Tube to tube sheet expansion 1

[Rizwan.O.]

We have a leaky tube-to-tube sheet joint in our water tube boiler. After decision from the company, we re-expanded the tubes, but the problem still remains. The question that I have is, how can we get to know if further expansion is permissible or not?
What measuring tools could help me in finding and calculating the thinning ratio?
And what physical conditions should I focus on when permitted to enter inside the drum?
Your expert opinion will be extremely appreciated.
Thanks

 

[EdStainless]

Thinning ratios are an approximation.
And since you don't know the original hole size or the original tube dimensions measuring now tells you nothing.
If these parts are all carbon steels and the leak has existed more than a few days, then forget it.
There will be corrosion products in the joint and re-rolling won't get you a seal.

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P.E. Metallurgy, consulting work welcomed

 

[r6155]

Try with seal weld.

Regards

 

[Rizwan.O.]

Considering your opinion, Is there any way to remove those corrosion products from the joint.

 

[0707]

Rizwan

I think re-expanding your boiler if it already has corrosion doesn't work, maybe it could result in plugging some pipes, but I doubt it, what is the percentage of pipes leaking? Removing the corrosion products from the expansion interstices is not a feasible job, I think you have to re-intubate your exchanger.

good luck

luis