Marketing InformationFKM Chemical Resistant Couplings are designed to provide flexible, watertight joints on chemical drainage systems. This range of couplings offers the chemical & process industries the advantage of a modern, mechanical jointing system for plain end cast iron, plastic, steel, glass, and Duriron® pipes and fittings. They consist of a high performance fluoroelastomer (FKM) sleeve, an outer stainless steel shear ring and two AISI 301 stainless steel clamping bands.