A ball valve is a valve driven by a stem and rotated around the axis of the ball valve. It can also be used for fluid regulation and control. Hard-sealed V-type ball valve has strong shear force between V-type ball core and metal seat of hardfacing carbide, especially for medium containing fibers and micro-solid particles. In the pipeline, the multi-pass ball valve can not only flexibly control the confluence, diversion and flow switching of medium, but also close any channel and connect the other two channels. Valves of this type shall generally be installed horizontally in pipes. Ball valves are divided into: pneumatic ball valves, electric ball valves, manual ball valves. Ball valve came out in 1950s. With the rapid development of science and technology and the continuous improvement of production technology and product structure, in a short period of 40 years, it has rapidly developed into a major type of valve. In developed western countries, the use of ball valves is increasing year by year.
In China, ball valves are widely used in petroleum refining, long-distance pipeline, chemical industry, paper-making, pharmaceuticals, water conservancy, power, municipal, iron and steel industries, occupying a pivotal position in the national economy. It has the action of rotating 90 degrees, the cock body is a sphere, with a circular through-hole or passage through its axis.
Ball valves in the pipeline are mainly used to cut off, distribute and change the direction of media flow, it only needs 90 degrees of rotation operation and a small moment of rotation to close tightly. Ball valves are most suitable for switching and shut-off valves, V-type ball valves. In addition to the pipe parameters, electric valves should pay special attention to the environmental conditions of their use. As the electric device in electric valves is an electromechanical equipment, its use status is greatly affected by its use environment. Under normal conditions, special attention should be paid to the use of electric ball valves and butterfly valves in the following environments.