All thermoplastic valves shall be wafer butterfly type constructed from PVC type 1 cell classification 12454 or CPVC type IV cell classification 23447. All valve seats and O-Rings shall be Buna-N, EPDM or FKM. Seat shall be a non-liner type mounted to the valve disc. All valves shall have built-in Santoprene™ thermoplastic elastomer (TFE) flange gaskets. Wafer style valves shall be for mounting between two flanges having bolt hole pattern that conform to ANSI/ASME B16.5 Class 150. Disc shall be centered with type 316L stainless steel stem. stem shall be isolated from the process medium for dry operation. Lever operated valves shall be equipped with high impact polypropylene handle having 7-position stops and built-in lockout capability. Gear operated valves shall be equipped with position indicator and high impact polypropylene handwheel. Valves shall be pressure rated at 150 psi for water at 73 deg F, as manufactured by Spears® manufacturing company.