The use of temporary attachments may be used for purpose of assembly, installation by tacking weld. Tacking weld may require a written procedure for application, tack welder may be required a qualified welder.
The method should be used in such a way that the can be easies removed without any damage occurring to the members.
(fit-up nozzle to shell)
All materials used for the temporary attachments should be compatible with parent material.
- Stainless steel tools for stainless steel or non-ferrite steel.
- Carbon steel for carbon steel.
All temporary attachment shall be carefully removed after used, where removal is carried out by
- Air-arc gouging or arc gouging,
- Disk grind cutting,
- Flame cutting,
The cut shall be made clear of any parent material such as that 3.0 mm of the temporary attachment.
100% inspection on the affected area of the parent material shall be carried out.
- Visual inspection
- Surface detection by MT or PT.
If any imperfections are found e.g. undercut or under flushing these areas shall be blended smooth or dressed by welding.
Base material thickness should be verified by the used of ultrasonic inspection or suitable depth gauge.
(MT for grinding marks after removing tack weld)
IMPOTANT: Removal of temporary attachments by hammering or bending may not permitted.