These are Schedule 80 PVC socket fittings. Schedule 80 is also NSF listed, has a 33F - 140 F working temp, and is available in gray. For UV resistance of PVC pipe and fittings, paint with a white water based latex paint. Both have a wide variety of uses in the chemical field and industrial plants, just to name a couple. All Schedule 80 socket fittings are manufactured in strict compliance to ASTM D 2467. PVC Schedule 40 and 80 fittings are produced from PVC Type I, cell classification 12454, conforming to ASTM Standard D 1784. Lasco is the manufacturer of the flanges. Nibco-Chemtrol is the manufacturer of the gaskets.