A reliable sealing flat gate valve

Abstract

The utility model relates to a flat gate valve of reliable sealing relates to valve technical field. The transmission pressure chamber and flange bottom surface open transmission pressure hole, be equipped with piston in transmission pressure hole, the valve rod passes through the hole and extends upwards, the annulus between step hole B and valve rod is equipped with sealing packing, and the upper portion of sealing packing is equipped with packing gland, and packing gland is connected with valve seat, and rubber pipe is installed in step hole A. The utility model has the advantages of: transmission pressure structure can realize when pipeline pressure is high, and sealing packing is tight, and does not produce leakage, and the pressure in pipeline is low, or the sealing packing between gate valve and valve rod is in the lax state when closing, guarantees reliable sealing while improving the service life of sealing packing, reduces the opening resistance of flat gate valve.

Description

Technical Field

[0001] This utility model relates to the field of valve technology, and in particular to a reliable flat gate valve. Background Technology

[0002] Flat gate valves are commonly used in engineering and technical fields such as natural gas, petroleum, chemical, environmental protection, urban pipelines, gas pipelines, venting systems, and gas storage devices. Flat gate valves generally use packing seals between the valve stem and the valve seat. After the valve plate rises and opens, it bears the pressure inside the pipeline. The preload applied to the packing seal is fixed. When the pressure inside the pipeline increases, leakage will occur. Excessive preload will cause the packing seal to wear quickly and have a short service life. Utility Model Content

[0003] To address the problem of unreliable sealing in current flat gate valves, this invention provides a flat gate valve with reliable sealing.

[0004] The technical solution provided by this utility model is: a reliably sealed flat gate valve, including a valve body, which is composed of a transverse flow channel and a vertical valve cylinder. Two parallel sealing surfaces are provided in the middle of the flow channel. A valve plate is installed in the sealing surface. The valve plate is divided into a main valve plate and an auxiliary valve plate. A valve stem is provided at the upper part of the main valve plate. A stepped head A with a narrow neck is provided at the lower part of the valve stem. Part of the two half-body pressure caps A are inserted into the narrow neck of the stepped head A, and part of the two half-body pressure caps are connected to the main valve plate by bolts. A valve seat is provided at the upper part of the valve cylinder. A flange is provided at the lower part of the valve seat. The valve cylinder is connected to the flange by bolts and a sealing ring. A threaded nut seat is provided at the upper part of the flange. A threaded rod is provided at the upper part of the valve stem. The threaded rod is connected to the threaded nut seat.

[0005] The flange has a through hole at its center, and a stepped hole B is provided on the upper part of the through hole. A stepped hole A is machined outward from the inner hole of stepped hole B. A pressure transmission chamber is machined outward from the inner hole of stepped hole A. A pressure transmission hole is opened between the pressure transmission chamber and the bottom surface of the flange. A piston is installed in the pressure transmission hole. The valve stem extends upward through the through hole. A sealing packing is provided in the annular space between stepped hole B and the valve stem. A packing gland is provided on the upper part of the sealing packing. The packing gland is threadedly connected to the valve seat. A rubber tube is installed in stepped hole A.

[0006] The piston is connected to the pressure transmission hole through a clearance fit with a sealing ring. The space above the piston is filled with lithium-based grease. A retaining ring is threaded to the bottom of the pressure transmission hole, and the inner diameter of the retaining ring is smaller than the outer diameter of the piston.

[0007] The contact area between the main valve plate and the auxiliary valve plate is an inclined plane. The direction of the inclined plane is as follows: the main valve plate descends, which compresses the two sides of the main valve plate and the auxiliary valve plate, widening their dimensions. A horizontal plate extends from the upper part of the main valve plate to one side of the auxiliary valve plate. A positioning cylinder is fixedly connected to the bottom of the horizontal plate. A stepped head B with a narrow neck is installed inside the positioning cylinder. The lower part of the positioning cylinder is connected to a half-body pressure cap B by bolts. The narrow neck of the stepped head B is inserted into the inner hole of the half-body pressure cap B. The auxiliary valve plate is fixedly connected to the bottom of the stepped head B. A compression spring is provided between the top of the stepped head B and the horizontal plate.

[0008] The valve body has a converter installed on the sealing surface. The two sides of the converter are sealed to the valve body through sealing rings. The inner side of the converter has a surface that can be sealed with the main valve plate and the auxiliary valve plate.

[0009] The outer end faces of the main valve plate and the auxiliary valve plate are machined into raised sealing ring surfaces.

[0010] The beneficial effects of this utility model are as follows: When the flat gate valve is opened, the pressure in the pipeline causes the piston to rise. The piston is responsible for transmitting the pressure without leakage. The pressure is transmitted to the pressure transmission chamber, where lithium-based grease compresses the rubber tube to contract. The rubber tube then compresses the sealing packing to contract. This structure enables the sealing packing to tighten when the pipeline pressure is high, preventing leakage. When the pipeline pressure is low, or when the gate valve is closed, the sealing packing and valve stem are in a loose state. This ensures reliable sealing while improving the service life of the sealing packing and reducing the opening resistance of the flat gate valve. Attached Figure Description

[0011] Appendix Figure 1 This is a schematic diagram of the structure of this utility model;

[0012] Appendix Figure 2 It is attached Figure 1 Enlarged view of point A;

[0013] Appendix Figure 3 It is attached Figure 1 Enlarged view of point B;

[0014] Appendix Figure 4 This is a schematic diagram of the valve body structure;

[0015] Appendix Figure 5 This is a schematic diagram of the valve seat structure;

[0016] Appendix Figure 6 This is a schematic diagram of the main valve plate.

[0017] Appendix Figure 7 This is a structural diagram of another embodiment of the valve body;

[0018] Appendix Figure 8 This is a schematic diagram of the structure of the converter.

[0019] In the diagram, 1-valve body, 101-flow passage, 102-sealing surface, 103-valve cylinder, 2-main valve plate, 201-sealing ring surface, 202-horizontal plate, 3-auxiliary valve plate, 4-valve seat, 401-flange, 402-threaded nut seat, 403-through hole, 404-pressure transmission hole, 405-pressure transmission chamber, 406-step hole A, 407-step hole B, 5-valve stem, 501-screw, 502-step head A, 6-half-body gland A, 7-sealing packing, 8-rubber tube, 9-piston, 10-retaining ring, 11-positioning cylinder, 12-step head B, 13-half-body gland B, 14-conversion body, 15-packing gland. Detailed Implementation

[0020] like Figures 1-8 As shown, a reliable sealed flat gate valve includes a valve body 1, which consists of a transverse flow passage 101 and a vertical valve cylinder 103. The flow passage 101 has two parallel sealing surfaces 102 in the middle. A valve plate is installed in the sealing surface 102. The valve plate is divided into a main valve plate 2 and a secondary valve plate 3. The upper part of the main valve plate 2 is provided with a valve stem 5, and the lower part of the valve stem 5 is provided with a stepped head A502 with a narrow neck. Two half-body glands A6 are partially inserted into the narrow neck of the stepped head A502, and partially connected to the main valve plate 2 by bolts. The upper part of the valve cylinder 103 is provided with a valve seat 4, and the lower part of the valve seat 4 is a flange 401. The valve cylinder 103 is connected to the flange 401 by bolts and a sealing ring. The upper part of the flange 401 is a threaded nut seat 402, and the upper part of the valve stem 5 is a threaded rod 501, which is threadedly connected to the threaded nut seat 402.

[0021] The flange 401 has a through hole 403 at its center. The upper part of the through hole 403 has a stepped hole B407. The inner hole of the stepped hole B407 is machined outward to form a stepped hole A406. The inner hole of the stepped hole A406 is machined outward to form a pressure transmission chamber 405. A pressure transmission hole 404 is opened between the pressure transmission chamber 405 and the bottom surface of the flange 401. A piston 9 is installed in the pressure transmission hole 404. The valve stem 5 extends upward through the through hole 403. A sealing packing 7 is installed in the annular space between the stepped hole B407 and the valve stem 5. A packing gland 15 is installed on the upper part of the sealing packing 7. The packing gland 15 is threaded to the valve seat 4. A rubber tube 8 is installed in the stepped hole A406.

[0022] The piston 9 is connected to the pressure transmission hole 404 through a gap fit of the sealing ring. The space above the piston 9 is filled with lithium-based grease. The bottom of the pressure transmission hole 404 is threaded to the retaining ring 10. The inner diameter of the retaining ring 10 is smaller than the outer diameter of the piston 9.

[0023] When the flat gate valve is opened, the pressure in the pipeline causes the piston 9 to rise. The piston 9 is responsible for transmitting the pressure without leakage. The pressure is transmitted to the pressure transmission chamber 405. The lithium-based grease in the pressure transmission chamber 405 compresses the rubber tube 8 to contract, and the rubber tube 8 compresses the sealing packing 7 to contract. This structure can ensure that when the pipeline pressure is high, the sealing packing 7 is tightened to prevent leakage, and when the pipeline pressure is low or the gate valve is closed, the sealing packing 7 is in a loose state with the valve stem 5. While ensuring reliable sealing, it can also improve the service life of the sealing packing 7 and reduce the opening resistance of the flat gate valve.

[0024] The contact area between the main valve plate 2 and the auxiliary valve plate 3 is an inclined plane. The direction of the inclined plane is as follows: the main valve plate 2 descends, which compresses the two sides of the main valve plate 2 and the auxiliary valve plate 3, widening their dimensions. A horizontal plate 202 extends from the upper part of the main valve plate 2 to one side of the auxiliary valve plate 3. The bottom of the horizontal plate 202 is fixedly connected to the positioning cylinder 11. A stepped head B12 with a narrow neck is installed inside the positioning cylinder 11. The lower part of the positioning cylinder 11 is connected to the half-body pressure cap B13 by bolts. The inner hole of the half-body pressure cap B13 carries the narrow neck of the stepped head B12. The bottom of the stepped head B12 is fixedly connected to the auxiliary valve plate 3. A compression spring is provided between the top of the stepped head B12 and the horizontal plate 202. When the main valve plate 2 rises, the compression spring causes the main valve plate 2 and the auxiliary valve plate 3 to separate, reducing the opening resistance.

[0025] A converter 14 is installed on the sealing surface 102 of the valve body 1. The two sides of the converter 14 are sealed to the valve body 1 through sealing rings. The inner side of the converter 14 is provided with a surface that can be sealed with the main valve plate 2 and the auxiliary valve plate 3. The converter 14 has low processing cost and can be replaced separately when damaged.

[0026] The outer end faces of the main valve plate 2 and the auxiliary valve plate 3 are machined into raised sealing ring surfaces 201 to reduce the amount of precision machining.

Claims

1. A reliably sealed flat gate valve, comprising a valve body (1), characterized in that: The valve body (1) consists of a transverse flow passage (101) and a vertical valve cylinder (103). The flow passage (101) has two parallel sealing surfaces (102) in the middle. A valve plate is installed in the sealing surface (102). The valve plate is divided into a main valve plate (2) and a secondary valve plate (3). The upper part of the main valve plate (2) is provided with a valve stem (5). The lower part of the valve stem (5) is provided with a stepped head A (502) with a narrow neck. The two half-body pressure caps A (6) are partially... The narrow neck of the stepped head A (502) is partially connected to the main valve plate (2) by bolts. The upper part of the valve cylinder (103) is provided with a valve seat (4), and the lower part of the valve seat (4) is a flange (401). The valve cylinder (103) is connected to the flange (401) by bolts and sealing rings. The upper part of the flange (401) is a threaded nut seat (402). The upper part of the valve stem (5) is a threaded rod (501), and the threaded rod (501) is threadedly connected to the threaded nut seat (402). The flange (401) has a through hole (403) at its center. The upper part of the through hole (403) has a stepped hole B (407). The inner hole of the stepped hole B (407) is machined outward to form a stepped hole A (406). The inner hole of the stepped hole A (406) is machined outward to form a pressure transmission chamber (405). A pressure transmission hole (404) is opened between the pressure transmission chamber (405) and the bottom surface of the flange (401). A piston (9) is installed in the pressure transmission hole (404). The valve stem (5) extends upward through the through hole (403). A sealing packing (7) is provided in the annular space between the stepped hole B (407) and the valve stem (5). A packing gland (15) is provided on the upper part of the sealing packing (7). The packing gland (15) is threaded to the valve seat (4). A rubber tube (8) is installed in the stepped hole A (406).

2. The reliably sealed flat gate valve according to claim 1, characterized in that: The piston (9) is connected to the pressure transmission hole (404) through a gap fit of the sealing ring. The space above the piston (9) is filled with lithium-based grease. The bottom of the pressure transmission hole (404) is threaded to the retaining ring (10). The inner hole of the retaining ring (10) is smaller than the outer diameter of the piston (9).

3. A reliably sealed flat gate valve according to claim 1, characterized in that: The contact area between the main valve plate (2) and the auxiliary valve plate (3) is an inclined plane. The direction of the inclined plane is as follows: the main valve plate (2) descends, pressing the main valve plate (2) and the auxiliary valve plate (3) to widen the dimensions on both sides. A horizontal plate (202) extends from the upper part of the main valve plate (2) to the side of the auxiliary valve plate (3). A positioning cylinder (11) is fixedly connected to the bottom of the horizontal plate (202). A stepped head B (12) with a thin neck is installed inside the positioning cylinder (11). A half-body pressure cap B (13) is connected to the lower part of the positioning cylinder (11) by bolts. The inner hole of the half-body pressure cap B (13) carries the thin neck of the stepped head B (12). The auxiliary valve plate (3) is fixedly connected to the bottom of the stepped head B (12). A compression spring is provided between the top of the stepped head B (12) and the horizontal plate (202).

4. A reliably sealed flat gate valve according to claim 1, characterized in that: A converter (14) is installed on the sealing face (102) of the valve body (1). The two sides of the converter (14) are sealed to the valve body (1) through sealing rings. The inner side of the converter (14) is provided with a face that can be sealed with the main valve plate (2) and the auxiliary valve plate (3).

5. A reliably sealed flat gate valve according to claim 1, characterized in that: The outer end faces of the main valve plate (2) and the auxiliary valve plate (3) are machined into raised sealing ring surfaces (201).

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