High-pressure sealing compensation type parallel double-flat-plate gate valve

Abstract

The utility model relates to a high-pressure sealing compensation type parallel double-flat-plate gate valve. Some general gate valves often have the problems of inner leakage, large required thrust, short service life and the like during system operation under severe conditions of high temperature, high pressure and the like. The high-pressure sealing compensation type parallel double-flat-plate gate valve comprises a valve body, valve seats, a valve rod, a valve clack assembly and a packing system assembly, the two valve seats are installed at the intersections of a middle cavity of the valve body and connecting pipes on the two sides respectively, and the two sealing faces of the valve seats face the inner space of the middle cavity of the valve body and are symmetrical and parallel to the axial center line of the middle cavity. The check valve is characterized in that the valve clack assembly is arranged between parallel sealing faces of the two valve seats in a valve body cavity, one end of the valve rod is connected with the valve clack assembly, and the sealing faces of the valve seats and the valve clack provide pre-tightening sealing through compression of belleville springs in the valve clack assembly. The utility model can solve the problems of internal leakage, large thrust and short service life of the conventional common gate valve in a system under harsh conditions such as high temperature and high pressure.

Description

Technical Field

[0001] The utility model belongs to the technical field of flat gate valves, and particularly relates to a high-pressure sealing compensation type parallel double flat gate valve, which is applied to the fluid control needs under harsh working conditions such as high temperature and high pressure, and is widely used in high-pressure fluid pipeline systems in the petroleum, chemical, electric power, pharmaceutical and other industries. Background Art

[0002] Gate valves are widely used in industrial systems such as power, oil refining, and chemical industry. They have the advantages of simple structure, good sealing performance, small flow resistance, and short structure length. General gate valves such as rigid single-disc gate valves, elastic disc gate valves, and wedge-type disc gate valves often have problems such as internal leakage, large thrust requirements, and short service life when operating in harsh conditions such as high temperature and high pressure. Utility Model Content

[0003] In view of the above problems, the utility model provides a high-pressure sealing compensation type parallel double-plate gate valve to solve the problems of internal leakage, large thrust and short life of current ordinary gate valves in systems with harsh conditions such as high temperature and high pressure.

[0004] To this end, the present invention adopts the following technical solution: a high-pressure sealing compensation type parallel double-flat gate valve, including a valve body, a valve seat, a valve stem, a valve disc assembly and a packing system assembly. Two valve seats are respectively installed at the intersection of the valve body middle cavity and the two side pipes. The two sealing surfaces of the valve seats face the space in the valve body middle cavity, and are symmetrical and parallel to the axial center line of the middle cavity. It is characterized in that the valve disc assembly is placed between the parallel sealing surfaces of the two valve seats in the valve body cavity, one end of the valve stem is connected to the valve disc assembly, and the sealing surfaces of the valve seat and the valve disc are compressed by the butterfly spring in the valve disc assembly to provide a pre-tightened seal.

[0005] Preferably, the valve flap assembly includes a valve flap body, a spring seat is arranged in the valve flap body, butterfly springs are installed at both ends of the spring seat, and also includes a spring guide sleeve for positioning and guiding the butterfly spring.

[0006] Preferably, an open sleeve is further included, wherein the open sleeve covers the small outer circles on the backs of the two valve discs and covers the butterfly spring and the spring seat between the valve discs.

[0007] Preferably, the back end face of the valve disc is provided with an end face annular groove, the spring guide is sleeved on the outer circle of the annular groove, and the two groups of butterfly springs in the valve disc are positioned and isolated by the spring seat.

[0008] Preferably, the valve stem and valve flap assembly is connected to the T-slot on the valve flap assembly through a square head and a rectangular groove at one end of the valve stem.

[0009] Preferably, a valve flap sleeve is further included, wherein the valve flap sleeve is composed of two semicircular rings which are divided after integral processing, and an inner ring groove is provided in the two semicircular rings to cooperate with the outer ring groove on the back of the valve flap.

[0010] Preferably, the upper and lower ends of the dividing surface of the valve flap sleeve are respectively equipped with positioning pins for alignment and closing, and a through hole for fastening is provided in the middle of the upper and lower ends of the dividing surface of the valve flap sleeve. After the valve flap sleeve is closed, the bolt passes through the through hole from one side of the valve flap sleeve and is screwed into the locking nut to lock and fasten it.

[0011] Preferably, the packing system assembly includes a stuffing box arranged on the valve body. The stuffing box adopts a self-sealing structure, and seals are achieved by contact between the inner conical surface of the sealing ring and the outer conical surface of the stuffing box, and pre-tightening is achieved through studs and nuts.

[0012] Preferably, a stuffing box is provided with a stuffing box hole, and a stuffing pad, a high-pressure stuffing group, a stuffing gland and a stuffing pressure plate are installed in the stuffing box hole from bottom to top. The valve stem extends out of the stuffing box after passing through the stuffing box from the valve cavity, and the components in the stuffing box hole realize the internal and external sealing of the stuffing box and the valve stem.

[0013] Preferably, the packing pressure plate is equipped with a butterfly spring group, the butterfly spring group is covered by a spring cover, the stud installed on the upper end face of the stuffing box passes through the butterfly spring group and the spring cover, and the nut is screwed into the stud and pressed on the end face of the spring cover.

[0014] The beneficial effects of the present invention are:

[0015] 1. The disc assembly adopts butterfly spring to provide pre-tightening, which has the function of compensating sealing. When the sealing surface is worn due to temperature and pressure fluctuations or long-term operation of the valve, the compression and rebound of the spring eliminate the influence of material expansion, contraction and reduction of sealing surface thickness. The disc and valve seat will not lock or separate, and the valve will still maintain good sealing.

[0016] 2. The valve disc adopts an open sleeve guide connection structure, so that the small displacement of the valve disc caused by the compression and rebound movement of the spring is limited to the axial range, thereby ensuring that the two sealing surfaces of the valve disc are always parallel, and the sealing between the valve disc and the valve seat is reliably and continuously guaranteed.

[0017] 3. The inner ring groove of the valve disc sleeve is buckled into the outer ring groove on the back of the valve disc, fixing the two valve discs into an assembly. The assembly matching structure of the ring groove ensures that the two sealing surfaces of the two valve discs are parallel after the assembly is completed, which helps the contact and sealing between the valve disc and the valve seat sealing surface.

[0018] 4. The T-slot connection between the valve stem and the valve disc assembly makes assembly simple and convenient, and the maintenance cost is low.

[0019] 5. The valve disc sleeve is divided into two parts after integral processing. The two semicircular valve disc sleeves have high matching degree, high assembly precision and simple assembly.

[0020] 6. The pressure self-sealing structure of the stuffing box is not affected by temperature and pressure changes, is easy to load and unload, and has excellent sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of a high-pressure sealing compensation type parallel double-plate gate valve provided by this utility model patent.

[0022] Figure 2 This is a structural diagram of the core component, the valve disc assembly.

[0023] Figure 3 Exploded view of the valve disc assembly.

[0024] In the figure: 1, valve body 2, valve seat 300, valve disc assembly 4, valve stem 5, stuffing box 6, sealing ring 7, pressure ring 8, four open rings 9, valve cover 10, packing gasket 11, high-pressure packing group 12, packing gland 13, packing pressure plate 14, butterfly spring group 15, spring cover 16, opening and closing nut 17, pneumatic actuator 301, valve disc 302, opening sleeve 303, valve disc sleeve 304, locking nut 305, spring guide sleeve 306, locating pin 307, spring seat 308, butterfly spring 309, bolt. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to specific embodiments.

[0026] like Figure 1-Figure 3 The illustrated high-pressure, seal-compensated, parallel double-plate gate valve comprises a valve body 1, a valve seat 2, a valve disc assembly 300, a valve stem 4, a stuffing box 5, a sealing ring 6, a pressure ring 7, a four-opening ring 8, a valve cover 9, and a packing system assembly. Two valve seats 2 are welded together at the intersection of the central cavity of the valve body 1 and the two side pipes. The two sealing surfaces of the valve seats 2 face the central cavity of the valve body 1 and are symmetrical and parallel to the axial centerline of the central cavity. The valve disc assembly is positioned between the parallel sealing surfaces of the two valve seats within the valve body cavity. One end of the valve stem is connected to the valve disc assembly. The sealing surfaces of the valve seat and valve disc are preloaded by compression of a butterfly spring within the valve disc assembly. When the valve disc 301 expands or contracts due to temperature fluctuations, the compression and rebound of the butterfly spring 308 compensate for the material changes, ensuring that the sealing surface does not swell or separate. If the sealing surface wears due to long-term operation, the butterfly spring 308 can also provide a compensatory seal, ensuring a tight fit.

[0027] Specifically, the valve stem 4 and the valve flap assembly 300 are connected to the T-shaped groove on the valve flap assembly 300 through the square head and rectangular groove at one end of the valve stem 4. This structure is simple and convenient to assemble and has low maintenance and repair costs.

[0028] Specifically, the valve disc assembly 300 includes a valve disc 301 , an opening sleeve 302 , a valve disc sleeve 303 , a locking nut 304 , a spring guide sleeve 305 , a positioning pin 306 , a spring seat 307 , a butterfly spring 308 , and a bolt 309 .

[0029] In one embodiment, an end face annular groove is provided on the back end face of the valve disc 301, and a spring guide sleeve 305 is installed on the outer circle of the annular groove to position and guide the butterfly spring 308. The backs of the two valve discs 301 with the spring guide sleeve 305 and butterfly spring 308 installed are aligned, and the two groups of butterfly springs 308 in the valve disc 301 are positioned and isolated by the spring seat 307.

[0030] The open sleeve 302 is sleeved on the small outer circle on the back of the two valve discs 301, covering the butterfly spring 308, spring seat 307 and other parts between the valve discs 301. When the valve disc 301 is switched, the spring preload force changes, which is reflected in the valve disc 301 as a small axial displacement. The open sleeve 302 plays the function of guiding and positioning the valve disc 301 and other parts, preventing the valve disc 301 from generating radial deflection and causing leakage accidents when a small displacement occurs.

[0031] In one embodiment, the valve flap sleeve 303 is composed of two semi-circular rings that are divided after integral processing. Inner ring grooves are provided in the two semi-circular rings, which cooperate with the outer ring grooves on the back of the valve flap 301 to ensure the parallelism of the sealing surfaces of the two valve flaps 301; the inner ring groove of the valve flap sleeve is buckled into the outer ring groove on the back of the valve flap, fixedly connecting the two valve flaps into an assembly. The assembly and matching structure of the ring grooves ensures the parallelism of the two sealing surfaces after the two valve flaps are assembled, which helps to contact and seal the valve flaps with the sealing surface of the valve seat.

[0032] Specifically, the inner annular groove of the valve disc sleeve 303 is inserted into and covers the outer annular groove on the back of the valve disc 301 from both sides of the valve disc 301 and then closed. Positioning pins 306 are respectively installed at the upper and lower ends of the dividing surface of the valve disc sleeve 303 for alignment and closing. A through hole for fastening is provided in the middle of the upper and lower ends of the dividing surface of the valve disc sleeve 303. When the valve disc sleeve 303 is closed, the bolt 309 passes through the through hole from one side of the valve disc sleeve 303 and is screwed into the locking nut 304 to lock it.

[0033] In one embodiment, the stuffing box 5 adopts a self-sealing structure, and sealing is achieved by the contact between the inner conical surface of the sealing ring 6 and the outer conical surface of the stuffing box 5, and a pre-tightening effect is achieved through bolts and nuts. The medium pressure is transmitted from the stuffing box 5 to the sealing ring 6, generating a self-tightening effect. This sealing structure has excellent sealing performance, is not affected by temperature and pressure fluctuations, and is easy to load and unload.

[0034] Specifically, the stuffing box 5 is provided with a stuffing box hole, in which a stuffing pad 10, a high-pressure stuffing group 11, a stuffing gland 12, and a stuffing pressure plate 13 are installed from bottom to top. The valve stem 4 passes through the stuffing box 5 from the valve cavity and then extends out of the stuffing box 5. The various components in the stuffing box hole realize the internal and external sealing of the stuffing box 5 and the valve stem 4.

[0035] In one embodiment, a butterfly spring assembly 14 is mounted on the packing pressure plate 13, and a spring cover 15 covers the butterfly spring assembly 14. A stud mounted on the upper end surface of the stuffing box 5 passes through the butterfly spring assembly and the spring cover 15. A nut is screwed into the stud and pressed against the end surface of the spring cover 15. The sealing force of the stuffing box is adjusted by adjusting the depth of the nut screwed into the stud. The butterfly spring assembly 14 stabilizes the sealing load of the stuffing box, thereby ensuring a long-term and effective good seal of the stuffing box.

[0036] The valve stem 4 is connected to the push rod of the pneumatic actuator 17 through the opening and closing nut 16. The pneumatic actuator 17 drives the valve stem 4 to move up and down, and the valve stem 4 drives the valve disc assembly 300 to slide between the two valve seats 4 to realize the opening and closing of the valve.

[0037] It should be understood that these embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the contents of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A high-pressure sealing compensation type parallel double flat gate valve, comprising a valve body (1), a valve seat (2), a valve stem (4), a valve disc assembly (300) and a packing system assembly, wherein two valve seats (2) are respectively installed at the intersection of the middle cavity of the valve body (1) and the two side pipes, and the two sealing surfaces of the valve seats (2) face the space inside the middle cavity of the valve body and are symmetrical and parallel to the axial center line of the middle cavity, characterized in that The valve flap assembly (300) is placed between the parallel sealing surfaces of the two valve seats in the cavity of the valve body (1), one end of the valve stem (4) is connected to the valve flap assembly (300), and the sealing surfaces of the valve seat (2) and the valve flap (301) are compressed by the butterfly spring (308) in the valve flap assembly to provide a pre-tightened seal.

2. A high pressure sealing compensation type parallel double plate gate valve according to claim 1, characterized in that The valve disc assembly (300) comprises a valve disc (301) body, a spring seat (307) is arranged in the valve disc body, butterfly springs (308) are installed at both ends of the spring seat (307), and a spring guide sleeve (305) for positioning and guiding the butterfly spring (308) is also included.

3. A high pressure sealing compensation type parallel double plate gate valve according to claim 2, characterized in that It also includes an open sleeve (302), which covers the small outer circles of the backs of the two valve discs (301) and covers the butterfly spring and the spring seat between the valve discs.

4. A high pressure sealing compensation type parallel double plate gate valve according to claim 3, characterized in that The back end face of the valve disc is provided with an end face annular groove, and the spring guide sleeve (305) is mounted on the outer circle of the annular groove. The two groups of butterfly springs in the valve disc are positioned and isolated by the spring seat.

5. A high-pressure sealing compensation type parallel double-plate gate valve according to any one of claims 1 to 4, characterized in that The valve stem (4) and the valve flap assembly are connected to the T-shaped groove on the valve flap assembly via a square head and a rectangular groove at one end of the valve stem.

6. A high pressure sealing compensation type parallel double plate gate valve according to claim 5, characterized in that It also includes a valve disc sleeve (303), which is composed of two semi-circular rings that are divided after integral processing, and an inner ring groove is provided in the two semi-circular rings to cooperate with the outer ring groove on the back of the valve disc.

7. A high pressure sealing compensation type parallel double plate gate valve according to claim 6, characterized in that Positioning pins (306) are respectively provided at the upper and lower ends of the dividing surface of the valve disc sleeve (303) for alignment and closing. Through holes for fastening are provided in the middle of the upper and lower ends of the dividing surface of the valve disc sleeve. After the valve disc sleeve is closed, a bolt (309) is passed through the through hole from one side of the valve disc sleeve and then screwed into a locking nut for fastening.

8. A high pressure sealing compensation type parallel double plate gate valve according to claim 1, characterized in that The packing system assembly includes a packing box (5) arranged on the valve body. The packing box adopts a self-sealing structure, and the inner conical surface of the sealing ring (6) contacts the outer conical surface of the packing box to achieve sealing, and the studs and nuts are used to achieve pre-tightening.

9. A high pressure sealing compensation type parallel double plate gate valve according to claim 8, characterized in that The stuffing box (5) is provided with a stuffing box hole, in which a stuffing pad (10), a high-pressure stuffing group (11), a stuffing gland (12) and a stuffing pressure plate (13) are installed from bottom to top. The valve stem (4) extends out of the stuffing box after passing through the stuffing box from the valve cavity. The components in the stuffing box hole realize the internal and external sealing of the stuffing box and the valve stem.

10. A high pressure sealing compensation type parallel double plate gate valve according to claim 9, characterized in that The packing pressure plate (13) is provided with a butterfly spring assembly (14), the butterfly spring assembly is covered with a spring cover (15), a stud mounted on the upper end face of the packing box passes through the butterfly spring assembly (14) and the spring cover, and a nut is screwed into the stud and pressed against the end face of the spring cover.

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