Rated Working Pressure 1 : The maximum internal pressure equipment is designed to contain and/or control. Working pressure is not to be confused with test pressure. (Spec 6A)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}