ABSTRACT
In the quality assurance and quality control of any manufactured product it is necessary to have defined standards against which quality can be assessed. Such standards will include not only standards of performance of the completed article but also design standards, construction standards (e.g. for dimensional tolerances or methods of manufacture), inspection standards (standardised inspection and test methods) and standards for the materials of construction. Since welding is defined in quality assurance terms as a 'special process' it follows that the ability of the welders and the procedures they use must come under the scrutiny of the quality control and quality assurance systems. Therefore a further set of standards must be defined which relate to the welder's ability (welder approval standards) and the quality of a welding procedure (welding procedure approval standards).
