Pipeline positioning detection and sealing leakage early warning device and its working method

Abstract

This invention relates to a pipe positioning detection and leak warning device. The device includes a housing, an expansion seal, and a cylinder. The housing has a pipe hole in its center, and the expansion seal has a sealing hole in its center. One end of the cylinder is sealed and fixed to one end of the housing, and the other end is sealed and connected to a liquid-conducting pipeline. The expansion seal includes a main seal and an auxiliary seal. A drainage channel communicating with the sealing hole is provided between the front ends of the main seal and the auxiliary seal, and it also communicates with a drainage hole on the rear end face of the housing. A piston-type sliding sealing body is provided inside the cylinder. The circumferential surface of the sealing body forms a sliding seal with the inner wall of the cylinder. Both ends of the sealing body are open, with one end having a conical opening for sealing the pipe, and the other end having a spring-loaded connection with the liquid-conducting pipeline end of the cylinder. A magnetic ring is nested circumferentially within the sealing body, and a magnetic sensor is fixedly installed outside the cylinder to sense and control the operation of the pipe sealing mechanism and the liquid-conducting pipeline. This structure achieves multiple sealing and leak warning functions, ensuring safe and reliable operation.

Description

Technical Field

[0001] This invention relates to the field of pipe sealing connection equipment, and is a pipe positioning detection and sealing leakage early warning device and its working method. Background Technology

[0002] Pipe sealing devices are mainly used for sealing pipe connections, ensuring a sealed connection between the pipe end and the equipment. Existing pipe sealing devices often use a sealing sleeve for locking, which is primarily suitable for pipes with fixed diameters and not applicable to pipes of different diameters. To address this, some existing technologies disclose solutions, mainly using expansion seals. These seals are created by pneumatic or hydraulic compression to form radial deformation, clamping and sealing the pipe. For example, Chinese patent publication CN205918889U, published on February 1, 2017, entitled "Airbag Sealing Device for Large Diameter Pipes without Adjustable Gaskets," discloses a structure using an inflatable airbag to achieve pipe diameter adaptation and sealing. This method is convenient and adaptable to a wide range of pipe diameters. However, a drawback of this type of sealing structure is that there are no warning signs before the seal fails, leading to sudden leakage and difficulty in rapid remediation. If the leaked liquid is corrosive, it can easily cause harm to operators and the environment. Therefore, a solution is needed to design for the expansion pipe sealing structure that can provide timely warnings of the sealing status and eliminate hazards. Summary of the Invention

[0003] To overcome the above-mentioned shortcomings, the purpose of this invention is to provide a pipe positioning detection and sealing leakage early warning device and its working method, thereby solving the technical problem that existing expansion pipe seals lack early warning of sealing failure, making it difficult to detect leakage problems in a timely manner and easily causing accidents. This objective is achieved through the following technical solution.

[0004] A pipe positioning detection and leak warning device includes a pipe sealing mechanism and a pipe positioning detection mechanism. The pipe sealing mechanism includes a housing and an expansion seal. The expansion seal is located inside the housing, and an expansion cavity is formed between the outer diameter of the expansion seal and the inner circumferential surface of the housing for pressurization and expansion. A pressurization port is provided on the outer circumferential surface of the housing. A pipe hole for axially passing through the pipe fitting is provided in the middle of the housing. A sealing hole is provided in the middle of the expansion seal, which is opposite to the pipe hole. The sealing hole compresses the expansion seal and changes its diameter as the expansion cavity expands, sealing the circumference of the pipe fitting. The pipe positioning detection mechanism includes a cylinder. One end of the cylinder is sealed and fixed to one end of the housing and communicates with the pipe hole at that end of the housing. The other end of the cylinder is sealed and connected to a liquid-passing pipeline. The key structural feature is that the expansion seal includes a main seal and an auxiliary seal. The expansion cavity is formed between the circumferential surface of the main seal and the inner circumferential surface of the housing. The front and rear ends of the main seal correspond to the front and rear axial surfaces inside the housing, respectively, to form a seal. The rear end of the main seal has a groove that is sealed and embedded in the auxiliary seal. Both the main seal and the auxiliary seal are provided with the sealing hole, and a leakage channel communicating with the sealing hole is provided between the main seal and the auxiliary seal. The rear end face of the cover is provided with a leakage hole, and the auxiliary seal is provided with a guide hole for connecting the leakage hole and the leakage channel. The cylinder of the pipe positioning detection mechanism is provided with a piston-type sliding sealing body. The circumferential surface of the sealing body forms a sliding seal with the inner wall of the cylinder. The middle part of the sealing body is provided with a through hole connecting both ends of the sealing body. The through hole is coaxial with the pipe hole of the cover. The diameter of the through hole is smaller than the diameter of the pipe. The end of the through hole facing the cover forms a conical opening that abuts against the end of the pipe. The diameter of the conical opening is larger than the diameter of the pipe. A spring is provided between the sealing body and the liquid passage end of the cylinder to abut against the sealing body. A magnetic ring is fixedly nested in the circumferential direction of the sealing body. A magnetic sensor is fixedly provided on the outside of the cylinder. When the sealing body compresses the spring to the position, it forms a magnetic induction with the magnetic ring. The magnetic sensor controls the operation of the pipe sealing mechanism and the liquid passage. Through the above structure, the pipe insertion detection mechanism detects the pipe fitting being inserted into place and forming the first seal. The main seal provides the second seal, and the auxiliary seal provides the third seal. Even if the first seal fails, the second seal can still provide a reliable seal. When the main seal initially fails, the auxiliary seal can still effectively prevent liquid leakage. Furthermore, fluid seepage through the drain hole indicates the failure state of the main seal, thus achieving an early warning purpose, allowing for timely shutdown for inspection and adjustment of the sealing status. Even if all seals fail, the pipe fitting is pushed out by the spring, and the magnetic ring of the sealing body disengages from the magnetic sensor. The magnetic sensor can effectively control the shutdown, effectively preventing large-scale leakage and accidents, ensuring safe and reliable operation.

[0005] The main sealing element has oblique sealing lips at both ends of its outer diameter, namely a front sealing lip and a rear sealing lip. The expansion cavity is formed between the circumferential surface of the main sealing element and the sealing lips at both ends and the inner circumferential surface of the housing. The front sealing lip and the rear sealing lip of the main sealing element correspond to the front end face and the rear end face of the inner axial direction of the housing, respectively, to form a seal. With this structure, the sealing state between the main sealing element and the housing becomes more reliable as the pressure in the expansion cavity increases. Furthermore, the seal formed between the sealing lips and the housing ensures that the radial diameter change effect is not easily affected by excessive friction between the two ends of the main sealing element and the inner end face of the housing during diameter change, resulting in a more stable and reliable diameter change.

[0006] A non-deformable conduit is installed inside the guide hole of the auxiliary seal. An annular flow guiding cavity, coaxial with the sealing hole, is formed between the rear end face of the auxiliary seal and the rear end face of the cover. That is, the conduit of the auxiliary seal communicates with the drain hole of the cover through the annular flow guiding cavity. This structure helps to ensure the unobstructed flow channel.

[0007] The guide holes of the auxiliary seal are arranged in a ring array relative to the axis of the sealing hole. This structure effectively ensures that the vent hole passage is unobstructed.

[0008] The auxiliary seal has a raised sealing surface on its rear end face that forms a seal with the inner rear end face of the housing. When the auxiliary seal is compressed and deformed, the raised sealing surface and the rear sealing lip of the main seal form the annular flow guide cavity. This structure is one specific embodiment of the annular flow guide cavity.

[0009] The housing is provided with a pressure relief port corresponding to the expansion chamber, and a pressure relief valve is installed at the pressure relief port. This structure ensures that the pressure inside the expansion chamber is within the normal range.

[0010] The pressure port of the casing is connected to a pressure pump, and a pressure sensor for monitoring the pressure inside the expansion chamber is fixedly installed at the pump port of the pressure pump or on the circumference of the casing. Both the pressure sensor and the magnetic sensor control the operation of the pressure pump. This structure enables automatic adjustment of the pressure inside the expansion chamber, making the operation relatively safe and reliable.

[0011] The drain hole is externally sealed to a level gauge tube, which has a valved outlet at the bottom and an air vent and level sensor at the top. The level sensor is connected to an external alarm device. This structure facilitates observation of the seal leakage status and enables automatic alarm, making operation safer and more reliable.

[0012] An auxiliary support is provided between the main seal and the auxiliary seal to form the leakage channel. This structure ensures that the leakage channel remains unobstructed even when the expansion seal is deformed.

[0013] The working method of this pipe positioning detection and sealing leakage early warning device is as follows: the front end of the cylinder of the pipe positioning detection mechanism is sealed with a liquid-passing pipeline. The pipe to be processed is inserted through the pipe hole at the rear end of the cover of the pipe sealing mechanism and extends into the cylinder of the pipe positioning detection mechanism through the pipe hole at the front end of the cover. The pipe pushes the sealing body in the cylinder to compress the spring until the magnetic sensor outside the cylinder senses the magnetic ring around the sealing body, which indicates that the end of the pipe is tightly sealed with the sealing body. At this time, the magnetic sensor controls the external pressure pump to pressurize the pressure port of the cover to the specified pressure. Under the expansion action of the expansion chamber, the main sealing element and the auxiliary sealing element change diameter and deform until the sealing holes of the main sealing element and the auxiliary sealing element clamp the pipe circumferentially. In a sealed state, after the liquid passage is opened, fluid enters from one end of the cylinder, passes through the sealing body, and enters the pipe fitting to form a flow. When the sealing body and the end of the pipe fitting leak, the fluid enters between the main seal and the cylinder, where the main seal forms a seal. When the sealing hole of the main seal fails initially, i.e., leakage occurs, the leaking fluid enters the drain channel, then through the guide hole of the auxiliary seal, and finally flows out through the drain hole of the cover. At this time, based on the outflow of the leaking fluid, it can be determined that the main seal has failed initially, thus achieving the purpose of early warning. When both the main seal and the auxiliary seal fail, the pipe fitting is pushed out under the action of the spring, the magnetic sensor detects that the magnetic ring is not in place, and sends a signal to close the liquid passage.

[0014] The present invention has a relatively compact overall structure, with pipe positioning detection and multiple sealing functions. It is suitable for sealing pipes of various diameters, and the pipe sealing is relatively reliable and stable. It also has a leakage early warning function, which can promptly determine the initial failure of the sealing element and ensure the reliability of the pipe joint seal. It is suitable for use as a sealing structure for automatic sealing and clamping of various pipes in position, or as an improvement on similar pipe sealing structures. Attached Figure Description

[0015] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0016] Figure 2 This is an exploded structural diagram of the present invention.

[0017] Figure 3 yes Figure 2 A partial structural diagram.

[0018] The numbers and names in the diagram are as follows: 1. Cover, 101. Pressurization port, 102. Pressure relief port, 103. Pipe hole, 104. Expansion chamber, 105. Drain hole, 106. Annular groove, 107. Liquid level pipe, 108. Pressure sensor, 2. Main seal, 201. Sealing hole, 202. Drain channel, 203. Front sealing lip, 204. Rear sealing lip, 3. Auxiliary seal, 301. Guide hole, 302. Annular guide chamber, 303. Conduit, 304. Raised sealing surface, 4. Pipe fitting, 5. Cylinder, 6. Sealing body, 601. Through hole, 602. Conical opening, 7. Magnetic ring, 8. Magnetic sensor, 9. Spring, 10. Liquid passage. Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings.

[0020] like Figures 1-3 As shown, the pipe positioning detection and leak warning device includes a pipe sealing mechanism and a pipe positioning detection mechanism. The pipe sealing mechanism includes a housing 1 and an expansion seal. The housing has a cylindrical structure and pipe holes 103 for pipe fittings 4 to pass through are provided in the middle of both axial ends. An expansion seal is provided inside the housing. The expansion seal includes a main seal 2 and an auxiliary seal 3. Both ends of the outer diameter of the main seal are provided with oblique and annular sealing lips, namely a front sealing lip 203 and a rear sealing lip 24. An expansion cavity 104 is formed between the circumferential surface of the main seal and the sealing lips at both ends and the inner circumferential surface of the housing. The front sealing lip and the rear sealing lip of the main seal abut against the front end face and the rear end face of the housing in the axial direction to form a seal. The rear end of the main seal is provided with a groove to seal and embed the auxiliary seal. Both the main seal and the auxiliary seal are provided with sealing holes 201 in the middle that are axially opposite to the pipe hole. When the sealing holes expand with the expansion cavity, they squeeze the expansion seal to change diameter and seal the circumferential direction of the pipe fitting inside the pipe hole. A venting channel 202 communicating with the sealing hole is provided between the inner end of the main sealing groove and the front end of the auxiliary sealing element. A venting hole 105 is provided on the rear end face of the cover. The auxiliary sealing element is provided with a guide hole 301 for connecting the venting hole and the venting channel. The outer circumferential surface of the cover is provided with a pressure port 101 and a pressure relief port 102 communicating with the expansion chamber. A pressure pump is connected to the external pressure port, and a pressure sensor 108 for monitoring the pressure in the expansion chamber is fixed at the pump port of the pressure pump or on the circumferential surface of the cover. The pressure sensor controls the operation of the pressure pump. A pressure relief valve is provided at the pressure relief port to realize the pressure relief operation.

[0021] The pipe positioning detection mechanism of the device includes a cylinder 5. One end of the cylinder is sealed and fixed to one end of the casing 1 and communicates with the pipe hole 103 at that end of the casing. The other end of the cylinder is sealed and connected to the liquid passage 10. A piston-type sliding sealing body 6 is provided inside the cylinder. The circumferential surface of the sealing body forms a sliding seal with the inner wall of the cylinder. A through hole 601 is provided in the middle of the sealing body to conduct through both ends of the sealing body. The through hole and the pipe hole of the casing are coaxial. The diameter of the through hole is smaller than the diameter of the pipe fitting 4. The end of the through hole facing the casing forms a conical opening 602 that abuts against the end of the pipe fitting. The diameter of the conical opening is larger than the diameter of the pipe fitting. A spring 9 is provided between the sealing body and the liquid passage end of the cylinder to abut against the sealing body. A magnetic ring 7 is circumferentially nested and fixedly provided on the sealing body. A magnetic sensor 8 is fixedly provided on the outside of the cylinder. When the sealing body compresses the spring to the position, it forms a magnetic induction with the magnetic ring. The magnetic sensor controls the operation of the pressurization pump of the pipe sealing mechanism and the opening and closing of the liquid passage.

[0022] Furthermore, in order to prevent the guide hole 301 from deforming and failing during the diameter change of the expansion seal and to ensure the unobstructed flow channel 202, the guide holes of the auxiliary seal are arranged in a ring array relative to the axis of the sealing hole 201, and each guide hole is provided with a non-deformable guide tube 303. An annular flow guide cavity 302 coaxial with the sealing hole is formed between the rear end face of the auxiliary seal 3 and the rear end face of the cover 1. The guide tube of the auxiliary seal communicates with the flow hole 105 of the cover through the annular flow guide cavity.

[0023] To facilitate the formation of the aforementioned annular flow guide cavity 302, the rear end face of the auxiliary seal 3 is provided with a raised sealing surface 304 that forms a seal with the inner rear end face of the housing 1. When the auxiliary seal is compressed and deformed, a sealed annular flow guide cavity is formed between the raised sealing surface and the rear sealing lip 204 of the main seal 2. Furthermore, the rear end face of the housing may also be provided with an annular groove 106 coaxial with the pipe hole 103. The annular groove communicates with the drain hole 105, which is beneficial for forming a reliable drain path with the aforementioned annular flow guide cavity.

[0024] Furthermore, the drain hole 105 is externally sealed to the level pipe 107. The bottom of the level pipe is provided with a liquid outlet with a valve, and the top of the level pipe is provided with an air hole and a level sensor. The level sensor is connected to an external alarm device to facilitate observation of the sealing leakage status and to realize automatic alarm.

[0025] Furthermore, in order to ensure that the leakage channel 202 can effectively flow when the expansion seal deforms, an auxiliary support is provided between the main seal 2 and the auxiliary seal 3 to form the leakage channel.

[0026] The device works as follows: The front end of the cylinder 5 of the pipe positioning detection mechanism is sealed and connected to the liquid-passing pipeline 10. The pipe to be processed 4 is inserted through the pipe hole 103 at the rear end of the cover 1 of the pipe sealing mechanism and extends into the cylinder of the pipe positioning detection mechanism through the pipe hole at the front end of the cover. The pipe pushes the sealing body 6 in the cylinder to compress the spring 9 until the magnetic sensor 8 outside the cylinder senses the magnetic ring 7 around the sealing body, which indicates that the end of the pipe is tightly sealed with the sealing body. At this time, the magnetic sensor controls the external pressure pump to pressurize the pressure port 101 of the cover to the specified pressure. Under the expansion action of the expansion chamber 104, the main sealing element 2 and the auxiliary sealing element 3 change diameter and deform until the sealing holes 201 of the main sealing element and the auxiliary sealing element form a clamping seal with the circumference of the pipe. In the sealed state, after the liquid-passing pipeline is opened, the fluid enters from one end of the cylinder, passes through the sealing body and enters the pipe to form a flow. When leakage occurs at the end of the sealing body and pipe fitting, fluid enters between the main seal and the cylinder, forming a seal. When the sealing hole of the main seal fails initially, i.e., leakage occurs, the leaking fluid enters the drain channel 202, then flows through the guide hole 301 of the auxiliary seal, and finally flows out through the drain hole 105 of the casing and into the liquid level pipe 107. By observing the liquid level pipe, the operator can determine that the main seal has failed initially, thus achieving the purpose of early warning. When the liquid level in the liquid level pipe reaches the set value, the alarm device sounds an alarm, achieving further early warning. When both the main seal and the auxiliary seal fail, the pipe fitting is pushed out under the action of the spring 9. The magnetic sensor detects that the magnetic ring is not in place and sends a signal to close the liquid flow pipeline, ensuring that there is no large-scale leakage of liquid and ensuring safe and reliable operation.

[0027] The above description is intended to illustrate the technical means of the present invention and is not intended to limit the scope of the invention. Any obvious improvements or substitutions made to the present invention by those skilled in the art based on existing common knowledge also fall within the protection scope of the claims of the present invention.

Claims

1. A pipe positioning detection and sealing leakage early warning device, the device comprising a pipe sealing mechanism and a pipe positioning detection mechanism, the pipe sealing mechanism comprising a housing (1) and an expansion seal, the expansion seal being located inside the housing, and an expansion cavity (104) for pressurization expansion being formed between the outer diameter of the expansion seal and the inner circumferential surface of the housing, the outer circumferential surface of the housing being provided with a pressurization port (101), the middle part of the housing being provided with a pipe hole (103) for axially passing through a pipe fitting (4), the middle part of the expansion seal being provided with a sealing hole (201) opposite to the pipe hole, and the sealing hole being squeezed to change the diameter of the expansion seal and seal the circumferential direction of the pipe fitting when the expansion cavity is pressurized and expanded; the pipe positioning detection mechanism comprising a cylinder (5), one end of the cylinder being sealed and fixed to one end of the housing and communicating with the pipe hole at that end of the housing, and the other end of the cylinder being sealed and connected to a liquid-conducting pipeline (10); characterized in that The expansion seal includes a main seal (2) and an auxiliary seal (3). The expansion cavity (104) is formed between the circumferential surface of the main seal and the inner circumferential surface of the housing. The front and rear ends of the main seal correspond to the front and rear axial surfaces of the housing (1) to form a seal. The rear end of the main seal is provided with a groove and is embedded in the auxiliary seal. Both the main seal and the auxiliary seal are provided with the sealing hole (201). A leakage channel (202) communicating with the sealing hole is provided between the main seal and the auxiliary seal. The rear end face of the housing is provided with a leakage hole (105). The auxiliary seal is provided with a guide hole (301) that connects the leakage hole and the leakage channel. The cylinder (5) of the pipe positioning detection mechanism is provided with a piston-type sliding sealing body. (6) A sliding seal is formed between the circumferential surface of the sealing body and the inner wall of the cylinder. A through hole (601) is provided in the middle of the sealing body to guide the two ends of the sealing body. The through hole and the pipe hole (103) of the cover are coaxial. The diameter of the through hole is smaller than the diameter of the pipe (4). A conical opening (602) is formed at the end of the through hole facing the cover to seal against the end of the pipe. The diameter of the conical opening is larger than the diameter of the pipe. A spring (9) is provided between the sealing body and the end of the liquid passage (10) of the cylinder to abut the sealing body. A magnetic ring (7) is fixedly nested in the circumferential direction of the sealing body. A magnetic sensor (8) is fixedly provided on the outside of the cylinder to form a magnetic induction with the magnetic ring when the sealing body presses the spring into place. The magnetic sensor controls the operation of the pipe sealing mechanism and the liquid passage.

2. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... The main sealing element (2) has oblique sealing lips at both ends of its outer diameter, namely a front sealing lip (203) and a rear sealing lip (204). The expansion cavity (104) is formed between the circumferential surface of the main sealing element and the sealing lips at both ends and the inner circumferential surface of the cover (1). The front sealing lip and the rear sealing lip of the main sealing element correspond to the front end face and the rear end face of the inner axial direction of the cover to form a seal.

3. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... The auxiliary seal (3) has a non-deformable conduit (303) inside the guide hole (301). An annular flow guide cavity (302) coaxial with the sealing hole is formed between the rear end face of the auxiliary seal and the rear end face of the cover (1). That is, the conduit of the auxiliary seal communicates with the drain hole (105) of the cover through the annular flow guide cavity.

4. The pipe positioning detection and sealing leakage early warning device according to claim 3, characterized in that... The guide holes (301) of the auxiliary seal (3) are arranged in a ring array relative to the axis of the sealing hole (201).

5. The pipe positioning detection and sealing leakage early warning device according to claim 3, characterized in that... The rear end face of the auxiliary seal (3) is provided with a raised sealing surface (304) that forms a seal with the inner rear end face of the cover (1). When the auxiliary seal is squeezed and deformed, the raised sealing surface and the rear sealing lip of the main seal form the annular guide cavity (302).

6. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... The cover (1) is provided with a pressure relief port (102) corresponding to the expansion chamber (104), and a pressure relief valve is provided at the pressure relief port.

7. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... The pressurization port (101) of the cover (1) is connected to a pressurization pump, and a pressure sensor (108) for monitoring the pressure inside the expansion chamber (104) is fixedly provided at the pump port of the pressurization pump or on the circumference of the cover. Both the pressure sensor and the magnetic sensor (8) control the operation of the pressurization pump.

8. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... The drain hole (105) is externally sealed to the level pipe (107). The bottom of the level pipe is provided with a liquid outlet with a valve, and the top of the level pipe is provided with an air hole and a level sensor. The level sensor is connected to an external alarm device.

9. The pipe positioning detection and sealing leakage early warning device according to claim 1, characterized in that... An auxiliary support is provided between the main seal (2) and the auxiliary seal (3) to form the leakage channel (202).

10. A method for operating the pipe positioning detection and sealing leakage early warning device as described in claim 1, characterized in that... The working method is as follows: The front end of the cylinder (5) of the tube positioning detection mechanism is sealed and connected to the liquid pipeline (10). The tube to be processed (4) is inserted through the pipe hole (103) at the rear end of the cover (1) of the tube sealing mechanism and extends into the cylinder of the tube positioning detection mechanism from the pipe hole at the front end of the cover. The tube pushes the sealing body (6) in the cylinder to compress the spring (9) until the magnetic sensor (8) outside the cylinder senses the magnetic ring (7) around the sealing body, which indicates that the end of the tube is tightly sealed with the sealing body. At this time, the magnetic sensor controls the external pressure pump to pressurize the pressure port (101) of the cover to the specified pressure. Under the expansion action of the expansion chamber (104), the main sealing element (2) and the auxiliary sealing element (3) change diameter deformation until the sealing hole (201) of the main sealing element and the auxiliary sealing element is sealed. The fluid is clamped and sealed around the pipe fitting. When the fluid passage is opened in the sealed state, the fluid enters from one end of the cylinder, passes through the sealing body, and enters the pipe fitting to form a flow. When the sealing body and the end of the pipe fitting leak, the fluid enters between the main sealing element and the cylinder, and the main sealing element forms a seal. When the sealing hole of the main sealing element fails initially, i.e., when leakage occurs, the leaked fluid enters the drain channel (202), then through the guide hole (301) of the auxiliary sealing element, and finally flows out through the drain hole (105) of the cover. At this time, based on the leakage of the fluid, it can be determined that the main sealing element has failed initially, thus achieving the purpose of early warning. When both the main sealing element and the auxiliary sealing element fail, the pipe fitting is pushed out under the action of the spring, the magnetic sensor senses that the magnetic ring is not in place, and sends a signal to close the fluid passage.

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