... solar collector 2,ISO9001:2008,CE Two target solar water heater tube is made of high borosilicate glass 3.3,which all ... high vacuum status,therefore,the vacuum layer between inner tube and outer tube will be more insulating which could prevent heat radiance ... (m².°c)Max stagnation temperature(temperature inside of empty vacuum tube)260°C-300°CPressure0.6MPaImpact ResistanceΦ≤25mm Two target solar ...