Gate Valves
Gate valves are used for fully open or fully closed service. Gate valves provide very low friction loss when fully open, since there is no obstruction in the flow path. Gate valves have either rising or non-rising stems. The former providing a visual indication of valve position and the latter used where vertical space is limited. Gate valves are not to be used for throttling. They are recommended for service with minimum line pressure drop, minimum fluid entrapment, and relatively infrequent action.
Common types of Gate valves:
- Parallel – Flat disc between two parallel seats
- Wedge – Flexible disc, two inclined seats and a slightly unequal inclined gate