At the onset of the process the bottom of the chamber is filled with water [deionised] upto a certain level. The load is already in place at this point. This water is drawn by a special high temperature centrifugal pump and passed through a steam operated heat exchanger. This heated water is pumped up into the upper part of the chamber. Spray manifold in chamber top distributes this water evenly over the load. This water collects at the bottom of the chamber and is again passed through the heat exchanger and sprayed over the load. This process of continual passing through the heat exchanger brings the water upto sterilisation temperature. Passing of this water over the load sterilizes the load. The circulating water also becomes sterile with the load eliminating any possible load contamination. At the completion of the sterilisation the circulating water is gradually cooled by passing it through the heat exchanger which now has cold water in the secondary side. The recirculation of this gradually cooling water over the load slowly brings down the temperature of the load.

Considering that the load will mostly consist of glass / plastic containers and flexible plastic bags due precaution has to be exercised to prevent deforming, bursting open or breaking. To this end pressure inside the chamber is always controlled to closely match the pressure within container. Thus damage resulting from internal overpresssure is eliminated.

During sterilisation cycles the unevacuated air in the chamber raises the chamber pressure above the steam pressure due to its heat induced expansion. From initial heating upto cooling this pressure can be monitored and controlled. Thus pressure is varied between required parameters. The container at no point is in risk of damage due to pressure difference between chamber and container.