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Reg. 611 (c), Reg.
611 (d), Reg. 611 (e)
QUALIFICATION
TESTS FOR WELDERS ENGAGED IN WELDING OF BOILERS AND STEAM-PIPES
UNDER CONSTRUCTION, ERECTION AND FABRICATION AT SITE IN INDIA
AND IN REPAIRING BOILERS AND STEAM-PIPES BY WELDING
Reg 611
(c) Groove and fillet welded pipe and tube specimens
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The groove welded pipe and tubes specimens shall be
marked and test pieces cut out as in Figure
XIII/3.
The test pieces shall be prepared for face bend, root
bend and etch test.
The pieces shall not be flattened, but tested in their
curved conditions. The penetration bead may be removed
to 0.8 mm. (1/32”) proud of the surface of the
material.
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Fillet welded branches
shall be tested for:- |
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(i) |
Visual
examination:-
The test welds so obtained shall be visually examined
for root penetration, freedom from undercut, disposition
of runs, uniformity of surface, shape of profile, smoothness
of joint, freedom from cavities and slag, dimensions of
weld deposit, quality of weld metal (overheating, surface
cracks, spongy surface, etc.). Any piece showing serious
defects shall be rejected. |
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(ii) |
Macro
examination:-
Each branch weld test piece shall be sawn as shown in
Figure XIII/4 and each portion so produced shall be prepared
and etched. The sections shall then be examined for degree
of fusion, degree of root penetration, absence of non-metalic
(slag) inclusions and quality of weld metal. The joint
should show good root fusion, complete freedom from basal
cracking, and the absence of any but very minor defects. |
Reg. 611
(d) Welded
Tube Joints
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A test length approximately 203 mm long shall be cut
from the tube with the welded joint disposed approximately
at the centre. After visual examination, one test piece
not exceeding 13 mm. for tubes 6 mm in thickness and
below and thrice the thickness of the tube for thickness
of over 6 mm. shall be cut longitudinally. The test
piece shall not be less than 76 mm. in length on either
side of the weld. The slight excess of internal bead
may be filed until it is not more than 0.8 mm. proud
of the general surface. The test piece shall then be
bent back with the root in tension through 90 degree round a
former of diameter equal to three times the thickness
of the tubes. With regard to alloy steel pipes and tubes,
the bend test specimen shall be bent without being straightened,
but after removal of the weld reinforcement down to
the level of but not below the surface round a former
of diameter 4t and through an angle of 90°. The
bending may be carried out by blows or by pressure.
Care shall be taken to ensure that the former is so
positioned that the weld is maintained at the crown
of the bend. The test specimen shall be capable of being
bent through 90 degree without signs of failure, although
slight premature failure at the edges of a specimen
need not be considered a cause for rejection. The opening
out of a slight defect due to incomplete root penetration
or lack of root fusion need not be considered a cause
for rejection, provided the defect has sound metal at
the back and on either side of it.
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Reg. 611
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(e)
Additional
tests before rejection
Should any of the test pieces tested in accordance
with the above sub-regulations fail to meet the specified
requirements, one further strip may be cut from the specimen
and subjected to the same test. If any test piece does
not reach the required standard two further welds shall
be made and the procedure in the above sub-regulation
repeated. If any of these welds does not reach the required
standard, the welder shall be deemed not to have qualified
for a certificate. |
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