1)welding neck, slip - on ,socket welding , blind 2)ASME , DIN ASA JIS UNI ,API, 3)ASTM A105,A182 ,S235 ... TUV CERT ,ISO9001 - 2000, WO , PED.7)Standard: ANSI B16.5, B16.47, MSS, SP-44, AWWA, API, DIN, JIS, HG ... )Production process cut material forged processing machinery packing (3)Certifications ASME B16.5 carbon steel forged socket welding flange