Fully Welded Ball Valve

1. Anti-fire safe design
 When the seat and O-ring are burnt, the seat retainer and body will be sealed by expanded graphite. Thus act anti-fire safe purpose. When the trunnion ball valve be used normally, its sealed by seat and ball surface, seat retainer sealed by O-ring and body, this is soft sealed and reliable sealing.

2. Anti-static device

Thus static electricity is conducted to ground and system safety is secured. In order to prevent friction among ball, stem and PTFE that generates static electricity which may light the combustibles and explosives that cause an accident, in this ball valve, static-conduction spring is set between the stem and the ball, the stem and the body. 

3. Bow-out proof stem

In order to prevent leakage resulting from burnout of packing set of the stem in a fire, thrust bearing is set at the contact position of the shoulder at lower part of the stem and valve body. Thus an inverse seal seat is formed which will prevent leakage and avoid accident. In addition, For the purpose of preventing the stem from flying off resulting in abnormal rising of the inner pressure of valve, shoulder is fixed at the lower part of the stem. 

4. Low torque in operation

The self-lubricated bearings are installed at the friction of stem, resulting in wear resistance, flexibility of operation and low torque.

5. DBB

When ball is full open or close position, the transmitter substance in center cavity of body can be released by drainage and emptying devices. In addition, the over loaded pressure in the center cavity of valve can be  released to low pressure end by self relief seat. 

6. Free leakage of body Sealed construction

The connective position of valve body and bonnet is double sealed by gasket and O-ring, on this base, such as factors as fire, high temperature, shock and uneven opening or closing of the torque all can't induce external leakage.

7. Extension stem 

For the underground installed valve, the stem can be lengthened and for the convenience of operation the corresponding compound injection nozzle and drainage valve can be extended to the top of valve.

8. Emergency sealing 

A concealed check valve is installed in side of each compound injection valve to prevent compound from out flowing due to the action of transmitter substance. The top of the compound injection valve is the connector for fast connection with compound injection gun. Compound injection holes are designed and compound injection valves are installed at locations of stem/cap and body support of side valve. When sealing of stem or seat is damaged to induce leakage, the compound can be used to do the second time sealing. 

9.   Automatic body cavity relief and various driving types

The valve can be drive by manual, electrical, pneumatic and pneumatic/hydraulic. the trunnion ball valve downstream seat will be pushed by un-normally pressure, and the release the unnormal pressure automatically, it doesn't damage to the sealing of upstream seat.