Pinch Valve Bodies:
Pinch valves have molded bodies reinforced along with fabric. Pinch valves commonly have a maximum operating temperature of 250oF. On 250oF, maximum operating pressure varies commonly from 100 psig for a 1-inch diameter valve and reduces to 15 psig for a 12-inch diameter valve. Unique pinch valves are available for temperature ranges of -100oF to 550oF and operating pressures of 300 psig.
Many pinch valves are supplied within the sleeve (valve body) exposed. The other style fully encloses the sleeve inside a metallic body. This categories controls flow either along with the conventional wheel and screw pinching device, hydraulically, or pneumatically within the pressure of the liquid or gas inside the metal case forcing the sleeve walls together to shut off flow.
Most exposed sleeve valves have limited vacuum application since of the tendency of the sleeves to collapse while vacuum is applied. A few of the encased valves could be used on vacuum service through applying a vacuum inside the metal casing and therefore preventing the collapse of the sleeve.