107. When the first threaded rod 105 moves upward, it can drive the lower valve seat 104 to move upward, so that the lower valve seat 104 can seal the bottom of the connecting groove 101. By rotating the handwheel 5, the bottom and top of the connecting groove 101 can be sealed at the same time, providing a double seal for the valve seal, which greatly improves the sealing effect of the valve.

[0022] Example 3: Please refer to Figure 1-10 The embodiment of the present invention provides a technical solution: a bellows stop valve with a backflow resistance structure, the indicator assembly 4 includes a pressure tank 401, the pressure tank 401 is installed on one side of the housing 306, one end of the bottom of the pressure tank 401 is connected to the inside of the air tank 403, the other end of the air tank 403 is connected to the inside of the bellows 303, a one-way valve 402 is provided at the bottom of the pressure tank 401 to communicate with the inside, a piston 405 is provided inside the pressure tank 401, the top of the piston 405 is connected to the indicator rod 409, the indicator rod 4 One end of the top of 09 extends out of the top of the pressure tank 401, and a second spring 404 is provided on the top of the piston 405; the bottom and the top end of the piston 405 are made of rubber, and an annular groove is provided in the middle of the piston 405. One side of the pressure tank 401 is threadedly connected to the set screw 408, and one end of the set screw 408 is provided with a third spring 407. One end of the third spring 407 is provided with a spring pin 406. One end of the spring pin 406 is a hemispherical structure, and one end of the spring pin 406 is engaged with the annular groove on the outer wall of the piston 405; In the opening and closing process of the stop valve in this embodiment, the valve stem moves up and down; at this time, friction is also generated between the packing and the valve stem; this friction not only increases the operating resistance, but also further aggravates the wear of the valve stem and the packing, especially under frequent operation conditions, the wear rate will be faster; the bellows 303 structure fundamentally eliminates the existence of this up and down movement friction. In addition, when the bellows 303 is in a stretched state, high-pressure air is injected into the pressure tank 401 through the one-way valve 402, so that the piston 405 inside the pressure tank 401 can move upward and compress the first The second spring 404 and the annular groove on the outside of the piston 405 will engage with the spring pin 406. When the bellows 303 is subjected to long-term reciprocating tension and causes metal fatigue cracking, the pressure inside the pressure chamber and the bellows 303 will drop. When the pressure drops to a specified threshold, the second spring 404 will push the piston 405 out of the engagement with the spring pin 406, causing the piston 405 to move downward, thereby allowing the indicator rod 409 to retract downward. When the indicator rod 409 retracts downward, it can remind the staff that the bellows 303 may be at risk of reduced sealing, so that timely maintenance can be carried out.

[0023] The overall working process of this solution is as follows: Valve installation and preparation Valve Installation: Install the stop valve in the piping system, ensuring that the water inlet 103 and water outlet 102 of the valve body 1 are properly connected to the upstream and downstream pipes, respectively. Also, check that the handwheel 5 is in the loosened state and the bellows 303 is in the naturally contracted state.

[0024] System inspection: Confirm that there is no debris blocking the piping system, and that the connection parts of the stop valves are well sealed and there is no leakage.

[0025] Valve opening operation Turn the handwheel 5 clockwise: The operator turns the handwheel 5 clockwise, which drives the internal components through the transmission mechanism 3. At this time, the connecting rod 302 moves upward, driving the bellows 303 to contract, and at the same time the pressure block 107 moves upward and separates from the upper valve seat 106.

[0026] Medium circulation: The medium enters the valve body 1 through the water inlet 103, pushes the upper valve seat 106 upward, opens the connecting groove 101, and the medium is smoothly discharged from the water outlet 102, and the valve is in the open state.

[0027] Valve closing operation Turn handwheel 5 counterclockwise: The operator turns handwheel 5 counterclockwise, causing second threaded rod 305 in transmission mechanism 3 to rotate and move downward. Connecting rod 302 simultaneously moves downward, stretching bellows 303. Pressing block 107 moves downward and contacts the top of upper valve seat 106, tightening it.

[0028] Double sealing: At the same time, the second threaded rod 305 drives the first threaded rod 105 to rotate through the square rod 308, and the first threaded rod 105 moves upward inside the pressure block 107, driving the lower valve seat 104 to move upward, sealing the bottom of the connecting groove 101, achieving simultaneous sealing of the bottom and top of the connecting groove 101, and the valve is in a closed state.

[0029] Bellows 303 sealing test Injecting high-pressure air: High-pressure air is injected into the pressure tank 401 through the one-way valve 402, so that the piston 405 inside the pressure tank 401 moves upward and compresses the second spring 404, and the annular groove outside the piston 405 engages with the elastic pin 406.

[0030] Testing for leak tightness: When bellows 303 experiences metal fatigue cracking due to prolonged reciprocating tension, the pressure inside pressure tank 401 and bellows 303 decreases. When the pressure drops to a specified threshold, second spring 404 pushes piston 405 out of engagement with spring pin 406. Piston 405 moves downward, causing indicator rod 409 to retract downward, alerting personnel to the risk of leaks in bellows 303.

[0031] Valve maintenance and inspection Regular observation: The operator regularly observes the status of the indicator rod 409. If the indicator rod 409 shrinks downward, it indicates that the sealing performance of the bellows 303 may be reduced.

[0032] Decommissioning and maintenance: The stop valve should be decommissioned in time for inspection and maintenance, and damaged bellows 303 or other sealing components should be replaced to ensure the sealing performance and reliability of the stop valve.

[0033] Through the above process, this solution can achieve efficient opening and closing of the valve. At the same time, through the double sealing mechanism and the bellows 303 sealing detection function, it ensures the high sealing and high reliability of the valve under complex working conditions, and effectively solves the problem of unstable sealing performance of existing valves under high pressure or high flow conditions.

[0034] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from all points of view, the embodiments should be regarded as illustrative and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and range of equivalents of the claims are included in the present invention. Any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0035] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A bellows stop valve with a backflow resistance structure, characterized in that: include: A valve body (1) is provided with a medium flow channel therein; Flanges (2) are installed at both ends of the valve body (1) and are used to connect the valve body (1) to an external pipeline; A transmission mechanism (3) is mounted on the top of the valve body (1) and is used to control the internal components of the valve body (1) and to control the opening and closing of the medium flow channel by cooperating with the internal components of the valve body (1); An indicating component (4) is installed on one side of the transmission mechanism (3) and is in communication with internal components of the transmission mechanism (3); A hand wheel (5) is mounted on the top of the transmission mechanism (3), connected to internal components of the transmission mechanism (3), and used to control the transmission mechanism (3).

2. The bellows stop valve with a backflow prevention structure according to claim 1, characterized in that: A water inlet (103) is provided at one end of the valve body (1), and a water outlet (102) is provided at the other end of the valve body (1). One end of the water outlet (102) is located above the water inlet (103). The water inlet (103) and the water outlet (102) are connected to each other through a connecting groove (101). A lower valve seat (104) is provided below the connecting groove (101). The lower valve seat (104) is welded to one end of a first threaded rod (105). The first threaded rod (105) is connected to the inner thread of the pressing block (107).

3. The bellows stop valve with a backflow prevention structure according to claim 2, characterized in that: The outer wall of the pressure block (107) is slidably connected to the upper valve seat (106), and the contact surface between the upper valve seat (106) and the pressure block (107) is provided with a rubber coating. The bottom of the upper valve seat (106) is fitted with the surface of the connecting groove (101) through lifting and lowering. A first spring (108) is provided on the top of the upper valve seat (106), and the first spring (108) is sleeved on the outside of one end of the bottom of the pressure block (107).

4. The bellows stop valve with a backflow prevention structure according to claim 3, characterized in that: The transmission mechanism (3) comprises a sealing component and a connecting component. The sealing component is sleeved on the outside of the connecting component and is used to seal the connecting component. The connecting component is used to drive the pressure block and the lower valve seat (104) to move vertically up and down.

5. The bellows stop valve with a backflow prevention structure according to claim 4, characterized in that: The connecting assembly includes a limit block (301), the interior of the limit block (301) is welded to the outer wall of the connecting rod (302), and the connecting rod (302) passes through the interior of the limit block (301), one end of the bottom of the connecting rod (302) is welded to the top of the pressing block (107), and protruding structures are provided at both ends of the limit block (301). The protruding structures on both sides of the limit block (301) are slidably connected to the grooves on the inner wall of the shell (306), and the shell ( 306) inner wall grooves are symmetrically distributed, one end of the top of the limit block (301) is welded to the bottom of the bellows (303), one end of the top of the bellows (303) is connected to the sealing plate (304), the sealing plate (304) is located between the top of the shell (306) and the top cover (307), the top cover (307) is connected to the shell (306) by bolts, and one end of the top of the top cover (307) is threadedly connected to the second threaded rod (305).

6. The bellows stop valve with a backflow prevention structure according to claim 5, characterized in that: The second threaded rod (305) is threadedly connected to the top end of the connecting rod (302) through a bearing, the interior of the connecting rod (302) is a hollow structure, and the bottom end of the second threaded rod (305) is inserted into the interior of the connecting rod (302), the bottom end of the second threaded rod (305) is sleeved on the outside of the square rod (308), the cross-section of the square rod (308) is a rectangular structure, the outer wall of the square rod (308) is slidably connected to the second threaded rod (305), the bottom end of the square rod (308) is welded to the top of the first threaded rod (105), and the surface threads of the first threaded rod (105) and the second threaded rod (305) are in opposite directions, and the top end of the second threaded rod (305) is fixedly mounted to the handwheel (5).

7. The bellows stop valve with a backflow prevention structure according to claim 6, characterized in that: The indicating assembly (4) comprises a pressure tank (401), the pressure tank (401) being mounted on one side of the housing (306), one end of the bottom of the pressure tank (401) being in communication with the interior of the air tank (403), the other end of the air tank (403) being in communication with the interior of the bellows (303), a one-way valve (402) being provided at the bottom of the pressure tank (401) and in communication with the interior, a piston (405) being provided inside the pressure tank (401), the top of the piston (405) being connected to an indicating rod (409), one end of the top of the indicating rod (409) extending out of the top of the pressure tank (401), and a second spring (404) being provided at the top of the piston (405).

8. The bellows stop valve with a backflow prevention structure according to claim 7, characterized in that: The bottom and one end of the top of the piston (405) are both made of rubber. An annular groove is provided in the middle of the piston (405). One side of the pressure tank (401) is threadedly connected to a set screw (408). A third spring (407) is provided at one end of the set screw (408). A spring pin (406) is provided at one end of the third spring (407). One end of the spring pin (406) is in a hemispherical structure, and one end of the spring pin (406) is engaged with the annular groove on the outer wall of the piston (405).

9. A method for using a bellows stop valve with a backflow resistance structure according to claim 8, characterized in that: The steps are as follows: S01. Preparation for valve opening: Install the stop valve in the pipeline system and ensure that the water inlet (103) and the water outlet (102) of the valve body (1) are correctly connected to the upstream and downstream of the pipeline respectively; S02. Valve opening operation: Turn the hand wheel (5) clockwise, the medium enters the valve body (1) through the water inlet (103), pushes up the upper valve seat (106), and is discharged from the water outlet (102); S03. Valve closing operation: Turn the hand wheel (5) counterclockwise to move the lower valve seat (104) upward, sealing the bottom of the connecting groove (101), thereby achieving simultaneous sealing of the bottom and top of the connecting groove (101); S04. Bellows (303) sealing test: When the bellows (303) is subjected to long-term reciprocating tension, resulting in metal fatigue cracking, the indicator rod (409) is retracted downward, prompting the staff that the bellows (303) may have a risk of reduced sealing; S05. Valve maintenance and inspection: Regularly observe the status of the indicator rod (409). If the indicator rod (409) shrinks downward, it indicates that the sealing performance of the bellows (303) may be reduced, and the stop valve should be stopped in time.

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