1.Standard:API,ASTM,JIS,DIN,GB,EN,BS. 2.Certification:ISO9001,API ASTM welded steel pipe Standard: ASTM A106, ASTM A53, API 5L, API 5CT, GB/TB163, GB/T8162 Steel grade:Q235,Q345,GR,B; ST52.3 and other special requirement Size range: OD 13.7~711mm, WT:2~40mm
