Working principle: * combined many collectors with water storage tank as complete projects, heat pipe in solar vacuum tube for heat transferring, by circulation pump and relative system to make transfer medium liquid take the heat to water tank. Key specifications: * solar vacuum tube with heat pipe A) size: 47 x 1, 500mm / 58 x 1, 800mm B) qty: 15 / 20 / 25 /30 C) hail resistance: diameter 25mm * material: stainless steel or anodized aluminum * temperature insulation layer in chest A) 30mm thickness imported polyurethane, machinery overall for keeping same temperature and high pressure foam B) heat preservation: 72 hours * max pressure bearing: 0.8mpa * 3 years international responsibility for free repairing or exchange due to original quality problems * packing: export carton and foam