ISO2531-1998,IS02531-2009. K And C Class We are the first one that produces centrifugal casting ductile ... .Material: Ductile iron(1) The standed:ISO2531-1998,EN545-2006, C Class ,K9, K8(2) Effective length:6M by bulk shipment,5 ... service life.(7) Checked by automatic inspection instrument Ductile Iron Pipe K7-K12