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.