دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a section of pipe with lefthand threads on one end and conventional right-hand threads on the other. In setting a liner, a back-off joint is attached to it so that the drill pipe may be disengaged from the liner by conventional right-hand rotation.

n: The pipe sub whose one respect is left hand thread and the other one is right hand thread.