CN211951648U

CN211951648U - Valve rod sealing structure of fixed ball valve

Info

Publication number: CN211951648U
Application number: CN202020203373.XU
Authority: CN
Inventors: 韩泽海; 牛超
Original assignee: Cnv Valve & Control Co inc
Current assignee: Cnv Valve & Control Co inc
Priority date: 2020-02-24
Filing date: 2020-02-24
Publication date: 2020-11-17
Anticipated expiration: 2030-02-24

Abstract

The utility model relates to a valve rod seal structure of fixed ball valve, including installing the valve rod in the valve body shaft hole, the valve rod is equipped with annular shaft shoulder, from up being equipped with thrust pad down between valve rod and the valve body in proper order, the valve rod backing ring, U-shaped spring seal packing subassembly and gland, thrust pad supports and leans on annular shaft shoulder, be equipped with 90O shape spring seal packing between valve rod backing ring bottom and the valve body, U-shaped spring seal packing subassembly is by the T shape support ring that sets up from bottom to top, U-shaped spring and lip seal assemble in proper order and form, the gland has flange portion, be equipped with the winding pad between flange portion and the valve body. In the valve rod sealing structure of the fixed ball valve, the 90-degree O-shaped spring sealing packing and the U-shaped spring sealing packing are matched with each other, the sealing pressing force is changed along with the change of a medium, the structure is simple, the sealing performance is good, the service life is long, and the sealing effect which is more stable than an O-shaped ring can be achieved under the condition that the working condition has special requirements.

Description

Valve rod sealing structure of fixed ball valve

Technical Field

The utility model relates to a ball valve technical field, in particular to valve rod sealing structure of fixed ball valve.

Background

The valve rod is a necessary component of the valve, and the function of the valve rod is to transmit the power actuator to the ball body to enable the ball body to rotate or move, so that the opening and closing or adjusting function of the valve is realized. The valve rod, the valve body and the valve cover rotate relatively in the opening and closing and adjusting process of the valve, and in order to prevent leakage, a seal is required to be arranged between the valve rod and the valve body or the valve cover, and the seal is a dynamic seal, so that leakage is easier to generate.

At present, O-shaped rings are mostly selected as sealing elements of dynamic sealing in the sealing design of a valve rod, but the O-shaped rings are selected except for temperature and material limitation, and the O-shaped ring sealing is not in accordance with the design requirement under the working condition with special requirements. Therefore, on the basis of the consideration that the medium can not use the O-shaped ring, a valve rod sealing structure with good sealing performance and poor service life needs to be designed.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the technical problem that will solve is: in order to overcome the defects of the prior art, the valve rod sealing structure of the fixed ball valve is provided.

In order to achieve the above technical effect, the utility model discloses a technical scheme is: the utility model provides a valve rod seal structure of fixed ball valve, is including installing the valve rod in the valve body axial bore, the valve rod is equipped with annular shaft shoulder, follows down from up coaxial thrust pad, valve rod backing ring, U-shaped spring seal packing subassembly and the gland of being equipped with in proper order between valve rod and the valve body, thrust pad supports and leans on annular shaft shoulder, be equipped with 90O shape spring seal packing between valve rod backing ring bottom and the valve body, U-shaped spring seal packing subassembly is assembled in proper order by the T shape support ring that sets up from bottom to top, U-shaped spring and lip seal and forms, the gland has flange portion, be equipped with the winding pad between flange portion and the valve body.

Preferably, the surface of the valve body contacting the medium is provided with a corrosion-resistant alloy layer.

Preferably, the valve rod and the annular shaft shoulder are of an integral structure, and the valve rod is rotatably connected with the valve body.

Preferably, a plurality of screws are uniformly distributed on the flange part in the circumferential direction, and the flange part is fixedly connected with the valve body through the screws.

Preferably, the vertical section of the valve rod backing ring is L-shaped, and the outer diameter of the bottom of the valve rod backing ring is larger than that of the thrust pad.

Preferably, the number of the U-shaped spring sealing packing assemblies is two, and the two U-shaped spring sealing packing assemblies are distributed between the valve stem gasket ring and the gland up and down.

Preferably, the lip seal has a downward opening.

Preferably, the lip seal and the 90 ° O-ring seal packing are both made of corrosion resistant material.

Compared with the prior art, the beneficial effects of the utility model are that: in the valve rod sealing structure of the fixed ball valve, the 90-degree O-shaped spring sealing packing and the U-shaped spring sealing packing are matched with each other, the sealing pressing force can change along with the change of a medium, the structure is simple, the sealing performance is good, the service life is long, and the sealing effect which is more stable than an O-shaped ring can be achieved under the condition that the working condition has special requirements.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and the embodiments, and it is obvious that the described embodiments are some embodiments, not all embodiments of the present invention.

Drawings

Fig. 1 is the structural schematic diagram of the valve rod sealing structure of the fixed ball valve of the present invention.

Fig. 2 is a schematic structural view of the U-shaped spring packing assembly of the present invention.

The reference numbers and corresponding designations in the drawings are: 1. the valve comprises a valve body, a valve rod, a thrust pad, a valve rod backing ring, a U-shaped spring sealing packing assembly, a gland, a 7.90-degree O-shaped spring sealing packing, a winding pad, a ring-shaped shaft shoulder, a T-shaped supporting ring, a U-shaped spring, a lip-shaped sealing ring and a flange, wherein the valve rod backing ring is 2, the thrust pad is 3, the valve rod backing ring is 4, the U-shaped spring sealing packing assembly is 5, the gland is 6, the.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic drawings and illustrate the basic structure of the present invention only in a schematic manner, and thus show only the components related to the present invention.

As shown in fig. 1-2, a valve rod sealing structure of a fixed ball valve comprises a valve rod 2 installed in an axial hole of a valve body 1, and is characterized in that the valve rod 2 is provided with an annular shaft shoulder 21, a thrust pad 3, a valve rod backing ring 4, a U-shaped spring seal packing assembly 5 and a gland 6 are coaxially arranged between the valve rod 2 and the valve body 1 from bottom to top in sequence, the thrust pad 3 abuts against the annular shaft shoulder 21, 90-degree O-shaped spring seal packing 7 is arranged between the bottom of the valve rod backing ring 4 and the valve body 1, the U-shaped spring seal packing assembly 5 is formed by sequentially assembling a T-shaped support ring 51, a U-shaped spring 52 and a lip seal 53 which are arranged from bottom to top, the gland 6 is provided with a flange part 61, and a winding pad 8 is arranged.

The surface of the valve body 1 contacting the medium is provided with a corrosion-resistant alloy layer. The corrosion-resistant alloy layer can protect the valve body 1 from corrosion, and the service life of the valve body is prolonged.

The valve rod 2 and the annular shaft shoulder 21 are of an integral structure, and the valve rod 2 is rotatably connected with the valve body 1.

A plurality of screws are uniformly distributed on the flange part 61 in the circumferential direction, and the flange part 61 is fixedly connected with the valve body 1 through the screws. In order to stably and fixedly install the gland 6 on the valve body 1, and tightly press the thrust pad 3, the valve rod backing ring 4 and the U-shaped spring sealing packing component 5.

The vertical section of the valve rod backing ring 4 is L-shaped, and the outer diameter of the bottom of the valve rod backing ring 4 is larger than that of the thrust pad 3. In order to fully cover and compress the thrust pad 3.

The number of the U-shaped spring sealing packing assemblies 5 is two, and the two U-shaped spring sealing packing assemblies 5 are distributed between the valve rod backing ring 4 and the gland 6 up and down. The sealing performance can be further improved by the two U-shaped spring seal packing assemblies 5 arranged at the upper layer and the lower layer.

The lip seal 53 has an opening facing downward. The opening faces the direction opposite to the medium pressure, and the opening of the lip-shaped sealing ring 53 is tightly pressed on the inner wall of the adjacent part under the action of the medium pressure to realize sealing.

The lip seal 53 and the 90 ° O-ring seal packing 7 are both made of a corrosion resistant material. In order to ensure that the lip-shaped sealing ring 53 and the 90-degree O-shaped spring sealing filler 7 can be used for a long time under the working condition of special media.

When in specific use: the gland 6 compresses the thrust pad 3, the valve rod backing ring 4 and the U-shaped spring sealing packing assembly 5 in a cavity formed by the valve rod 2 and the valve body 1. When the medium in the cavity of the valve body 1 escapes under the action of pressure, the escaped medium diffuses along the gap between the valve rod 2 and the valve body 1 and reaches the positions of the 90-degree O-shaped spring sealing filler 7 and the U-shaped spring sealing filler assembly 5, and due to the pre-tightening action of the 90-degree O-shaped spring sealing filler 7 and the U-shaped spring 52, the lip-shaped sealing ring 53 is tightly pressed on the inner wall of the adjacent part, so that the medium with slightly lower pressure cannot pass through the barrier. Along with the increase of escaping media, the pressure in the grooves of the 90-degree O-shaped spring sealing filler 7 and the U-shaped spring sealing filler component 5 gradually rises, the lip-shaped sealing ring 53 is better attached to the outer wall under the pressure action of the T-shaped supporting ring 51, the final pressure and the pressure in the middle cavity reach balance to realize sealing, and the winding pad 8 plays the last sealing to prevent the media from leaking out of the gland 6.

The sealing packing structure of the valve rod has the advantages that in the working process, the sealing packing force of the U-shaped spring sealing packing component 5 changes along with the change of media, enough sealing packing force can be guaranteed, excessive friction force cannot be generated, small abrasion loss is compensated through lip opening and deformation, the sealing effect and the sealing service life are guaranteed, compared with extrusion sealing like an O-shaped ring, the U-shaped spring sealing packing component 5 is better in comprehensive performance and longer in service life, and under the condition that the working condition has special requirements, the sealing effect which is more stable than the O-shaped ring sealing can be achieved.

The present invention is not limited to the above specific embodiments, and for those skilled in the art, the above conception can be used without any creative work, and all the changes made fall within the protection scope of the present invention.

Claims

1. A valve rod sealing structure of a fixed ball valve comprises a valve rod (2) arranged in a shaft hole of a valve body (1), it is characterized in that the valve rod (2) is provided with an annular shaft shoulder (21), a thrust pad (3), a valve rod pad ring (4), a U-shaped spring sealing packing component (5) and a gland (6) are coaxially arranged between the valve rod (2) and the valve body (1) from bottom to top in sequence, the thrust pad (3) is abutted against the annular shaft shoulder (21), 90-degree O-shaped spring sealing packing (7) is arranged between the bottom of the valve rod backing ring (4) and the valve body (1), the U-shaped spring sealing packing component (5) is formed by assembling a T-shaped support ring (51), a U-shaped spring (52) and a lip-shaped sealing ring (53) from bottom to top in sequence, the gland (6) is provided with a flange part (61), and a winding pad (8) is arranged between the flange part (61) and the valve body (1).

2. The stem seal structure of a stationary ball valve according to claim 1, wherein the medium-contacting surface of the valve body (1) is provided with a corrosion-resistant alloy layer.

3. A stem seal structure of a stationary ball valve according to claim 2, wherein said stem (2) and said annular shoulder (21) are of an integral construction, the stem (2) being rotatably connected to the valve body (1).

4. The valve stem sealing structure of the fixed ball valve according to claim 3, wherein a plurality of screws are uniformly distributed on the flange portion (61) in the circumferential direction, and the flange portion (61) is fixedly connected with the valve body (1) through the screws.

5. The stem seal structure of a stationary ball valve according to claim 1, wherein the stem gasket ring (4) has an L-shaped vertical cross-section, and the outer diameter of the bottom of the stem gasket ring (4) is larger than the outer diameter of the thrust pad (3).

6. The stem seal structure of a fixed ball valve according to claim 5, wherein there are two U-shaped spring packing assemblies (5), and the two U-shaped spring packing assemblies (5) are arranged up and down between the stem gasket ring (4) and the gland (6).

7. The stem seal structure of a stationary ball valve according to claim 6, wherein the lip seal (53) is opened downward.

8. The stem seal arrangement of a stationary ball valve according to claim 7, characterized in that the lip seal (53) and the 90 ° O-ring spring packing (7) are made of corrosion resistant material.