Gate Valves, also known as a sluice valve, is a valve which opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats.
They are planar, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired.
The gate faces can be parallel, but are most commonly wedge-shaped. The valves are primarily used to permit or prevent the flow of liquids.
Gate valves shouldn’t be used for regulating flow, unless they are specifically designed for that purpose.
Because of their ability to cut through liquids, gate valve is often used in the petroleum industry. For extremely thick fluids, a specialty valve often known as a knife gate valve is used to cut through the liquid.