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AIM: To weld build up over the reducer ID for proper matching
with the connecting
CRA Cladded pipe.
Need of weld buildup: ID mismatch was observed during fit up
stage of reducer
and CRA Cladded pipe. The root cause of the problem was
identified that the
reducers were procured according the thickness of pipe without
considering the
Cladded thickness. To solve this problem suggestion was made by
L&T to put weld
overlay over the ID of the reducers and the methodology was
approved by
COMPANY.
Methodology adopted: It was proposed to test a mock up piece
according to the
Approved Method Statement. The COMPANY Approved method statement
for weld
overlay is attached along with.
Execution stage of work: The various steps followed for the work
execution are:-
1. A surplus eccentric reducer (IMIR No. 93/5) was identified
for the actual
execution of the test.
2. COMPANY approved WPS was identified according to the
requirements of the
job.
3. COMPANY approved welder (qualified into the required welding
process i.e.
GTAW) was identified and d about the job to be done.
4. Marking was done before actual start and witnessed by GL
& ADMA.
Marking on the reducer.
5. First run was overlaid and shown to GL & COMPANY.
First run overlaid.
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6. In the same manner with subsequent runs one layer was
completed and
witnessed by GL & ADMA.
First layer Completed
7. On completion of first layer DP test was carried out in
presence of GL & ADMA.
Result of DP was found OK. Report attached
DP testing being carried out
8. After DP and Cleaning Second layer was overlaid in the same
manner and DP
was carried out. Result of the testing was found OK. Report
attached
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Second layer completed & DP being carried out.
9. Then the test piece was offered for RT. RT film was witnessed
by GL and found
OK. See report attached.
RT marking shown on the test piece.
10. After successful completion of RT the test piece was sent
for machining.
Machining of the reducer was a great hurdle for which Mr. J K
Das (Machine
shop foremen) found out a solution and a casing was made as
shown in figure.
Reducer & the casing made for machining
In this casing any type of reducer (Concentric/Eccentric) can be
easily fixed and
machined which reduces the job set up time as well. SS bolts
were used and
packing of SS sheets was used for tightening the reducer into
the casing.
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11. Machining was done by putting the reducer into the
casing.
Reducer fitted into casing Machining in progress
12. After machining all the length, thickness, ID, OD was
checked and found
within the limits.
13. Final product after machining is as shown under.
14. After final machining a trial fit up was shown to COMPANY
and found OK.