Page 15 - Quick Guide to Welding and Weld Inspection by S.E. Hughes, Clifford Matthews

A Quick Guide to Welding and Weld Inspection

welding procedure qualification documents consist of a
Welding Procedure Specification (WPS) and a Procedure
Qualification Record (PQR) containing essential and non-
essential variables.
Spend one minute reading about essential, non-essential and
supplementary essential variables.
5. Why does a welder need qualification? (one
minute)
Welders require qualification to prove that they have
sufficient knowledge and skill to produce a weld in
accordance with a welding procedure and achieve a result
that meets the relevant specification. A welder qualification
test form records the range of variables qualified from the
essential variables.
Spend one minute looking at the variables contained in a
WPQ form.
6. What are welding defects? (two minutes)
There is no such thing as a perfect weld because all welds
contain imperfections of some sort. These imperfections need
to be assessed to determine if they will have a detrimental
effect on the welded joint. They are normally assessed against
the acceptance criteria specified in the relevant code or
standard but only an imperfection found to be outside the
acceptance criteria limits will be classed as a defect and
require action to be taken. The action to be taken could
include:
. rejection of the component;
. removal of the defect and re-welding of the joint;
. a fitness-for-purpose analysis being carried out with a
concession being granted allowing the defect to remain.
Spend two minutes determining what defects can occur in
welds.

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Woodhead Publishing Ltd – A Quick Guide to Welding and Weld Inspection
Data Standards Ltd, Frome, Somerset – 17/9/200900QG Welding Prelims.3d Page 14 of 14