دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a device used to control the rate of flow in a line to open or shut off a line completely, or to serve as an automatic or semi-automatic safety device. Those used extensively include the check valve, gate valve, globe valve, needle valve, plug valve, and pressure relief valve.

any of several valves: plug, gate, butterfly, needle, etc., used in oil field operations.