Pe3408 high-density, manufactured from selected resins. use for farm/ranch water systems, electrical or cable tv conduit, construction and excavations, city service lines, mine and industrial drainage, sprinkler systems, irrigation, skating rinks, air conditioning, submersible pumps, etc. not to be exposed to direct sunlight for extended periods. not for use for compressed air systems. use with insert fittings and stainless steel clamps. meets or exceeds astm-d2239 and astm-d2737. nsf approval for drinking water use. working pressures based on psi at 73.4 degrees fahrenheit. at higher temperature working pressure is less.