Failure of Stainless Steel Pipe in Fertiliser Plant — Examination

THE sample submitted consisted of a short length of 2‐in.‐bore stainless steel pipe which had been sawn in half longitudinally. There was a fracture at one end of the sample, whilst at the other it had been threaded externally to take a heavy stainless steel nozzle. Fig. 1 shows diagrammatically the position of the sample relative to the adjacent components. This assembly was part of a fertiliser plant handling a mixture of chemicals consisting chiefly of ammonium nitrate but also including potassium chloride.