Hot Sale Solar Water Heaters Made in China 1.Solar Water ... vacuum tube is rising, As the thermosiphon principle, the hot water rise up, and arrive in the water tank, ... circulation way until the water become very hot. The highest temperature of water tank can be 95 degree Celsius, During this ... layer: 50~60 mm polyurethane foam.5. Stand angle: 15 degree, 20 degree, 25 degree, 30 degree, 38 degree