Scrubber Inlet 360deg Repairment (Starboard & portside) for M/V MAASTRICHT MAERSK

项目名称:

Scrubber Inlet 360deg Repairment (Starboard & portside) for M/V MAASTRICHT MAERSK

项目开始时间:

2024-05-30 14:23


项目类型:

othere

项目描述:

There are cracks and corrosion of inlet duct of marine scrubbers. in need of repair.


进展:

Check for cracks and corrosion in the inlet duct of marine scrubber.

Check for cracks and corrosion in the inlet duct of marine scrubber.

We found a lot of black clay covering the inlet and flow divider.The worker used a shovel and polish machine to clean up dirt.
After cleaning , we removed the black clay of the inlet and found there’s corrosion all over the circle , which was consistent with the result of corrosion from the appearance:
Corrosion all over the circle, large cracks can be observed on both sides
Thickness measurement:
After cleaning and lapping start thickness measurement , the left and right sides were found serious corrosion ( Remaining thickness:3mm~4mm), but the top and bottom were mild corrosion(Remaining thickness >4mm)
Add fix plate above the crack so that crack is in the middle of the plate and plate is aligned with the crack direction:

进展:

Welding the plates & Grinding smooth

Welding the plates & Grinding smooth

Each plate has welds at both ends, the weld fuses with the inlet's shell, this ensures that after a certain plate is corroded and leaked, washing water will not enter other plate areas.
During the welding process, it is necessary to ensure that the interlayer temperature of the weld is below 80℃.
Due to the corroded area is large,so we chose to use spare plates to cover all the corroded area.

进展:

Do a good VT check to prevent missing any areas of welding. PT checking after welding

Check all welds to avoid welding crack.

进展:

Job done

Conclusion / summary

The 360 deg welding work was done well and the leak was repaired.
However, we know that corrosion will continue (although the risk of leakage is greatly reduced), so it is still necessary for the crew to check the Inlet every month.
For this 360° welding maintenance, I have the following experiences:
1.All welds should be welded at least twice to avoid weak welds, this also reduces missed welds;
2.Before welding, clean the welding area, otherwise the residual dirt will be difficult to weld, you can use a shovel and iron brush and polish machine to clean up;
3.The double plate is deformed during transportation and needs to be fixed by Seawave using support bindings during transportation;
4.Inlet's interior is not smooth, there are many welds in the middle of the plate does not match 100%, workers spend a lot of time cutting spare parts, so prepare a spare plate, in case the plate does not cover the shell 360°;
5.Check the back of the inlet, as there are areas where the shell is weak and thin and can easily burn through when welded(Pay special attention when the thickness is less than 3mm);
6.When welding the top area of the Inlet , set up the stages can be used;
7.  Finally, remove the iron sheet and insulation of the outer ring of the scrubber, check the weld condition, and repair welding according to the inspection condition.
8.The plates is completely covered on the inside,so it won’t leak.
The remaining wall thickness at welds near the damper side of the double plate > 3.00 mm.

Scrubber Inlet 360deg Repairment (Starboard & portside) for M/V MAASTRICHT MAERSK

项目名称:

Scrubber Inlet 360deg Repairment (Starboard & portside) for M/V MAASTRICHT MAERSK

项目开始时间:

2024-05-30 14:23


面积:

装修风格:

othere

装修单元类型:

There are cracks and corrosion of inlet duct of marine scrubbers. in need of repair.

区域:


进展:

Check for cracks and corrosion in the inlet duct of marine scrubber.

Check for cracks and corrosion in the inlet duct of marine scrubber.

We found a lot of black clay covering the inlet and flow divider.The worker used a shovel and polish machine to clean up dirt.
After cleaning , we removed the black clay of the inlet and found there’s corrosion all over the circle , which was consistent with the result of corrosion from the appearance:
Corrosion all over the circle, large cracks can be observed on both sides
Thickness measurement:
After cleaning and lapping start thickness measurement , the left and right sides were found serious corrosion ( Remaining thickness:3mm~4mm), but the top and bottom were mild corrosion(Remaining thickness >4mm)
Add fix plate above the crack so that crack is in the middle of the plate and plate is aligned with the crack direction:

进展:

Welding the plates & Grinding smooth

Welding the plates & Grinding smooth

Each plate has welds at both ends, the weld fuses with the inlet's shell, this ensures that after a certain plate is corroded and leaked, washing water will not enter other plate areas.
During the welding process, it is necessary to ensure that the interlayer temperature of the weld is below 80℃.
Due to the corroded area is large,so we chose to use spare plates to cover all the corroded area.

进展:

Do a good VT check to prevent missing any areas of welding. PT checking after welding

Check all welds to avoid welding crack.

进展:

Job done

Conclusion / summary

The 360 deg welding work was done well and the leak was repaired.
However, we know that corrosion will continue (although the risk of leakage is greatly reduced), so it is still necessary for the crew to check the Inlet every month.
For this 360° welding maintenance, I have the following experiences:
1.All welds should be welded at least twice to avoid weak welds, this also reduces missed welds;
2.Before welding, clean the welding area, otherwise the residual dirt will be difficult to weld, you can use a shovel and iron brush and polish machine to clean up;
3.The double plate is deformed during transportation and needs to be fixed by Seawave using support bindings during transportation;
4.Inlet's interior is not smooth, there are many welds in the middle of the plate does not match 100%, workers spend a lot of time cutting spare parts, so prepare a spare plate, in case the plate does not cover the shell 360°;
5.Check the back of the inlet, as there are areas where the shell is weak and thin and can easily burn through when welded(Pay special attention when the thickness is less than 3mm);
6.When welding the top area of the Inlet , set up the stages can be used;
7.  Finally, remove the iron sheet and insulation of the outer ring of the scrubber, check the weld condition, and repair welding according to the inspection condition.
8.The plates is completely covered on the inside,so it won’t leak.
The remaining wall thickness at welds near the damper side of the double plate > 3.00 mm.

进展:

进展:

进展: