دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a surface unit similar to a pumping unit but having no individual power plant. Usually, several pump jacks are operated by pull rods or cables from one central power source. Commonly, but erroneously, beam pumping units are called pump jacks. Compare beam pumping unit.

the main rocking unit of a rod pumped well. Older uses were in central power units.