Abstract: A peristaltic type pump for pumping ink to a printing section of a corrugated paperboard finishing machine capable of both pumping ink to the printing section and pumping excess ink from the printing section back to an ink supply as well as pumping a cleaning fluid to the printing section and pumping excess cleaning fluid back to a sump. The pump includes at least one pumping element for pumping the ink or cleaning fluid to the printing section and at least one but preferably two pumping elements for pumping the excess ink or excess cleaning fluid back to the ink supply or sump respectively. Each pumping element includes a rotor having at least two but preferably three or more lobes for compressing two portions of a semicircular portion of a flexible tube surrounding the rotor to confine a finite quantity of ink or cleaning fluid in the tube between two of the lobes in sucession during rotation of the rotor to force the ink or cleaning fluid from an inlet to an outlet of the pump.