Definitions for "Purge valve"
a valve on a snorkel, mask or regulator that allows it to be cleared of water Rebreather: A device that reuses air by scrubbing or removing the carbon dioxide from it. There are usually no bubbles emitted.
a valve usually located at the high point of the condenser or receiver for blowing out noncondensible gases.
Valve for clearing a regulator
a valuable tool for increased nitrous performance