Style SEMSD Flex-Rubber Expansion Joints are generally used in heating and air conditioning systems, for hot and cold water service, and for mild chemicals and oils. Manufactured using double sphere neoprene tube and cover. End fittings are 150# Zinc plated carbon steel flanges, with a steel bead flange retainer. No separate retaining rings are ever required. Working pressures up to 225 psi. Temperatures up to 220°F. Standard sizes range from 2" through 12" I.D.