The stop valve opening and closing parts (valve disc) are driven by the valve stem and move up and down in a straight line along the axis of the valve seat (sealing surface). It is one of the most widely used valves. The reason why it is so popular is that it is not only suitable for medium and low pressure, but also for high pressure. The stop valve realizes the functions of medium transportation, stop and regulation, and can replace some small-diameter regulating valves.