Double Flue/Single Flue, Three pass fully wet back, Single flue, 2pass dry back and Pneumatic overfeed boiler designs – Available. SALIENT FEATURES Large heating surface areas. Large furnace and grate areas. High efficiency. Optimum exhaust gas temperatures. Optimum fuel to air ratio. BENEFITS Shell and tube type boiler and hence, best suited for process steam heating needs. Low fuel bills. Increased tube life. Rugged construction long life of the boiler. High safety standards. No heat recovery unit required.