Page 204 - Welding of Aluminium and its Alloys

Welding procedure and welder approval 187

Table 10.3 Bend coupon testing requirements – BS EN 288 Part 4

Material Former diameter
group
Temper or O F H14 H16 H18 H19 T4 T5 T7
condition H112 H24 H26 H28 H29 T6
H12 H34 H36 H38 H39
H22
H32
21 2t 3t 3t 3t 4t 4t — — —
22.1 3t 3t 3t 4t 5t 5t — — —
33.2 6t 6t 6t 6t 6t 6t — — —
23 4t — — — — — 6t 7t 8t

t = the bend coupon thickness.

Table 10.4 Thickness approval range

Test piece thickness t Range of approval
Butt, T-butt, branches, Butt, T-butt, branches,
single run, one or multi-run, all fillets
both sides
t £ 3 0.8t to 1.1t t to 2t
3 < t £ 12 0.8t to 1.1t 3 to 2t
12 < t £ 100 0.8t to 1.1t 0.5t to 2t (max. 150)
t > 100 0.8t to 1.1t 0.5t to 1.5t

All dimensions in millimetres.

The ranges of approval of the essential variables are given in Clause 8 of
the specification and comprise the following:
• The manufacturer. The approval is restricted to the manufacturer and
workshops or sites under his technical and quality control. Procedure
approval cannot be sub-contracted to a third party or transferred between
fabricators.
• The parent metal. In order to reduce the number of tests required the
alloys have been formed into groups with similar characteristics, as
shown in Table 10.1.
• Parent metal thickness is approved over a range dependent upon the test
piece thickness. For the purposes of this the thickness is regarded (1) as
the thinner of the two materials when dissimilar thicknesses are welded
in a butt joint; (2) as the thinner of the two materials in a fillet weld; (3)
as the thickness of the branch for a set-on branch; and (4) as the thick-
ness of the main pipe for a set-in or set-through branch (Table 10.4).