What are the methods for the valve seat structure commonly used in vacuum ball valves?

What are the methods for the valve seat structure commonly used in vacuum ball valves?

(1) General valve seat The general valve seat is generally used on a ball valve with a diameter equal to less than 200mm. Generally, the valve seat is mainly under the preload or fluid pressure effect, the valve seat is pressed against the ball, and the valve seat data is plastically deformed to reach the seal, and the sealing effect depends on the valve seat under the effect of the fluid or preloading. Under the effect of force, the degree of spherical out-of-roundness and microscopic unevenness of the surface can be compensated. The valve seat has a simple structure, is convenient to manufacture and manufacture, and is widely used.

(2) Elastic valve seat elastic valve seat method is relatively more, but the natural gas pipeline is commonly used in the spiral spring spring valve seat and the disc spring spring valve seat, both of which are based on the elastic force and fluid of the spring. The pressure will face the valve seat and then reach the seal. These two seats have a good two-way seal and excellent elastic compensation, but for the spiral spring valve seat, the stiffness of each spring is difficult to achieve, resulting in uneven force on the seat. , affecting the sealing performance of the valve. In contrast, the disc-shaped spring is simple, compact, easy to process, and has a uniform force. Therefore, the use is appropriate and extensive.

(3) The rotary valve seat ball valve forms a crescent-shaped narrow passage between the ball and the valve seat before the opening or closing, so the natural gas is saved and the high-speed turbulent flow is violent, which often causes the valve seat to be eroded. Internal leakage. The main feature of the rotary valve seat is that the valve seat can rotate along the axis of the channel during the opening and closing process. The valve seat can be rotated by the switch valve, which can evenly wear the valve seat in the circumferential direction, improve the working condition and prolong the service life. .