... . K7&K9&K8 3.ling according to ISO4179 ductile iron socket spigot pipe Standard: JIS, AISI, ASTM, GB, DIN, ENPlace of ... High pressure steel prof...tolernace: normal standard toleranceShape: round,square,rectangularsurface: pickled, acid, polished, black,ectcertificate: ISO, BV, API, CSC,DNV,ectnormal ... is supplied with shipment, Third Part Inspection is acceptable. ductile iron socket spigot pipe