Floating valve plate gate valve

Abstract

The present invention discloses a floating valve plate type gate valve, comprising a valve body, a valve stem, a valve plate bracket and two valve plates; a first annular groove is opened in the circumferential direction on the outer peripheral surface of the convex column on the valve plate, a second annular groove is opened in the circumferential direction on the hole wall of the through mounting hole, one end of more than two first valve plate retainers respectively extends into the first annular groove, and the other end respectively extends into the second annular groove; a limiting groove is opened on the outer peripheral surface of the valve plate, a second valve plate retainer is installed on the valve plate bracket, and at least a part of the second valve plate retainer extends into the limiting groove. The present invention can greatly reduce the thrust required for switching, ensure that the leakage of the gate valve under various medium pressure conditions from low pressure to high pressure meets the use requirements, realize bidirectional high-pressure sealing, and improve the sealing performance under high pressure conditions. At the same time, the structure is simple, the valve plate is easy to install, and the valve plate can be prevented from rotating, reducing the stress concentration between the valve plate and the valve seat during full opening.

Description

Technical Field

[0001] The invention relates to the field of gate valves, in particular to a floating valve plate type gate valve. Background Art

[0002] Gate valves are widely used in the petrochemical industry. They have reliable cut-off, small leakage, and a large caliber coverage, and can adapt to cut-off occasions in various working conditions.

[0003] The common gate valves on the market include wedge gate valves, flat gate valves and double flat wedge gate valves. The wedge gate valves and double flat wedge gate valves both require a sufficiently large valve stem thrust to provide sealing surface pressure, so existing gate valves require a large closing torque, and the sealing surface processing accuracy is high, resulting in a large leakage; the flat gate valve has a fixed valve plate and seals close to the valve plate through a floating valve seat, so a large initial surface pressure is required, resulting in a large switching torque and uncontrollable leakage. After a period of use, the leakage is difficult to meet the original design requirements. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a floating valve plate gate valve which can greatly reduce the thrust required for switching, ensure that the leakage of the gate valve under various medium pressure conditions from low pressure to high pressure meets the use requirements, and can achieve medium-assisted downstream sealing and two-way high-pressure sealing. The valve plate is easy to install, has a reliable floating effect, can prevent the valve plate from rotating, and reduce the stress concentration between the valve plate and the valve seat during full opening.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a floating valve plate type gate valve, comprising a valve body, a valve stem, a valve plate bracket and two valve plates, wherein a fluid channel is provided in the valve body, the valve plate bracket is located in the fluid channel, one end of the valve stem extends into the fluid channel and is connected to the valve plate bracket, a through mounting hole is opened on the valve plate bracket, one end surface of the two valve plates are provided with convex columns, the convex columns on the two valve plates are movably inserted into the through mounting holes from both ends of the through mounting holes, and an elastic member is provided between the convex columns on the two valve plates in the through mounting holes;

[0006] A first annular groove is formed on the outer circumferential surface of the protruding column on the valve plate in the circumferential direction, a second annular groove is formed on the hole wall of the through mounting hole in the circumferential direction, and one end of two or more first valve plate retainers extends into the first annular groove respectively, and the other end extends into the second annular groove respectively;

[0007] A limiting groove is formed on the outer peripheral surface of the valve plate, and a second valve plate retainer is installed on the valve plate bracket, and at least a part of the second valve plate retainer extends into the limiting groove.

[0008] Furthermore, the elastic member is composed of two mutually symmetrical butterfly springs stacked together.

[0009] Furthermore, one end of the first valve plate retainer is connected to the boss through a spring pin.

[0010] Furthermore, two valve seats are included, both of which are installed in the fluid channel and located on opposite sides of the valve plate bracket, and are used to form a sealing fit with the two valve plates respectively to disconnect the fluid channel.

[0011] Furthermore, the end surface of the boss on one of the valve plates has a socket, and the end surface of the boss on the other valve plate has a boss, the boss is inserted into the socket, and a screw passes through one of the valve plates and is screwed from the boss to the other valve plate.

[0012] The beneficial effects of the present invention are embodied in:

[0013] The present invention can greatly reduce the thrust required for switching, ensure that the leakage of the gate valve under various medium pressure conditions from low pressure to high pressure meets the use requirements, and can realize medium-assisted downstream sealing, can realize two-way high-pressure sealing, effectively reduce the size of the driving part, avoid the need for traditional gate valves to convert the thrust applied to the valve stem into a thrust on the valve seat through a wedge block to form a sealing surface pressure, improve the sealing performance under high pressure conditions, and solve the technical problem of the bulky traditional gate valve transmission mechanism. At the same time, the structure is simple, the valve plate is easy to install, the floating effect is reliable, the valve plate can be prevented from rotating, and the stress concentration between the valve plate and the valve seat during full opening is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0015] Figure 2 It is a schematic diagram of the installation structure of the valve plate bracket and the valve plate in one embodiment of the present invention.

[0016] Figure 3 It is an exploded view of the installation structure of the valve plate bracket and the valve plate in one embodiment of the present invention.

[0017] The components in the accompanying drawings are marked as: 1 valve body, 2 valve stem, 3 valve plate bracket, 31 through mounting hole, 32 second annular groove, 4 valve plate, 41 boss, 42 first annular groove, 43 limit groove, 44 socket, 45 boss, 46 screw, 5 valve seat, 6 butterfly spring, 7 first valve plate retainer, 8 second valve plate retainer, 71 spring pin. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0019] See also Figure 1 , Figure 2 and Figure 3 .

[0020] The floating valve plate 4-type gate valve of the present invention comprises a valve body 1, a valve stem 2, a valve plate bracket 3 and two valve plates 4, wherein a fluid channel is provided in the valve body 1, the valve plate bracket 3 is located in the fluid channel, one end of the valve stem 2 extends into the fluid channel and is connected to the valve plate bracket 3, a through mounting hole 31 is opened on the valve plate bracket 3, and a convex column 41 is provided on one end surface of the two valve plates 4, the convex columns 41 on the two valve plates 4 are respectively movably inserted into the through mounting hole 31 from both ends of the through mounting hole 31, and an elastic member is provided between the convex columns 41 on the two valve plates 4 in the through mounting hole 31;

[0021] A first annular groove 42 is formed on the outer circumferential surface of the protruding column 41 on the valve plate 4 in the circumferential direction, and a second annular groove 32 is formed on the hole wall of the through-hole 31 in the circumferential direction, and one end of two or more first valve plate retainers 7 extends into the first annular groove 42 respectively, and the other end extends into the second annular groove 32 respectively;

[0022] A limiting groove 43 is formed on the outer peripheral surface of the valve plate 4, and a second valve plate retainer 8 is installed on the valve plate bracket 3. At least a portion (the “at least a portion” is set as required to be able to effectively limit) of the second valve plate retainer 8 extends into the limiting groove 43.

[0023] The present invention is a parallel gate valve, and its working principle is the same as that of the existing gate valve, which is to close and open the fluid channel with the valve plate by rotating the valve stem. However, based on the existing technology, the present invention changes the two valve plates from fixed installation to floating installation, and provides the initial surface pressure through the elastic member. With this design, the sealing pressure ratio required for the sealing surface can be provided by the medium pressure to perform auxiliary sealing, which greatly reduces the thrust required for the switch. When closing, only the elastic member needs to provide the pressing force required for low-pressure sealing to achieve sealing under low-pressure conditions. As the pressure increases, the medium will push the valve plate close to the sealing surface to achieve the sealing pressure ratio required by any medium pressure, thereby achieving sealing and ensuring that the leakage of the gate valve under various medium pressure conditions from low pressure to high pressure meets the use requirements. In particular, in high-pressure differential situations, the use of medium pressure auxiliary sealing can effectively reduce the size of the driving part, and can achieve medium-assisted downstream sealing, which can achieve two-way high-pressure sealing and meet the requirements of special working conditions.

[0024] Moreover, the present invention adopts a floating double valve plate design. Under high-pressure conditions, the medium pressure is used to push the floating valve plate to press the downstream valve seat to achieve sealing. Under low-pressure conditions, an elastic member is used to provide an initial surface pressure to achieve sealing. This avoids the need for traditional gate valves to convert the thrust applied to the valve stem into a thrust on the valve seat through a wedge block to form a sealing surface pressure, improves the sealing performance under high-pressure conditions, and solves the technical problems of large switching torque and bulky transmission mechanism of traditional gate valves.

[0025] Existing wedge gate valves are generally one-way sealed, but in tank areas and reactor devices, there may be a situation where the medium pressure difference is reversed. Therefore, in some special occasions, the valve is required to meet the requirements of two-way sealing in a sealed state. The present invention can meet the requirements of such working conditions and can achieve two-way sealing, solving the technical problem that the traditional structure cannot be two-way sealed. At the same time, the medium pressure is used for auxiliary sealing, making the sealing efficient and reliable.

[0026] The present invention limits the valve plate by the first valve plate retainer and the second valve plate retainer. The structure is simple, the valve plate is easy to install, the floating effect is reliable, and the elastic member is convenient to compress. During installation, the bosses and the elastic member on the two valve plates are placed in the through mounting holes of the valve plate bracket, and the elastic member is compressed by squeezing. When it is compressed to the point where the first valve plate retainer can be rotated in the second annular groove on the valve plate bracket, the compression is stopped and the valve plate bracket is rotated 90 degrees. At this time, the limiting groove on the valve plate is located directly above the valve plate, and the second valve plate retainer is fixed to the valve plate bracket so that the valve plate is connected by limiting the limiting groove to prevent the valve plate from rotating again. The valve plate is limited by the cooperation of the first valve plate retainer and the second valve plate retainer with the corresponding grooves, and a floating installation is achieved, so that the elastic member is in a reliable compressed state.

[0027] In the traditional structure, when the valve is opened, if no additional constraints are imposed on the two valve plates, the valve plates will be stretched open by the elastic force of the elastic member, the part that has not separated from the valve seat cannot be stretched open due to the restriction of the valve seat, and the part that has separated from the valve plate will tend to be stretched open due to the elastic force of the elastic member between the valve plates, which will form a stress concentration area on the sealing surface at the edge of the contact area between the valve plate and the valve seat, which will destroy the sealing performance of the sealing surface. The present invention achieves a limiting effect through the first valve plate retainer, reduces the stress concentration between the valve plate and the valve seat during the full opening process, prolongs the service life of the sealing surface, and increases the overall sealing reliability of the valve.

[0028] The invention has a reasonable and compact structure, is easy to implement, has high space utilization, is convenient for compressing the elastic member, and is convenient for floating installation of the valve plate.

[0029] In one embodiment, two valve seats 5 are further included, which are both installed in the fluid channel and located on opposite sides of the valve plate bracket 3, and are used to form a sealing match with the two valve plates 4 to disconnect the fluid channel. Sealing the valve seat with the valve plate is a commonly used sealing method, which is easy to manufacture and install.

[0030] In one embodiment, the elastic member is composed of two symmetrical disc springs 6 stacked together. The two disc springs stacked together provide the valve plate with initial surface pressure, which has a compact structure and reliable performance, and solves the technical problem of insufficient initial surface pressure on traditional gate valves.

[0031] The traditional wedge-shaped gate valve applies the closing thrust to the valve stem, which is then transmitted to the angled wedge block. The wedge block and the pressure plate then open the valve seat, or directly act on the valve seat to form a sealing pressure ratio on the sealing surface to achieve sealing. The present invention adopts a compact disc spring to provide the initial surface pressure required for sealing between the valve plate and the valve seat. As the pressure increases, the medium will exert a thrust on the floating valve plate, which will increase the surface pressure between the sealing surfaces, assist the sealing between the gate valve plate and the valve seat, and achieve effective sealing under high pressure, thereby ensuring that the gate valve has good sealing performance within the entire pressure range.

[0032] The floating valve plate design is adopted, and the compact disc spring is used to provide the initial surface pressure required for the valve plate seal, ensuring the compact structure layout of the valve trim.

[0033] In one embodiment, one end of the first valve plate retainer 7 is connected to the boss 41 via a spring pin 71. This design further locks the first valve plate retainer and improves structural stability.

[0034] In one embodiment, the end surface of the protrusion 41 on one of the valve plates 4 has an insertion hole 44, and the end surface of the protrusion 41 on the other valve plate 4 has a boss 45, the boss 45 is inserted into the insertion hole 44, and a screw 46 passes through one of the valve plates 4 and is screwed onto the other valve plate 4 from the boss 45. In this arrangement, after the elastic member is pre-compressed, the two valve plates are connected and pre-tightened with screws, the two valve plates can be accurately docked, and the gap between the two valve plates can be adjusted, so that the floating valve plate with double disc springs can be easily installed, which solves the problem that the traditional butterfly valve is cumbersome to install and cannot be repaired on the device site, and at the same time improves the performance of the gate valve, is easy to assemble and use, and can be quickly disassembled.

[0035] It should be understood that the examples and implementation modes described herein are for illustrative purposes only and are not intended to limit the present invention. Those skilled in the art may make various modifications or changes based on the examples and implementation modes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A floating valve plate type gate valve, comprising a valve body, a valve stem, a valve plate bracket and two valve plates, wherein a fluid channel is provided in the valve body, the valve plate bracket is located in the fluid channel, one end of the valve stem extends into the fluid channel and is connected to the valve plate bracket, characterized in that: The valve plate bracket is provided with a through mounting hole, and one end surface of the two valve plates is provided with a convex column, and the convex columns on the two valve plates are movably inserted into the through mounting hole from both ends of the through mounting hole, and an elastic member is provided between the convex columns on the two valve plates in the through mounting hole; A first annular groove is formed on the outer circumferential surface of the boss on the valve plate in the circumferential direction, and a second annular groove is formed on the hole wall of the through mounting hole in the circumferential direction. One end of two or more first valve plate retainers extends into the first annular groove respectively, and the other end extends into the second annular groove respectively; one end of the first valve plate retainer is connected to the boss through a spring pin; The outer peripheral surface of the valve plate is provided with a limiting groove, and a second valve plate retainer is installed on the valve plate bracket, and at least a part of the second valve plate retainer extends into the limiting groove; The first valve plate retainer and the second valve plate retainer are both square; The end surface of the protrusion on one of the valve plates has an insertion hole, and the end surface of the protrusion on the other valve plate has a boss, which is inserted into the insertion hole. A screw passes through one of the valve plates and is screwed from the boss to the other valve plate.

2. The floating valve plate type gate valve according to claim 1, characterized in that: The elastic member is composed of two mutually symmetrical butterfly springs stacked together.

3. The floating valve plate type gate valve according to claim 1 or 2, characterized in that: It also includes two valve seats, which are both installed in the fluid channel and located on opposite sides of the valve plate bracket, and are used to form a sealing fit with the two valve plates respectively to disconnect the fluid channel.

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