When to specify tube to tubesheet joint mock-up test?
When to specify tube to tubesheet joint mock-up test?
(OP)
Are there any guidelines as to when a mock-up of tube to tubesheet joint would be recommended? Such an 'engineering judgement' is highly subjective, similar to defining what is 'critical'.





RE: When to specify tube to tubesheet joint mock-up test?
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Plymouth Tube
RE: When to specify tube to tubesheet joint mock-up test?
RE: When to specify tube to tubesheet joint mock-up test?
RE: When to specify tube to tubesheet joint mock-up test?
A Vendor or Fabricator will typically have a tube rolling (expanding) procedure for each of or a number of combinations of tube to tube sheet joint designs. A mock-up and test would be specified for a joint configuration or detail that does not exactly fall within the parameters of the procedure. Say, for example, expanding a work-hardenable material into a close tolerance hole. The Vendor or Fabricator might have a procedure that specifies 8% to 10% tube wall reduction, but that might not apply in this case. Perhaps the optimum joint strength is achieved at 5% tube wall reduction. The mock-up and pull test could be used to find this out.
You also might want such a mock-up and test if the bundle experiences significant temperature differential between tube sheets or between passes in multiple pass exchangers.