... /GB-12459/GB-T13401,Gost17375MateriaCarbon steel: ASTM A234 GR WPB , ST37.2 , ST35.8……Alloy steel: A234 WP5/WP9/WP11/WP22/WP91, ... , rust-proof oil, transparent oil, galvanizing,, hot galvanizingStainless steel: pickled,Polish Application FieldsChemical Industry /Petroleum Industry /Power Industry ... L/CCERTIFICATESGB/T19001-2008-ISO 9001:2008 seamless pipe fitting elbow a234 wpb sch40,80,xs,xxs