Steam circuits have to be equipped with steam traps to evacuate the condensed water out of the steam lines. When the water reaches a certain level in the steam trap, a mechanism opens a valve and the water is flushed out. Bimetals are well known actuators for steam trap use. The main disadvantage of bi-metals, however, is their linear temperature response. Such a response causes a temperature equilibrium, which leads finally to an undesired continuous leaking of the water rather than a flushing out action. The use of a Shape Memory Belleville Disc actuator avoids such unwanted leaking, and ensures a proper periodic flushing out of the condensed water.