Welding

At the inletduct of the boiler.
Some cracks have to be welded.
We detect these kind of cracks by using IR photography when the unit is running.
These crakcs occur because of quick temperaturevariations during start-up when the tempearture varies from zero till 300° C and after that it rises to appr 600° C (so from 32°F to 572°F and up to 1112°F).
Also when we have load variations the material has a difficult time.
At some places the inside of the duct can be covered with cladding and insulation but that is not always usable everywhere.

Here in LARGE....