ERW welded steel pipe 1) Standard:API 5L,ASTM 36.10M,A106,A53,DIN 1629,1626,BS,JIS.etc 2) Material: ASTM A106/A53,ST37 ... ,35, ERW welded steel pipe1) Standard:API 5L,ASTM 36.10M ... ,gas,chemical,power,shipbuilding,boiler,construction,,metallurgy,etc ERW welded steel pipe