Glossary “pressure relief valve” Definition:
1). A valve held closed by a spring or other means, which automatically relieves pressure in excess of its setting. 2). Carburetor fuel bowl vent operated by vapor pressure from evaporated fuel. 3). AIR system valve that functions to relieve pump-output pressure that exceeds a predetermined amount. 4). Valve in an engine oil pump having a calibrated spring working against a moveable plunger or ball to regulate maximum oil pressure.