All thermoplastic repair couplings shall be constructed from white or gray Polyvinyl Chloride (PVC) Type I compound having a cell classification of 12454 conforming to ASTM D1784. All repair couplings shall be furnished with double O-ring seal in EPDM or FKM elastomer material. Socket X Spigot or Socket X Socket end connections shall be offered. Repair couplings in 1/2 to 3 in shall have an internal pressure rating of 235 psi at 73 deg F, 2-1/2 to 4 in, 200 psi at 73 deg F, 6 in 150 psi at 73 deg F as manufactured by Spears® Manufacturing Company and be certified for use in potable water applications by NSF® International.