Expanding Exchanger/Fin-Fan Tubes 1.5" or Greater

[HRS713]

We have some site requirements that specify tubes in heat exchangers and air coolers be strength welded when tube diameters are greater than or equal to 1 1/2". Speaking with some manufacturers, they don't seem to have an issue with rolling tubes in 1 1/2" or larger tubes. Other than higher risk of maintaining a good roll/seal across a larger surface area, can't think of many other issues especially if the manufacturers feel comfortable with it. Only reason we have some concerns with welding in this specific application is due to heat treatment requirements and avoiding that if possible.

Thanks in advance for your time.