ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
(OP)
Hi All,
The history docket for a tube bundle we received from our manufacturer demonstrates that several tubes fall outside of the manufacturer's specified percent wall reduction range. We are now concerned that the tube-to-tubesheet joint strength is not adequate for these tubes and we may have to reject this tube bundle.
Can a shear load test (A-3) be used to confirm if the tube-to-tubesheet joint strength is adequate?
i.e. if L (test) > Lmax (calculated as per A-2), then OK?
Additional Information:
- tubes and tubesheet material: titanium
- % wall reduction range specified: 4% - 8%
- roller expansion: expanded, enhanced with two or more grooves
- designed using the no-test joint efficiencies
- successfully tested in accordance with UG-99
Any help would be greatly appreciated.
The history docket for a tube bundle we received from our manufacturer demonstrates that several tubes fall outside of the manufacturer's specified percent wall reduction range. We are now concerned that the tube-to-tubesheet joint strength is not adequate for these tubes and we may have to reject this tube bundle.
Can a shear load test (A-3) be used to confirm if the tube-to-tubesheet joint strength is adequate?
i.e. if L (test) > Lmax (calculated as per A-2), then OK?
Additional Information:
- tubes and tubesheet material: titanium
- % wall reduction range specified: 4% - 8%
- roller expansion: expanded, enhanced with two or more grooves
- designed using the no-test joint efficiencies
- successfully tested in accordance with UG-99
Any help would be greatly appreciated.





RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Are you more concerned with joint strength or leak tightness? I am not sure the former directly says much about the latter.
I believe my concern with an over-rolled joint would be related to the ability to re-roll the joint in the future if it were to start leaking. That, in turn, might depend on how much it was over-rolled.
In any case, it would normally be your manufacturers' responsibility to prove the joint in a way you can accept.
Regards,
Mike
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
We are more concerned with leak tightness (sorry I forgot to address this in my initial post).
Our shell and tube heat exchanger has oil on the shell side and water on the tube side. The water pressure is greater than the oil pressure. Therefore, if a leak occurs at the tube-to-tubesheet joint, water will contaminate the oil and may potentially result in a multiple bearing loss at our steam turbine.
So, does testing for joint strength not necessarily address leak tightness?
Also, does the fact that the tube bundle was successfully tested in accordance with UG-99 mean that it is actually OK - regardless if some tubes fall out of the manufacturer's percent wall reduction range?
Jennifer
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
I would say that joint strength does not directly prove tightness.
If it is feasible you might consider a more sensitive tightness test such as an air test or even a helium test of the joints. One of these, provided you can identify a realistic acceptance criteria, can more directly tell you what you want to know.
For an air test with bubble soultion, no visible bubbles is pretty common, for helium you will have to identify an acceptable leak rate.
For the fluids in your service an air-soap test should be adequate.
Regards,
Mike
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Regards,
Mike
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
The tube bundle is already sitting at our station. (Note: to avoid confusion from my OP, we still have the opportunity to reject this tube bundle even if it has already left the manufacturer's shop.)
So, it would be difficult to ask the manufacturer to perform surface welding since it would take several weeks to ship the tube bundle back to their shop and then back to our station.
Nevertheless, it is still an option and we will take it into consideration.
Thank you.
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Regards,
Mike
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
rmw
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
rmw... yes, this tube bundle will go into a shell that can be pressurized. It is not a condenser bundle.
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Then you are good to go with some of the suggestions already made.
I can't imagine why your vendor didn't sell you welded tube to tubesheet joints. Were they asleep at the switch or something, or did they lack the capability?
rmw
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Again, thank you very much everyone for all of your help!
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
That is an interesting point about tubes tightening up during working temperature and pressure. Thanks again.
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
I will state on the other hand that of all the Ti tubed Hx's (with either all Ti or overlayed Ti tubesheets) were welded. Seal welded, that is, not strength welded.
I'm sitting here puzzling on how a Ti tube in a Ti tubesheet is going to tighten up at temperature when the coefficient of expansion is identical. I'm willing to learn, however.
rmw
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Cheers,
gr2vessels
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
Now just for my own curiosity...
It seems that there is no correlation between percent wall reduction and joint shear load strength. Or percent wall reduction and leak tightness. (Or so it seems through some quick research).
If this is the case, then how do manufacturer's know what percent wall reduction will give adequate joint shear load strength and leak tightness?
RE: ASME VIII-Div 1 Tube-to-Tubesheet Joint Shear Load Test
It will depend on the tolerance between tube OD and tubesheet hole ID as well, and also on whether or not grooves are present (and how many).
Regards,
SNORGY.