Doyle & Roth is one of the old-timers in the heat-transfer industry, having been founded in 1932. Our principal business has been the engineering, design and fabrication of shell and tube heat transfer equipment. In addition to our line of "standardized" equipment (about 25% of our sales volume), Doyle & Roth is a major producer of custom-fabricated shell and tube equipment (about 70% of our sales volume).