... the city, mild discharge and water diversion project. Introduction QZ series submersible axial flow pump, QH series submersible mixed flow pumps ... 20% -30%, 3% -5% efficiency, and excellent resistance to cavitation. QZ, QH series of pump flow with a single large ... long life. QZ, QH series of impeller and impeller base material cast iron, ductile iron, bronze (bronze) and stainless steel, etc., for ...