... black painting, rust-proof oil, transparent oil, galvanizing,, hot galvanizingAlloy steel:Shot blasted, black painting, rust-proof oil, ... transparent oil, galvanizing,, hot galvanizingStainless steel: pickled,Polish Application FieldsChemical Industry /Petroleum Industry ... L/CCERTIFICATESGB/T19001-2008-ISO 9001:2008 seamless pipe fitting elbow a234 wpb sch40,80,xs,xxs