ERW welded steel pipe 1) Standard:API 5L,ASTM 36.10M,A106,A53,DIN ... .etc 2) Material: ASTM A106/A53,ST37,35, ERW welded steel pipe1) Standard:API 5L,ASTM 36.10M,A106,A53,DIN ... ,gas,chemical,power,shipbuilding,boiler,construction,,metallurgy,etc ERW welded steel pipe