Gas pipe 1.Outer diameters:21-219mm 2.Wall thickness:1-22mm 3.Material: 10#/20#/45# 4.Surface: Oiled or black painted Our products has been widly used in petroleum, chemical industry, mechnical industry, vessel,boiler and electric power and so on, it win opinion by many customers.our products scope is:OD:21-219mm,wall thick:1-30mm.Leading products:Structural seamless steel tube:GB/T8162-2008; ...