The opening and closing part of the expansion gate valve is a gate. The movement direction of the gate is perpendicular to the direction of the fluid. It is used as a cut-off medium. When it is fully opened, the entire flow is straight. At this time, the pressure loss of the medium is minimal. Gate valves are usually suitable for working conditions that do not need to be opened and closed frequently and keep the gates fully open or fully closed. They are not suitable for use as regulation or throttling.