In alloy / stainless steel sheet, highly resistant to heat, with expansion joint.
In steel tubes of different materials depending on the working temperatures, arranged concentrically to the combustion chamber, with independent expansion joints for each tube of the heat exchanger.
In steel sheet, insulated with mineral wool and finished in zinc-coated or aluminium sheet. It is possible to install a rear door, submarine type, lined with refractory material, for the inspection of the combustion chamber.
All kind of commercial fuel, be it liquid or gaseous, can be used.