Used in cold water pressure applications only, such as irrigation and underground residential sprinkler systems; also used to make outdoor furniture. Pipe sizes are the same as iron pipe sizes. Meets ASTM-D1785. Approved for potable water piping systems. Solvent weld, use with pressure fittings. PSI ratings at 73 degrees Fahrenheit- Schedule 40 range from 370 (1-1/4" pipe) to 600 (1/2" pipe) depending on ID size.