... is used in petroleum,chemical,electric power,boiler etc as they Resistance to high temperature, low temperature resistance,Corrosion resistanceASTM SA335 A335P22A335P5A335P9A335P91stainless ... ,X60,X65,X70,X80ERW STEEL PIPEUsed in general structure stents, low voltage liquid transportation, etcGB/T13793-1992GB3091-2001A53A333 GR6Sprial steel pipeApply to ...