Plast-O-Matic Valves”Series PRA pneumatically controlled pressure regulator, also known as apressure-reducing valve, maintains a constant downstream pressure fromfive to 125 PSI with a high accuracy over varying flowrates. Theair-controlled pressure regulator is designed for highly corrosive andultra-pure chemicals. It uses compressed air and two rolling diaphragmsto control liquid pressure with greater accuracy than spring-loadedregulators. The instrument routinely handles inlet pressure up to 150 PSI.Available in a number of rugged thermoplastics, including Grade 1 Type1 PVC, natural polypropylene, and Kynar PVDF.  Elastomers are FKMor EPDM. Pipe sizes range from 1/2″ through three inches.