Gate Valves

Gate valves are mainly used to allow or prevent the flow of liquids, the typical gate valves are not used for regulating flow, unless they are specifically designed for this purpose.
Shut-off valves are known for either rising or nonrising arm. Rising the stems provide a visual indication of the position of the valve, since the arm is secured to the gate so that the gate-side and lower the boom and a single valve is used.

Nonrising stem valves pointer can be rotated to the upper arm indicates the position of the valve, since the gate is moving up or down the arm forming threads by raising or lowering the arm. Nonrising stems are used underground or where vertical space is limited.