Fireproof reinforced sealing type polytetrafluoroethylene valve seat structure

Abstract

The utility model provides a fireproof reinforced sealing type teflon valve seat structure which comprises a valve body, a butterfly plate and a pressing plate, an I-shaped metal valve seat is arranged between the valve body and the pressing plate, a sealing piece is arranged between the upper end of the metal valve seat and the valve body, and a teflon valve seat with a spring on the back face is embedded in the lower end of the metal valve seat. Through double sealing of the metal valve seat and the teflon valve seat, the valve can still guarantee basic sealing in the process that the teflon valve seat is burnt down; and meanwhile, the cold flow property of the teflon material can be overcome, so that the teflon valve seat and the butterfly plate always maintain a long-term stable sealing specific pressure, and the butterfly valve can maintain the bidirectional zero-leakage performance with long service life.

Description

Technical Field

[0001] The utility model relates to the field of valves, in particular to a polytetrafluoroethylene valve seat structure. Background Art

[0002] With the use of butterfly valves in the control process, fire protection requirements have been put forward for high-performance butterfly valves that handle hydrocarbons and flammable media in the petroleum, petrochemical and chemical industries. Fire-proof high-performance butterfly valves are used in situations where reliable sealing is required in a fire environment. During normal operation, the elastic valve seat contacts the butterfly plate and maintains a seal. When a fire occurs, once the PTFE valve seat is burned or softened, the valve can still ensure the specified basic seal. However, PTFE material has cold flow properties and will undergo plastic deformation (creep) under long-term continuous loads. When the butterfly plate is pressed against the sealing surface for a long time and exceeds a specific compressive stress, the sealing valve seat will produce "cold flow" (creep) and lose elasticity, the sealing pressure ratio is reduced, and the valve sealing performance is reduced or even fails. Utility Model Content

[0003] 1. Technical issues to be resolved

[0004] The utility model aims to provide a polytetrafluoroethylene valve seat structure which can prevent fire and overcome the cold flow property of polytetrafluoroethylene.

[0005] (II) Technical solution

[0006] To achieve the above purpose, the utility model is implemented through the following technical solutions: a fire-proof enhanced sealing type polytetrafluoroethylene valve seat structure, including a valve body, a butterfly plate, and a pressure plate. An "I"-shaped metal valve seat is arranged between the valve body and the pressure plate, a sealing member is arranged between the upper end of the metal valve seat and the valve body, a polytetrafluoroethylene valve seat with a spring on the back is embedded in the lower end of the metal valve seat, and the front of the polytetrafluoroethylene valve seat is in contact with the butterfly plate.

[0007] Preferably, both sides of the upper end of the metal valve seat abut against the valve body and the pressure plate, and there is a gap between the lower end and the valve body and the pressure plate.

[0008] Preferably, the sealing member is made of metal.

[0009] Preferably, the metal valve seat can be directly machined from the valve body.

[0010] (III) Beneficial effects

[0011] The utility model provides a fire-proof enhanced sealing type polytetrafluoroethylene valve seat structure. It has the following beneficial effects:

[0012] The utility model uses double sealing of metal valve seat and PTFE valve seat. When the PTFE valve seat is burned, the valve can still ensure basic sealing. A spring is arranged on the back of the PTFE valve seat, which can overcome the cold flow of PTFE material, so that the PTFE valve seat always maintains a long-term stable sealing pressure ratio with the butterfly plate, so that the butterfly valve can maintain a long-life two-way zero leakage performance. The gap between the "I"-shaped metal valve seat and the lower end and the valve body and the pressure plate can better conduct heat, and it is easy to expand when heated, so that the metal valve seat and the butterfly plate are easy to fit and seal. At room temperature, the metal valve seat is elastically deformed by the medium pressure, which is conducive to two-way sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the utility model.

[0014] In the figure, 1. valve body; 2. seal; 3. metal valve seat; 4. spring; 5. PTFE valve seat; 6. butterfly plate; 7. pressure plate. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] A fireproof enhanced sealing type polytetrafluoroethylene valve seat structure includes a valve body, a sealing member, and a metal valve seat. The metal valve seat is fixed in the valve body by a pressure plate, and the metal valve seat and the valve body are sealed by a sealing member. The polytetrafluoroethylene valve seat is embedded in the metal valve seat, and a spring is installed on the back of the polytetrafluoroethylene valve seat. The spring can overcome the cold flow of the polytetrafluoroethylene valve seat, so that the polytetrafluoroethylene valve seat always fits with the butterfly plate, ensuring that the polytetrafluoroethylene butterfly valve maintains a long-life bidirectional zero leakage performance. This solution relies on double sealing of the metal valve seat and the polytetrafluoroethylene valve seat. During the process of the polytetrafluoroethylene valve seat being burned, the valve can still ensure basic sealing; the polytetrafluoroethylene valve seat of this solution is provided with a spring on the back, which can overcome the cold flow of the polytetrafluoroethylene material, so that the polytetrafluoroethylene valve seat always maintains a long-term stable sealing pressure ratio with the butterfly plate, so that the butterfly valve can maintain a long-life bidirectional zero leakage performance.

[0017] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fire-proof enhanced sealing type polytetrafluoroethylene valve seat structure, including a valve body, a butterfly plate, and a pressure plate, characterized in that: An "I"-shaped metal valve seat is arranged between the valve body and the pressure plate, a sealing member is arranged between the upper end of the metal valve seat and the valve body, a PTFE valve seat with a spring on the back is embedded in the lower end, and the front side of the PTFE valve seat abuts against the butterfly plate.

2. A fire-resistant enhanced sealing polytetrafluoroethylene valve seat structure according to claim 1, characterized in that: The two sides of the upper end of the metal valve seat are in contact with the valve body and the pressure plate, and there is a gap between the lower end and the valve body and the pressure plate.

3. The fire-resistant enhanced sealing polytetrafluoroethylene valve seat structure according to claim 1, characterized in that: The sealing element is made of metal.

4. The fire-resistant enhanced sealing type polytetrafluoroethylene valve seat structure according to claim 1, characterized in that: The metal valve seat is directly processed from the valve body.

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