What would be the possible options to join Titanium Heat Exchanger tubes to a PTFE / Teflon tubesheet? These are 38 mm tubes, 2 mm thick. 6 m total length. Seamless tubes. Is this a reasonable design decision? Full titanium tubesheet would be excessively expensive & isn't needed since only the tube-side fluid needs Ti because of corrosive nature. The other options might be Ti clad Stainless tubesheets or an SS tubesheet with an epoxy coating. But not sure if joining those to Titanium tubes is any easier?