... Closed,externally ventilated QDS type submersible motor pump is mainly composed by three parts:pump,mechanical seal and motor.Pump is at the bottom ... centrifugal impleller.Motor is at the upper part of motor pump and is a single-phase asynchronous motor or three- ... are applied in all static joints of the submersible pump.Inner-insralled protector prevents the pump from damages due to abnormal power,clog ...