Abstract: A hot blast stove for preheating combustion air for an associated blast furnace, having a continuous, substantially cylindrical shaped peripheral wall extending from a base to a domed cover. The peripheral wall includes a first cylindrical portion defined by a refractory ring wall of a predetermined thickness, surrounded by insulation, and enclosed by a continuous metal shell; and, a second, diametrically larger, cylindrical portion disposed above the first cylindrical portion, defined by a continuation of the refractory ring wall of the first portion, surrounded by a predetermined thickness of insulating brick and insulation. The second portion is enclosed by a continuous metal shell which joins the domed cover. An annular interconnecting portion joins the cylindrical portions and includes a metal shell that diverges outwardly from the metal shell of the first portion to obliquely join the metal shell of the cylindrical portion.