Product Details

Good quality Glass solar vacuum tube

for water heater use

Specification:

size:

* 47mmx1500mm

* 58mmx1800mm

* 70mmx2000mm

composition : borax and silica glass

Three-high vacuum tube technology:

Dimension	Φ47	Φ58
Material of Tube	3.3 High Boron Silicon	3.3 High Boron Silicon
Glass Expansion Ratio	3.3±0.1×10^-6K^-1	3.3±0.1×10^-6K^-1
Outer Diameter of Tube	Φ47±0.7	Φ58±0.7
Inner Diameter of Tube	Φ37±0.7	Φ48±0.7
Thickness of Glass	1.6±0.15	1.6±0.15
Transmittance	≥0.89	≥0.89
Selective Coating	SS-CU-AL-N/AL	SS-CU-AL-N/AL
Absorptivity	≥0.86(AM1.5)	≥0.86(AM1.5)
Emissivity	≤0.080(80±5)	≤0.080(80±5)
Vacuum Degree	≤5.0×10^-3Pa	≤5.0×10^-3Pa
Collecting Performance Parameter under Sunshine	≥190m²/kw	≥190m²/kw
Hailstone Resistance	25mm	25mm