This type of pump has a structure suitable for handling saturated liquifies gases with high vapor pressure such as ammonia and propylene The pump features a circulation line on the back side of the motor body. To prevent vaporization and gas accumulation in the motor, the circulation liquid is discharged pump chamber impeller outlet and enters front bearing housing and rotor chamber, and then passes through the reverse circulation piping before returning to the vapor zone in the suction tank, thereby forming a type of bypass piping.
Suitability for economically handling volatile fluids, such as refrigerants, liquefied gasses and other low boilers, and low NPSH margins.