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What do the letters “F.C” below the control valve in the diagram mean⊙?⊙？
FAIL CLOSE: Fault shutdown. Air release valve
Fault close... This is a pneumatic control valve; in the event of a problem with the air supply, a spring inside the cylinder pushes the valve to the closed position.
All the answers upstairs are correct; this is the most basic thing
Learned* \ud83d\udc4d
FC = FAIL CLOSE: failure to close; FO = FAIL OPEN: failure to open; FL = FAIL LOCK: failure to maintain the locked state. A pneumatic valve generally refers to a valve that returns to a state most favorable for production or relatively safe when the air supply is exhausted. It is generally determined by the process engineering department.
Fault closed: two states of the valve, Fault Closed (FC) and Fault Open (FO)
In the case of an accident, it operates even in gas-open mode. Conversely, even if it’s F.O