The tubesheet is 3" thick so 2 -1/2 " to 3" is quite adequate.
Both the tubes and tubesheets are carbon steel. The plugs are not to be pulled out and the tubes are not to be re-used. In fact, the condenser is to be replaced within the next year.
The torq-n-seal has promise for future use...
I want to plug several tubes in a sulphur condenser but don't want to seal weld the plugs. Does anyone have experience with this? Any advice re potential problems with this method? Is there a standard length that the plug should be? What kind of fit is required? The tubes are 1 1/4" OD x 12 BWG...