A manufacturer of BOP and other well equipment. Also a common term for a section of the BOP stack that utilizes a large rubber donut that can seal on irregular surfaces or even on itself
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}