... solar collector Features:1. This system consists of solar vacuum tube, heat pipe, water tank, stand, P/T valve. 2. It is very high ... .8. 72 hours heat preservation.Working Principle: Compact heat pipe pressure solar water hater is heat pipe, The heat pipe is hollow ... rainy3. Magnesium bar: protect inner tank to be corroded.4. Quality Certificate: ISO: 9001:2000, CE.5. Brand: SUNRISE /OEM.6 ...