... life 15 years 3. CE,SRCC,SGS,Solar Keymark,ISO9001:2008 Solar glass vacuum tube Description: 3- target tubes consist of 3 ... s emissivity is 30%-40% lower than common one.Solar glass vacuum tube Advantage1.Unique three-layer absorption technology (stainless steel/ ... temperature endurance and preventing peeling off even when the glass gets waxy degeneration3.Unique Three-layer against degeneration, color ...