... .Anti-freezen & pressurized 3.10 years warranty Pressurized solar collector system Working principle:when the diffeference of collector temperature and ... rock woolHeat Pipe pure red copper TU1+water,transfer power>=150W,Working pressure,4Mpa,welding pressure 4MpaDust Ring GasketSilicon ... boron and silicon content 3.3,Structure,Gradual change SS-AL-Nx/Cu selective absorption coating,Vacuum Degree,P<= ...