The Universal Couplings are designed for pipelines , As a wide tolerance system it will fit most standard pipe materials and therefore dramatically reduces the number of dedicated Couplings which need to be stocked for maintenance purposes , It is suitable for steel , GRP, PVC, PE, Ductile Iron , Cast Iron and Asbestors Cement . When connecting PE pipes , It is important that pipe inserts are fitted to the PE pipes . 1) All the couplings are assembled by " D " bolts . 2) Bolts ,Nuts and Washers are in carbon steel Grade 4.8 , 8.8 with zinc plated , dacromet coating or according to customer's request. 3) Body material is Ductile iron GGG500-7 . 4) Fusion bonded epoxy powder coating in blue, black or red or according to customer's request . 5) Gaskets material : E.P.D.M. , NBR or SBR .