5 features about fixed ball valve that you have to know

Ball valve is widely used in the field of food, medicine, petroleum, chemical, natural gas, iron and steel, environmental protection, paper and other transfer line medium cutting or circulation. It is the type which has a sphere with the fixed shaft, the fixed shaft are connected together by the two sections with the ball bearing; when it is closed, and together with the function of the medium pressure, the ball will not produce displacement.

Shafts are connected together with the ball, the upper and lower shaft is equipped with rolling bearings or sliding bearings, in order to reduce the open and close when the journal of the frictional force, and to reduce the operating torque. Therefore, the fixed ball valve is suitable for high pressure and large diameter valves. Fixed type ball valve usually are equipped with the activities of the valve seat ring, which can produce a displacement under the action of the pressure of the media, and the seal ring is pressed tightly on the sphere, so as to ensure the sealing performance of the valve.

The features of Fixed ball valve are listed as follows:

1. labor-saving operation: the ball sphere is supported by fluctuation of bearings up and down, which reduces friction and eliminates the inlet pressure promote sphere and sealing seat form the great seal load caused by excessive torque.

2. Reliable sealing property: PTFE unisexual material sealing ring is embedded in stainless steel seat, and the metal seat end is equipped with spring which guarantee enough pre-stressing force of seals, so that the valve continues to ensure good sealing performance under the action of spring, even though the sealing surface wears out during using process.

3. Fire resisting structure: in order to prevent the sudden heat or fire appearance which will lead to PTFE ring burning or large leakage to encourage the fire, there are fire rings set in the place between ball sphere and valve. If the ring burned, the seat ring is rapidly put to the sphere under the force of spring, and forms the metal to metal seal, so as to have a certain degree of sealing effect.

4. Automatic relief function: when the medium abnormal pressure stagnated in the valve mid-plane rises to more than the spring preliminary force, the seat back from sphere to achieve automatic relief effect.

5. Drain line: drainage hole is set both on the upper and lower side of the ball body, which can check whether the valve seat leakage occurs, in the work, when the valve is in fully open or seated, after uninstalling mid-plane pressure, it can directly replace the packing, as well as discharge mid-plane retentate to reduce the pollution of media.