SML Cast Iron Drainage System En877 Cast Iron Pipe Clamps Grip Collar Couplings STAINLESS STEEL COUPLING, CAST IRON PIPE COUPLING, NO HUB COUPLING YU KUNYU Metal pipes and fittings are connected by the cast iron pipe coupling with elastomeric gasket. There are various options of couplings for your choice to satisfy the different applications of pipe system.Stainless steel couplings for European standard EN877.Stainless steel couplings or clamping components is in accordance with EN10088-1 to ensure resistance to corrosion.