Ball valve is evolved from the plug valve, with the same rotation 90 degrees lifting action. The ball valve only needs to rotate 90 degrees of operation and very small turning moment can close tight. Full equality of the valve cavity for the media to provide a small resistance, through the flow channel.

The main features of the valve itself is compact, easy operation and maintenance for water, solvents, acids, and natural gas general working media, but also applies to poor working conditions of media, such as oxygen, hydrogen peroxide, methane and ethylene. Ball valve body can be integrated or can be combination

The closing piece of the ball valve is a ball, and the ball rotates around the center line of the valve body to achieve the opening and closing of a ball valve. In the pipeline, it is mainly used to cut off, distribute and change the flow direction of the medium. Ball valve is a new type of valve widely used in recent years. It has so many advantages as follows: with the lowest flow resistance (actually 0 because not stuck at work (without lubricant) so it can be used in corrosive medium and low boiling point liquid; the pressure and temperature range, can be completely sealed; it can be quickly opened and closed, some the structure of the opening and closing time is only 0.05~0.1s to ensure that it can be used for automated test system. Quick opening and closing valve, operation without shock. The spherical closure can be automatically positioned at the boundary position; the fully open and fully closed, the ball and seat sealing surface and the dielectric isolation, the high-speed media through the valve sealing surface does not cause erosion; the advantages of compact structure, light weight, it may be considered for low temperature medium, most reasonable structure of the valve system; and body symmetry, especially the welded body structure, can well withstand the pressure from the pipeline; 9 off parts can withstand the pressure differential.11; the all welded ball valve can be buried underground, so that the valve parts from erosion, the high life of up to 30 years, the most ideal oil and natural gas pipeline valve.

The ball valve can be divided according to the structure:

A floating ball valve ball is floating medium pressure, the ball can produce a certain displacement, and tight at the outlet end of the sealing surface, to ensure that the export end seal.

Floating ball valve structure is simple, good sealing, but the ball to withstand the work of the media load all passed to the export sealing ring, so it is necessary to consider whether the sealing ring material can withstand the working load of the ball medium. This kind of structure is widely used in medium and low pressure ball valves.

Two, fixed ball valve, ball valve is fixed, no movement after compression. Fixed ball valve with a floating seat, pressure by the media, the valve seat to move, so that the sealing ring tightly pressed on the sphere, to ensure sealing. Usually with the ball in the upper and lower shaft with bearings, operating torque, suitable for high pressure and large diameter of the valve.

In order to reduce the valve operating torque and increase the reliability of the seal, valve seal has emerged in recent years, both the pressure injection of a special lubricant in the sealing surface, to form a layer of film that enhances the sealing, and reduce operating torque, more suitable for large-diameter high-pressure valve.

Three elastic ball valve the ball valve is elastic ball and seat rings are metal materials, sealing pressure than the large, rely on the pressure of the medium itself is not up to the requirements of sealing, external force must be. This valve is suitable for high temperature and high pressure medium.

An elastic sphere is an elastic slot at the lower end of the inner wall of a sphere to obtain elasticity. When the channel is closed, the ball head is opened with the wedge head of the valve stem to seal tightly with the valve seat. Before rotating the ball, loosen the wedge head, and then the ball will be restored to its original shape, so that there is a small gap between the ball and the valve seat, which can reduce the friction and operation torque of the sealing surface.

The ball valve can be divided into straight through type according to its channel position, the three and right angles. The latter two ball valves are used to distribute the medium and change the flow direction of the medium.

Its many characteristics make the ball valve widely used in petroleum, chemical, power generation, paper making, atomic energy, aviation, rocket and other departments, as well as in people's daily life.