ABSTRACT
Over the past few decades demand for reliability of engineering systems has increased significantly. This has been a direct result of the everincreasing cost of 'down time' of major capital plant, where loss of revenue can often exceed £30k per day. In the recent past there has also been a number of major failures of welded structural components and pressure parts which have become headline news, sometimes resulting in loss of life. Such failures include Flixborough Chemical Plant, Milford Haven Bridge, the Alexander Kieland offshore accommodation rig; their cost runs into millions of pounds. Such failures may occur as a result of workmanship or material deficiencies but, equally, are often due to inadequate design. Fortunately, the number of such multi-million pound disasters is limited, but every year equally large sums of money are lost in fabrication workshops due to welding problems. Welds or parent materials crack due to a variety of reasons; porosity and slag makes seams unacceptable; distortion renders components unusable without major rework; unsuitable welding consumables are used or specified properties are not achieved. Problems such as these are encountered every day in industry and result in loss of profit to the fabricator, loss of reputation and often associated delay to major projects. Many of these problems can be avoided if the fabricator follows a systematic course of quality assurance at all stages of his operation.
