A type of lift plug valve

Abstract

This application relates to the technical field of valves and discloses a lift-type plug valve, which includes a valve body, a valve cover disposed on the valve body, a plug disposed in the valve body, a valve stem disposed on the plug, and an operating mechanism disposed on the valve stem. The plug has a flow channel hole, and a slider is fixedly connected to the lower end of the plug. A sealing ring is embedded in the circumferential surface of the slider. The valve body has a sealing groove for the slider to extend into. A transmission mechanism connects the valve stem and the plug. When the plug valve of this application is opened, the transmission mechanism drives the plug to rise first and then rotate; when closed, the plug rotates first and then falls. This reduces wear between the sealing surface of the valve body and the plug, ensuring the sealing performance of the plug valve during long-term use and extending its service life.

Description

Technical Field

[0001] This application relates to the technical field of valves, and in particular to a lift-type plug valve. Background Technology

[0002] As a fundamental and crucial shut-off valve in industrial pipeline systems, the plug valve's working principle primarily relies on the rotational movement of the valve stem, which drives the internal core component—the plug body—to rotate at a corresponding angle within the valve cavity. By changing the orientation of the flow channel orifice on the plug body, precise control of the fluid passage is achieved, enabling functions such as media flow, shut-off, or flow regulation. Due to its relatively simple structure, low flow resistance, and rapid opening and closing, plug valves are widely used in many industries, including petroleum, chemical, natural gas, city gas, and water treatment, exhibiting significant advantages, especially in applications requiring rapid shut-off. The performance reliability of this type of valve directly affects the operational safety and efficiency of the entire pipeline system; therefore, continuous optimization of its structural design and sealing technology has always been a focus of research and development in the valve field.

[0003] A typical plug valve structure usually includes core components such as a valve body, plug, valve cover, valve stem, and operating mechanism. Specifically, the valve body has a precisely machined valve cavity to accommodate the plug, and the plug has a flow channel hole that matches the pipe diameter. One end of the valve stem is reliably connected to the plug, and the other end extends out of the valve body and is connected to an operating mechanism such as a manual, gear, or automatic actuator. To ensure the sealing integrity of the valve cavity and prevent media leakage along the valve stem, multiple sealing structures, such as stuffing boxes, O-rings, or injection sealing systems, are usually installed where the valve stem passes through the valve cover. When the valve opens or closes, the operating mechanism drives the valve stem to rotate, which in turn rotates the plug approximately 90 degrees. When the plug flow channel hole is aligned with the pipe axis, the valve is fully open, and the media flows smoothly; when the plug rotates to the point where the flow channel hole is perpendicular to the pipe axis, the valve closes, relying on the tight fit between the outer conical or cylindrical surface of the plug and the valve body sealing seat to cut off the media.

[0004] Although the traditional plug valve structure described above is widely used, it suffers from an inherent technical flaw that severely impacts its service life and sealing reliability. The core issue lies in the fact that throughout the entire opening and closing process, the sealing surface of the plug and the inner sealing seat of the valve body maintain constant close contact and intense relative sliding friction. This continuous mechanical friction inevitably leads to gradual wear of the materials on these two critical sealing surfaces. Initially, this may manifest as increased operating torque and difficulty in opening and closing; after long-term operation, it can result in scratches, grooves, and even deformation of the sealing surface. The direct consequence is a significant decrease in the valve's sealing performance, leading to internal leakage and an inability to effectively cut off the medium. This not only wastes energy or materials but, when transporting hazardous media (such as flammable or toxic gases), can potentially cause serious safety and environmental accidents. Therefore, how to fundamentally eliminate or significantly reduce wear between the plug and the valve body has become a pressing technical challenge in this field. Summary of the Invention

[0005] To ensure the sealing performance of the plug valve during long-term use, this application provides a lift-type plug valve.

[0006] The lifting plug valve provided in this application adopts the following technical solution:

[0007] A lift-type plug valve includes a valve body, a valve cover mounted on the valve body, a plug disposed within the valve body, a valve stem mounted on the plug, and an operating mechanism mounted on the valve stem. The plug has a flow channel hole, and a slider is fixedly connected to its lower end. A sealing ring is embedded in the circumferential surface of the slider. The valve body has a sealing groove for the slider to extend into. A transmission mechanism connects the valve stem and the plug. This transmission mechanism can drive the plug and the slider to move axially and then rotate during the opening action, or to rotate first and then move axially during the closing action. This allows the sealing ring on the slider to rotate relative to the sealing surface of the valve body in a non-contact state, and to contact or disengage during axial movement.

[0008] By adopting the above technical solution, when the valve stem's operating mechanism opens the plug, the transmission mechanism between the valve stem and the plug causes the plug and slider to move axially first, separating the sealing ring on the slider from the sealing surface on the inner wall of the valve body. Then, the transmission mechanism drives the plug and slider to rotate, connecting the flow channel hole on the plug with the pipe. Conversely, when the valve stem's operating mechanism closes the plug, the transmission mechanism causes the plug and slider to rotate first, causing the flow channel hole on the plug to align with the pipe. Then, the transmission mechanism drives the plug and slider to slide axially, bringing the sealing ring on the slider into contact with the sealing surface on the inner wall of the valve body, thus achieving a seal between the plug and the valve body. The transmission mechanism precisely controls the timing of the combined motion of the plug and slider. During opening and closing, the sealing ring and the valve body sealing surface only come into contact or separate in the final stage of axial movement, remaining in a non-contact state throughout the entire rotational motion. It eliminates the wear problem caused by continuous sliding friction between the sealing surfaces of traditional plug valves, extends the service life of the valve, maintains the valve's reliable sealing performance for a long time, and effectively prevents internal leakage of the medium.

[0009] Optionally, the transmission mechanism includes a connecting screw rod disposed on the valve stem and a lifting column connected to the connecting screw rod. The lifting column has a connecting screw hole that is threadedly engaged with the connecting screw rod. The plug is disposed on the lifting column. When the connecting screw rod extends into the bottom end of the connecting screw hole, the plug moves axially to a position flush with the pipe. The connecting screw rod is provided with a limiting component. The limiting component is used to fix the connecting screw rod and the lifting column when performing the closing action, until the plug rotates to a position where the flow channel hole is misaligned with the pipe during the closing process, at which point the limiting component releases the connecting screw rod and the lifting column.

[0010] By adopting the above technical solution, when the valve stem is rotated by the operating mechanism to open the plug, the valve stem first drives the connecting screw to rotate in the connecting screw hole, causing the lifting column to move the plug axially upward until the connecting screw contacts the bottom wall of the connecting screw hole. At this point, the lifting column stops moving upward. When the valve stem continues to rotate, the connecting screw will cause the lifting column and the plug to start rotating, thereby connecting the flow channel hole on the plug with the pipeline. This achieves the principle of the plug moving upward first and then rotating during the opening process, reducing the friction between the sealing ring and the valve body sealing surface. The threaded pair formed by the connecting screw and the lifting column reliably converts the rotational motion of the valve stem into the axial lifting force required by the plug, resulting in a simple structure and high transmission efficiency.

[0011] When closing the stopcock, the limiting component first secures the connecting screw and the lifting column together. This allows the connecting screw to rotate in the closing direction, driving the stopcock to rotate first. Then, when the stopcock rotates to the point where the flow channel hole is misaligned with the pipe, the limiting component releases the connecting screw and the lifting column. This allows the connecting screw to continue rotating in the closing direction while simultaneously rotating within the connecting screw hole. Consequently, the lifting column and the stopcock move axially downwards, ultimately bringing the sealing ring on the slider into contact with the sealing surface of the valve body to complete the seal. This prevents the sealing ring from contacting the sealing surface on the valve body during stopcock rotation, reducing wear on the sealing ring. The limiting component ensures that the stopcock remains in the raised position during the initial stage of the closing action (i.e., when the stopcock rotates), releasing only after it has rotated to the correct position (i.e., when the flow channel hole of the stopcock is misaligned with the pipe) to achieve a downward seal. This ensures the precise execution of the "rotate first, then move downward" action sequence, avoiding friction on the sealing surface due to misoperation.

[0012] Optionally, the limiting assembly includes a guide sleeve disposed on the connecting screw, a limiting block disposed on the guide sleeve, and a mounting spring disposed on the limiting block. The guide sleeve is disposed on the side of the lifting column away from the plug. A limiting groove is formed on the lifting column. When the plug moves axially to a position flush with the pipe, the limiting block extends into the limiting groove. An mounting cylinder is provided on the valve cover. The transmission mechanism is disposed in the mounting cylinder. An unlocking element is provided on the inner wall of the mounting cylinder. The unlocking element can move the limiting block out of the limiting groove when the plug rotates to a position where the flow channel hole is misaligned with the pipe during the closing process.

[0013] By adopting the above technical solution, when the valve stem drives the connecting screw to rotate in the opening direction, the connecting screw drives the guide sleeve and the limiting block to rotate together until the plug moves up to the position level with the pipeline. At this point, the limiting block rotates to the position of extending into the limiting groove, thereby fixing the guide sleeve and the lifting column relatively in the horizontal direction. This fixes the connecting screw and the lifting column, preventing the connecting screw from rotating relative to the lifting column. This allows the connecting screw to rotate in the closing direction to first drive the lifting column and the plug to rotate. Then, when the plug rotates to the position opposite to the pipeline, the unlocking component moves the limiting block out of the limiting groove, allowing the connecting screw to rotate relative to the lifting column. Subsequently, when the connecting screw continues to rotate in the closing direction, it causes the lifting column and the plug to move downward along the axial direction, thereby allowing the slider to enter the sealing groove, achieving complete sealing of the valve. This achieves the effect that when the valve stem rotates in the closing direction, it first drives the plug to rotate and then moves downward.

[0014] Optionally, the unlocking component includes an unlocking spring and an unlocking block disposed on the inner wall of the mounting cylinder. The unlocking spring can drive the unlocking block to move towards the side closer to the lifting column. The unlocking block is provided with a guide slope. The inner wall of the mounting cylinder is provided with an unlocking groove for accommodating the unlocking spring and the unlocking block. The guide slope is used to guide the unlocking block into the unlocking groove during the opening of the stopcock. The limiting block is provided with a guide groove. When the stopcock rotates to a position where the flow channel hole and the pipe are misaligned during the closing process, the unlocking block extends into the guide groove. The guide groove is inclined from the guide sleeve towards the lifting column. When the unlocking block slides in the guide groove, it can guide the limiting block to move out of the limiting groove.

[0015] By adopting the above technical solution, when the valve stem drives the connecting screw to rotate in the opening direction, the connecting screw will drive the guide sleeve and the limiting block to rotate. When the limiting block rotates to the position where it abuts against the unlocking block, the limiting block will abut against the guide inclined surface, and as the limiting block continues to rotate, it will push the unlocking block into the unlocking groove, so that the unlocking block will not obstruct the rotation of the limiting block, the guide sleeve, and the connecting screw in the opening direction. When the valve stem drives the connecting screw to rotate in the closing direction, since the limiting block is located in the limiting groove on the lifting column, the connecting screw will drive the lifting column. Rotating together with the stopcock, when the stopcock rotates to the position where the flow channel hole and the pipe are misaligned, the unlocking block moves towards the lifting column under the action of the unlocking spring and extends into the guide groove. When the connecting screw continues to drive the guide sleeve and the limiting block to rotate in the closing direction, the unlocking block will slide in the guide groove and lift the limiting block away from the lifting column, so that the limiting block moves out of the limiting groove. This causes the connecting screw to rotate relative to the lifting column when it continues to rotate in the closing direction, thereby causing the lifting column to drive the stopcock to move axially downward to the position where the sealing ring abuts against the sealing groove.

[0016] Optionally, a dovetail groove is provided on the circumferential sidewall of the slider, and the sealing ring is embedded in the dovetail groove.

[0017] By adopting the above technical solution, the dovetail groove provides a stable mechanical limit for the elastic sealing ring, which can effectively prevent the elastic sealing ring from falling off the slider or rolling and twisting when subjected to fluid pressure impact or squeezing and friction with the sealing surface, thus ensuring the installation stability and sealing reliability of the sealing ring.

[0018] Optionally, the valve cover is provided with a fixing ring, the valve body is provided with a fixing groove, the fixing ring extends into the fixing groove, the fixing groove is provided with a winding pad, and the valve cover and the valve body are connected by bolts.

[0019] By adopting the above technical solution, during installation, the spiral wound gasket is first placed in the fixing groove, then the fixing ring of the valve cover is inserted into the fixing groove of the valve body, and finally the bolts are tightened onto the valve cover and valve body. The fixing ring embedded in the fixing groove allows the T-shaped tenon structure of the valve cover to mechanically constrain the valve body when it is subjected to media pressure, reducing stress deformation and enhancing the concentricity and stability of the connection between the valve cover and valve body. As a high-performance static sealing element, the spiral wound gasket provides excellent sponge effect and sealing compensation capability, ensuring the sealing integrity at the connection between the valve cover and valve body under high temperature, high pressure, or cyclic temperature and pressure changes, preventing media leakage from the connection between the valve cover and valve body.

[0020] Optionally, the valve body is provided with a recovery connector, which is connected to the water inlet pipe, and a safety valve is provided on the recovery connector.

[0021] By adopting the above technical solution, the recovery pipe and the safety valve constitute a safety pressure relief system. When abnormal high pressure is generated inside the valve body due to temperature changes or other reasons, the safety valve will automatically open and release the overpressure medium to the inlet pipe through the recovery pipe. This effectively protects the valve and its downstream pipeline system from overpressure damage, significantly improves the safety of equipment operation, reduces the possibility of medium overflowing the valve body when the valve cavity is abnormally pressurized, prevents medium overflow from polluting the environment, and directly recovers the overflowed medium to the inlet pipe, reducing resource waste.

[0022] Optionally, the cross-section of the flow channel hole is symmetrical vertically.

[0023] By adopting the above technical solution, compared with the trapezoidal flow channel hole opened on the plug of the ordinary plug valve, the symmetrical flow channel hole allows for a larger medium flow rate, making the medium flow more smoothly through the flow channel hole and facilitating medium circulation.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. By setting a transmission mechanism between the valve stem and the plug, the plug moves upward and then rotates when opening, and rotates and then moves downward when closing. This ensures that the sealing ring and the sealing surface of the valve body are separated when the plug rotates, thereby reducing the friction on the sealing surface of the valve body and ensuring the long-term sealing performance of the plug valve.

[0026] 2. By rotating the valve stem, the connecting screw is driven to rotate, thereby causing the lifting column to move up or down relative to the connecting screw. This makes the transmission mechanism simple in structure and provides a good lifting effect on the cock.

[0027] 3. The valve body is equipped with a recovery pipe that connects to the water inlet pipe. When the internal pressure of the valve body rises abnormally, the medium will flow back into the water inlet pipe along the recovery pipe, reducing the risk of medium leakage and reducing resource waste. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of this application.

[0029] Figure 2 This is a partial cross-sectional structural diagram of the sealing ring used in Embodiment 1 of this application.

[0030] Figure 3 This is a cross-sectional structural diagram of the connecting screw used in Embodiment 2 of this application.

[0031] Figure 4 This is a partial structural diagram of the unlocking spring shown after the installation cylinder is hidden in Embodiment 2 of this application.

[0032] Figure 5 This is a partial structural diagram of the installation spring after concealing the mounting cylinder and guide sleeve in Embodiment 2 of this application.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Valve body; 11. Sealing groove; 12. Fixing groove; 121. Spiral wound gasket; 13. Recycling pipe; 131. Safety valve; 2. Valve cover; 21. Fixing ring; 22. Mounting cylinder; 221. Unlocking groove; 3. Plug; 31. Flow channel hole; 32. Slider; 321. Sealing ring; 322. Dovetail groove; 4. Valve stem; 5. Operating mechanism; 6. Transmission mechanism; 61. Connecting screw; 62. Lifting column; 621. Connecting screw hole; 622. Limiting groove; 7. Limiting assembly; 71. Guide sleeve; 72. Limiting block; 721. Guide groove; 73. Mounting spring; 8. Unlocking component; 81. Unlocking spring; 82. Unlocking block; 821. Guide slope. Detailed Implementation

[0035] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0036] This application discloses a lift-type plug valve.

[0037] Example 1

[0038] Reference Figure 1 and Figure 2 A lifting plug valve includes a valve body 1, a valve cover 2, a plug 3, a valve stem 4, and an operating mechanism 5. The valve cover 2 is disposed on the valve body 1, the plug 3 is disposed in the valve body 1, and the operating mechanism 5 is disposed on the valve stem 4 to drive the valve stem 4 to rotate. The plug 3 has a flow channel hole 31, and a slider 32 is fixedly connected to the lower end of the plug 3. A sealing ring 321 is embedded in the circumferential surface of the slider 32, and a sealing groove 11 is provided on the valve body 1 for the slider 32 to extend into.

[0039] Reference Figure 2 The flow channel hole 31 has a symmetrical cross-section along the vertical direction. This design allows the fluid to flow more smoothly through the flow channel hole 31 and reduces flow resistance.

[0040] Reference Figure 1 and Figure 2 A transmission mechanism 6 is connected between the valve stem 4 and the plug 3. The transmission mechanism 6 can drive the plug 3 and the slider 32 to move axially and then rotate when performing the opening action, or to rotate first and then move axially when performing the closing action. This allows the sealing ring 321 on the slider 32 to rotate relative to the sealing surface of the valve body 1 in a non-contact state, and to contact or disengage during axial movement. This can effectively reduce the wear between the sealing surface of the plug 3 and the valve body 1, and improve the sealing reliability and service life of the valve.

[0041] Reference Figure 2 The slider 32 is a component with certain strength and wear resistance, and its shape is usually a square column. The shape of the sealing groove 11 matches that of the slider 32. The slider 32 and the valve 3 can be fixedly connected by welding, which can ensure the firmness and stability of the connection between the two.

[0042] Reference Figure 2 The slider 32 has a dovetail groove 322 on its circumferential sidewall. The shape of the dovetail groove 322 is designed to prevent the sealing ring 321 from falling off. The sealing ring 321 is usually made of rubber, such as nitrile rubber, which has good elasticity and sealing performance. The sealing ring 321 is embedded in the dovetail groove 322. Through the constraint of the dovetail groove 322, the sealing ring 321 can fit tightly against the slider 32, achieving a good sealing effect.

[0043] Reference Figure 2 The valve cover 2 has a retaining ring 21, and the valve body 1 has a retaining groove 12. The retaining ring 21 extends into the retaining groove 12, and a spiral wound gasket 121 is placed in the retaining groove 12. The retaining ring 21 is a ring-shaped component, and the connection between the retaining ring 21 and the valve cover 2 can be integrally formed to ensure the strength of the connection. The spiral wound gasket 121 is usually made of wound metal strip and has good sealing performance. The valve cover 2 and the valve body 1 are connected by bolts, which ensures the tightness and stability of the connection between the valve cover 2 and the valve body 1.

[0044] Reference Figure 1The valve body 1 is equipped with a recovery connector 13, which is connected to the inlet water pipe. A safety valve 131 is installed on the recovery connector 13. The recovery connector 13 is a pipe component, and its material can be carbon steel. The recovery connector 13 can be connected to the valve body 1 by welding. The safety valve 131 is a component capable of automatically controlling pressure. When the pressure inside the pipe exceeds a set value, the safety valve 131 will automatically open to release the pressure and ensure the safety of the pipeline system.

[0045] The implementation principle of a lift-type plug valve according to an embodiment of this application is as follows: When the valve is open, the operating mechanism 5 drives the valve stem 4 to rotate. The valve stem 4 drives the transmission mechanism 6 to make the plug 3 and the slider 32 move axially first. The sealing ring 321 on the slider 32 disengages from the sealing surface of the valve body 1. Then the plug 3 rotates again. At this time, the sealing ring 321 and the sealing surface of the valve body 1 rotate relative to each other in a non-contact state, avoiding wear. When the valve is closed, the plug 3 rotates first, and then the plug 3 and the slider 32 move axially again, so that the sealing ring 321 on the slider 32 contacts the sealing surface of the valve body 1, achieving a seal. This movement mode effectively reduces the wear between the plug 3 and the valve body 1, improves the sealing reliability and service life of the valve, and solves the problem of decreased sealing performance caused by wear in traditional plug valves.

[0046] Example 2

[0047] Reference Figure 3 The difference between this embodiment and Embodiment 1 is that the transmission mechanism 6 includes a connecting screw 61 and a lifting column 62. The connecting screw 61 is mounted on the valve stem 4, and the lifting column 62 is threadedly connected to the connecting screw 61. The lifting column 62 has a connecting screw hole 621 that mates with the threaded connection of the connecting screw 61. The connecting screw 61 is a threaded rod, and its material can be carbon steel, which has high strength.

[0048] Reference Figure 3 The connection between the connecting screw 61 and the valve stem 4 can be a keyed connection, which ensures torque transmission between them. The lifting column 62 is typically a cylindrical component, and its material can be the same as that of the slider 32, such as stainless steel. The connecting screw hole 621 on the lifting column 62 matches the thread of the connecting screw 61. When the connecting screw 61 rotates, the lifting column 62 can move axially through the threaded engagement.

[0049] Reference Figure 3 When the connecting screw 61 extends into the bottom of the connecting screw hole 621, the plug 3 moves axially to a position flush with the pipe. The connecting screw 61 is provided with a limiting component 7, which is used to fix the connecting screw 61 and the lifting column 62 when the closing action is performed, until the plug 3 rotates to a position where the flow channel hole 31 is misaligned with the pipe during the closing process, at which point the limiting component 7 releases the connecting screw 61 and the lifting column 62.

[0050] Reference Figure 3 , Figure 4 and Figure 5 The limiting assembly 7 includes a guide sleeve 71, a limiting block 72, and a mounting spring 73. The guide sleeve 71 is mounted on the connecting screw 61, the limiting block 72 is mounted on the guide sleeve 71, and the mounting spring 73 is mounted on the limiting block 72. The mounting spring 73 has a tendency to drive the limiting block 72 towards the lifting column 62. The guide sleeve 71 is typically a sleeve-shaped component, and its material can be a copper alloy, which has good wear resistance and self-lubricating properties.

[0051] Reference Figure 3 , Figure 4 and Figure 5 The guide sleeve 71 is located on the side of the lifting column 62 away from the plug 3, and a limit groove 622 is formed on the lifting column 62. When the plug 3 moves axially to a position flush with the pipe, the limit block 72 extends into the limit groove 622 under the action of the mounting spring 73, thereby fixing the connecting screw 61 and the lifting column 62.

[0052] Reference Figure 3 and Figure 4 The valve cover 2 is provided with an installation cylinder 22, and the transmission mechanism 6 is set in the installation cylinder 22. The inner wall of the installation cylinder 22 is provided with an unlocking component 8. The unlocking component 8 can move the limiting block 72 out of the limiting groove 622 when the valve 3 is rotated to the position where the flow channel hole 31 is misaligned with the pipeline during the closing process.

[0053] Reference Figure 3 and Figure 5 The unlocking component 8 includes an unlocking spring 81 and an unlocking block 82 disposed on the inner wall of the mounting cylinder 22. The unlocking spring 81 can drive the unlocking block 82 to move towards the side closer to the lifting column 62. The unlocking block 82 is provided with a guide slope 821. The inner wall of the mounting cylinder 22 is provided with an unlocking groove 221 for accommodating the unlocking spring 81 and the unlocking block 82. The guide slope 821 is used to guide the unlocking block 82 into the unlocking groove 221 during the opening of the valve 3.

[0054] Reference Figure 3 and Figure 5 The limiting block 72 is provided with a guide groove 721. When the stopcock 3 rotates to a position where the flow channel hole 31 is misaligned with the pipe during the closing process, the unlocking block 82 extends into the guide groove 721. The guide groove 721 is inclined from the guide sleeve 71 toward the lifting column 62. When the unlocking block 82 slides in the guide groove 721, it can guide the limiting block 72 to move out of the limiting groove 622. In this embodiment, the number of limiting blocks 72, mounting springs 73, unlocking blocks 82, and unlocking springs 81 are preferably two, corresponding to two limiting grooves 622 on the lifting column 62 and two unlocking grooves 221 on the mounting cylinder 22.

[0055] The implementation principle of a lifting plug valve in this application embodiment is as follows: through the threaded engagement of the connecting screw 61 and the lifting column 62, and the setting of the limiting component 7 and the unlocking component 8, the sequence of axial movement and rotation of the plug 3 and the slider 32 is precisely controlled, so that the sealing ring 321 on the slider 32 rotates relative to the sealing surface of the valve body 1 in a non-contact state, and contacts or disengages during axial movement, further ensuring reduced wear between the plug 3 and the valve body 1, and improving the sealing reliability and service life of the valve.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A lift-type plug valve, comprising a valve body (1), a valve cover (2) disposed on the valve body (1), a plug (3) disposed in the valve body (1), a valve stem (4) disposed on the plug (3), and an operating mechanism (5) disposed on the valve stem (4), wherein the plug (3) is provided with a flow channel hole (31), characterized in that: The lower end of the plug (3) is fixedly connected to a slider (32). A sealing ring (321) is embedded on the circumferential surface of the slider (32). A sealing groove (11) is provided on the valve body (1) for the slider (32) to extend into. A transmission mechanism (6) is connected between the valve stem (4) and the plug (3). The transmission mechanism (6) can drive the plug (3) and the slider (32) to move axially and then rotate when performing the opening action, or to rotate and then move axially when performing the closing action, so that the sealing ring (321) on the slider (32) and the sealing surface of the valve body (1) rotate relative to each other in a non-contact state, and contact or separate when moving axially. The transmission mechanism (6) includes a connecting screw (61) disposed on the valve stem (4) and a lifting column (62) connected to the connecting screw (61). The lifting column (62) has a connecting screw hole (621) that is threadedly engaged with the connecting screw (61). The plug (3) is disposed on the lifting column (62). When the connecting screw (61) extends into the bottom end of the connecting screw hole (621), the plug (3) moves axially to a position flush with the pipe. The connecting screw (61) is provided with a limiting component (7). The limiting component (7) is used to fix the connecting screw (61) and the lifting column (62) when performing the closing action until the plug (3) rotates to a position where the flow channel hole (31) is misaligned with the pipe during the closing process. Then the limiting component (7) releases the connecting screw (61) and the lifting column (62). The limiting assembly (7) includes a guide sleeve (71) on the connecting screw (61), a limiting block (72) on the guide sleeve (71), and a mounting spring (73) on the limiting block (72). The guide sleeve (71) is located on the side of the lifting column (62) away from the stopcock (3). A limiting groove (622) is provided on the lifting column (62). When the stopcock (3) moves axially to a position flush with the pipe, the limiting block (72) extends into the limiting groove (622). An mounting cylinder (22) is provided on the valve cover (2). The transmission mechanism (6) is located in the mounting cylinder (22). An unlocking member (8) is provided on the inner wall of the mounting cylinder (22). The unlocking member (8) can move the limiting block (72) out of the limiting groove (622) when the stopcock (3) rotates to a position where the flow channel hole (31) is misaligned with the pipe during the closing process.

2. The lift-type plug valve according to claim 1, characterized in that: The unlocking component (8) includes an unlocking spring (81) and an unlocking block (82) disposed on the inner wall of the mounting cylinder (22). The unlocking spring (81) can drive the unlocking block (82) to move towards the side closer to the lifting column (62). The unlocking block (82) is provided with a guide slope (821). The inner wall of the mounting cylinder (22) is provided with an unlocking groove (221) for accommodating the unlocking spring (81) and the unlocking block (82). The guide slope (821) is used to guide the opening of the stopcock (3) during the opening process. The unlocking block (82) enters the unlocking groove (221). The limiting block (72) is provided with a guide groove (721). When the stopcock (3) rotates to the position where the flow channel hole (31) is misaligned with the pipe during the closing process, the unlocking block (82) extends into the guide groove (721). The guide groove (721) is inclined from the guide sleeve (71) towards the lifting column (62). When the unlocking block (82) slides in the guide groove (721), it can guide the limiting block (72) to move out of the limiting groove (622).

3. A lift-type plug valve according to claim 1, characterized in that: The slider (32) has a dovetail groove (322) on its circumferential sidewall, and the sealing ring (321) is embedded in the dovetail groove (322).

4. A lift-type plug valve according to claim 1, characterized in that: The valve cover (2) is provided with a fixing ring (21), and the valve body (1) is provided with a fixing groove (12). The fixing ring (21) extends into the fixing groove (12), and the fixing groove (12) is provided with a winding pad (121). The valve cover (2) and the valve body (1) are connected by bolts.

5. A lift-type plug valve according to claim 1, characterized in that: The valve body (1) is provided with a recovery connector (13), which is connected to the water inlet pipe, and a safety valve (131) is provided on the recovery connector (13).

6. A lift-type plug valve according to claim 1, characterized in that: The flow channel hole (31) is symmetrical in the vertical direction.

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