دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: see master valve.

n: 1. a large valve located on the Christmas tree and used to control the flow of oil and gas from a well. Also called master gate. 2. the blind or blank rams of a blowout preventer (obsolete).

n: A valve located on the Christmas tree that controls all flow from the wellbore. A correctly functioning master valve is so important that two master valves are fitted to most Christmas trees. The upper master valve is used on a routine basis, with the low

the main shut-in valve on the well.