Gate Valve

A gate valve, known as a sluice valve, is a valve that opens by lifting a barrier (gate) out of the path of the fluid. CENTROFLOW Gate valves made in China require very little space along the pipe axis and hardly restrict the flow of fluid when the gate is fully opened. The gate faces can be parallel but are most commonly wedge-shaped (in order to be able to apply pressure on the sealing surface).

     
The opening and closing part of the gate valve is the gate. The direction of movement of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully open and closed, and cannot be adjusted and throttled. The gate has two sealing surfaces. The two sealing surfaces of the most commonly used mode gate valve form a wedge. The wedge angle varies according to the valve parameters, usually 50, and 2°52'' when the medium temperature is not high. The gate plate of the wedge gate valve can be made into a whole body, called a rigid gate, or a gate that can produce trace deformation to improve its process and make up for the deviation caused by the angle of the sealing surface during processing. This kind of gate is called an elastic gate.

When the CENTROFLOW gate valve is closed, the sealing surface can only rely on medium pressure, that is, relying on the medium pressure to press the sealing surface of the gate plate to the seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves are forcibly sealed, that is, when the valve is closed, the gate plate is forcibly pressed to the valve seat by external force to ensure the sealing of the sealing surface.

The gate plate of the gate valve moves straight with the stem, which is called the lifting rod gate valve, also known as the open rod gate valve. Usually, there is a trapezoidal thread on the lifting rod, which changes the rotation movement into a linear motion through the nut at the top of the valve and the guide groove on the valve body, that is, the operating torque is changed to the operation thrust.

When the valve is opened, the lifting height of the gate is equal to 1:1 times the valve diameter, the channel of the fluid is completely unblocked, but when running, this position cannot be monitored. In actual use, the vertex of the stem is used as the sign, that is, the position that cannot be opened, as its fully open position. In order to consider the phenomenon of locking in temperature changes, it is usually opened to the vertex position and then reversed back 1/2-1 times as the position of the fully open valve. Therefore, the fully open position of the valve is determined according to the position of the gate.
         
In CENTROFLOW gate valves, the stem nut is located on the gate plate, and the handwheel rotates to drive the stem to rotate and lift the gate plate. This kind of valve is called a rotary rod gate valve or a hidden rod gate valve.