Thermoplastic [PVC, CPVC, Polypropylene, PTFE, or PVDF (Kynar)] pressure relief valve, [ 1/2" through 2"] NPT threads is to be of the 90º angle pattern and featuring a solid, machined, and polished virgin PTFE shaft. The valve's seals shall be comprised of three (3) [Buna-N, EPDM, or Viton] molded u-cups to provide for a low friction operation in conjunction with the PTFE shaft.
Valve is to have Fail-Dry® Safety Design which incorporates a vented chamber between the middle u-cup and the u-cup nearest the spring chamber.
Manufacturer shall, at the factory, set the pressure relief valve at [specify between 5 and 100] PSI. All units are to be 100% individually tested at the factory. As manufactured by Plast-O-Matic Valves, Inc., Cedar Grove, NJ.