A bypass is an additional auxiliary line around the pump. In most cases, this line is used to return a partial flow from the suction side to the pressure side of the pump in order to control volumes or pressures. In hygienic applications, positive displacement pumps are often fitted with a bypass to allow cleaning flows to bypass the pumps because the volume flow range is limited. These bypasses are not required for HYGHSPIN twin-screw pumps. With their extremely large operating range, cleaning flows from CIP or SIP process can be run completely through the pump.