A blowout preventer wellhead shut-off valve

Abstract

This invention belongs to the field of petroleum machinery technology, specifically a blowout preventer wellhead shut-off valve, including a valve body with a sealing port inside. A support frame is fixedly connected to the upper surface of the valve body, and a support plate is slidably connected to one end of the support frame. A valve stem is rotatably connected to the lower surface of the support plate, and a valve core is fixedly connected to one end of the valve stem, with the valve core's size matching the sealing port's size. A sealing frame is fixedly connected inside the valve core, and a fixing rod is provided on one side of the sealing frame. The fixing rod is fixedly connected to the inside of the valve core. Several rotating rods are rotatably and slidably connected between the sealing frame and the fixing rod. A baffle is fixedly connected to the surface of the rotating rod, and several conical plates are fixedly connected to the surface of the baffle. This device improves the valve core, enabling it to achieve both sealing and unblocking states.

Description

Technical Field

[0001] This invention belongs to the field of petroleum machinery technology, specifically a blowout preventer wellhead shut-off valve. Background Technology

[0002] Oil and gas well media carry high pressure, and fluid leakage is prone to occur when the formation pressure is unstable. By using a shut-off valve, the high-pressure media in the well can be blocked after closing, and the channel can be quickly cut off in case of abnormal pressure rise or sudden operation failure, thus preventing major safety accidents such as blowouts, oil and gas leaks, fires and explosions from the source.

[0003] The existing blowout preventer wellhead shut-off valves are used to open and close by driving the valve core to move and cooperate with the sealing port inside the valve seat.

[0004] When the aforementioned existing blowout preventer wellhead shut-off valves are in use, the medium transported at the wellhead is generally mixed with impurities such as sand, rock cuttings, and solid lumps. When the medium flows through the valve seat sealing port, these impurities easily adhere to and accumulate on the sealing contact surface, causing blockage of the sealing port. When the sealing port is blocked, it is generally necessary to manually disassemble the valve body and disassemble the valve core components for manual cleaning. This operation requires suspending wellhead production operations, and the operation process is cumbersome, resulting in a decrease in wellhead fluid transport efficiency.

[0005] Therefore, the present invention provides a blowout preventer wellhead shut-off valve. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies and solve the problem mentioned in the background technology that the manual disassembly of valve bodies and valve core components for cleaning is cumbersome and leads to a decrease in wellhead fluid delivery efficiency.

[0007] The technical solution adopted by the present invention to solve its technical problem is as follows: The present invention provides a blowout preventer wellhead shut-off valve, including a valve body, a sealing port provided inside the valve body, a support frame fixedly connected to the upper surface of the valve body, a support plate slidably connected to one end of the support frame, a valve stem rotatably connected to the lower surface of the support plate, a valve core fixedly connected to one end of the valve stem, and the size of the valve core matches the size of the sealing port, a sealing frame fixedly connected inside the valve core, a fixing rod provided on one side of the sealing frame, the fixing rod being fixedly connected to the inside of the valve core, a plurality of rotating rods being rotatably and slidably connected between the sealing frame and the fixing rod, a baffle fixedly connected to the surface of the rotating rod, and a plurality of conical plates fixedly connected to the surface of the baffle.

[0008] Preferably, a hydraulic cylinder is fixedly connected to the upper surface of the support frame, and a support plate is fixedly connected to the telescopic end of the hydraulic cylinder.

[0009] Preferably, a rotating plate is fixedly connected to the surface of the valve stem, a motor is fixedly connected to the upper surface of the rotating plate, a telescopic rod is fixedly connected to the output end of the motor, and a gear is fixedly connected to the surface of the telescopic rod.

[0010] Preferably, a gear ring is rotatably connected inside the sealing frame, the gear ring meshes with a gear, a lever is fixedly connected to the inner side of the gear ring, and a sliding plate is fixedly connected to one end of the lever, the inside of the sliding plate and one end of the lever are slidably connected.

[0011] Preferably, the valve stem has a spiral groove on its surface, and a limit rod is fixedly connected to the surface of the support frame, with one end of the limit rod slidably connected to the inside of the spiral groove.

[0012] Preferably, the support plate is internally fixedly connected to a fixing frame, the fixing frame is internally fixedly connected to an inner protrusion, and an outer protrusion is provided on one side of the inner protrusion.

[0013] Preferably, one end of the rotating rod is fixedly connected to a push rod, a slider is slidably connected to the outer wall of the fixed frame, a second spring is fixedly connected between the slider and the push rod, and one end of the push rod is in contact with the inner side wall of the fixed frame under normal conditions.

[0014] Preferably, the rotating rod has a sealing cavity inside, and a piston is slidably connected inside the sealing cavity. The piston is fixedly connected to the inner wall of the sealing frame.

[0015] Preferably, an exhaust pipe is fixedly connected to the surface of the rotating rod, an airbag is fixedly connected to one end of the exhaust pipe, a cleaning plate is fixedly connected to the surface of the airbag, a first spring is fixedly connected between the cleaning plates, and the cleaning plates and the cone plate mesh with each other.

[0016] Preferably, both sides of the baffle are provided with toothed grooves, and the toothed grooves between adjacent baffles mesh with each other.

[0017] The beneficial effects of this invention are as follows: 1. The blowout preventer wellhead shut-off valve of the present invention, when it is necessary to clean the blocked sealing port, can drive the telescopic rod to drive the gear to rotate. The gear and the gear ring mesh, so that the gear ring drives the lever to rotate. The lever rotates in the inner groove of the sliding plate, so that the sliding plate drives the rotating rod to rotate. The rotating rod can drive the baffle to rotate at a certain angle, so that the baffle is tilted. Then, the valve core is driven to rotate. The valve core drives the baffle to rotate. The baffle drives the gear groove to rotate, which can scrape and clean the impurities blocking the sealing port. At the same time, during the rotation of the baffle, the fluid inside the valve body can flush the impurities at the sealing port. This device improves the valve core so that the valve core can achieve two states: sealing and unblocking. It avoids the long-term accumulation of impurities such as sand in the valve seat sealing position, which leads to a reduction in the flow inside the valve body and thus reduces the production and transportation efficiency of wellhead operations.

[0018] 2. The blowout preventer wellhead shut-off valve of the present invention is equipped with a protrusion and a rotating rod. When the baffle rotates to clean the sealing port, the push rod at one end of the rotating rod is squeezed by the protrusion, causing the rotating rod to drive the baffle to slide laterally. The baffle drives the cone plate to move laterally. When there are impurities blocking the space between the two baffles, the cone plate moves laterally, which can break up the impurities between the baffles, thus preventing impurities from blocking the space between the baffles. This device can effectively break up the clumps of impurities between the baffles, avoiding large impurities from getting stuck in the gaps between the baffles and causing rotational jamming, making it difficult for the baffles to reset, thereby causing poor sealing of the valve sealing surface, leading to internal leakage of the medium inside the valve body and sealing failure.

[0019] 3. The blowout preventer wellhead shut-off valve of the present invention is equipped with an air bladder and a piston. When the rotating rod drives the baffle to move laterally, the piston inside the sealing frame slides in the sealing cavity inside the rotating rod, allowing the gas inside the rotating rod to enter the air bladder through the exhaust pipe. The air bladder inflates and deforms, causing the air bladder to push the cleaning plate upward. The cleaning plate can clean the impurities accumulated between the cone plates. When the rotating rod returns to its original position, the piston returns to its original position and pumps the gas in the air bladder into the rotating rod, causing the first spring to drive the cleaning plate to return to its original position. This device can clean the impurities between the cone plates through the cleaning plate, avoiding the accumulation of impurities between the cone plates, which would reduce the cone plate's breaking function, make it difficult to clean clumps of impurities, and affect the baffle's return and jamming, thus causing the valve body to fail to seal. Attached Figure Description

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a schematic diagram of the structure of the support frame, valve stem, and valve core of the present invention; Figure 4 This is a top view of the valve core structure of the present invention; Figure 5 This is a schematic diagram of the sealing structure of the baffle on the lower surface of the valve core according to the present invention; Figure 6 This is a schematic diagram of the structure of the fixing frame and baffle of the present invention; Figure 7 This is a partial structural cross-sectional view of the fixing frame of the present invention; Figure 8 This is a schematic diagram of the structure of the baffle of the present invention; Figure 9 This is a structural cross-sectional view of the baffle of the present invention. Figure 10 This is a schematic diagram of the cleaning plate of the present invention; In the diagram: 1. Valve body; 11. Sealing port; 2. Support frame; 21. Hydraulic cylinder; 22. Limiting rod; 23. Support plate; 3. Valve stem; 31. Spiral groove; 32. Rotating plate; 33. Motor; 331. Telescopic rod; 332. Gear; 4. Valve core; 41. Sealing frame; 411. Piston; 42. Gear ring; 421. Pulley; 43. Fixing rod; 431. Fixing frame; 432. Inner protrusion; 433. Outer protrusion; 44. Baffle; 441. Conical plate; 442. First spring; 443. Airbag; 444. Cleaning plate; 45. Rotating rod; 451. Push rod; 452. Second spring; 453. Sliding plate; 454. Sealing cavity; 455. Exhaust pipe. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0023] Example 1: As Figures 1 to 10 As shown in the embodiment of the present invention, a blowout preventer wellhead shut-off valve includes a valve body 1. The valve body 1 has a sealing port 11 inside. A support frame 2 is fixedly connected to the upper surface of the valve body 1. A support plate 23 is slidably connected to one end of the support frame 2. A valve stem 3 is rotatably connected to the lower surface of the support plate 23. A valve core 4 is fixedly connected to one end of the valve stem 3, and the size of the valve core 4 matches the size of the sealing port 11. A sealing frame 41 is fixedly connected inside the valve core 4. A fixing rod 43 is provided on one side of the sealing frame 41. The fixing rod 43 is fixedly connected to the inside of the valve core 4. A plurality of rotating rods 45 are rotatably and slidably connected between the sealing frame 41 and the fixing rod 43. A baffle 44 is fixedly connected to the surface of the rotating rod 45. A plurality of conical plates 441 are fixedly connected to the surface of the baffle 44. Both sides of the baffle 44 are provided with toothed grooves, and the toothed grooves between adjacent baffles 44 mesh with each other.

[0024] Specifically, existing blowout preventer wellhead shut-off valves open and close by driving the valve core 4 to move and engage with the sealing port 11 inside the valve seat. However, since the medium transported during wellhead mining is generally mixed with impurities such as sand, rock cuttings, and solid lumps, these impurities tend to adhere to and accumulate on the sealing contact surface when the medium flows through the valve seat sealing port 11, causing blockage of the sealing port 11. When the sealing port 11 is blocked, it is generally necessary to manually disassemble the valve body 1 and disassemble the valve core 4 components for manual cleaning. This operation requires suspending wellhead production operations, making the process cumbersome and resulting in a decrease in wellhead fluid transport efficiency.

[0025] To solve the above problems, this device is used as follows: When it is necessary to close the valve body 1, the support plate 23 can be driven to slide on the surface of the support frame 2. The support plate 23 drives the valve stem 3 to descend, and the valve stem 3 then drives the valve core 4 to descend. The valve core 4 contacts the sealing port 11 inside the valve body 1, and the valve core 4 seals the sealing port 11, thereby realizing the closing operation of the valve body 1. When the sealing port 11 is blocked, the rotating rod 45 can be driven to rotate the baffle 44. The baffle 44 rotates to an inclined state and opens the inside of the valve core 4. The valve rod 3 drives the valve core 4 to rotate, and the valve core 4 drives the baffle 44 to rotate. The toothed groove on one side of the baffle 44 contacts the impurities in the sealing port 11. The toothed groove on the baffle 44 breaks up the impurities in the sealing port 11. The valve core 4 drives the baffle 44 to continue to descend. When the sealing port 11 is cleared, the internal fluid flows out through the through hole inside the valve body 1, thus realizing the clearing operation of the blockage inside the sealing port 11.

[0026] This device improves the valve core 4, enabling it to achieve both sealing and unblocking states. This prevents impurities such as sand from accumulating in the valve seat sealing position for extended periods, which would reduce the flow rate inside the valve body 1 and consequently decrease production and transportation efficiency during wellhead operations.

[0027] like Figure 2 As shown, a hydraulic cylinder 21 is fixedly connected to the upper surface of the support frame 2, and a support plate 23 is fixedly connected to the telescopic end of the hydraulic cylinder 21.

[0028] Specifically, when it is necessary to drive the valve stem 3 to descend, the hydraulic cylinder 21 can be opened. The extension end of the hydraulic cylinder 21 drives the support plate 23 to descend, the support plate 23 drives the valve stem 3 to descend, the valve stem 3 drives the valve core 4 to descend, and the valve core 4 contacts the sealing port 11, thereby realizing the valve closing operation.

[0029] like Figures 3 to 5As shown, a rotating plate 32 is fixedly connected to the surface of the valve stem 3, a motor 33 is fixedly connected to the upper surface of the rotating plate 32, a telescopic rod 331 is fixedly connected to the output end of the motor 33, a gear 332 is fixedly connected to the surface of the telescopic rod 331, a gear ring 42 is rotatably connected inside the sealing frame 41, the gear ring 42 and the gear 332 mesh with each other, a lever 421 is fixedly connected to the inner side of the gear ring 42, and a sliding groove plate 453 is fixedly connected to one end of the rotating rod 45, the interior of the sliding groove plate 453 and one end of the lever 421 are slidably connected.

[0030] Specifically, when it is necessary to drive the rotating rod 45 to rotate the baffle 44, the motor 33 can be turned on. The motor 33 drives the telescopic rod 331 to rotate, and the telescopic rod 331 drives the gear 332 to rotate. The gear 332 meshes with the gear ring 42, causing the gear ring 42 to drive the lever 421 inside it to rotate. The lever 421 rotates and slides in the groove inside the slide plate 453. The slide plate 453 can then drive the rotating rod 45 to rotate, and the rotating rod 45 drives the baffle 44 to rotate, causing the baffle 44 to rotate from a horizontal state to an inclined state.

[0031] Example 2: Figure 3 As shown in the comparative embodiment one, another embodiment of the present invention is as follows: the surface of the valve stem 3 is provided with a spiral groove 31, the surface of the support frame 2 is fixedly connected with a limiting rod 22, and one end of the limiting rod 22 is slidably connected to the inside of the spiral groove 31.

[0032] like Figure 7 and Figure 8 As shown, a fixing frame 431 is fixedly connected inside the support plate 23, and an inner protrusion 432 is fixedly connected inside the fixing frame 431. An outer protrusion 433 is provided on one side of the inner protrusion 432.

[0033] like Figure 9 As shown, a push rod 451 is fixedly connected to one end of the rotating rod 45, a slider is slidably connected to the outer wall of the fixing frame 431, and a second spring 452 is fixedly connected between the slider and the push rod 451. Under normal conditions, one end of the push rod 451 is in contact with the inner side wall of the fixing frame 431.

[0034] like Figure 9 and Figure 10 As shown, a sealing cavity 454 is provided inside the rotating rod 45. A piston 411 is slidably connected inside the sealing cavity 454. The piston 411 is fixedly connected to the inner wall of the sealing frame 41. An exhaust pipe 455 is fixedly connected to the surface of the rotating rod 45. An air bag 443 is fixedly connected to one end of the exhaust pipe 455. A cleaning plate 444 is fixedly connected to the surface of the air bag 443. A first spring 442 is fixedly connected between the cleaning plates 444. The cleaning plates 444 and the cone plate 441 mesh with each other.

[0035] Specifically, when the baffle 44 cleans and unclogs the impurities inside the sealing port 11, some of the clumps of impurities can easily enter between the two baffles 44, causing the baffle 44 to get stuck when it is reset and rotated, making it difficult for the baffle 44 to reset, thus making it difficult for the valve core 4 to seal the sealing port 11.

[0036] To avoid the aforementioned problems, this device operates as follows: When the rotating rod 45 drives the baffle 44 to rotate to an inclined state, the push rod 451 rotates with the rotating rod 45. Simultaneously, the push rod 451 rotates from the inclined state to the vertical state, and then the hydraulic cylinder 21 is opened to drive the valve rod 3 to descend. As the valve rod 3 descends, the spiral groove 31 on its surface rotates under the action of the limit rod 22, causing the valve rod 3 to drive the rotating plate 32 and the valve core 4 to rotate. The rotating plate 32 drives the motor 33 to rotate, keeping the gear ring 42 and the gear 332 in a meshing state. At the same time, the valve core 4 drives the baffle 44 and the rotating rod 45 to rotate. The rotating rod 45 drives the push rod 451 to rotate on the surface of the fixed frame 431. The push rod 451 contacts the inner protrusion 432, causing the push rod 451 to push the rotating rod 45 to slide towards the inside of the sealing frame 41. The rotating rod 45 drives the baffle 44 to slide synchronously, and the baffle 44 drives the conical plate 441 on its surface to slide synchronously. When there are agglomerated impurities between the baffles 44, one baffle 44 moves. In one state, the other baffle 44 is stationary. The moving baffle 44 drives the cone plate 441 to move and perform frictional crushing on the clumps between them. At the same time, during the movement of the rotating rod 45, the piston 411 inside the sealing frame 41 slides in the sealing cavity 454 inside the rotating rod 45, causing the gas inside the rotating rod 45 to flow into the airbag 443 through the exhaust pipe 455. The airbag 443 inflates and deforms, and the airbag 443 squeezes and pushes the cleaning plate 444. When the cleaning plate 444 slides outward from the baffle 44, it engages with the cone plate 441, thus cleaning the impurities between the cone plates 441. When the push rod 451 moves to the inner protrusion 432, the inner protrusion 432 squeezes the push rod 451 to reset, causing the rotating rod 45 to drive the baffle 44 to reset. The piston 411 resets to the initial position of the sealing cavity 454, at which time the gas in the airbag 443 is sucked out, so that the cleaning plate 444 is reset by the first spring 442.

[0037] Working principle: When it is necessary to close the valve body 1, the hydraulic cylinder 21 is opened. The extension end of the hydraulic cylinder 21 drives the support plate 23 to descend, the support plate 23 drives the valve stem 3 to descend, the valve stem 3 drives the valve core 4 to descend, and the valve core 4 contacts the sealing port 11, thus realizing the valve closing operation. The valve core 4 also blocks the sealing port 11, thus realizing the valve body 1 closing operation. When the sealing port 11 is blocked, the motor 33 can be turned on. The motor 33 drives the telescopic rod 331 to rotate, and the telescopic rod 331 drives the gear 332 to rotate. The gear 332 meshes with the gear ring 42, which causes the gear ring 42 to drive the lever 421 inside to rotate. The lever 421 rotates and slides in the groove inside the slide plate 453. The slide plate 453 can then drive the rotating rod 45 to rotate. The rotating rod 45 drives the baffle 44 to rotate, causing the baffle 44 to rotate from a horizontal state to an inclined state. When the rotating rod 45 drives the baffle 44 to rotate to the inclined state, the push rod 451 rotates with the rotating rod 45. At the same time, the push rod 451 rotates from the inclined state to the vertical state. Then, the hydraulic cylinder 21 is opened to drive the valve rod 3 to descend. When the valve rod 3 descends, the spiral groove 31 on its surface rotates under the action of the limit rod 22, so that the valve rod 3 drives the rotating plate 32 and the valve core 4 to rotate. The valve core 4 drives the baffle 44 to rotate. The baffle 44 can break up the accumulated impurities in the sealing port 11 through the surface groove. At the same time, the rotation of the baffle 44 can drive the fluid to move, and the fluid can flush the inner wall of the sealing port 11. The rotating plate 32 drives the motor 33 to rotate, keeping the gear ring 42 and gear 332 in a meshing state. At the same time, the valve core 4 drives the baffle 44 and the rotating rod 45 to rotate. The rotating rod 45 drives the push rod 451 to rotate on the surface of the fixed frame 431. The push rod 451 contacts the inner protrusion 432, causing the push rod 451 to push the rotating rod 45 to slide towards the inside of the sealing frame 41. The rotating rod 45 drives the baffle 44 to slide synchronously. The baffle 44 drives the conical plate 441 on the surface to slide synchronously. When there are clumps of impurities between the baffles 44, one baffle 44 is in a moving state and the other baffle 44 is in a fixed state. The moving baffle 44 drives the conical plate 441 to move and perform friction and breakup operations on the clumps between them. At the same time, during the movement of the rotating rod 45, the piston 411 inside the sealing frame 41 rotates on the rotating rod. The piston 45 slides within the sealed cavity 454, causing the gas inside the rotating rod 45 to flow into the airbag 443 through the exhaust pipe 455. The airbag 443 inflates and deforms, squeezing the cleaning plate 444 and pushing it to slide outwards towards the baffle 44. As the cleaning plate 444 slides outwards, it engages with the cone plate 441, thus cleaning the impurities between the cone plates 441. When the push rod 451 moves to the inner protrusion 432, the inner protrusion 432 squeezes the push rod 451 to reset, causing the rotating rod 45 to drive the baffle 44 to reset. The piston 411 resets to the initial position of the sealed cavity 454, at which point the gas in the airbag 443 is drawn out, causing the cleaning plate 444 to reset via the first spring 442, thus cleaning the impurities between the cone plates 441.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A blowout preventer wellhead shut-off valve, characterized in that: The valve body (1) includes a valve body (1) with a sealing port (11) inside. A support frame (2) is fixedly connected to the upper surface of the valve body (1). A support plate (23) is slidably connected to one end of the support frame (2). A valve stem (3) is rotatably connected to the lower surface of the support plate (23). A valve core (4) is fixedly connected to one end of the valve stem (3). The size of the valve core (4) matches the size of the sealing port (11). A sealing frame (41) is fixedly connected inside the valve core (4). A fixing rod (43) is provided on one side of the sealing frame (41). The fixing rod (43) is fixedly connected to the inside of the valve core (4). Several rotating rods (45) are rotatably and slidably connected between the sealing frame (41) and the fixing rod (43). A baffle (44) is fixedly connected to the surface of the rotating rod (45). Several cone plates (441) are fixedly connected to the surface of the baffle (44).

2. The blowout preventer wellhead shut-off valve according to claim 1, characterized in that: A hydraulic cylinder (21) is fixedly connected to the upper surface of the support frame (2), and a support plate (23) is fixedly connected to the telescopic end of the hydraulic cylinder (21).

3. A blowout preventer wellhead shut-off valve according to claim 2, characterized in that: A rotating plate (32) is fixedly connected to the surface of the valve stem (3), a motor (33) is fixedly connected to the upper surface of the rotating plate (32), a telescopic rod (331) is fixedly connected to the output end of the motor (33), and a gear (332) is fixedly connected to the surface of the telescopic rod (331).

4. A blowout preventer wellhead shut-off valve according to claim 3, characterized in that: The sealing frame (41) is rotatably connected to a gear ring (42), which meshes with a gear (332). A lever (421) is fixedly connected to the inner side of the gear ring (42), and a sliding plate (453) is fixedly connected to one end of the rotating rod (45). The interior of the sliding plate (453) is slidably connected to one end of the lever (421).

5. A blowout preventer wellhead shut-off valve according to claim 4, characterized in that: The valve stem (3) has a spiral groove (31) on its surface, and a limit rod (22) is fixedly connected to the surface of the support frame (2). One end of the limit rod (22) is slidably connected to the inside of the spiral groove (31).

6. A blowout preventer wellhead shut-off valve according to claim 5, characterized in that: The support plate (23) is internally fixedly connected to a fixing frame (431), and the fixing frame (431) is internally fixedly connected to an inner protrusion (432). An outer protrusion (433) is provided on one side of the inner protrusion (432).

7. A blowout preventer wellhead shut-off valve according to claim 6, characterized in that: One end of the rotating rod (45) is fixedly connected to a push rod (451), and a slider is slidably connected to the outer wall of the fixed frame (431). A second spring (452) is fixedly connected between the slider and the push rod (451). Under normal conditions, one end of the push rod (451) is in contact with the inner wall of the fixed frame (431).

8. A blowout preventer wellhead shut-off valve according to claim 7, characterized in that: The rotating rod (45) has a sealing cavity (454) inside, and a piston (411) is slidably connected inside the sealing cavity (454). The piston (411) is fixedly connected to the inner wall of the sealing frame (41).

9. A blowout preventer wellhead shut-off valve according to claim 8, characterized in that: An exhaust pipe (455) is fixedly connected to the surface of the rotating rod (45). An airbag (443) is fixedly connected to one end of the exhaust pipe (455). A cleaning plate (444) is fixedly connected to the surface of the airbag (443). A first spring (442) is fixedly connected between the cleaning plates (444). The cleaning plates (444) and the cone plate (441) mesh with each other.

10. A blowout preventer wellhead shut-off valve according to claim 1, characterized in that: Both sides of the baffle (44) are provided with toothed grooves, and the toothed grooves between adjacent baffles (44) mesh with each other.

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