... of CCC,CE&ISO9001 4Manufacture solar vacuum tube 1,vacuum tube length:47/1500mm,58/1800.2,vacuum ... axial structure high borosilicate 3.3 glass vacuum tube with tube wall thickness of 1.6mm.Inner tank ... hours72 hoursHailstone resistanceDia=25mmGuarantyWater tank for 5 years, tube and frame for 15 years Working principle:1 ... valve will open its valve,the tap water flow in the tank ,if the water is full ...