They are used for the solution heat treatment and the quenching of great im-portance pieces mainly for the aeronautics industry. The temperature uniformity in the treatments as well as the transference time from the furnace to the cooling bath must be very exact. The minimum necessary elements are: the elevated chamber furnace with quickly activated doors, the elevation and lowering device of the load and the quenching tank placed under it. Nevertheless there are several layouts, two of which, one with buried tank and another one with moveable tank, are shown in the sketch of next page.