... 3)Sample offer 4)OEM service Working principle Of Pressurized heat pipe Solar Collector: 1) The operation of the solar collector is ... .6MPa7. Hail resistance: 25mm8. The standards of vacuum tubes with heat pipe: 14, 16, 18, 20, 24, 30 tubes .9.Water ... efficiency: >= 55%(>=42% in winter) 11. Heat preservation: 72h to 80h Split pressurized Solar Thermal Collector Features:1. The upright tank can ...