Thermoplastic [PVC, Polypropylene, PVDF (Kynar) or PTFE] three port pressure relief valve [ 1/2", 3/4", 1"] NPT threads, with flat PTFE diaphragm, backed by Viton, as the primary seal. Adjusting bolt and lock nut are to be all plastic. Valve is to have Fail-DryŽ Safety Design incorporating a vented chamber between the flat diaphragm and a secondary elastomer diaphragm to protect the spring chamber. [Optional:] Manufacturer shall factory set the pressure relief valve at [between 5 and 100] PSI.
ADD: "With tamper-proof option" after pressure setting, if required.
All units are to be 100% individually tested at the factory. As manufactured by Plast-O-Matic Valves, Inc., Cedar Grove, NJ.