Polyurethane feeding tube and associated adaptors

1. Field of the Invention A feeding tube assembly includes a feeding tube, a polyurethane feeding tube adaptor having an inlet conduit and an outlet conduit, and a removable cap for selectively closing the inlet conduit. The surface configuration of the cap that causes frictional engagement with the inlet conduit is noncomplementary therewith in a common transverse plane and has a cross-sectional shape substantially different than that of the corresponding surface configuration of the inlet conduit. This difference in surface configurations can be established by providing one or both of the surfaces with a series of protuberances, indentations, or other surface variations.