... pipe, ERW pipe, Seamless pipe, Casing pipe.Spec:GRB-X42-X100 our company (XINYUANTAI STEEL PIPE ... manufacturer.we already passed *ISO certificate, and API 5L and API 5CT cetificate.* our products are seamless steel pipe ... STANDARD GB3091-2001 GB9711.1 GB9711.2 API5L API 5CT MATERIAL ST37,ST44,ST52, Q235B/Q345B/L245 ... GB/T8163-1999 GB3087-1999 GB5310-1999 API5L API 5CT MATERIAL ST37,ST44,ST52,Q345B/20#/45 ...