Pressure-Relief Valve 1 : A valve that opens at a preset pressure to relieve excessive pressure within a vessel or line; also called a RELIEF VALVE, SAFETY VALVE, OR POP VALVE (ITOGP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}