Normally Closed (Normally Open) 1. A switch position where the usual arrangement of contacts permits (prevents) the flow of electricity in the circuit. 2. In a solenoid valve, an arrangement whereby the disk or plug is seated (open) when the solenoid is de-energized. 3. A field contact that is closed (open) for a normal process condition and open (closed) when the process condition is abnormal. 4. A valve with means provided to move to and/or hold in its closed (open) position without actuator energy supply. 5. Relay contacts that are closed (open) when the coil is not energized.