Thinning in Tube wall for contact expansion tube to tubesheet joint.
Thinning in Tube wall for contact expansion tube to tubesheet joint.
(OP)
For Contact (light) Expansion Tube to tubesheet joint what should be the minimum % thinning in tube wall thickness shall take place so that same can be inspected based on diameter of tube after expansion.
Regards
Vishal
Regards
Vishal





RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
Generally this unmeasurable.
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P.E. Metallurgy, Plymouth Tube
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
Please advise how much thinning is measurable. whether I can specify 3 to 5% thinning (for Carbons Steel tubes) for contact expansion type of joints and whether same is measurable.
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
Typically this is controlled by rolling torque, there is a huge step function in torque at contact and with a simple mock-up it is easy to verify the values.
Often 'roll to contact' is used before welding to assure uniform alignment, and you don't want the joint tight to help prevent trapped gas defects in the strength welds.
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P.E. Metallurgy, Plymouth Tube
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
You / your organization needs to define if contact expansion is to have another meaning. You mention 3-5% thinning. This is beyond what is normally meant by contact expansion and, in my opinion, if done prior to welding the joint would result in poor quality welds. See thread292-425729: unexpanded & expanded length of tube totubesheet joint & thread292-425973: recess type tube to tubesheet weld.
Now, if you are trying to establish an allowable tube-tubesheet joint load for 3-5% expansion per your previous post, thread292-425641: Expanded length of tube(ltx) to be considered in tubesheet calculation , then you likely need to conduct mock-up testing per Appendix A. Note that tubewall thinning and expanded length are not strictly related.
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
On Edit: Perhaps I misunderstand the point of your posts. Perhaps you just want to know how to calculate a tube ID that corresponds to 3-5% wall thinning?
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.
With this we have not faced any problem and Base on this, I understand we can conclude that 3-5% expansion is measurable and can be used in tubesheet calculation.
Thanks
Vishal
RE: Thinning in Tube wall for contact expansion tube to tubesheet joint.