PVC Schedule 40 pressure fittings used for potable water, chilled water, irrigation, golf course construction, and pool & spa. PVC (Polyvinyl Chloride). PVC is one of the thermoplastic materials most frequently specified for a variety of products used in the Pipe and Fittings Industry. Due to its excellent rigidity, corrosion and chemical resistance properties, it is also used in many chemical related areas. Design Standards - NIBCO PVC Schedule 40 pressure fittings conform to ASTM Standards D-2466. Included in the standard are thread and socket specifications, by length, wall thickness, burst, material, quality and identification requirements. PVC 40 fittings are manufactured from material conforming to ASTM D1784 and meeting cell Class 12454-B. NSF approved