the gate valve is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. When fully opened, the typical gate valve has no obstruction in the flow path, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired. The gate faces can form a wedge shape or they can be parallel. Gate valves are primarily used to permit or prevent the flow of liquids and shouldn’t be used for regulating flow, unless they are specifically designed for that purpose