Direct drive system for electric servo pump 1.PC pump,Beltless,Reverse rotation prevented 2.12KW, 21KW, 31KW, ... 3.CE,ISO Stars Progressing Cavity Pump Pumping Units, Direct drive system for electric servo pump---NAS-B SeriesThis system contains Control ... controlled by electromagnet, prevention of reverse rotation, rotary inertial auto-released tardily while power off.Automatic Data recording , USB ...