CN213929486U

CN213929486U - Back pressure valve

Info

Publication number: CN213929486U
Application number: CN202022872231.5U
Authority: CN
Inventors: 刘茯蔚
Original assignee: Xiongchuan Valve Technology Hebei Co ltd
Current assignee: Henan Xiongchuan Fluid Engineering Co ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2021-08-10
Anticipated expiration: 2030-12-04

Abstract

The application provides a back pressure valve which comprises a valve body, wherein an input cavity is arranged on one side of the valve body, an output cavity is arranged at the bottom of the valve body, a sealing cavity communicated with the input cavity is arranged in the valve body, a communicating hole communicated with the output cavity is arranged at the bottom of the sealing cavity, and the sealing cavity is communicated with the output cavity through the communicating hole; the bottom of the sealing cavity is provided with a sealing ring, the sealing cavity is internally provided with an elastic and liftable valve rod, and the end part of the conical surface of the valve rod is inserted in the communicating hole; a compression screw is arranged in the sealing cavity and is pressed above the sealing ring; a circle of groove is formed in the bottom of the sealing cavity, and an annular compensating rubber ring is arranged in the groove, so that the compensating rubber ring is in abutting contact with the sealing ring. The beneficial effect of this application is: the bottom surface of the sealing cavity is inwards sunken to form a groove, the compensation rubber ring is arranged in the groove, a gap is formed between the sealing ring and the bottom surface of the sealing cavity when the sealing ring deforms, the compensation rubber ring can compensate the gap between the sealing ring and the bottom surface of the sealing cavity, and the independent separation of the sealing cavity and the output cavity when the end part of the valve rod is inserted into the communicating hole is guaranteed.

Description

Back pressure valve

Technical Field

The utility model relates to a back pressure valve technical field, concretely relates to back pressure valve.

Background

The back pressure valve is also called a pressure stabilizing valve, namely a valve with pressure stabilizing performance. In industrial applications, the back pressure valve is generally provided with more than two connections, at least two of which are used to connect to the fluid line, the line connection connected to the fluid inflow direction being called the inlet end, for short the inlet, and the line connection connected to the fluid outflow direction being called the outlet end, for short the outlet, the remaining connections being mostly used to connect to the instruments or acting as a second inlet or outlet.

The pressure stabilizing performance of the back pressure valve refers to the performance of stabilizing the pressure at the inlet end. When the pipeline pressure at the inlet end rises, the backpressure valve releases an overpressure part exceeding the set pressure, so that the pressure at the inlet end returns to the set pressure, namely a backpressure valve pressure stabilizing mechanism.

The valve body in the backpressure valve and the sealing ring are the key for realizing the pressure stabilizing performance of the backpressure valve, once sealing fails, an inlet and an outlet area are communicated, and the pressure stabilizing performance of the backpressure valve loses functions. However, the sealing ring is deformed by the extrusion of the valve body, the extrusion of the compression screw above the sealing ring, long-term use under natural conditions and other factors, so that the overall sealing performance of the back pressure valve is influenced, the inlet is communicated with the outlet, and the back pressure valve fails.

Disclosure of Invention

The purpose of this application is to provide a back pressure valve to the above problem.

In a first aspect, the application provides a back pressure valve which comprises a valve body, wherein an input cavity is arranged on one side of the valve body, an output cavity is arranged at the bottom of the valve body, a sealing cavity communicated with the input cavity is arranged in the valve body, a communication hole is formed in the bottom of the sealing cavity, and the sealing cavity is communicated with the output cavity through the communication hole; the bottom of the sealing cavity is provided with a sealing ring, the center of the sealing ring is provided with a first through hole with the aperture consistent with that of the communicating hole, an elastic valve rod capable of lifting and moving is arranged in the sealing cavity corresponding to the communicating hole, one end of the valve rod is provided with a conical surface, and the end part of the valve rod with the conical surface is inserted in the communicating hole; an annular compression screw is arranged in the sealing cavity and is circumferentially pressed above the sealing ring; the bottom of the sealing cavity is provided with a circle of groove corresponding to the lower part of the sealing ring, and the groove is internally provided with a circular ring-shaped compensation rubber ring, so that the top surface of the compensation rubber ring is in butt contact with the bottom surface of the sealing ring.

According to the technical scheme provided by the embodiment of the application, the cross-sectional shape of the groove can be preferably set to be rectangular, trapezoidal, triangular or circular.

According to the technical scheme provided by the embodiment of the application, the groove is preferably arranged right below the corresponding compression screw.

According to the technical scheme provided by the embodiment of the application, the diameter of the cross section of the compensation rubber ring is preferably set to be 1 mm.

According to the technical scheme that this application embodiment provided, the top of valve body is equipped with the handle, and the below of handle is connected with the load spring, and the below of load spring is connected with the piston that stretches into in the valve body, and the bottom of piston is connected with the valve rod.

The invention has the beneficial effects that: the utility model provides a back pressure valve, at the sunken slot that sets up inwards of seal chamber bottom surface, set up elastic compensation rubber ring in the slot, can make compensation rubber ring surface and sealing washer surface butt contact under the effect of elastic force, thereby the compensation produces the gap between sealing washer and the seal chamber bottom surface when the sealing washer takes place to deform, the gap between compensation rubber ring compensational seal circle and the seal chamber bottom surface, guarantee the valve rod tip and peg graft the independent partition of seal chamber and output chamber when the intercommunication is downthehole, reach the requirement of guaranteeing the back pressure valve gas tightness.

Drawings

FIG. 1 is a schematic view of a first embodiment of the present application;

FIG. 2 is a schematic diagram of an overall structure of a prior art back pressure valve according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a partial structure of a prior art back pressure valve according to an embodiment of the present disclosure;

FIG. 4 is an enlarged schematic view of portion A of FIG. 1;

FIG. 5 is a schematic view of a first embodiment of the present application in which a groove having a rectangular cross section is aligned with the center of the cross section of the seal ring;

FIG. 6 is a schematic view of a groove having a trapezoidal cross section aligned with the outer side of the cross section of the sealing ring according to the first embodiment of the present invention;

FIG. 7 is a schematic view of a groove having a triangular cross section aligned with the outer side of the cross section of the sealing ring according to the first embodiment of the present invention;

FIG. 8 is a schematic view of a first embodiment of the present application in which a groove having a triangular cross-section is aligned with the center of the cross-section of the seal ring;

FIG. 9 is a schematic view of a first embodiment of the present application in which the circular cross-section groove is aligned with the center of the cross-section of the seal ring;

FIG. 10 is a schematic view of a first embodiment of the present application in which a groove having a circular cross-section is aligned with the outer side of the cross-section of the sealing ring;

the text labels in the figures are represented as: 1. a valve body; 2. a seal ring; 3. a compression screw; 4. a valve stem; 5. a force bearing spring; 6. a handle; 7. an input chamber; 8. an output cavity; 9. a piston; 10. sealing the cavity; 11. a compensation rubber ring; 12. a trench; 34. a first sealing surface; 41. a first conical surface; 71. the upper surface of the compensation rubber ring; 72. the lower surface of the compensation rubber ring.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following detailed description of the present invention is provided in conjunction with the accompanying drawings, and the description of the present section is only exemplary and explanatory, and should not be construed as limiting the scope of the present invention in any way.

As shown in fig. 1 and fig. 2, the back pressure valve of the present embodiment includes a valve body 1, an input chamber 7 is disposed on one side of the valve body 1, an output chamber 8 is disposed at the bottom of the valve body 1, a seal chamber 10 communicated with the input chamber 7 is disposed in the valve body 1, a communication hole is disposed at the bottom of the seal chamber 10, and the seal chamber 10 is communicated with the output chamber 8 through the communication hole; the bottom of the sealing cavity 10 is provided with a sealing ring 2, the center of the sealing ring 2 is provided with a first through hole with the aperture consistent with that of the communicating hole, an elastic valve rod 4 capable of lifting and moving is arranged in the sealing cavity 10 corresponding to the communicating hole, one end of the valve rod 4 is provided with a conical surface, and the end part of the valve rod 4 with the conical surface is inserted in the communicating hole; an annular compression screw 3 is arranged in the sealing cavity 10, and the compression screw 3 is circumferentially pressed above the sealing ring 2.

In this embodiment, when the pressure of the fluid introduced into the input chamber 7 is not greater than the set pressure of the back pressure valve, the valve rod 4 is inserted into the communicating hole, so as to ensure the isolation between the input chamber 7 and the output chamber 8, and the end of the valve rod 4 is set to be a conical surface structure, so that the conical surface structure is clamped in the communicating hole and the first through hole. When the pressure of the fluid introduced into the input cavity 7 is greater than the set pressure of the backpressure valve, the fluid entering the sealing cavity 10 pushes the piston 9 to drag the valve rod 4 to rise in the sealing cavity 10, so that the valve rod 4 is separated from the communication hole, the communication hole is opened, the redundant fluid enters the output cavity 8 and is discharged out of the valve body 1 through the output cavity 8, and the pressure stabilizing function of the backpressure valve is ensured. The fluid in this embodiment may be either a gas or a liquid.

In this embodiment, a handle 6 is arranged above the valve body 1, a force bearing spring 5 is connected below the handle 6, a piston 9 extending into the valve body 1 is connected below the force bearing spring 5, and the bottom end of the piston 9 is connected with the valve rod 4.

As shown in fig. 2 and 3, the set pressure of the back pressure valve in the prior art is realized by: the handle 6 is rotated clockwise, the force bearing spring 5 is compressed to generate a vertically downward spring force, and the downward pressure acts on the piston 9 and is then transmitted to the sealing ring 2 through the valve rod 4. The handle 6 is rotated to adjust a set pressure for stabilizing the pressure in the back pressure valve.

When the back pressure valve is in a stable working state, the pressure of the fluid introduced into the input cavity 7 is P1 which is consistent with the set pressure, when an abnormality occurs, the pressure of the fluid medium introduced into the input cavity 7 rises to (P1+ delta P), the force balance with the force bearing spring 5 is broken, the piston 9 is pushed to move upwards, the valve rod 4 is separated from the sealing ring 2, and the fluid medium flows from the input cavity 7 to the output cavity 8 and is discharged out of the valve body 1. In the process, the pressure of the fluid medium in the input chamber 7 decreases until the pressure decreases to P1, and the equilibrium state before the pressure increase is reached again.

As shown in fig. 3, the first sealing surface 34 is a sealing surface between the sealing ring 2 and the valve body 1, and the first tapered surface 41 is a sealing surface where the valve stem 4 contacts and seals with the first through hole of the sealing ring 2. The first sealing surface 34 and the first conical surface 41 are two most central sealing surfaces of the back pressure valve and are key for realizing a pressure stabilizing function of the back pressure valve. In the prior art, the first conical surface 41 mainly meets the sealing requirement through the matching design of the conical surface of the valve rod 4, the thickness of the sealing ring 2, the material of the sealing ring 2 and the like, and the position of the first sealing surface 34 can generate obvious deformation along with the long-time use of the sealing ring 2 and the pressure action of the compression screw 3, so that a large gap is generated at the position of the first sealing surface 34, and the pressure stabilizing sealing performance of the back pressure valve is influenced.

The first sealing surface 34 is a static seal and presses the sealing ring 2 against the valve body 1 when the pressing screw 3 is screwed into the valve body 1. The seal ring 2 is elastically and plastically deformed by the combined pressing of the compression screw 3 and the valve body 1, so that a sealing stress is generated on the first sealing surface 34 to exert a sealing function. The material of the sealing ring 2 is polytetrafluoroethylene, polychlorotrifluoroethylene or polyetheretherketone. When the sealing ring 2 is extruded by the compression screw 3 and the valve body 1, deformation can be generated, and particularly when the sealing ring 2 is made of polytetrafluoroethylene, the creep resistance of the polytetrafluoroethylene is poor, the sealing stress at the first sealing surface 34 is lost more quickly, and the sealing failure speed is higher.

This sealing stress is generated during the assembly of the back pressure valve, and the compression screw 3 cannot be tightened again in the operating state of the back pressure valve, so that leakage occurs in the event of failure.

The back pressure valve is typically connected to and located downstream of the reaction system. The chemical reactions are mostly accompanied by heat generation and dissipation, resulting in an increase and decrease in the temperature of the reaction system, which causes a temperature change of the sealing ring 2 when these system fluids with temperature change flow through the back pressure valve. When the temperature of the sealing ring 2 rises, the sealing ring 2 expands, irreversible permanent deformation is generated after expansion, the sealing stress at the first sealing surface 34 is greatly weakened, and when the temperature of the sealing ring 2 is reduced, the sealing stress at the first sealing surface 34 is reduced due to contraction of the sealing ring 2, so that the sealing at the position is failed and leakage is caused.

There is another case: when the backpressure valve is in a vibration environment, the compression screw 3 screwed on the valve body 1 is easy to loosen, the pressing force exerted on the sealing ring 2 by the compression screw 3 is reduced, and the sealing stress at the first sealing surface 34 is weakened, so that the sealing hidden trouble is caused. The failure of the seal at the first sealing surface 34 of the sealing ring 2 therefore directly affects the service life of the back pressure valve.

The practical situation is that in a back pressure valve with a common structure in the market, the sealing between the sealing ring 2 and the valve body 1 at the first sealing surface 34 always fails first, the service life potential of the sealing between the sealing ring 2 and the valve rod 4 at the first conical surface 41 is difficult to fully play, and the normal service life of the back pressure valve is seriously influenced. While also causing additional maintenance costs to the user, resulting in unnecessary economic losses.

Therefore, in this embodiment, a circle of groove 12 is provided below the bottom of the sealing cavity 10 corresponding to the sealing ring 2, and an annular compensation rubber ring 11 is provided in the groove 12, so that the top surface of the compensation rubber ring 11 is in abutting contact with the bottom surface of the sealing ring 2.

In this embodiment, as shown in fig. 1 and 4, a circle of groove 12 is disposed below the sealing ring 2 corresponding to the sealing cavity 10 in the valve body 1, an elastic compensation rubber ring 11 is disposed in the groove 12, and the compensation rubber ring 11 can be always in abutting contact with the surface of the sealing ring 2 under the action of elastic force, so as to make up a gap between the sealing ring 2 and the bottom surface of the sealing cavity 10, that is, a gap generated at the position of the first sealing surface 34, thereby ensuring the sealing performance of the back pressure valve, and always keeping the isolation independence between the sealing cavity 10 and the output cavity 8 when the valve rod 4 does not rise.

The reliability of auxiliary sealing is ensured, the sealing life of the sealing ring 2 and the valve rod 4 at the first conical surface 41 is exerted to the maximum extent, and therefore the service life of the back pressure valve is effectively prolonged.

The compensation rubber ring 11 realizes sealing by means of elastic deformation, the compensation rubber ring 11 is extruded by the valve body 1 and the sealing ring 2 to generate elastic deformation, and sealing stress is generated at the upper surface 71 of the compensation rubber ring and the lower surface 72 of the compensation rubber ring to realize sealing. Because the compensation rubber ring 11 is in a pressed state and elastically deforms, even if the compression screw 3 of the back pressure valve is loosened in a vibration environment, the compression amount of the compensation rubber ring 11 is slightly reduced, the sealing stress on the upper surface 71 of the compensation rubber ring and the lower surface 72 of the compensation rubber ring is not obviously affected, and sealing can still be achieved. In contrast, in the prior art seal design of fig. 2 and 3, as long as the compression screw 3 is loosened in a vibration environment, the sealing stress at the first sealing surface 34 will be sharply reduced to create a leakage hazard because the seal ring 2 is solid and has a large elastic modulus and a small elastic deformation.

On the other hand, since the compensation rubber 11 is an elastic body, it is disposed in the groove 12. The sealing ring 2 generates elastic-plastic deformation under the joint extrusion of the compression screw 3 and the valve body 1, and creeps towards the compensation rubber ring 11 and the groove 12, so that the compression on the compensation rubber ring 11 is increased, and the sealing stress at the first sealing surface 34 can be increased and the sealing effect is promoted.

Also, the back pressure valve operates under alternating temperature conditions, and the seal ring 2 will expand and contract concomitantly. The sealing ring 2 expands and flows toward the compensation rubber ring 11 and the groove 12, so that the compression of the compensation rubber ring 11 is objectively increased, and the sealing stress on the upper surface 71 and the lower surface 72 of the compensation rubber ring is increased to promote the sealing effect. The shrinkage of the sealing ring 2 is reduced, the compression amount of the compensation rubber ring 11 is only slightly reduced, the sealing stress at the upper surface 71 and the lower surface 72 of the compensation rubber ring is not obviously influenced, and the sealing can still be realized.

Therefore, a compensation rubber ring 11 is arranged between the valve body 1 and the sealing ring 2, the reliability of auxiliary sealing at the first sealing surface 34 is ensured, the sealing service life of the sealing ring 2 and the valve rod 4 at the first conical surface 41 is exerted to the maximum extent, and the service life of the back pressure valve is effectively prolonged.

Because the compensation rubber ring 11 is located at the most core sealing position of the back pressure valve, the structure is compact, the large-diameter-cut compensation rubber ring 11 is not suitable for specification, the diameter-cut compensation rubber ring 11 specification below 1.8 mm (1.78 mm) is only suitable for selection, and the diameter-cut compensation rubber ring 11 with the diameter of 1mm is preferred.

In the present embodiment, as shown in fig. 5 to 10, the cross-sectional shape of the groove 12 may be preferably set to be rectangular, trapezoidal, triangular or circular, wherein the force uniformity effect with the rectangular cross-section is the best.

In this embodiment, the groove 12 is preferably provided directly below the corresponding compression screw 3. Because the stress borne by the sealing ring 2 under the compression screw 3 is concentrated, after long-time extrusion, the deformation of the sealing ring 2 at the position right opposite to the compression screw 3 is smaller, and the deformation of the sealing ring 2 at the positions corresponding to the two sides of the compression screw 3 is larger. When the groove 12 is arranged at a position right below the corresponding compression screw 3, the compensation rubber ring 11 arranged in the groove 12 is subjected to small-degree creep deformation under the action of positive pressure of the compression screw 3 at a position right opposite to the compression screw 3, so that the plastic deformation of the compensation rubber ring 11 is most stable, the compensation rubber ring 11 is stably abutted against the lower surface of the sealing ring 2, and a gap is prevented from being generated between the lower surface of the sealing ring 2 and the bottom surface of the cavity of the sealing cavity 10. In a similar way, the compensation rubber ring 11 generates a large degree of creep deformation at the positions corresponding to the two sides of the compression screw 3, so that the deformation of the sealing ring 2 at the positions corresponding to the two sides of the compression screw 3 can be compensated. Reliable isolation between the sealed chamber 10 and the output chamber is ensured by the above process.

The principles and embodiments of the present application are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts of the present application. The foregoing is only a preferred embodiment of the present application, and it should be noted that there are objectively infinite specific structures due to the limited character expressions, and it will be apparent to those skilled in the art that a plurality of modifications, decorations or changes may be made without departing from the principle of the present application, and the technical features described above may be combined in a suitable manner; such modifications, variations, combinations, or adaptations of the invention using its spirit and scope, as defined by the claims, may be directed to other uses and embodiments, or may be learned by practice of the invention.

Claims

1. The back pressure valve is characterized by comprising a valve body, wherein an input cavity is arranged on one side of the valve body, an output cavity is arranged at the bottom of the valve body, a sealing cavity communicated with the input cavity is arranged in the valve body, a communication hole is formed in the bottom of the sealing cavity, and the sealing cavity is communicated with the output cavity through the communication hole;

the bottom of the sealing cavity is provided with a sealing ring, the center of the sealing ring is provided with a first through hole with the aperture consistent with that of the communicating hole, an elastic valve rod capable of lifting and moving is arranged in the sealing cavity corresponding to the communicating hole, one end of the valve rod is provided with a conical surface, and the end part of the valve rod with the conical surface is inserted in the communicating hole;

an annular compression screw is arranged in the sealing cavity and is circumferentially pressed above the sealing ring;

the bottom of the sealing cavity is provided with a circle of groove corresponding to the lower part of the sealing ring, and the groove is internally provided with a circular ring-shaped compensation rubber ring, so that the top surface of the compensation rubber ring is in butt contact with the bottom surface of the sealing ring.

2. The back pressure valve of claim 1, wherein the groove may be provided with a rectangular, trapezoidal, triangular, or circular cross-sectional shape.

3. The back pressure valve of claim 1, wherein the groove is disposed directly below a corresponding compression screw.

4. The back pressure valve of claim 1, wherein a diameter of a cross section of the compensation rubber ring is set to 1 mm.

5. The back pressure valve of claim 1, wherein a handle is arranged above the valve body, a force bearing spring is connected below the handle, a piston extending into the valve body is connected below the force bearing spring, and the valve rod is connected to the bottom end of the piston.