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 deg F, SCH 40 range from 370 (1-1/4 in pipe) to 600 (1/2 in pipe) depending on ID size.