Custom Search
Normally Closed (NC)
The term Normally Closed
Sponsored Links
The term Normally Closed (NC) applies to manual valves or dampers which the operator must leave closed in normal operation.
A control valve which should go to closed position on control signal failure should be labeled FC, i.e. Fail Closed. The control signal may be pneumatic, hydraulic or electric.
Sponsored Links
Related Topics
- Control Valves - Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators and positioners
Sponsored Links
Related Documents
- Fail Closed (FC) - A control valve which should go to closed position on control signal or air failure would be labeled FC
- Fail Last (FL) - A control valve which should stay put on control signal or air failure would be labeled FL
- Fail Open (FO) - A control valve which should go to the open position on control signal or air failure should be labeled FO
- Normally Open (NO) - The term Normally Open
