Due to its high melting temperature (~ 2450 °C), beryllium oxide is used as refractory material in combustion chambers/furnaces. The purpose of the refractory is containment of the combustion process and flue gas, re-radiation of heat to accelerate the combustion process and protection of personnel through its insulating properties. The wall of a furnace separates combustion gases at 2600 °C from a liquid coolant at 100 °C, with gas and liquid-side convection coefficients of 50 and 1000 W/m2K. The composite wall is composed of a 10 mm thick layer of beryllium oxide on the gas side (kBO = 15 W/mK at an assumed average temperature of 2000 K) and a 20 mm thick slab of stainless steel on the liquid side (kss = 16.6 W/mK at an assumed average temperature of 400 K). The contact resistance between the oxide and the steel is 0.05 m2K/W.