A feeding set adaptor (100) and related system for delivering solutions utilize a feeding set adaptor which engages a pump engaging portion (200) of an infusion set and the feeding set adaptor structure to provide monitoring portions for detecting pressures within the infusion set, a sample cell (124) for determining the presence of air within an infusion set, and an anti-fleeflow device (300) for selectively preventing freeflow through the infusion set. The feeding set adaptor is configured for mounting on an infusion pump (320) which moves solution through the infusion set for delivery to a patient.