Working principle for API gate valve

When the API gate valve closed, the valve can seal up rely on external force or rely on the medium pressure,The other side of the pressure on the sealing surface of the door depends on medium pressure to ensure the sealing surface is sealed, which is self-sealing.Most of the valve is forced seal, that is, when the valve is closed,the gate is forced toward the seat to ensure the sealing surface is sealed.Gate valve disc and stem works in a straight line with the stem, called the lift bar gate valve (also known as the bar gate valve). Usually there is a trapezoidal thread on the lifter. The rotating motion is changed into a straight line through the nut at the top of the valve and the guide groove on the valve body. That is to say, the operating torque is changed into the operating thrust. When opening the valve,when the gate lift height is equal to 1:1 times of the valve path, the passage of the fluid is completely unblocked, but at run time, this position is unable to monitor. In actual use,the top of the stem is used as a symbol, the open position, as its fully open position.Lock phenomenon should be considered when temperature changes, usually open to the vertex position first, and then half of the loop, as the valve fully open position. Therefore, the opening position of the valve is determined by the position of the gate.