A Gate Valve, also known as a Sluice Valve, is a Valve that 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 are planar.
The gate faces can form a wedge shape or they can be parallel.
Typical Gate Valves should never be used for regulating flow,
unless they are specifically designed for that purpose. On opening
the Gate Valve, the flow path is enlarged in a highly nonlinear
manner with respect to percent of opening. This means that flow
rate does not change evenly with stem travel. Also, a partially
open gate disk tends to vibrate from the fluid flow.
Most of the flow change occurs near shutoff with a relatively high
fluid velocity causing disk and seat wear and eventual leakage if
used to regulate flow. Typical Gate Valves are designed to be fully
opened or closed. When fully open, the typical Gate Valve has no
obstruction in the flow path, resulting in very low friction loss.
Gate Valves Images