A solar system mainly consists of the following components: collectors, pump group and storage tank. The pump group transports the solar liquid heated by collectors into the storage tank where its water is thus heated up. When the water in the tank has reached its maximum temperature, the pump group switches off and no more heat is taken away from the solar collectors. This is why they usually get so hot. So hot that the solar liquid vapourises in conventional collectors. As a consequence the solar liquid ages rapidly or even gets harmed. Additionally, all the components are afflicted by the high temperatures. In order to protect the solar liquid as well as the components, the 4flex+ tubes provide a patented overheat protection in the capacitor. As soon as the temperature in the capacitor rises up to 90° C, bimetal discs lying on top of each other close a valve that prevents more working fluid from rising from the heat pipe into the capacitor. It also prevents from giving off heat to the solar liquid. Thus it is effectively avoided that the solar liquid vapourises (see right part of the picture). When the storage tank can take up heat again, when the pump group works again, when the solar liquid is recirculated and the temperature in the capacitor drops below 90° C, the bimetal discs open the valve and the system returns to its normal operating state.
