MULTIMAX SERIES Boiler is a hybrid design membrane water wall type boiler combining the advantages of water tube & smoke tube designs. The radiation zone of the furnace is covered on three sides by water tubes and screen tubes forming the first pass and the conventional smoke tube shell has tubes lined up forming the second and third pass of flue gases. Thus, the water wall furnace recovers the radiation heat of the furnace,and the smoke tube shell provides large water & steam holding capacities to give the maximum advantage.