Fail locked (last position) (FL), letter form
ISA 5.1 / PIP PIC001
Drawn as
The letters "FL" written just below (sometimes beside) a valve body.
Meaning
On loss of motive power the valve stays where it was. Typical for motor-operated and double-acting valves. Set the valve's fail action to FL.
Variants
- Also written "FLP" or "FAIL LAST"
- The fail position is the shelf (no-air) position, not the normal operating position
Tags
FL
Not physical hardware. Read it, then skip it in the 3D model.