Sets out the requirements for the fusion welding of aluminium structures and equipment by inert-gas arc welding processes. The Standard provides for three categories of butt welds and one category of fillet weld. Tables of aluminium alloys suitable for welding, details of welded connections, methods of qualification of procedures and personnel, workmanship, weld quality and inspection requirements are included. Appendices are also included as a checklist of matters for discussion and guidance on the selection and extent of non-destructive examination.