HDG steel pipe 1. many different sizes of the products 2..low ... according to requirementsAnti-corrosion and high-temperature resistant with black paintingAll the production process are made under the ISO: ... Drawn,Seamless,ERW,LSAW,SSAW,7) Surface treatment:bare,black painting,anti rust oil,hot dipped galvanized,3pe,etc8) ... ,chemical,power,shipbuilding,boiler,construction,,metallurgy,etc HDG steel pipe