Page 215 - Welding of Aluminium and its Alloys

198 The welding of aluminium and its alloys

welding results, to set and control the parameters in accordance with an
approved welding procedure, to test the operation of the welding unit
and to be capable of recognising and reporting any malfunctions.Annex
B of the specification gives information of what knowledge the opera-
tor/resistance weld setter would typically be expected to have.
Provided that the operator/resistance weld setter successfully completes
one of the above tests then there is no limit to their range of approval.This
is provided that they continue to work with the same type of welding unit,
the welding process is not changed and they work in accordance with an
approved procedure.Automatic and robotic welding approval using a multi-
run technique gives approval for welding with a single run but not vice
versa; approval to weld without a sensor gives approval for welding with a
sensor but not vice versa; changing the robot type, system or control unit
requires re-approval as does any change to the other essential variables.
Provided that the operator/resistance weld setter works with reasonable
continuity, i.e. no break is longer than six months, and there is no reason to
question their competence then the approval is valid for a period of two
years.The employer must endorse on the approval certificate at six monthly
intervals that this is so. If the employer keeps records of non-destructive or
mechanical tests carried out at a maximum of six month periods and these
confirm that the required quality is being maintained then the examining
body can endorse the approval certificate at the end of the two year valid-
ity period for further periods of two years.