WQD, WQ series submersible sewage pump consists of pump, mechanical seals and motor, Pump is at the lower part of sewage pump, and the structure is impeller and shell, Motor located at the upper part of the motor pump which is the single phase or three-phase electric motor Mechanical seal is between pump and motor and it is a kind of double end mechanical seal, O rings are applied in all static joints of the submersible pump.