Direct drive system for electric servo pump 1.PC pump,Beltless,Reverse rotation prevented 2.12KW, 21KW, 31KW,200rpm 3. ... CE,ISO Stars Progressing Cavity Pump Pumping Units, Direct drive system for electric servo pump---NAS-B SeriesThis system contains Control ... of overload can resist pump blocked by sand, and apply to general oil well, viscous oil well, and sand containing well, etc. Beltless, no ...