Engineer, Energy Conversion Research Section, Research Div., Philadelphia Electric Co., Philadelphia, Pa
Pages: 13 Published: Jan 1979
This paper describes the results of a five year testing program utilizing acoustic emission (AE) techniques to locate defects in buried gas distribution pipelines. Several weld failures on these lines emphasized the need to develop inspection techniques in order to locate weld flaws in high stress regions to permit prompt repair and assure system integrity. Acoustic emission testing was found to be a feasible technique to locate the flaws. To date over 40 000 m of oxyacetylene welded buried steel pipelines have been tested on the Philadelphia Electric gas system.
This paper discusses some of the procedural and calibration problems encountered in applying the AE technique. The manner in which the emitters were ranked is developed. The contributions of mechanical and electrical error involved in locating the flaw is discussed in the paper. Correlation of AE results with visual examination and other methods of nondestructive evaluation (NDE) is accomplished through comparing the AE emitter ranking with the flaw criticality.
acoustic emission, pipelines, gas pipeline, oxyacetylene welds, crack propagation
Paper ID: STP35075S