Product Name : CAST TRUNNION BALL VALVE
Size & Pressure : 150# DN50-DN1200 / 300# DN50-DN1200 / 600lb DN50-DN1200 / 900# DN50-DN900 / 1500# DN50-DN600

CAST TRUNNION BALL VALVE
1.Blow-out proof stem
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.In addition,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.
2.Key lock
Locks can be used to lock the manual valve when  it is fully open or closed so as to prevent non-working personnel from pulling the handle which may result in misoperation of valve.It can also avoid opening or closing of valve resulting from the shock from pipelines or unpredictable factors that may cause an accident.For working pipelines such as combustible and explosive oil,gas and chemical medium,or for field piping site,the locking mechanism is especially useful.
3.Anti-fire safe design
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.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.
4.Anti-static device
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.Thus static electricity is conducted to ground and system safety is secured.
5.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 factors as fire,high temperature,shock and uneven opening or closing of the torque all can  t induce external leakage.
6. Double block&bleed(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.
7.Emergency sealing
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.A concealed check valve is insta