What is a gate valve
Opening and closing of the gate is the gate, the gate movement direction perpendicular to the flow direction, gate valves only as full open and full closed, can't regulate and throttle
There are two gate sealing surface, two of the most commonly used mode of gate valve sealing surface to form wedge-shaped, wedge-shaped angle with the valve parameters vary, usually 50, medium temperature low is 2 ° 52 '. Wedge gate valve's gate can be made into a group, called rigid disc; also can be made to produce micro-deformation of the gate, in order to improve its technology, cover sealing surface angle of deviation in the process, the gate is called elastic plate.
When the gate is closed, can only rely on the media pressure on the sealing surface is sealed, that rely on media pressure will press the seal into the other side of the gate to ensure that the sealing surfaces of the valve seat seal, this seal is. Most of the gate is the forced seal, that is when the valve is closed, relying on external forces forced the Rams to seat, to ensure that the sealing surface of the sealing.
When you open the valve, when the gate lifting height is equal to the size of valve 1:1 time when the fluid channels completely open, but at run time, this location is not monitored. When in actual use, is based on the apex of the stem as a symbol, which means that the fixed location, as its full open position. Consider locking phenomenon in a temperature change, usually in the opening to the top position, then fell back to 1/2-1, as a full open position of the valve. Therefore, full open position of the valve, press shutter position (stroke) to determine.
Gate valve gate valve with linear motion, called the shower valve (also called rising stem gate valves). Usually with trapezoidal threaded on the lift rod through the nut at the top of the valve guides and valve body, turn the rotary motion into linear motion, thrust or torque turn operation.
Gate valve, valve stem nut located on the gate, handwheel turn valve stem turn, leaving the RAM upgrade, this valve is called the rotating stem gate valve or floodgate valve of dark pole.