Flanged gate valve is the connection of flange gate valve, this connection is the most common. Flange gate valves are usually used in high pressure piping because they are stable and reliable.
Gate valve types can be divided into wedge type and line type gate valve and wedge type gate valve according to the sealing surface configuration. Such valves shall generally be installed horizontally in the pipe.
When the gate valve is closed, the sealing surface can be sealed only by medium pressure, that is, the sealing surface of the gate plate is pressed to the seat on the other side by medium pressure to ensure sealing of the sealing surface, which is self-sealing. Most gate valves are sealed by force, that is, when the valve is closed, to rely on external forces to force the gate to the seat to ensure sealing cover sealing.
Gate valve gate with the stem of a straight line movement, called the lifting rod gate valve.usually with trapezoidal threads on the lifting rod, the rotary motion is changed into a straight motion through the nut on the top of the valve and the guide groove on the valve body, that is, the operating torque is changed into the operating thrust.
When the valve is opened, when the height of the gate is 1:1 times the size of the valve, the flow channel is fully open, but this position cannot be monitored during operation.in practical use, the valve stem is marked by the vertex, that is, the open position, as its full open position.in order to consider the temperature change in the lock phenomenon, usually open to the vertex position, and then rewind 1/2-1 turn, as the full open valve position. Therefore, the full open position of the valve is determined by the position of the gate.
Some gate valves, stem nuts are located on the gate plate. The hand wheel turns to drive the stem to move and the gate plate is lifted. This type of valve is called rotary stem gate valve or dark stem gate valve.