solar water heater glass three target vacuum tubes (manufactory & factory ) Quality Choice

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