API 6A gate valve, non-rising stem, rising stem, welded, threade, d, union or colar connection end. casting/forging body. API 6A gate valve: The ... in order to replace the fill of the valve-stem when the valve bears pressure.The seal surface is welded with hard alloy of ... spring, operation torque is little. The wedge valve gate is sealed by wedge seal surface ,it can adjust fit compactness between the ...