vacuum tube
vacuum tube 1)High Quanlity 2) The most competitive price 3)Long Life-span
vacuum tube for solar water heater and solar collector:
Specification:
1)Inner tube/outer tube diameter:37/47mm,47mm/58mm
2)Length of tube:1500mm,1800mm,2000mm,2100mm
3)Material:high double borocilicate glass
4)Thickness of tube:1.6mm, 2,1mm
5)Selective absorbing coating:tri-elements coating(ALN/ALN-SS/CU) or AL-N-AL Coating
6)Expansion coefficient:3.3*10-6
7)Excellet solar absorption:.>93%
8)Low heat reflection properties:<0.86%
9)Heat preservation:72-80 hours
10)Hail resistance:25mm
vacuum tube