Abstract: A disposable fluid infusion pumping chamber cassette comprises a sandwich type construction which lends itself to a multiplicity of control and monitoring functions including pressure monitoring, air bubble detection monitoring, adaption to multiple inputs, and leak detection monitoring, the cassette includes a rigid face member and a rigid back member having an elastomeric diaphragm positioned therebetween, provides for the transmission of fluid from one end of the cassette to the other, and includes an enlarged recess portion forming the pumping chamber, with exposed openings in the face member opposite the pumping chamber to permit the passage of a plunger and opposed openings adjacent the fluid passage to permit the selective actuation of valving members therein, with a flow control member mounted upon the face member adjacent the passage between the pumping chamber and fluid outlet thereof, which is utilized to either open the passage to free flow of fluid or to block it off completely.