How shear load testing of expanded tube to tubesheet joint can be validated at op conditions?

[srijey]

Shear load testing or pull out testing of fully expanded tube to tubesheet joint at lab conditions may not prove the joint integrity at the operating conditions. Though this is only a mechanical strength test and not a leak test, how this mock up test can ensure that the maximum allowable axial load at operating temperature is more than the lowest axial load at which failure occurs in the lab. In other words, how one can determine (by experiment) L1 (test) as shown in A-5 of Appendix A 2013 Section VIII- Division 1? The essence of my query is how this lab strength testing (shear load testing) can assure a reliable joint at the operating conditions? I understand that this is not a leak test and that is why this strength testing seems to be a redundant one without any confidence on the reliability or the indicated joint efficiency.