... (1 1/4"--120")Rubber material: EPDM,NBR, NRRubber sphere: Single sphere, Double sphere Flange: ANSI B16.5, DIN2501, BS4504 Flange material: ... Carbon steelFlange surface: Galvanized Main Material: No.NameMaterial1Outer/inner rubberNR,EPDM, ... water,hot water,oil,acid,alkali etc EPDM double sphere rubber expansion bellow joint