Thermoplastic [PVC, Polypropylene, PTFE, or PVDF (Kynar) ] pressure relief valve,
[ 1/4" or 1/2"] NPT threads, is to be of the 90º angle pattern and feature a one piece [Buna, EPDM, Viton, or Kalrez] elastomer diaphragm for sealing. The valve is to have a solid, machined, and polished virgin PTFE plunger in the spring chamber. The valve shall have an overall height of not more the 5 5/8" including the adjustment bolt, and an overall body diameter of not more than 2 1/2". The valve is to have 300 series or similar stainless steel fasteners.
Manufacturer shall, at the factory, set the pressure relief valve at [specify between 5 and 150] PSI. All units are to be 100% individually tested at the factory. As manufactured by Plast-O-Matic Valves, Inc., Cedar Grove, NJ.