Page 35 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

A Quick Guide to Welding and Weld Inspection

maintained by suitably qualified persons using suitable
procedures and equipment. PWHT may be required
before and after NDE when hydrogen cracking is a
possibility.
. Ensure required NDE is carried out and review the results.
. Visually inspect and measure the completed weld and
assess any imperfections in accordance with the relevant
code acceptance criteria.
. Maintain weld records with weld identification.
. Ensure any required pressure testing of piping and
pressure vessels is carried out after PWHT and results
recorded.
. Take final dimensional checks after pressure testing.
. Collect and collate all the relevant documentation and
pass the completed package to the relevant acceptance
authority.
Repairs
When a defect is identified during the inspection, three main
options exist, depending upon the severity of the defect and
the component being welded. The component can be
scrapped, it can be given a concession or it can be repaired.
. A concession is a situation where a defect is deemed not to
have too detrimental an effect on the component and the
client agrees in writing that the defect can remain in place.
In some cases the concession conditions may mean a
limitation is placed on the component service conditions
and/or a repair is required at a more convenient time.
. A repair can in some cases require a different welding
process, different consumables or some other change to
the original procedure to be used. There may be
limitations on the number of repairs or thermal cycles
applied to the component depending on the material used.
A repair procedure should be in place detailing what
actions are required.

20

Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200902QG Welding chap2.3d Page 20 of 21