Pilot-operated gate valve

Abstract

The utility model relates to a pilot-operated gate valve which comprises a valve body, a gate plate, a pilot-operated block and a valve cover. A balance cavity is formed in the upper end of the valve body, a valve plate groove is formed in the valve body of the balance cavity, the flashboard is slidably installed in the valve plate groove, a connecting groove is formed in the upper end of the flashboard, and a flow guide groove is formed in the lower end of the flashboard. A balance channel communicated with the flow guide groove is formed in one side of the gate plate, and a pressure relief channel is formed in the other side of the gate plate. The lower end of the connecting groove is communicated with the pressure relief channel through a stepped pilot hole; the pilot block is slidably mounted in the pilot hole. The spring is utilized to enable the pilot block and the valve rod to form a linkage and split type pilot structure, the service life is long, and the reliability is high; pressure of a medium in the balance cavity and pressure of a medium in the runner hole are automatically communicated, and pressure building of the middle cavity is avoided without external force intervention; when the gate valve is opened and the valve rod moves upwards, the spring resets, the pilot block ascends accordingly, pressure on two sides of the gate plate is balanced, and opening is easy.

Description

Technical Field

[0001] This utility model belongs to the field of valve technology and relates to a pilot-operated gate valve. Background Technology

[0002] Gate valves, as pipeline fluid shut-off valves, are an indispensable and important component in various large, medium, and small projects, including petrochemical, coal chemical, steel smelting, and public works. They account for a high proportion of total valve applications and have enormous market potential. With continuous technological advancements, control gate valves are gradually replacing manual gate valves to improve the automation level of equipment. Currently, most market solutions are based on the basic structure of manual gate valves, with pneumatic or electric drive devices added to achieve control gate valve retrofitting, offering relatively high cost-effectiveness. However, these products often encounter problems when applied to high-temperature and high-pressure conditions. Differences in temperature rise before and after the valve, and variations in material thermal expansion, can lead to valve jamming or seizing. Additionally, pressure buildup in the valve cavity after closure can prevent the valve from opening properly. Existing products generally address the pressure buildup problem through internal pressure relief holes or external bypass pipelines, but these solutions are often incomplete or require manual intervention. There is a need for a pilot-operated internal structure that can automatically release the pressure in the middle cavity the instant the valve is opened. The existing pilot-operated gate valves generally have a small valve core at the lower end of the valve stem. When closed, it cuts off the pressure in the middle cavity with the inner hole of the gate. When opened, it can release the pressure in the middle cavity first. However, due to limitations in design, manufacturing precision and actual application conditions, the sealing reliability is often not high, internal leakage is prone to occur, and the safe service life cannot be guaranteed. There is an urgent need for a pilot-operated gate valve that can provide a reliable seal and has a long service life. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this utility model provides a pilot-operated gate valve.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0005] A pilot-operated gate valve, comprising:

[0006] The valve body has a balance chamber at its upper end, and a valve plate groove is provided on the valve body of the balance chamber; flow channel holes are respectively provided on the valve body on both sides of the lower end of the balance chamber.

[0007] A gate is slidably installed in a valve plate groove. The upper end of the gate has a connecting groove, and the lower end of the gate has a guide groove. One side of the gate has a balance channel connected to the guide groove, and the other side of the gate has a pressure relief channel. The lower end of the connecting groove is connected to the pressure relief channel by a stepped pilot hole.

[0008] A pilot block is slidably installed in a pilot hole. The lower end of the pilot block is provided with a sealing round head that can cooperate with the pilot hole. The upper end of the pilot block is provided with a top block, and a spring is provided between the top block and the inner boss of the pilot hole.

[0009] The valve cover is fixedly installed on the upper end of the balance chamber. The valve cover is provided with a stuffing box that can cooperate with the balance chamber. A valve stem is provided in the middle of the stuffing box, and a connecting rod is provided at the lower end of the valve stem. The connecting rod can slide up and down in the connecting groove.

[0010] Preferably, a sealing packing is provided between the stuffing box and the valve stem, and a packing pressure plate for pressing the sealing packing is provided on the valve cover, with a packing gland provided between the packing pressure plate and the sealing packing.

[0011] Preferably, the packing pressure plate is connected to the packing box using a first connector.

[0012] Preferably, the valve cover is connected to the valve body using a second connector.

[0013] Preferably, the stuffing box is connected to the valve cover using a third connector.

[0014] Preferably, a sealing ring is provided between the stuffing box and the inner wall of the balance chamber.

[0015] Preferably, the upper end of the balancing cavity is provided with a fixing groove, and a four-ring for fixing the sealing ring is provided in the fixing groove, and a washer is provided between the four-ring and the sealing ring.

[0016] Preferably, the valve plate groove is provided with wear-resistant sealing surfaces on both sides that can cooperate with the gate.

[0017] Preferably, the inner boss and the sealing head are provided with an inclined sealing surface at the mating point.

[0018] Compared with the prior art, this utility model has the following advantages:

[0019] This invention utilizes a spring to link the pilot block and valve stem, featuring a split pilot structure that offers long service life and high reliability. The pressure of the medium in the balance chamber and the medium in the flow channel orifice is automatically connected, eliminating the need for external force and preventing pressure buildup in the middle chamber. At the moment the valve stem moves upward when the gate valve opens, the spring resets, causing the pilot block to rise accordingly, balancing the pressure on both sides of the gate and facilitating easy opening. A wear-resistant sealing surface is provided between the gate and the valve body, increasing service life and improving sealing performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] Figure 2 for Figure 1Enlarged view of point A in the image.

[0022] Figure 3 This is a schematic diagram of the valve body structure of this utility model.

[0023] In the diagram: 1. Valve body; 2. Balance chamber; 3. Valve plate groove; 4. Flow channel hole; 5. Connecting groove; 6. Guide groove; 7. Balance channel; 8. Pressure relief channel; 9. Pilot hole; 10. Pilot block; 11. Sealing head; 12. Top block; 13. Inner boss; 14. Spring; 15. Valve cover; 16. Packing box; 17. Valve stem; 18. Connecting rod; 19. Sealing packing; 20. Packing pressure plate; 21. Packing gland; 22. First connecting piece; 23. Second connecting piece; 24. Third connecting piece; 25. Sealing ring; 26. Fixing groove; 27. Four-ring; 28. Washer; 29. ​​Wear-resistant sealing surface; 30. Gate; 31. Inclined sealing surface. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0025] This embodiment proposes a pilot-operated gate valve, including a valve body 1, a gate 30, a pilot block 10, and a valve cover 15;

[0026] like Figures 1-3 As shown, a balance chamber 2 is provided at the upper end of the valve body 1, and a valve plate groove 3 is provided on the valve body 1 of the balance chamber 2; flow channel holes 4 are respectively provided on the valve body 1 on both sides of the lower end of the balance chamber 2.

[0027] The gate 30 is slidably installed in the valve plate groove 3. The gate 30 can move up and down in the valve plate groove 3. When the gate 30 is at the lowest end, it can completely close the two flow channel holes 4.

[0028] The upper end of the gate plate 30 is provided with a connecting groove 5, which is a T-shaped groove, so that the connecting rod 18 can be easily installed in the connecting groove 5;

[0029] A flow guide groove 6 is provided at the lower end of the gate 30; a balance channel 7 connected to the flow guide groove 6 is provided on one side of the gate 30, and a pressure relief channel 8 is provided on the other side of the gate 30; when the gate 30 disconnects the flow channel hole 4, the fluid can enter the flow guide groove 6 through the balance channel 7, and then the fluid can enter the balance chamber 2 through the flow guide groove 6 and the valve plate groove 3.

[0030] The lower end of the connecting groove 5 is connected to the pressure relief channel 8 via a stepped pilot hole 9.

[0031] The pilot block 10 is slidably installed in the pilot hole 9. The lower end of the pilot block 10 is provided with a sealing round head 11 that can cooperate with the inner boss 13 of the pilot hole 9. The upper end of the pilot block 10 is provided with a top block 12. A spring 14 is provided between the top block 12 and the inner boss 13 of the pilot hole 9. The spring 14 gives the pilot block 10 an upward force.

[0032] After the sealing head 11 leaves the inner boss 13, the fluid inside the balance chamber 2 can enter the pressure relief channel 8 through the connecting groove 5 and the pilot hole 9 and then be discharged from the flow channel hole 4.

[0033] The valve cover 15 is fixedly installed on the upper end of the balance chamber 2. The valve cover 15 is provided with a stuffing box 16 that can cooperate with the balance chamber 2. The middle part of the stuffing box 16 is provided with a valve stem 17. The lower end of the valve stem 17 is provided with a connecting rod 18. The connecting rod 18 can slide up and down in the connecting groove 5.

[0034] Furthermore, a sealing packing 19 is provided between the stuffing box 16 and the valve stem 17, and a packing pressure plate 20 for pressing the sealing packing 19 is provided on the valve cover 15. A packing gland 21 is provided between the packing pressure plate 20 and the sealing packing 19. The sealing packing 19 ensures that there is no leakage between the valve stem 17 and the valve body 1.

[0035] Furthermore, the packing pressure plate 20 is connected to the packing box 16 by a first connecting member 22, which is a connecting bolt, to facilitate installation and maintenance.

[0036] Furthermore, the valve cover 15 is connected to the valve body 1 by a second connector 23, which is a connecting bolt, to facilitate installation and maintenance.

[0037] Furthermore, the stuffing box 16 is connected to the valve cover 15 by a third connector 24, which is a connecting bolt, to facilitate installation and maintenance.

[0038] Furthermore, a sealing ring 25 is provided between the stuffing box 16 and the inner wall of the balance chamber 2 to prevent leakage between the stuffing box 16 and the valve body 1.

[0039] Furthermore, a fixing groove 26 is provided at the upper end of the balancing cavity 2, and a four-open ring 27 for fixing the sealing ring 25 is provided in the fixing groove 26. A washer 28 is provided between the four-open ring 27 and the sealing ring 25. The four-open ring 27 is easy to assemble.

[0040] Furthermore, the valve plate groove 3 is provided with wear-resistant sealing surfaces 29 on both sides that can cooperate with the gate 30, and the wear-resistant sealing surfaces 29 make the valve have a longer service life.

[0041] Furthermore, an inclined sealing surface 31 is provided at the mating point between the inner boss 13 and the sealing round head 11, which makes the sealing effect of the pilot hole 9 better.

[0042] Working principle: This utility model adds a pilot structure to the upper end of the gate 30. The pilot block 10 can be linked with the valve stem 17 through the spring 14. When the valve stem 17 moves upward, the spring 14 returns to its original position, lifting the pilot block 10. The sealing head 11 is separated from the inclined sealing surface 31. The fluid inside the balance chamber 2 can enter the pressure relief channel 8 through the connecting groove 5 and the pilot hole 9 and then be discharged from the flow channel hole 4, so that the pressure inside the two flow channel holes 4 is balanced, and the gate 30 can be opened easily. The split pilot mechanism composed of the pilot block 10 and the spring 14 has a long service life and high reliability. The inclined sealing surface 31 makes the sealing effect between the pilot block 10 and the pilot hole 9 good.

[0043] It is understood that the above embodiments are merely exemplary models used to illustrate the principles of this utility model, and this utility model is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of this utility model, and these modifications and improvements are also considered to be within the protection scope of this utility model.

Claims

1. A pilot operated gate valve, characterized in that it comprises: a valve body (1), an upper end of the valve body (1) being provided with a balance chamber (2), the valve body (1) at the lower end of the balance chamber (2) being provided with a valve plate groove (3), flow passage holes (4) being respectively provided on both sides of the valve body (1) at the lower end of the balance chamber (2); a gate plate (30), the gate plate (30) being slidingly installed in the valve plate groove (3), the gate plate (30) being provided with a connecting groove (5) at the upper end thereof, the gate plate (30) being provided with a flow guide groove (6) at the lower end thereof, the gate plate (30) being provided with a balance passage (7) at one side thereof, the balance passage (7) being in communication with the flow guide groove (6), the gate plate (30) being provided with a pressure relief passage (8) at the other side thereof, the connecting groove (5) being in communication with the pressure relief passage (8) by means of a stepped pilot hole (9) at the lower end thereof; a pilot block (10), the pilot block (10) being slidingly installed in the pilot hole (9), the pilot block (10) being provided with a sealing round head (11) at the lower end thereof, the sealing round head (11) being capable of cooperating with the pilot hole (9); the pilot block (10) being provided with a top block (12) at the upper end thereof, the top block (12) and an inner boss (13) of the pilot hole (9) being provided with a spring (14) therebetween; a valve cover (15), the valve cover (15) being fixedly installed at the upper end of the balance chamber (2), the valve cover (15) being provided with a packing box (16) capable of cooperating with the balance chamber (2), the packing box (16) being provided with a valve rod (17) at the middle portion thereof, the valve rod (17) being provided with a connecting rod (18) at the lower end thereof, the connecting rod (18) being capable of sliding up and down in the connecting groove (5).

2. A pilot operated gate valve according to claim 1, characterised in that a sealing packing (19) being provided between the packing box (16) and the valve rod (17), the valve cover (15) being provided with a packing pressing plate (20) for pressing the sealing packing (19), the packing pressing plate (20) and the sealing packing (19) being provided with a packing pressing cover (21) therebetween.

3. A pilot operated gate valve according to claim 2, characterised in that, the packing pressing plate (20) being connected with the packing box (16) by means of a first connecting piece (22).

4. A pilot operated gate valve according to claim 1, wherein the valve cover (15) being connected with the valve body (1) by means of a second connecting piece (23).

5. A pilot operated gate valve according to claim 1 wherein, the packing box (16) being connected with the valve cover (15) by means of a third connecting piece (24).

6. A pilot operated gate valve according to claim 1 wherein, a sealing ring (25) being provided between the packing box (16) and the inner side wall of the balance chamber (2).

7. A pilot operated gate valve according to claim 6, characterised in that, a fixing groove (26) being provided at the upper end of the balance chamber (2), a four-opening ring (27) for fixing the sealing ring (25) being provided in the fixing groove (26), the four-opening ring (27) and the sealing ring (25) being provided with a gasket (28) therebetween.

8. A pilot operated gate valve according to claim 1 wherein, wear-resistant sealing surfaces (29) capable of cooperating with the gate plate (30) being provided on both sides of the valve plate groove (3).

9. A pilot operated gate valve according to claim 1 wherein, an inclined sealing surface (31) being provided at the cooperation position of the inner boss (13) and the sealing round head (11).

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