All class solar vacuum tube

Outer Diameter and Inner Diameter (MM) 47/37 58/47 70/58 Length of Tube (MM) 1200,1500,1600,1800 1500,1600,1800,2000, 2100Thickness of Tube (MM) 1.60selective absorbing surface 3layers(AL-N-AL) Material: Borosilicate glass 3.3 Color Blue Thermal Expansion 3.3*10-6/k Maximum Strength 0.6 Mpa Absorption of Selective Coating above92% Emission of Selective Coating below6 % Stagnation Temperature above200m2°C/KW Solar Irradiation for Water Temperature Rise below4.4MJ/ m2 (Dia58/47MM)Coefficient of Average Heat Loss below 0.49W/(m2 °C)Vacuum above 5.0*10-2Pa(anti heat loose) Remark: We have ability to produce the vacuum solar tube according to your required length
All class solar vacuum tube