PVC material is Type 1 according to the America Society for Testing Materials (ASTM) D-1784. Fittings conform to ASTM D-24-66. Temperature rating 140°F (60 °C). PSI is based on water at 73°F (23 °C). Derate 50% at 110°F ( 40 °C) and 78% at 140°F (60 °C). Not recommended for use in compressed air or gas systems. Schedule 40 pipe should never be threaded.