Gate valve: its closing part (wedge disc) moves along the passage axis vertically. It is used as a fully-open or fully-closed stop medium in piping. It is generally not used to adjust flow. Characteristics of gate valve: flow resistance is small; opening and closing moment is small; medium flows unrestrictedly; structure length is short, range of use is wide. But a larger installation space is required because size and opening height of the gate valve are large.