... SP-75 DIN2605 JISB2311 JISB2312 JISB2313, BS, GB, ISOmaterialCarbon steel(ASTM A234WPB,,A234WPC,A420WPL6. 20#,Q235,10#,20#,A3, Q235A ... , 20G,16Mn, ect)Stainless steel(ASTM A403 WP304,304L,316,316L,321. 1Cr18Ni9Ti, 00Cr19Ni10,00Cr17Ni14Mo2 ... Petroleum Corporation.We are also qualified the standard material supplier of China National Offshore Oil Corporation and China Petroleum ...