Abstract: A tubesheet protector device is provided for use with a boiler having at least one tube for receiving a fluid extending therethrough. The tubes extend approximately perpendicularly from a tubesheet covering an inlet of the boiler. The tubesheet protector device includes insulating board mounted on the tubesheet having holes therein for receiving ferrules. Each ferrule includes a shank adapted to be received in one of the tubes and a polygon-headed collar coupled with the shank. Both the collar and the shank of the ferrule are wrapped in insulation. The collar has dimensions larger than the outside diameter of the tube, and the collar and the shank both have a common through bore for transporting fluid from outside the boiler to the interior of the tubes extending through the boiler.