... TP316 , WP316L/TP316L, WP321/TP321 , WP310/TP310…..SurfactreatmentCarbon steel:Shot blasted, black painting, rust-proof oil, transparent oil, ... rust-proof oil, transparent oil, galvanizing,, hot galvanizingStainless steel: pickled,Polish Application FieldsChemical Industry /Petroleum Industry /Power ... CCERTIFICATESGB/T19001-2008-ISO 9001:2008 seamless pipe fitting elbow a234 wpb sch40,80,xs,xxs