A pinch valve includes a body with a passageway extending therethrough, a flexible sleeve mounted within the body and surrounding the passageway, and a cavity between the sleeve and the body. An inlet opening provides control fluid flow into the cavity, while an outlet opening allows for fluid exhaust from the cavity. The diameters of the inlet and outlet openings are fixed, with the inlet diameter being smaller than the outlet diameter. A two-way control valve opens and closes the outlet opening, and thereby controls opening and closing of the pinch valve.