Plast-O-Matic Valves” Series MFR shutoff valve is a 1/2″ palm- or foot-operated device with no metals or external fasteners. Designed for high-purity or corrosive environments, the balanced, compact valves are designed for liquid service to 150 PSI. The balanced aspect means the valve outlet pressure, commonly known as backpressure, can be as high as the inlet pressure without affecting performance. The normally closed design has a spring return and will automatically close “fail safe” when hand or foot force is removed. The valve is offered in Grade 1 Type 1 PVC or natural polypropylene for heavy-duty applications.