Locked open valve
PIP PIC001 / company legend practice
Drawn as
A valve body with the letters "LO" written beside or above it.
Meaning
The valve is locked in the open position, for example the isolation valves under a PSV or on a vent, so it cannot be shut by mistake. Model it as normally open and note "LO". The lock or seal is a padlock or chain; the body type is read from the bow-tie, and gate-valve is only the default.
Variants
- The letters can be below the body or at the end of a leader
- Some legends add a small padlock or a "C" hook
- Ball valves with LO/LC have an open circle in the bow-tie
Tags
HV