Plast-O-Matic Valves”Series MFR shutoff valve is a 1/2″ palm- or foot-operated device withno metals or external fasteners. Designed for high-purity or corrosiveenvironments, the balanced, compact valves are designed for liquidservice to 150 PSI.  The balanced aspect means the valve outletpressure, commonly known as backpressure, can be as high as the inletpressure without affecting performance. The normally closed design hasa spring return and will automatically close “fail safe” when hand orfoot force is removed. The valve is offered in Grade 1 Type 1 PVC ornatural polypropylene for heavy-duty applications.