What Does Gate Valve Mean?
A gate valve has a flat closure element that slides into the flow stream to stop the fluid. They are one of the most commonly used valves, and are primarily used to permit or prevent the flow of liquids.
Gate valves can be used in demanding environments such as high-temperature and high-pressure environments. They are often used in:
- Power plants
- Water treatment
- Offshore applications
Gate valves are also known as knife valves, slide valves, sluice valves or linear motion valves.
Corrosionpedia Explains Gate Valve
A gate valve opens by lifting a gate out of the path of the fluid. The distinct feature of a gate valve is that 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.
Gate valves are usually divided into two types: parallel and wedge-shaped. Typical gate valves are designed to be fully opened or closed. Gate valves should never be used for regulating flow, unless they are specifically designed for that purpose.
Gate valves are characterized as having either a rising or a nonrising stem. Rising stems provide a visual indication of valve position. Nonrising stem valves may have a pointer threaded onto the upper end of the stem to indicate valve position. Nonrising stems are commonly used underground or where vertical space is limited.
Gate valves are primarily designed for on-off services. They are best used in systems which require infrequent use of the valve. They are designed for full-area flow to minimize the pressure drop and allow the passage of a pipe-cleaning pig. Since most of the flow change occurs near the shutoff, the relatively high fluid velocity causes disk and seat wear and eventual leakage if the valve is used to regulate flow.
Gate valves are used in many industrial applications, including:
- Oil and gas industry