Inspection of Finned Tubes

[Inspengrmm]

Hi,

We are operating a heating coil downstream of a primary reformer (furnace) at an ammonia plant with tube dia of 48 mm. The flue gases of the furnace are being used for steam generation from Boiler Feed Water inside the tubes. The tubes are finned externally on the entire exposed length.

Can anyone share their experience on external inspection of finned tubes for symptoms related to overheating and consequent life assessment?

Regards,

 

[metengr]

External inspection can be evaluation of the fin profile and spacing. If tube swelling from creep is occurring, this can be an indicator. Other than actual tube samples, you can try remote field eddy current testing to evaluate tube wall loss or borescope inspection of the tube ID surfaces to check for oxide spalling or blistering.

 

[vanmorrison]

Inspengrmm, What is the material and tube thickness?
What symptoms do you expect from overheating of these tubes?

 

[0707]

For overheating, take a sample of the fins that you suspect that are overheated and make a metallographic analysis, maybe it will be worthwhile. For assessment of remaining life, you should also consider, if possible, to install in the more susceptible fins, skin thermocouples.

regards LM