Valve seat sealing mechanism applicable to low temperature working conditions

Abstract

The invention discloses a valve seat sealing mechanism applicable to low temperature working conditions. A lip seal ring is arranged between a valve seat and a valve body; a support spring ring is arranged between two lips of the lip seal ring; a pressing ring is further arranged between the valve body and the valve seat; a pretensioned spring is arranged between the pressing ring and the valve body; and the pretensioned spring drives the pressing ring to abut against the valve seat and the support spring ring. The valve seat sealing mechanism has the beneficial effects that on the one hand, the valve seat can be closely attached to a ball body, so that the ball body and the valve seat have good sealing performance, and on the other hand, acting force is applied to the support spring ringthrough the pressing ring, and the lip seal ring is deformed by compression of the support spring ring, the lips are opened, so that the lip seal ring is attached to the valve body and the valve seatmore closely, even at a very low temperature, the lips of the lip seal ring are contracted to a certain extent, reliable sealing of the lip seal ring can still be ensured, and the better sealing between the valve seat and the valve body is achieved.

Description

technical field [0001] The invention relates to the field of valves, in particular to a valve seat sealing mechanism which adopts a lip sealing ring and is suitable for low-temperature working conditions. Background technique [0002] As a cut-off valve for pipeline systems, ball valves are widely used in various industrial fields such as petroleum, chemical industry, electric power, and urban construction. They have the advantages of small fluid resistance, good sealing performance, and rapid switching. During use, the ball of the ball valve does not move, but only rotates, and the ball can be rotated 90° to open or close the pipeline. The sphere of the fixed ball valve is generally supported by the upper and lower support shafts or support plates. By applying the spring force behind the valve seat and the medium force in the pipeline, the valve seat can be tightly attached to the sphere, so as to achieve the reliability of the sealing surface of the valve seat. seal. [...

AI Technical Summary

Problems solved by technology

[0003] At present, conventional ball valves usually use rubber O-rings to seal the valve seat and valve body, but the rubber O-rings will crack or lose elasticity at low temperatures and cannot be effectively sealed.

Therefore, the O-ring can not be used for sealing between the valve seat and the valve body of the cryogenic fixed ball valve, but the lip sealing ring is used for sealing. Support, but the lip of the lip seal ring shrinks greatly at low temperature. At this time, the interference between the lip seal ring, the valve seat and the valve body matching surface will be greatly reduced, and it is difficult to ensure that the lip seal ring reliable sealing of

In addition, the elasticity of the lip seal ring decreases at low temperatures, and the material becomes hard, which is not conducive to the sealing of the lip seal ring.

In order to make the lip seal ring reliably seal at a lower temperature, people try to solve the sealing problem by increasing the interference between the seat, the valve body and the lip seal ring, but too much interference will lead to The installation of the lip seal ring is difficult, and even the lip seal ring will be damaged during installation. Therefore, for ball valves with very low temperature, it is difficult to ensure the seal between the valve seat and the valve body by adopting the conventional lip seal ring sealing mechanism design. Reliable sealing

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