Because the hydraulic oil pump, valve throttling mouth gap, and subjected to intense shear effect, leading to some macromolecular polymers in the oil such as tackifier molecular fracture, into small molecules, reduce viscosity, when the viscosity decreased to a certain degree of oil cannot be used, so demand has good shear resistance.

Electric hydraulic pump station is by the quantitative plunger pump, control valve, fuel tanks, electrical, instrumentation and other combination of an independent hydraulic power plant, this pump station is down pressure maintaining performance, single oil into the oil return performance.