Allowable Working Pressure or Stress : The maximum stress allowed by code or other agreement or study as a fraction of test pressure. Design pressure of the system is related to hoop stress
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}