12.6
CAST PADEARS AND WELDED TRUNNIONS
12.6.1
Cast padears and trunnions shall be designed taking into account the following aspects:
The geometrical considerations as indicated in Section 12.4.
The stress analysis and finite element design process (modelling and load application).
Load paths, trunnion geometry and space and support for slings and grommets.
The manufacturing process and quality control.
Sling keeper plates shall be incorporated into the padear/trunnions design to prevent the loss of
slings or grommets during load application and lifting. These devices shall be proportioned to
allow easy rigging and de-rigging whilst being capable of supporting the weight of the sling
section during transportation.
12.7
INSPECTION OF LIFT POINTS
12.7.1
All lift points shall be inspected prior to any lifting operation. For the first lift, the level of inspection for
welds which form part of the load transfer system in the lift point shall be:
a.
100% visual for all welds, and
b.
100% MPI (Magnetic Particle Inspection) for all fillet welds, partial penetration welds and butt
welds, and
c.
100% UT (Ultrasonic Testing) for all butt welds.
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GUIDELINES
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0027/ND Rev 11
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12.7.2
For subsequent lifting operations using the same lift points, a visual inspection will be adequate
provided that:
a.
The visual inspection shows no damage to the lift point material and welding
b.
The rigging system is similar to that used for previous lifts and that the lift points have been
designed for that rigging system
c.
No excessive or uncontrolled loading has, or suspected to have, occurred during the preceding
lifts
d.
All design utilisations for primary load transfer in the lift points are less than 0.8.
12.7.3
Where the visual inspection shows that damage has occurred, appropriate repairs are to be taken
which shall be subject to the 100% visual, MPI and UT requirements given in Section 12.7.1.
12.7.4
Where excessive or uncontrolled loading has occurred, and member /weld utilisations are less than
0.8, all primary welds are to be inspected with 100% visual and 50% MPI with butt welds also tested
with 50% UT.
12.7.5
Where excessive or uncontrolled loading has occurred, and member /weld utilisations are greater than
0.8, all primary welds are to be inspected with 100% visual and 100% MPI with butt welds also tested
with 100% UT.
12.7.6
Where the rigging system used is different to the design rigging system, all primary welds are to be
inspected with 100% visual and 100%MPI with butt welds also tested with 100%UT.
12.7.7
For lift points with utilisations of primary load transfer members /welds greater than 0.8, the level of
inspection shall be a minimum of 100% visual, 20%MPI with butt welds also tested with 20%UT.
12.7.8
The extent of NDT shall be submitted for review.
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