A blowout preventer for electrical cables

Abstract

The utility model discloses a kind of cable blowout preventer use release and spray subassembly, including valve body, the upper portion and the lower portion of its one side side wall are respectively opened with first mounting hole and second mounting hole along horizontal direction, to be installed switch valve and release and spray swivel joint respectively;Third mounting hole is opened in the other side top of valve body along longitudinal direction, to install pressure gauge;First communication passage is opened with third mounting hole hole bottom intercommunication from second mounting hole hole bottom along horizontal direction, second communication passage is opened with first mounting hole hole bottom side wall along horizontal direction and penetrates the back side wall of valve body, third communication passage is opened with first communication passage penetration from first mounting hole middle part along longitudinal direction;Switch valve controls the opening and closing between second communication passage and third communication passage, release and spray swivel joint controls the opening and closing between first communication passage and external release and spray pipeline;The release and spray subassembly not only can reduce the risk of damage to valve core, prolong service life, and assembly accuracy and stability are higher, applicable to mobile operation.

Description

Technical Field

[0001] This utility model relates to the field of blowout preventer technology, and in particular to a blowout prevention assembly for a cable blowout preventer. Background Technology

[0002] With the continuous development of oil and gas field drilling and development technologies, a series of operations such as logging, wireline / steel wire perforation, and bridge-fracturing are carried out. The most important means to ensure the safety of these operations is to equip the wells with comprehensive wireline blowout preventers (BOPs). Due to the development of shale gas in China, the pressure of oil and gas wells is increasing, requiring equipment to withstand higher pressures and placing increasingly stringent demands on on-site safety operations. High-pressure wellhead BOPs have broad application prospects, and the BOP pressure relief assembly is a key component in well site operations, enabling safe pressurized production operations.

[0003] Traditional pressure relief assemblies have only a single pressure relief valve, and the valve core needs to be opened and closed frequently in high-pressure working environments, which makes the valve core and its key seals extremely easy to be damaged. Therefore, in order to extend the service life of the valve core and sealing rings, reduce the labor intensity of workers, and ensure safety, a special cable blowout preventer pressure relief assembly suitable for use in high-pressure environments has been developed. Utility Model Content

[0004] The purpose of this invention is to provide a blowout prevention assembly for cable blowout preventers that solves the above-mentioned technical problems.

[0005] Therefore, the technical solution of this utility model is as follows:

[0006] A blowout preventer assembly for cables includes a valve body. A first mounting hole and a second mounting hole are horizontally formed on the upper and lower parts of one side wall, respectively, and a third mounting hole is longitudinally formed on the top of the other side. A first connecting channel is formed horizontally from the bottom of the second mounting hole, communicating with the bottom of the third mounting hole. A second connecting channel is formed horizontally from the bottom side wall of the first mounting hole, communicating with the back side wall of the valve body. A third connecting channel is formed longitudinally from the middle of the first mounting hole, communicating with the first connecting channel. A switching valve is installed in the first mounting hole to control the opening and closing of the connection between the first and third connecting channels. The second mounting hole is closed; a venting rotary joint is installed in the second mounting hole, which includes a rotary joint, a connecting seat, and a shut-off valve; the bottom end of the connecting seat is inserted and fixed in the second mounting hole, and a venting blind hole is opened axially from the center of the bottom end, and a venting through hole is opened radially at the top end, which intersects with the venting blind hole; the rotary joint is sleeved on the outer side of the top end of the connecting seat, and an annular groove is opened on its inner wall, which communicates with the venting through hole, and a connector is formed on one side wall that extends radially outward, and an axial through hole is opened on the connector that communicates with the annular groove; one end of the shut-off valve is connected to the connector, and the other end is connected to the venting joint; a pressure gauge is installed in the third mounting hole.

[0007] Furthermore, the valve body is composed of an integrally formed longitudinal section and a transverse section, with its longitudinal section being L-shaped; the first and second mounting holes are opened on the side wall of the longitudinal section away from the transverse section, so that the switching valve and the blowout rotary joint are arranged vertically at intervals; the third mounting hole is opened on the top surface of the transverse section, so that the pressure gauge is arranged vertically on the top side of the transverse section in a parallel manner with the longitudinal section; a mounting screw hole is opened at each of the two apex corners of the top of the longitudinal section of the valve body and at the symmetrical position of its bottom, so that the valve body can be fixed to the designated position of the blowout preventer by bolts inserted in the mounting screw holes.

[0008] Furthermore, a third connecting channel is opened longitudinally and extends through the bottom surface of the valve body, and a pressure sensor is threadedly connected at the port of the third connecting channel located on the bottom surface of the valve body.

[0009] Furthermore, a connecting pipe is fixed at the outer port of the second connecting channel, and an annular groove with a built-in rubber sealing ring and a polytetrafluoroethylene retaining ring is opened on the other end of the connecting pipe wall, so that the connecting pipe is sealed and inserted into the monitoring hole on the designated pipeline of the blowout preventer.

[0010] Furthermore, a disassembly channel is provided horizontally from the bottom of the first mounting hole, penetrating one side wall of the valve body, and a first plug is threaded at the outer end of the disassembly channel.

[0011] Furthermore, the switching valve includes a first valve core, a valve sleeve, and a second valve core; the second valve core and the valve sleeve are sequentially inserted into a first mounting hole, with the bottom end of the valve sleeve fixed to the hole wall; the second valve core has a cylindrical structure, with a first annular space formed between its bottom end and the first mounting hole, and multiple first radial pressure transmission holes communicating with the first annular space are opened on its side wall, so that the second connecting channel communicates with each of the first radial pressure transmission holes through the first annular space; a second annular space is formed between the top outer wall of the second valve core and the first mounting hole, and multiple second radial pressure transmission holes communicating with the second annular space are opened on its side wall, so that the third connecting channel communicates with each of the second radial pressure transmission holes through the second annular space; the first valve core is inserted into the valve sleeve, with its top end threadedly connected to the valve sleeve and having a rotating hole on its end face, and its bottom end being a tapered end that mates with a tapered platform on the inner wall of the second valve core.

[0012] Furthermore, the top of the valve sleeve is designed as an external hexagonal end and located on the outside of the valve body. A limit plug is provided on the adjacent side of the valve sleeve, and it is set in such a way that one side wall surface fits against one side wall surface of the external hexagonal end of the valve sleeve, and is fixed to the valve body by an internal hexagonal screw to achieve the limit fixation of the valve sleeve.

[0013] Furthermore, a lip seal is provided between the second valve core and the valve sleeve, and two annular grooves with built-in lip seals are opened at intervals on the outer wall of the middle part of the second valve core to seal the outer wall of the second valve core with the hole wall.

[0014] Furthermore, the other end of the venting connector has an outer annular boss on its outer wall, and a connector nut is fitted on its outer side. One end of the connector nut has an inner annular boss to limit the valve between the shut-off valve and the outer annular boss. The inner diameter of the connector nut and the internal thread on its inner wall are adapted to the outer diameter of the connection end of the on-site venting pipeline and the external thread on its outer wall, respectively. The outer diameter of the venting connector is smaller than the inner diameter of the connection end of the on-site venting pipeline, so that the connection end of the on-site venting pipeline is plugged into the venting connector and threadedly fixed to the connector nut.

[0015] Furthermore, an annular groove with a built-in rubber sealing ring and a polytetrafluoroethylene retaining ring is provided on the outer wall of the bottom end of the connector, so that a seal is formed between the walls of the second mounting hole of the connector; an annular groove is provided on the outer wall of the connector on both sides of the vent hole, with a rubber sealing ring and a polytetrafluoroethylene retaining ring installed in the annular groove on the front side, and a rubber sealing ring installed in the annular groove on the rear side, so that a seal is formed between the outer wall of the connector and the inner wall of the rotary joint.

[0016] Compared with existing technologies, this blowout preventer assembly integrates a switching valve and a rotary blowout connector into the valve body structure, forming a complete structure that can be applied to blowout preventers and is easy to assemble and disassemble. This blowout preventer assembly is suitable for various harsh working environments and frequent disassembly. It not only reduces the risk of valve core damage and extends its service life, but also has higher assembly precision and stability, ensuring the operational quality of the product, and facilitates parts replacement and maintenance. In addition, the flexible structural design of this blowout preventer assembly makes it suitable for mobile operations and allows for arbitrary adjustment of the setting direction. It is suitable for use on blowout preventers in different scenarios and has good market application and promotion prospects. Attached Figure Description

[0017] Figure 1 This is a bottom view of the blowout relief assembly for the cable blowout preventer of this utility model;

[0018] Figure 2 This is a side sectional view of the blowout relief assembly for the cable blowout preventer of this utility model. Figure 1 (AA sectional view);

[0019] Figure 3 This is a side sectional view of the switching valve of the blowout assembly for the cable blowout preventer of this utility model.

[0020] Figure 4 This is a schematic diagram of the channel design and the flow direction of the internal liquid in the blowout preventer assembly of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the following embodiments are by no means intended to limit the present invention.

[0022] See Figures 1-4 The blowout preventer assembly for this cable includes a valve body 1, a switching valve, a blowout rotary joint, a pressure gauge 11, and a pressure sensor 29.

[0023] A first mounting hole 30 is provided horizontally on the upper part of one side wall of the valve body 1, and a second mounting hole 31 is provided horizontally on the lower part. A third mounting hole is provided longitudinally on the top of the other side of the valve body 1. In this embodiment, the valve body 1 is composed of an integrally formed longitudinal and transverse section, making its longitudinal cross-section L-shaped. The first mounting hole 30 and the second mounting hole 31 are provided on the side wall of the longitudinal section, so that the switching valve and the discharge rotary joint are arranged vertically and alternately on one side of the valve body 1. The third mounting hole is provided on the top surface of the transverse section, and the pressure gauge 11 is arranged vertically on the top side of the transverse section in a parallel manner with the longitudinal section. Furthermore, the functional components of the discharge assembly for the cable blowout preventer are centrally arranged, making the structural design of the assembly more compact.

[0024] A first connecting channel 25, which is horizontally connected to the bottom of the third mounting hole, is provided at the bottom of the second mounting hole 31. This allows the pressure gauge installed in the third mounting hole to monitor the pressure in the first connecting channel 25 in real time. When the pressure in the first connecting channel 25 is too high, the pressure is promptly detected and the release rotary joint is opened to release the pressure.

[0025] A second connecting channel is formed horizontally along the bottom sidewall of the first mounting hole 30, penetrating the back sidewall of the valve body 1, and the second connecting channel is perpendicular to the first connecting channel 25; see [link to documentation]. Figure 1 A connecting pipe 24 is threadedly fixed at the second communication channel port located on the back side of the valve body 1. An annular groove with a built-in rubber sealing ring and a polytetrafluoroethylene retaining ring is provided on the other end of the connecting pipe 24 for sealing the monitoring hole opened on the designated pipeline of the blowout preventer.

[0026] A third connecting channel 26 is longitudinally formed from the middle of the first mounting hole 30, penetrating the bottom surface of the valve body 1. The third connecting channel 26 is perpendicularly intersecting the first connecting channel, so that the third connecting channel 26, the first connecting channel 25, and the second connecting channel have the same pressure. A pressure sensor 29 is threadedly connected to the port of the third connecting channel 26 on the bottom surface of the valve body 1, so as to monitor the pressure in the first channel in real time, just like the pressure gauge 11. In practical applications, the pressure sensor 29 also has the function of remote pressure monitoring. By transmitting the pressure value to the central control room in real time, the purpose of remote monitoring of pressure changes can be achieved, reducing the labor intensity of on-site operators who frequently observe the pressure gauge 11, and improving the safety of on-site operations. The pressure sensor 29 can be set with different specifications of sensors as needed.

[0027] As a preferred technical solution in this embodiment, see [link to example]. Figure 1 A mounting screw hole 27 is provided at each of the two apex corners on the top side of the longitudinal part of the valve body 1 and at the symmetrical position on its bottom side, so that the valve body 1 can be fixed at the designated position of the blowout preventer by the hexagonal bolts 27 that pass through the mounting screw holes.

[0028] See Figure 3 The switch valve is inserted and installed in the first mounting hole 30; for ease of description, as Figure 3 As shown, the left end of each component constituting the switching valve is considered the top, and the right end is considered the bottom. Specifically, the switching valve includes a first valve core 2, a valve sleeve 4, a limit plug 6, and a second valve core 8. The second valve core 8 and the valve sleeve 4 are sequentially inserted into the first mounting hole 30, and the bottom end of the valve sleeve 4 is threaded onto the wall of the first mounting hole 30. The second valve core 8 is a cylindrical structure with its bottom outer diameter contracted to form a first annular space with the first mounting hole. Four first radial pressure transmission holes communicating with the first annular space are evenly distributed along the circumference on the side wall, allowing the second communication channel to pass through. The first annular space is connected to each of the first radial pressure transmission holes; the top outer wall of the second valve core 8 is provided with four second radial pressure transmission holes along the circumference, and an annular groove is provided on the wall of the first mounting hole corresponding to the opening position of the four second radial pressure transmission holes, so that a second annular space is formed between the top outer wall of the second valve core 8 and the first mounting hole, and the third connecting channel is connected to each of the second radial pressure transmission holes through the second annular space; the first valve core 2 is inserted into the valve sleeve 4, and its top end is threaded to the valve sleeve 4, and its bottom end is a tapered end that matches the tapered platform on the inner wall of the second valve core 8.

[0029] Preferably, the top end of the first valve core 2 is built into the valve sleeve 4, and its end face is provided with an internal hexagonal hole, so as to facilitate the insertion and cooperation of the first valve core 2 with an external hexagonal tool. By rotating the first valve core 2, the length of its extension into the second valve core 8 can be adjusted to control the communication between the two second radial pressure transmission holes and the third communication channel. A spring retaining ring 3 for limiting is provided on the inner wall of the top end of the valve sleeve 4 to prevent the first valve core 2 from coming out of the valve sleeve 4.

[0030] Preferably, in order to ensure the sealing of the switching valve during use, a lip seal is provided between the second valve core 8 and the valve sleeve 4, and an annular groove with two built-in lip seals 7 is provided on the outer wall of the middle part of the second valve core 8, so that the third communication channel on the valve body 1 can only be connected to the second communication channel through the inner cavity of the second valve core 8.

[0031] Preferably, the top of the valve sleeve 4 is designed as an external hexagonal end and is located outside the valve body 1; in order to prevent the valve sleeve 4 from disengaging, a limit plug 6 is provided on the adjacent side of the valve sleeve 4, which is set in such a way that one side wall surface is in contact with one side wall surface of the external hexagonal end of the valve sleeve 4, and is fixed to the valve body 1 by an internal hexagonal screw 5 to achieve the limit and fixation of the valve sleeve 4.

[0032] As a preferred embodiment, a disassembly channel 28 is provided horizontally along the bottom of the first mounting hole 30, penetrating one side wall of the valve body 1. A first plug 12 is threadedly connected to the port of the disassembly channel 28 located on the side wall of the valve body 1. In this embodiment, the first plug 12 is a 3 / 8" NPT plug. In practical applications, the disassembly channel is used to allow disassembly tools to be inserted into the disassembly channel and push the components of the valve to the outside of the first mounting hole 30 when replacing the switching valve by removing the plug 12, thereby achieving quick disassembly of the switching valve.

[0033] The rotary nozzle is inserted and installed in the second mounting hole 31; similarly, for ease of description, as... Figure 2 As shown in the orientation, the left end of each component constituting the venting rotary joint is considered the top end and the right end is considered the bottom end; specifically, the venting rotary joint includes a rotary joint 15, a connecting seat 18, a shut-off valve 20, and a venting connector 21;

[0034] The bottom end of the connecting seat 18 is inserted and threaded into the second mounting hole 31. A venting blind hole is axially formed from the center of the bottom end, and a venting through hole is radially formed at the top end, intersecting the bottom of the venting blind hole. The rotary joint 15 is sleeved on the outer side of the top end of the connecting seat 18, with its top end abutting against the annular protrusion at the top end of the connecting seat 18 and its bottom end abutting against the outer wall of the valve body 1. An annular groove communicating with the venting through hole is formed on the inner wall of the rotary joint 15, and a connector extends radially outward from one side wall. The connector has an axial through hole communicating with the annular groove, allowing the axial through hole to sequentially connect to the first communicating channel 25 through the annular groove, the venting through hole, and the venting blind hole. The shut-off valve 20... One end is threadedly connected to the end of the connector of the rotary joint 15 via the NPT male and female thread 19, and the other end is threadedly connected to the venting connector 21; the other end of the venting connector 21 has an outer annular boss on its outer wall, and a connector nut 22 is fitted on its outer side. One end of the connector nut 22 has an inner annular boss, which limits it between the shut-off valve 20 and the outer annular boss; the inner diameter of the connector nut 22 and the internal thread on its inner wall are adapted to the outer diameter of the connection end of the on-site venting pipeline and the external thread on its outer wall, respectively. The outer diameter of the venting connector 21 is smaller than the inner diameter of the connection end of the on-site venting pipeline, so that the connection end of the on-site venting pipeline is plugged into the venting connector 21 and simultaneously forms a threaded fixed connection with the connector nut 22.

[0035] In the structural design of this venting rotary joint, on the one hand, the structural cooperation between the rotary joint 15 and the connecting seat 18 enables the venting rotary joint to rotate accordingly based on the location of the on-site venting pipeline relative to the location of the blowout preventer, eliminating the single direction of the pipeline. By adding a rotation function, it avoids pipeline bending and facilitates its connection with the on-site venting pipeline. On the other hand, the structural cooperation between the connector nut 22 and the venting connector 21 not only enables the butt connection between the venting connector 21 and the on-site venting pipeline, but also achieves a fixed connection using the connector nut 22. The advantage of this connection method is that the on-site venting pipeline and the venting connector 21 are fixedly connected by rotating the connector nut 22, avoiding the inconvenience of rotating the on-site venting pipeline to achieve a threaded connection.

[0036] Preferably, the connector nut 22 is also designed with a connector guard wire 23. The connector guard wire 23 is a cylindrical structure with one end closed. It is sleeved on the other end of the discharge connector 21 and is threaded to the connector nut 22 through the external thread provided on the outer wall, so as to protect the discharge connector 21 and the connector nut 22 when the discharge assembly is not in use.

[0037] In practical applications, to ensure the sealing of the internal pipeline of the venting rotary joint, an annular groove is provided on the outer wall of the bottom end of the connecting seat 18. The outer wall of one side of the connecting seat 18 and the wall of the second mounting hole 31 are sealed by a rubber sealing ring 13 and a polytetrafluoroethylene retaining ring 14 set in the annular groove. This combined sealing method is beneficial to improving the sealing pressure. An annular groove is provided on the outer wall of the connecting seat 18 on both sides of the venting through hole. A rubber sealing ring 16 and a polytetrafluoroethylene retaining ring 17 are provided in the annular groove on the front outer wall of the connecting seat 18, and a separate rubber sealing ring is provided in the annular groove on the rear outer wall of the connecting seat 18, so that the outer wall of the connecting seat 18 and the inner wall of the rotary joint 15 are sealed.

[0038] Pressure gauge 11 can be directly installed via a pressure gauge fixing connector threaded into the third mounting hole, preferably using a shock-resistant pressure gauge. When the installation space for pressure gauge 1 is limited, pressure gauge 1 can be first connected to a pressure gauge union 9, with a pressure gauge gasket 10 placed at the connection point to achieve a sealed connection; then, pressure gauge union 9 can be threaded into the pressure gauge fixing connector. By adding connecting parts, the length of the bottom connection part of pressure gauge 11 can be increased, making it easier to install or replace pressure gauge 11 in a smaller space.

[0039] In practical applications, the blowout venting assembly for the cable blowout preventer can be fixed to the housing of any blowout preventer by bolts passing through its four corners, and the connection between the blowout venting assembly and the monitoring pipeline can be achieved by inserting the sealed connecting pipe located at the second communication channel port into the mounting hole opened on the designated pressure monitoring pipeline of the blowout preventer.

[0040] The specific working principle of the blowout preventer (BOP) venting assembly is as follows: The connecting pipe 24 of the BOP venting assembly is sealed and inserted into the monitoring hole opened on the designated pipeline of the BOP. The venting connector 21 is connected to the connection end of the on-site venting pipeline. In the working state, the first valve core 2 of the switching valve is in the normally open state. Since the second connecting channel in the valve body 1 is connected to the third connecting channel 26 through the switching valve, and the third connecting channel 26 is directly connected to the first connecting channel 25, the pressure can be displayed in real time by the pressure gauge 11 when there is gas or liquid in the pipeline to be monitored by the BOP. The pressure sensor 29 connected to the end of the third connecting channel 26 can synchronously send the real-time monitored pressure to the central control room. In actual operation, when the venting assembly can be used to monitor the pressure in real time, if the pressure value is too high and exceeds the safety threshold, the shut-off valve 20 can be opened to achieve effective pressure relief.

Claims

1. A blowout prevention assembly for a cable blowout preventer, characterized in that, The valve body (1) has a first mounting hole (30) and a second mounting hole (31) horizontally opened on the upper and lower parts of one side wall, respectively, and a third mounting hole longitudinally opened on the top of the other side; a first connecting channel (25) connected to the bottom of the third mounting hole is opened horizontally from the bottom of the second mounting hole, a second connecting channel penetrating the back side wall of the valve body (1) is opened horizontally from the bottom side wall of the first mounting hole, and a third connecting channel (26) connected to the first connecting channel (25) is opened longitudinally from the middle of the first mounting hole; a switch valve is installed in the first mounting hole (30) to control the opening and closing of the connection position between the first connecting channel (25) and the third connecting channel (26); the second mounting hole (31) The device is equipped with a rotary joint for venting, which includes a rotary joint (15), a connecting seat (18), and a shut-off valve (20). The bottom end of the connecting seat (18) is inserted and fixed in the second mounting hole (31), and a venting blind hole is opened axially from the center of the bottom end. A venting through hole is opened radially at the top end of the connecting seat (18) and intersects with the venting blind hole. The rotary joint (15) is sleeved on the outside of the top end of the connecting seat (18). An annular groove is opened on its inner wall and intersects with the venting through hole. A connecting head is formed on one side wall of the rotating joint and an axial through hole is opened on the connecting head and intersects with the annular groove. One end of the shut-off valve (20) is connected to the connecting head and the other end is connected to the venting joint (21). A pressure gauge (11) is installed in the third mounting hole.

2. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, The valve body (1) is composed of an integrally formed longitudinal and transverse section, with an L-shaped longitudinal section. The first and second mounting holes are opened on the side wall of the longitudinal section away from the transverse section, so that the switch valve and the blowout rotary joint are arranged vertically at intervals. The third mounting hole is opened on the top surface of the transverse section, so that the pressure gauge (11) is arranged vertically on the top side of the transverse section in a parallel manner with the longitudinal section. A mounting screw hole is opened at each of the two apex corners of the top of the longitudinal section of the valve body (1) and at the symmetrical position of its bottom, so that the valve body (1) can be fixed with bolts passing through the mounting screw holes at the designated position of the blowout preventer.

3. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, The third connecting channel (26) is opened longitudinally and passes through the bottom surface of the valve body (1). A pressure sensor (29) is threadedly connected at the port of the third connecting channel (26) located on the bottom surface of the valve body (1).

4. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, A connecting pipe (24) is fixed at the outer port of the second connecting channel. The other end of the connecting pipe (24) has an annular groove with a built-in rubber sealing ring and a polytetrafluoroethylene retaining ring, so that the connecting pipe (24) is sealed and inserted into the monitoring hole on the designated pipeline of the blowout preventer.

5. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, A disassembly channel (28) is provided horizontally from the bottom of the first mounting hole, which passes through one side wall of the valve body (1). A first plug (12) is threadedly connected to the outer port of the loading and unloading channel (28).

6. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, The switching valve includes a first valve core (2), a valve sleeve (4), and a second valve core (8); the second valve core (8) and the valve sleeve (4) are sequentially inserted into the first mounting hole (30), and the bottom end of the valve sleeve (4) is fixed to the hole wall; the second valve core (8) is a cylindrical structure, and a first annular space is formed between its bottom end and the first mounting hole, and multiple first radial pressure transmission holes communicating with the first annular space are opened on its side wall, so that the second connecting channel communicates with each first radial pressure transmission hole through the first annular space; a second annular space is formed between the top outer wall of the second valve core (8) and the first mounting hole, and multiple second radial pressure transmission holes communicating with the second annular space are opened on its side wall, so that the third connecting channel communicates with each second radial pressure transmission hole through the second annular space; the first valve core (2) is inserted into the valve sleeve (4), its top end is threaded to the valve sleeve (4) and a rotating hole is provided on its end face, and its bottom end is a tapered end that cooperates with the tapered platform on the inner wall of the second valve core (8).

7. The blowout prevention assembly for a cable blowout preventer according to claim 6, characterized in that, The top of the valve sleeve (4) is designed as an external hexagonal end and located outside the valve body (1). A limit plug (6) is provided on the adjacent side of the valve sleeve (4), and it is set in such a way that one side wall is in contact with one side wall of the external hexagonal end of the valve sleeve (4), and is fixed to the valve body (1) by an internal hexagonal screw (5) to achieve the limit fixation of the valve sleeve (4).

8. The blowout prevention assembly for a cable blowout preventer according to claim 6, characterized in that, A lip seal is provided between the second valve core (8) and the valve sleeve (4). Two annular grooves with built-in lip seals (7) are opened at intervals on the outer wall of the middle part of the second valve core (8) to seal the outer wall of the second valve core (8) with the hole wall.

9. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, The other end of the venting connector (21) has an outer annular boss on its outer wall, and a connector nut (22) is fitted on its outer side. One end of the connector nut (22) has an inner annular boss to limit the position between the shut-off valve (20) and the outer annular boss. The inner diameter of the connector nut (22) and the internal thread on its inner wall are adapted to the outer diameter of the connection end of the field venting pipeline and the external thread on its outer wall, respectively. The outer diameter of the venting connector (21) is smaller than the inner diameter of the connection end of the field venting pipeline, so that the connection end of the field venting pipeline is plugged into the venting connector (21) and threadedly fixed to the connector nut (22).

10. The blowout prevention assembly for a cable blowout preventer according to claim 1, characterized in that, An annular groove with a built-in rubber sealing ring and a polytetrafluoroethylene retaining ring is provided on the outer wall of the bottom end of the connector (18), so that a seal is formed between the walls of the second mounting hole (31) of the connector (18); an annular groove is provided on the outer wall of the connector (18) on both sides of the vent hole. A rubber sealing ring and a polytetrafluoroethylene retaining ring are provided in the annular groove on the front side, and a rubber sealing ring is provided in the annular groove on the rear side, so that a seal is formed between the outer wall of the connector (18) and the inner wall of the rotary joint (15).

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