Stainless steel ball valves structure in the form of the main seal, sealing the choice of materials to affect the properties and performance of the valves seal, and reliability factors. Now mainly uses stainless steel ball valves the combination sealing seat composed of elastic expansion ring atmosphere of ethylene and polyethylene lip seal seat structure. Stainless steel ball valvess are widely used in various piping systems quickly cut off, changing the medium flow and automatic control, can be manual, electric or pneumatic drive.
Stainless steel ball valves sealing structure mainly consists of three parts, one of the main auxiliary valves body seal adjusted by sealing gasket to achieve; Second primary seal between the valves body and the valves stem by the standard "V"-shaped filler or 0-ring to achieve the outer seal structure, composed of ball valvess. Third seal between the sphere and the main and auxiliary valves, achieved by the sealing seat to form a primary seal of the ball valves structure. Sealability of the structure of the main seal to affect the performance of the ball valves, is the the critical sealing structure of the ball valves design and manufacture. This article will focus on the non-metallic sealing ball valvess main seal (also known as soft seal) structural problems.
A ball valves sealing requirements: national standards for non-metallic seal valves tightness GB/T13927 "universal valves pressure test" Class A;
2 affect the stainless steel ball valves sealability due sealing surface roughness and the ball roundness parameter;
3 main ball valves seal structure elastic expansion ring with PTFE lip seal seat combination seal seat, it can rely on good metal elastic expansion ring the elastoplastic deformation capacity, enhance its overall elastoplastic deformation capacity and compensation ability to improve the sealing capability of the ball valves;
Using a sealing seat with a resilient element. Obtained with the adjustment of the pre-compression no longer rely on the seal adjustment shims and by the elastic element. A sealing seat with a resilient element, in addition to obtain the necessary pre-compression amount, but also within the range of elastic deformation of the elastic element to preload the pressure ratio to compensate for the relatively long life of the stainless steel ball valves.

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