A gate valve, 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 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.

Gate valves are primarily used to permit or prevent the flow of liquids, but typical 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 valves are 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.

Gate valves are actuated by a threaded stem which connects the actuator (e.g. hand wheel or motor) to the gate. They are characterized as having either a rising or a nonrising stem, depending on which end of the stem is threaded. Rising stems are fixed to the gate and rise and lower together as the valve is operated, providing a visual indication of valve position. The actuator takes the form of a nut which is rotated around the threaded stem to move it. Nonrising stem valves are fixed to, and rotate with, the actuator, and are threaded into the gate. They may have a pointer threaded onto the upper end of the stem to indicate valve position, since the gate's motion is concealed inside the valve. Nonrising stems are used underground or where vertical space is limited.

There are different kinds of gate valves, each adapted for different pressures and different usage.

1.Forged Gate valve Generally, forged type would be used when the size of gate valve is smaller than 2"(DN50).Forged steel is the main material.Flanged, Socket Welded, Thread and Butt Welded connections are available.

2.Casting Iron Gate Valve Casting Iron gate valve usually used in the program of water at low pressure and temperature with soft seat.

The body is made by casting iron or ductile iron with rubber seat.

3.Casting Steel Gate Valve Casting Steel gate valve is largely used in all kind of liquids.The body is made by casting steel.

4. knife gate valve A knife gate valve is used to cut through extremely thick fluids and dry bulk solids. The design of this valve makes it inherently self-cleaning, as the knife is cleared of abrasives with each stroke as it passes the seat rings and skirts. The gate unit of this type of valve is thin compared to other gate valve types and is guided in place by the water-type body that sandwiches the gate.