Improvements in flattening test performance in high frequency induction welded steel pipe mill

Areas of improvement in the acceptance criteria to the flattening test described in the pipe line international standards (API 5L and ISO 3183) are discussed. The aim is to make the flattening test acceptance criteria for the high frequency induction welded (HFIW) steel pipe clearly stated and defined so that there will be no argument about its interpretation. Recommendations for improving the mill set up to enhance the flattening test performance are also presented based on practical implementation in Saudi Steel Pipe Company. The process capability index is also used as quantitative tool to measure and monitor the performance of the flattening test using the height of the first weld crack as a basis of measurement.