Self-decompression imported sealed double disc gate valve

Abstract

The present invention relates to a self-depressurizing inlet sealed double-disc gate valve, comprising a valve body and a valve seat below the valve body, a valve stem is arranged in the valve body, a conical wedge block is arranged below the valve stem, the conical surface of the wedge block gradually increases from bottom to top, the valve core is provided with expansion blocks on both sides of the wedge block, the valve stem is connected to a sealing seat, the sealing seat is provided with a through hole penetrating the sealing seat, a pressure relief rod is placed in the through hole, the pressure relief rod comprises a rod body and a rod head, the rod body is sleeved with a pressure relief piston, the through hole is provided with a pressure relief hole retaining ring on one side of the pressure relief piston, and the rod body is sleeved with a butterfly spring and a spring. The present invention has the advantages of achieving medium inlet sealing and self-depressurization of the medium in the valve cavity when opening.

Description

Technical Field

[0001] The invention relates to the technical field of gate valves, and in particular to a self-depressurizing inlet sealed double-disc gate valve. Background Art

[0002] Generally, the parallel double-disc gate valve is a double fixed seat gate valve. First, due to the excellent sealing performance on both sides of the valve, the medium entering the valve cavity will be sealed in it. Under the action of external heat, the temperature of the medium in the cavity will rise, and the medium blocked in the cavity will gradually change from cold to hot, and the liquid may vaporize. The volume expands rapidly. Since the volume of the cavity cannot be increased, the pressure in the valve cavity rises sharply, affecting the normal opening of the valve. Second, the fixed seat double-disc gate valve mainly relies on the back pressure of the sealing disc for outlet sealing. If the pressure at the inlet end of the medium is too large and exceeds the stiffness of the inlet sealing disc, the medium inlet cannot be sealed, and the inlet sealing working condition requirements cannot be met. Summary of the invention

[0003] In view of the deficiencies in the prior art, the object of the present invention is to provide a self-depressurizing inlet sealed double-disc gate valve, which has the advantages of achieving medium inlet sealing and automatic pressure relief when the medium in the valve cavity is opened.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a self-pressure-relieving inlet sealed double-disc gate valve, comprising a valve body and a valve seat below the valve body, a valve stem is arranged in the valve body, a conical wedge block is arranged below the valve stem, the area of ​​the conical surface of the wedge block gradually increases from bottom to top, the valve seat is provided with expansion blocks on both sides of the wedge block, the valve stem is connected to a sealing seat, the sealing seat is provided with a pressure relief port penetrating the sealing seat, a pressure relief rod is placed in the pressure relief port, the sealing surface of the pressure relief rod is connected to the sealing surface of the pressure relief piston, a pressure relief hole retaining ring is arranged on one side of the pressure relief piston in the pressure relief port, and the rod body of the pressure relief rod is sleeved with an adjusting disc spring and a pressure relief spring.

[0005] By adopting the above technical solution, the valve stem moves upward, the valve stem will drive the wedge block to move upward, and the two expansion blocks will shrink toward the middle. Initially, the pressure relief rod and the pressure relief piston will be pushed toward the middle cavity together. When the pressure relief piston hits the retaining ring in the pressure relief hole, the pressure relief piston stops moving, and as the wedge block continues to move upward, the expansion block continues to shrink toward the middle. Under the action of the pressure relief spring, the pressure relief rod disengages from the sealing surface of the pressure relief piston, and the medium in the middle cavity of the valve body is depressurized to the upstream and downstream of the valve through the pressure relief hole until the valve is fully opened and the actuator stops.

[0006] The present invention is further configured as follows: a channel is provided in the valve body, the two ends of the sealing seat facing the channel are integrally connected with blind holes, the sealing seat is clamped with a sealing disk through the two blind holes, and a through hole penetrating the sealing disk is provided in the middle of the sealing disk.

[0007] By adopting the above technical solution, first, two parts are designed on the valve gate, one is a sealing seat and a sealing disc, and the pressure-bearing area of ​​the sealing disc is larger than the sealing surface area. A through hole is designed in the middle of the sealing disc, which allows the medium to enter the back of the sealing disc when the valve is closed, so that the sealing disc generates back pressure. The back pressure force increases the sealing force between the sealing disc and the valve seat sealing surface, and realizes the upstream medium inlet sealing. Second, when the valve is closed, part of the medium will accumulate in the valve cavity. When the external temperature rises, the medium in the cavity expands, and the expansion and vaporization of the medium increases the pressure in the cavity. When the valve is opened, the high-pressure medium in the cavity will first be depressurized through the pressure relief hole. When the pressure in the cavity is released to normal pressure, the valve opens normally.

[0008] The present invention is further configured as follows: an actuator for driving the valve stem to move up and down is arranged above the valve body.

[0009] By adopting the above technical solution, the actuator allows the valve stem to move up and down.

[0010] The present invention is further configured as follows: a valve cover is arranged above the valve body.

[0011] By adopting the above technical solution, the valve cover and the valve body are matched, and a valve stem is arranged in the valve cover and the valve body.

[0012] The present invention is further configured such that a sealing ring is provided at the connection between the sealing disk and the sealing seat.

[0013] By adopting the above technical solution, the sealing ring increases the sealing performance between the sealing disk and the sealing seat.

[0014] The present invention is further configured such that: a sealing ring is provided on the outer circle of the pressure relief piston.

[0015] By adopting the above technical solution, the sealing ring increases the sealing performance between the pressure relief piston and the through hole.

[0016] In summary, the present invention has the following beneficial effects:

[0017] When the valve stem moves upward, the valve stem will drive the wedge block to move upward, and the two expansion blocks will shrink toward the middle. Initially, the leakage-stopping rod and the pressure relief piston will be pushed toward the middle cavity together. When the pressure relief piston hits the retaining ring in the pressure relief hole, the pressure relief piston stops moving, and as the wedge block continues to move upward, the expansion block continues to shrink toward the middle, and the sealing surface of the pressure relief rod is separated from the sealing surface of the pressure relief piston. The high-pressure medium in the middle cavity is relieved upstream and downstream until the valve is fully opened and the actuator stops. The present invention has the advantages of realizing the sealing of the medium inlet and automatic pressure relief when the medium in the valve middle cavity is opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment;

[0019] Figure 2 for Figure 1 A partial enlarged view of the middle A area;

[0020] Figure 3 for Figure 1 A partial enlarged view of area B.

[0021] Figure numerals: 1. actuator; 2. valve cover; 3. valve stem; 4. valve body; 5. sealing seat; 6. sealing disk sealing ring; 7. sealing disk; 8. wedge block; 9. liquid inlet hole; 10. valve channel; 11. expansion block; 12. valve seat; 13. retaining ring for pressure relief valve hole; 14. sealing ring of pressure relief piston; 15. pressure relief piston; 16. sealing surface of pressure relief rod; 17. pressure relief rod; 18. pressure relief hole 19. pressure relief spring; 20. adjusting disc spring; 21. pressure relief port. DETAILED DESCRIPTION

[0022] The present invention will be further described with reference to the accompanying drawings.

[0023] A self-relieving inlet sealed double-disc gate valve, such as Figure 1-Figure 3 As shown, it includes a valve body 4 and a valve seat 12 located below the valve body 4, a valve stem 3 is arranged in the valve body 4, a conical wedge block 8 is arranged below the valve stem 3, the conical surface area of ​​the wedge block 8 gradually increases from bottom to top, the valve seat 12 is provided with expansion blocks 11 located on both sides of the wedge block 8, the valve stem 3 is connected to a sealing seat 5, the sealing seat 5 is provided with a pressure relief port 21 penetrating the sealing seat 5, a pressure relief rod 17 is placed in the pressure relief port 21, the sealing surface 16 of the pressure relief rod 17 is connected to the sealing surface of the pressure relief piston 15, a pressure relief hole retaining ring 13 located on one side of the pressure relief piston 15 is arranged in the pressure relief port 21, and the rod body of the pressure relief rod 17 is sleeved with an adjusting disc spring 20 and a pressure relief spring 19.

[0024] The sealing seat 5 is provided with a pressure relief hole 18 on the other side of the pressure relief rod 17 .

[0025] The valve body 4 is provided with a channel 10, and the two ends of the sealing seat 5 facing the channel 10 are integrally connected with two blind holes. The sealing seat 5 is clamped with a sealing disk 7 through the two blind holes, and a through hole 9 penetrating the sealing disk 7 is provided in the middle of the sealing disk 7.

[0026] An actuator 1 for driving the valve stem 3 to move up and down is arranged above the valve body 4 .

[0027] A valve cover 2 is arranged above the valve body 4 .

[0028] A sealing disk sealing ring 6 is provided at the connection between the sealing disk 7 and the sealing seat 5 .

[0029] A pressure relief piston sealing ring 14 is disposed on the side of the pressure relief piston 15 .

[0030] Working process:

[0031] When the valve is opened: the actuator 1 is started, and the valve stem 3 drives the wedge block 8 to move upward first. Since the cone surface of the wedge block 8 is larger at the top and smaller at the bottom, when the wedge block 8 moves upward, the expansion blocks 11 on both sides will shrink toward the middle. Initially, the pressure relief rod 17 and the pressure relief piston 15 will be pushed toward the middle cavity together. When the pressure relief piston 15 hits the pressure relief hole retaining ring 13, the pressure relief piston 15 stops moving, and as the wedge block 8 continues to move upward, the expansion block 11 continues to shrink toward the middle, and the sealing surface 16 of the pressure relief rod 17 disengages from the sealing surface of the pressure relief piston 15. The medium is depressurized to the upstream and downstream of the valve through the through hole 9, and the back pressure of the sealing disk 7 decreases accordingly, and the sealing force on the inlet sealing surface also decreases accordingly. During the opening process, the friction force on the sealing surface also decreases, and the opening force also decreases accordingly, until the valve is fully opened and the actuator 1 stops working.

[0032] When the valve is closed: the actuator 1 is started, and the valve stem 3 drives the wedge block 8 to move downward first. Since the cone surface of the wedge block 8 is large at the top and small at the bottom, when the wedge block 8 moves downward, the expansion blocks 11 on both sides are pushed toward the upstream and downstream pipelines. At the same time, the pressure relief rod 17 is pressed toward the pressure relief piston 15 by the expansion block 11, and the pressure relief piston 15 is combined with the sealing surface 16 of the pressure relief rod 17 to block the upstream medium. The sealing seat 5 and the sealing disk 7 are pushed toward the inlet valve seat 12, that is, the upstream and downstream pipeline direction, by the expansion block 11. The sealing surface of the sealing disk 7 is combined with the sealing surface of the valve seat 12. At the same time, the upstream medium enters the back of the sealing disk 7, causing the sealing disk 7 to generate back pressure, and the back pressure acts on the sealing surface, thereby increasing the sealing force between the sealing disk 7 and the valve seat 12, and realizing the valve inlet sealing until the valve is fully closed, and the actuator 1 stops working.

[0033] Working principle: 1. Two parts are designed on the valve gate, one is the sealing seat 5 and the other is the sealing disc 7. The back pressure bearing area of ​​the sealing disc 7 is larger than the sealing surface area. A through hole 9 is designed in the middle of the sealing disc 7. When the valve is closed, the medium can enter the back of the sealing disc 7 to generate back pressure on the sealing disc 7. The back pressure force increases the sealing force on the sealing surface between the sealing disc 7 and the valve seat 12, thus achieving the sealing of the upstream medium inlet. 2. When the valve is closed, part of the medium will accumulate in the middle cavity of the valve. When the external temperature rises, the medium in the middle cavity expands, and the expansion and vaporization of the medium increases the pressure in the middle cavity. When opening, the valve can be opened normally after the pressure is released first.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the design concept of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-depressurizing inlet sealed double-disc gate valve, comprising a valve body (4) and a valve seat (12) located below the valve body (4), wherein a valve stem (3) is arranged in the valve body (4), and characterized in that: A conical wedge block (8) is arranged below the valve stem (3), and the area of ​​the conical surface of the wedge block (8) gradually increases from bottom to top. The valve seat (12) is provided with expansion blocks (11) located on both sides of the wedge block (8). The valve stem (3) is connected to a sealing seat (5), and the sealing seat (5) is provided with a pressure relief port (21) penetrating the sealing seat (5). A pressure relief rod (17) is placed in the pressure relief port (21), and the sealing surface (16) of the pressure relief rod (17) is in contact with the sealing surface (16) of the pressure relief piston (15). The pressure relief port (21) is provided with a pressure relief hole retaining ring (13) on one side of the pressure relief piston (15); the rod body of the pressure relief rod (17) is sleeved with an adjusting disc spring (20) and a pressure relief spring (19); a channel (10) is provided in the valve body (4); a blind hole is designed on the side of the sealing seat (5) facing the channel (10); the two sealing seats (5) are connected with a sealing disk (7) through two blind holes; and a through hole (9) penetrating the sealing disk (7) is provided in the middle of the sealing disk (7).

2. A self-depressurizing inlet sealed double-disc gate valve according to claim 1, characterized in that: An actuator (1) for driving the valve stem (3) to move up and down is arranged above the valve body (4).

3. A self-depressurizing inlet sealed double-disc gate valve according to claim 1, characterized in that: A valve cover (2) is arranged above the valve body (4).

4. A self-depressurizing inlet sealed double-disc gate valve according to claim 1, characterized in that: A sealing disk sealing ring (6) is provided at the connection between the sealing disk (7) and the sealing seat (5).

5. The self-depressurizing inlet sealed double-disc gate valve according to claim 1, characterized in that: The outer circle of the pressure relief piston (15) is provided with a sealing ring (14).

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