A linear relationship with stainless steel gear pump flow rate and rotational speed, relative to the low speed of the stainless steel pump, high speed of the stainless steel pump, can increase the flow and head but power obviously increase, high speed accelerate the abrasion between the rotor and stator, must make the stainless steel pump premature failure, and high speed stainless steel pump stator length is very short, easy to wear and tear, thus shortens the service life of the screw pump.By retarding mechanism or to reduce the speed stepless speed regulation mechanism, keep the speed under three hundred revolutions per minute, within the scope of the reasonable compared with the high-speed operation of the stainless steel pump, can prolong service life of a few times.