High-pressure flat gate valve for wellhead

Abstract

The high-pressure flat gate valve comprises a valve body, a left valve seat, a right valve seat, a gate plate, a valve cover and a valve rod, a valve cavity is formed in the valve body, the valve cover is installed at the top of the valve body, the gate plate is arranged in the valve cavity, the left valve seat and the right valve seat are located on the left side and the right side of the gate plate respectively, and a supporting lug is fixedly arranged at the upper end of the valve cover. A totally-closed bearing lubricating mechanism is arranged at the upper end of the valve rod and comprises a bearing seat, a bearing gland and a plurality of bearing sealing rings, a valve rod threaded part is arranged at the upper end of the valve rod and provided with a valve rod nut, and a hand wheel is arranged at the upper end of the valve rod nut. A chain positioning mechanism is arranged between the hand wheel and the support lug; a valve rod protection sleeve is arranged at the top of the valve rod, and the lower end of the valve rod protection sleeve is connected with the upper end of the valve rod nut. According to the technical scheme, the structural design is reasonable, misoperation can be prevented, use is convenient, the sealing performance is good, lubricating oil is not prone to volatilization, and practicability is good.

Description

Technical Field

[0001] This utility model relates to the field of gate valve technology, specifically to a high-pressure flat gate valve for wellhead applications. Background Technology

[0002] High-pressure flat gate valves are widely used in oil and gas wells, water injection wells, and other fields. However, the wellhead medium pressure is high, requiring stringent valve safety standards. Existing flat gate valves mainly consist of a valve body, valve seat, valve cover, gate, valve stem, valve stem nut, handwheel, and bearings. However, existing flat gate valves have an unreasonable structural design. They lack positioning components in the fully open or fully closed positions, making them prone to misoperation. Furthermore, positioning during installation and transportation is cumbersome, and their use is inconvenient. The valve seat is generally designed for only one-way sealing, leading to leakage at the valve body connection and poor sealing performance. Dust easily enters the valve stem mounting hole, and lubricating oil evaporates easily, requiring frequent maintenance and resulting in poor practicality. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a high-pressure flat gate valve for wellheads that has a reasonable structural design, can prevent misoperation, is easy to use, has good sealing performance, does not easily evaporate lubricating oil, and is practical.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a high-pressure flat gate valve for wellheads, comprising a valve body, a left valve seat, a right valve seat, a gate plate, a valve cover, and a valve stem. The valve body contains a valve cavity, the valve cover is mounted on the top of the valve body, the gate plate is disposed within the valve cavity, the left and right valve seats are located on the left and right sides of the gate plate, respectively, a lug is fixedly provided on the upper end of the valve cover, and a fully enclosed bearing lubrication mechanism is provided on the upper end of the valve stem. This fully enclosed bearing lubrication mechanism includes a bearing seat, a bearing cap, and multiple bearing sealing rings. The upper end of the valve stem has a valve stem thread, a valve stem nut is provided on the valve stem thread, a handwheel is provided on the upper end of the valve stem nut, and a chain positioning mechanism is provided between the handwheel and the lug.

[0005] A valve stem protective sleeve is provided at the top of the valve stem, and the lower end of the valve stem protective sleeve is connected to the upper end of the valve stem nut.

[0006] The present invention is further configured such that: the chain positioning mechanism includes a chain and a padlock; the handwheel is provided with a handwheel through hole; the lug is provided with a lug through hole; one end of the chain is connected to the padlock; and the other end of the chain passes through the handwheel through hole and the lug through hole in sequence and is then connected to the padlock.

[0007] The present invention is further configured such that: a first medium channel is provided at the left end of the valve body in the valve cavity, and a second medium channel is provided at the right end of the valve body in the valve cavity; a first valve seat mounting groove is provided at the right end of the first medium channel; the left valve seat is installed in the first valve seat mounting groove; a first O-ring and a second O-ring are provided on the left valve seat, and the first O-ring and the second O-ring are in opposite directions; the left valve seat forms a bidirectional seal through the first O-ring and the second O-ring.

[0008] The present invention is further configured such that: a second valve seat mounting groove is provided at the left end of the second medium channel, the right valve seat is installed in the second valve seat mounting groove, and a third O-ring and a fourth O-ring are provided on the right valve seat, and the third O-ring and the fourth O-ring are in opposite directions, and the right valve seat forms a bidirectional seal through the third O-ring and the fourth O-ring.

[0009] The present invention is further configured such that: the number of bearing sealing rings is set to 5, and the valve stem nut, bearing seat, bearing cover and bearing sealing rings form a closed cavity.

[0010] The present invention is further configured such that: a plurality of thrust bearings are provided inside the closed cavity, and each thrust bearing is sleeved on the valve stem nut.

[0011] The present invention is further configured such that: the valve body is provided with an oil cup mounting through hole in a local position of the closed cavity, a lubricating oil cup is provided in the oil cup mounting through hole, and the inner end of the lubricating oil cup is threadedly connected to the oil cup mounting through hole; and the bearing seat is provided with a lubricating oil through hole aligned with the position of the oil cup mounting through hole.

[0012] The present invention is further configured such that: a locking nut is provided on the bearing cover, the outer surface of the locking nut is provided with an external thread, the upper end of the valve cover is provided with a cover mounting groove, the upper end of the cover mounting groove is provided with an internal thread connection part, the locking nut is threadedly connected to the internal thread connection part, and the lower end face of the locking nut presses against the bearing cover.

[0013] The beneficial effects of this utility model are as follows: Compared with the prior art, this utility model has a reasonable structural design. After the lugs are welded onto the valve cover, the valve can be locked in the fully open or fully closed position when needed through the chain positioning mechanism, preventing accidental operation and improving the safety of the product under high-pressure conditions. The lugs also serve as lifting and positioning lugs during installation and transportation, making them more convenient to use. The central gasket seal between the valve body and the valve cover uses a triangular sealing ring gasket, which has a compact structure and improves high-pressure safety. Both the left and right valve seats can achieve bidirectional valve seat sealing, resulting in good sealing performance between the valve seat and the valve body and reducing leakage.

[0014] It adopts a fully enclosed bearing lubrication mechanism to prevent external contaminants from entering, and the lubricating oil does not easily evaporate, which improves the valve stem transmission performance and lubrication life, reduces the number of maintenance times, and extends the service life of the valve. The bearing cover is designed with a locking nut to prevent the bearing cover from loosening due to long-term valve opening and closing movements, which improves the reliability of the valve under high-pressure conditions and makes it practical.

[0015] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0017] Figure 2 This is a partial structural schematic diagram of an embodiment of the present utility model;

[0018] Figure 3 This is a partial enlarged view of an embodiment of the present utility model. Detailed Implementation

[0019] In the description of this embodiment, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] See Figures 1 to 3 This utility model discloses a high-pressure flat gate valve for wellheads, comprising a valve body 1, a left valve seat 2, a right valve seat 3, a gate plate 4, a valve cover 5, and a valve stem 6. The valve body 1 has a valve cavity 11, the valve cover 5 is installed on the top of the valve body 1, the gate plate 4 is disposed in the valve cavity 11, the left valve seat 2 and the right valve seat 3 are respectively located on the left and right sides of the gate plate 4, a support lug 7 is fixedly provided on the upper end of the valve cover 5, and a fully enclosed bearing lubrication mechanism is provided on the upper end of the valve stem 6. The fully enclosed bearing lubrication mechanism includes a bearing seat 81, a bearing cap 82, and multiple bearing sealing rings 83. A valve stem threaded portion 61 is provided on the upper end of the valve stem 6, and a valve stem nut 9 is provided on the valve stem threaded portion 61. A handwheel 10 is provided on the upper end of the valve stem nut 9, and a chain positioning mechanism is provided between the handwheel 10 and the support lug 7.

[0021] A valve stem protective sleeve 12 is provided on the top of the valve stem 6, and the lower end of the valve stem protective sleeve 12 is connected to the upper end of the valve stem nut 9.

[0022] Preferably, two lugs 7 are provided, symmetrically arranged, and welded to the upper ends of the left and right sides of the valve cover 3, respectively. The upper end of the valve body 1 is locked to the valve cover 5 with bolts. The upper end of the valve stem nut 9 is fixed to the handwheel 10 by welding or by bolt connection.

[0023] To make the structural design of this utility model more reasonable, as a preferred embodiment, the chain positioning mechanism includes a chain 13 and a padlock 14. The handwheel 10 is provided with a handwheel through hole, and the lug 7 is provided with a lug through hole. One end of the chain 13 is connected to the padlock 14, and the other end of the chain 13 passes through the handwheel through hole and the lug through hole in sequence before being connected to the padlock 14.

[0024] The valve body 1 is provided with a first medium channel 15 at the left end of the valve cavity 11, and the valve body 111 is provided with a second medium channel 16 at the right end of the valve cavity. The first medium channel 15 is provided with a first valve seat mounting groove at the right end. The left valve seat 2 is installed in the first valve seat mounting groove. The left valve seat 2 is provided with a first O-ring 17 and a second O-ring 18, and the first O-ring 17 and the second O-ring 18 are in opposite directions. The left valve seat 2 forms a bidirectional seal through the first O-ring 17 and the second O-ring 18.

[0025] The second medium channel 16 is provided with a second valve seat mounting groove at its left end. The right valve seat 3 is installed in the second valve seat mounting groove. The right valve seat 3 is provided with a third O-ring 19 and a fourth O-ring 20, and the third O-ring 19 and the fourth O-ring 20 are in opposite directions. The right valve seat 3 forms a bidirectional seal through the third O-ring 19 and the fourth O-ring 20.

[0026] Preferably, one of the first O-ring 17 and the second O-ring 18 is a piston-type O-ring and the other is a spring-type O-ring, which makes the left valve seat have good sealing performance and is not prone to leakage; one of the third O-ring 19 and the fourth O-ring 20 is a piston-type O-ring and the other is a spring-type O-ring, which makes the right valve seat have good sealing performance and is not prone to leakage.

[0027] The upper end of the gate plate 4 is fixed to the lower end of the valve stem 6 by a key or by bolts. The gate plate 4 moves up and down by the lifting and lowering of the valve stem 6, so that the gate plate 4 blocks the valve cavity 11 from the first medium channel 15 and the second medium channel 16 or connects the valve cavity 11 with the first medium channel 15 and the second medium channel 16.

[0028] Preferably, there are 5 bearing seal rings 83, and the valve stem nut 9, bearing seat 81, bearing cap 82 and bearing seal rings 83 form a closed cavity.

[0029] The enclosed cavity is provided with a plurality of thrust bearings 21, and each thrust bearing is sleeved on the valve stem nut 9. Preferably, this embodiment provides a total of 2 thrust bearings. The valve stem nut 9 is integrally provided with a positioning protrusion 91 at the position of the valve stem nut 9 in the enclosed cavity. One thrust bearing is located above the positioning protrusion 91, and the other thrust bearing is located below the positioning protrusion 91.

[0030] The valve body 1 has an oil cup mounting through hole located in a partial position of the closed cavity. A lubricating oil cup 22 is installed inside the oil cup mounting through hole, and the inner end of the lubricating oil cup 22 is threadedly connected to the oil cup mounting through hole. The bearing seat 81 has a lubricating oil through hole aligned with the position of the oil cup mounting through hole. Preferably, a return spring and a ball are installed inside the lubricating oil cup 22. The ball is pressed against the inner end of the inlet of the lubricating oil cup by the elastic force of the return spring.

[0031] The bearing cap 82 is provided with a locking nut 23, and the outer surface of the locking nut 23 is provided with an external thread. The upper end of the valve cover 5 is provided with a cap mounting groove, and the upper end of the cap mounting groove is provided with an internal thread connection part. The locking nut 23 is threadedly connected to the internal thread connection part, and the lower end face of the locking nut 23 presses against the bearing cap 82.

[0032] In this embodiment, the valve cover 5 is designed as an integral piece, and a triangular sealing ring gasket 24 is provided between the valve cover 5 and the valve body 1. In this technical solution, the intermediate gasket seal adopts a triangular sealing ring gasket, which has a compact structure and improves high pressure safety.

[0033] In practical applications, after welding the lugs 7 onto the valve cover 5, the valve can be locked in the fully open or fully closed position when needed via a chain positioning mechanism, preventing accidental operation and improving the safety of the product under high-pressure conditions. The lugs 7 also serve a lifting and positioning function, acting as lifting lugs during installation and handling. The rational structural design makes it more convenient to use.

[0034] The intermediate gasket between valve body 1 and valve cover 5 adopts a triangular sealing ring gasket, which has a compact structure and improves high pressure safety.

[0035] Both the left valve seat 2 and the right valve seat 3 can achieve bidirectional valve seat sealing, resulting in good sealing performance between the valve seat and the valve body and making leakage less likely.

[0036] This embodiment uses a fully enclosed bearing lubrication mechanism to prevent external contaminants from entering, and the lubricating oil is not easily volatile, which improves the valve stem transmission performance and lubrication life, reduces the number of maintenance times, and extends the valve's service life.

[0037] The bearing cover 82 is designed with a locking nut 23 to prevent the bearing cover from loosening due to long-term valve opening and closing movements.

[0038] The valve cover 5 features an integrated design, which is simpler than conventional valve structures, reduces many structural elements, improves the reliability of the valve under high-pressure conditions, and offers good practicality. The above description of the specific embodiments of this utility model is only for further illustration and should not be construed as limiting the scope of protection of this utility model. Any non-essential improvements and adjustments made to this utility model by those skilled in the art based on the above description fall within the scope of protection of this utility model.

Claims

1. A high-pressure flat gate valve for wellheads, comprising a valve body (1), a left valve seat (2), a right valve seat (3), a gate (4), a valve cover (5), and a valve stem (6), wherein a valve cavity (11) is provided inside the valve body (1), the valve cover (5) is installed on the top of the valve body (1), the gate (4) is disposed inside the valve cavity (11), and the left valve seat (2) and the right valve seat (3) are respectively located on the left and right sides of the gate (4), characterized in that: The valve cover (5) is fixedly provided with a lug (7) at the upper end, and the valve stem (6) is provided with a fully enclosed bearing lubrication mechanism at the upper end. The fully enclosed bearing lubrication mechanism includes a bearing seat (81), a bearing cap (82) and multiple bearing seals (83). The valve stem (6) is provided with a valve stem thread (61) at the upper end, and a valve stem nut (9) is provided on the valve stem thread (61). A handwheel (10) is provided on the upper end of the valve stem nut (9), and a chain positioning mechanism is provided between the handwheel (10) and the lug (7). The valve stem (6) is provided with a valve stem protective sleeve (12) at the top, and the lower end of the valve stem protective sleeve (12) is connected to the upper end of the valve stem nut (9).

2. The high-pressure flat gate valve for wellheads according to claim 1, characterized in that: The chain positioning mechanism includes a chain (13) and a padlock (14). The handwheel (10) is provided with a handwheel through hole, and the lug (7) is provided with a lug through hole. One end of the chain (13) is connected to the padlock (14), and the other end of the chain (13) passes through the handwheel through hole and the lug through hole in sequence and is then connected to the padlock (14).

3. A high-pressure flat gate valve for wellheads according to claim 2, characterized in that: The valve body (1) is provided with a first medium channel (15) at the left end of the valve cavity (11), and the valve body (111) is provided with a second medium channel (16) at the right end of the valve cavity. The first medium channel (15) is provided with a first valve seat mounting groove at the right end. The left valve seat (2) is installed in the first valve seat mounting groove. The left valve seat (2) is provided with a first O-ring (17) and a second O-ring (18), and the first O-ring (17) and the second O-ring (18) are in opposite directions. The left valve seat (2) forms a bidirectional seal through the first O-ring (17) and the second O-ring (18).

4. A high-pressure flat gate valve for wellheads according to claim 3, characterized in that: The second medium channel (16) is provided with a second valve seat mounting groove at the left end. The right valve seat (3) is installed in the second valve seat mounting groove. The right valve seat (3) is provided with a third O-ring (19) and a fourth O-ring (20). The third O-ring (19) and the fourth O-ring (20) are in opposite directions. The right valve seat (3) forms a bidirectional seal through the third O-ring (19) and the fourth O-ring (20).

5. A high-pressure flat gate valve for wellheads according to claims 1 to 4, characterized in that: The number of bearing seals (83) is set to 5, and the valve stem nut (9), bearing seat (81), bearing cap (82) and bearing seals (83) form a closed cavity.

6. A high-pressure flat gate valve for wellheads according to claim 5, characterized in that: The enclosed cavity is provided with several thrust bearings (21), and each thrust bearing is sleeved on the valve stem nut (9).

7. A high-pressure flat gate valve for wellheads according to claim 6, characterized in that: The valve body (1) has an oil cup mounting through hole located in a partial position of the closed cavity. A lubricating oil cup (22) is provided in the oil cup mounting through hole, and the inner end of the lubricating oil cup (22) is threadedly connected to the oil cup mounting through hole. The bearing seat (81) has a lubricating oil through hole aligned with the position of the oil cup mounting through hole.

8. A high-pressure flat gate valve for wellheads according to claim 7, characterized in that: The bearing cap (82) is provided with a locking nut (23), and the outer surface of the locking nut (23) is provided with an external thread. The upper end of the valve cover (5) is provided with a cap mounting groove, and the upper end of the cap mounting groove is provided with an internal thread connection part. The locking nut (23) is threadedly connected to the internal thread connection part, and the lower end face of the locking nut (23) presses against the bearing cap (82).

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