When the hand wheel forged steel gate valveis closed, the sealing surface can only be sealed by medium pressure, that is to say, the sealing surface of the gate can only be pressed by the medium pressure on the valve seat on the other side to ensure self-sealing of the sealing sealing surface. Most gate valves are forced to seal, that is, when the valve is closed, external forces are forced to press the gate onto the seat to ensure a sealed seal surface.
Movement mode: The gate of the handwheel thread gate valve moves linearly with the valve stem, also known as the opening gate valve. Usually, the trapezoidal thread is disposed on the lift rod, and the rotary motion becomes linear motion through the nut at the top end of the valve and the guide groove on the valve body, that is, the operating torque becomes the operating thrust.
When the valve is open, when the lift height of the gate is equal to 1:1 of the valve diameter, the fluid passage is completely clear, but the position cannot be monitored during operation.
In actual use, the apex of the valve stem is used as a marker, is where the valve is open, as its fully open position. In order to account for temperature changes, the locking phenomenon usually opens to the vertex position and then returns to the 1 / 2-1 circle as the position to fully open the valve. Therefore, the fully open position of the valve is determined based on the position of the baffle (ie, the stroke). Some gate valve stem nuts are placed on the gate, and the rotation of the handwheel drives the valve stem to rotate, thereby lifting the gate. Rotary lever gate valve or dark rod gate valve.