Centrifugal pump export pneumatic valves to shut down after the start

the motor in the start stage, its rotor rotate speed from slow to fast, reach the rating, its stator current is from big to small, reach the normal current. The starting current of the motor general up to twice the rated current value. For safety operation must try to make the motor in the case of light load startup, to enter the normal operation and then add the load to the rated value. Will flow pump start-up power for/about, so that it can avoid the emergence of the maximum current, so the centrifugal pump pneumatic valves are closed. After being set speed stability, open the pneumatic valve, should assure a shorter open time and generally not more than 1 min, or internal friction heat pump will cause damage to the pump parts.