snifter valve
noun
variants:
or snifting valve
Definition of snifter valve
1
: a small valve opening into the atmosphere from a cylinder, from a condenser, or from the air chamber of a steam pump to allow the escape or entrance of air and the release of accumulated water at each stroke of the piston
— called also sniffle valve
2
: any of various valves (as in an internal combustion engine) resembling a snifter valve