Definition - What does Gate Valve mean?
A Gate valve is a device that is used to ensure that a streamlined flow of liquid can be restricted with minimum flow rate. The valve can also stop the fluid flow once the valve closure is completely shut. The gate valve has a flat closure element that slides into the flow stream to stop the fluid. Gate valves are mostly used in high-temperature and high-pressure environments such as-:
- The oil industry
- Petrochemical plants
- Power plants
- Water treatment
- Offshore applications
Petropedia 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. These kinds of valves are often used when a straight-line flow of fluid and minimum restriction is desired. The valves are usually divided into two types, i.e., 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.