Pressure solar water heater with heat pipe

This is a compact type pressure solar water heater. In the vacuum tubes, there is no water, there is a heat pipe,and itstopside is inserted into the tank. The heat pipe with the advanced no-freezen technlgy, so youdon't need to worry about freezen, it can work in -20 degree; We used the advanced welding technolgy (argon welding), and take the SUS316L-1.2mm as the inner tank, the lift time of system is more than 10years. We install relief valve to the cold water inlet, and install air vent and T.P. valve to the tank to protect it against the high temperature and pressure. So, it is safety. Working principle: The vacuum tubes absorb the solar energy then convert into heat energy, toheat the heat pipe in the tubes, then the heat pipe transfer the heat energy to the water in tank. For the heat pipe, there is a vacuum space in the middle of the heat pipe with special non-toxic liquid at the bottom of the heat pipe. When the heat pipe is heated, the liquid in the heat pipe is also heated and turns into the vapour. Then the hot vapour rises to top end of heat pipe which is inserted in the cold water heater, then the hot vapour transfer the energy to the cold water by the heat pipe. After the energy is transferred, the hot vapour turns into the cooled liquid, then flows down to the bottom of the heat pipe. Repeating the cycle, then the water is heated.