... seamless tube, straight welding or spiral welding tubes. 2) Standard: API, ANSI, ASME, JIS, DIN 3) As customer requirement 4) Surface ... industries. We have passed the current international standard ISO9001: 2000, API Q1 6H-0013, ASME certificate. The production is according to ... standards of GB, HG, SH, SY, DL, JB, API, ASTM, DIN, and JISB. We also provide non-standards products ...