Product Description The evacuated tubes consists of two concentric glass tubes which are sealed in a semi-circular shape on one side and are joined to one another on the other side. The space between the tubes is evacuated and hermetically sealed (evacuated insulation). To use solar energy, the internal glass tube is coated with an environmentally friendly, highly selective layer on the outside, thus turning it into an absorber. The selective coating is protected in the evacuated space. The aluminum nitride sputter coating used is characterized by an extremely low emission and a high absorption rate. Product Process Product Parameters Tube Structure All-glass double deck co-axial structure Glass material Borosilicate 3.3 glass Outer tube diameter and glass thickness Φ58+/-0.7mm; glass thickness 1.6+/-0.15mm Inner tube diameter and glass thickness Φ47+/-0.7mm; glass thickness 1.6+/-0.15mm Tube Length 1800mm Absorber coating Coating Material Cu/SS-AIN(H)/SS-AIN(L) Sediment method Three targets magnetron sputtering plating Absorptivity 0.93~0.96 Emittance ≤6.0%(80ºC+/-5ºC) Vacuum degree P ≤5.0X10-3(Pa) Transmittance of glass tube T ≥0.89(AM1.5 ISO9806-1:1994 Stagnation parameter Y: 240~250 m2ºC/KW Average heat loss ULT≤0.6 W/(m2*ºC) Hail resistance Φ25mm Pressure endure 0.6 MPA Remarks Cover glass tube Protect the whole tube. The space between the cover glass tube and the inner glass tube is mechanically evacuated to create a vacuum environment Inner glass tube Filled with heat transfer fluid (generally water) and directly plugged to the water storage tank Selective absorbing coating Absorbs solar radiation and transfers to the fluid in the inner tube. Retainer Keeps the inner tube fixed. Getter Absorbs the residual air in the space between the cover glass tube and inner glass tube. Company Profile Since its establishment in 2002, Shandong Longguang Tianxu Solar Energy Co., Ltd (hereinafter referred to as "Tianxu") has always engaged itself in the R&D, production, sales and service of high borosilicate glass tubes and new energy products including solar water heaters, solar vacuum tubes, solar heat collecting project, air source heat pump, photovoltaic products, etc. Tianxu has 10 sets of electric furnaces, 70 sets of solar vacuum tube production line and 3 sets of solar water heater production lines. The annual output has reached one million tons of high borosilicate glass, over 16 million solar vacuum tubes makes Tianxu the largest manufacturing base of high borosilicate glass tubes and solar vacuum tubes. In 2015, Tianxu established a joint venture company with Beijing Tsinghua Solar Co., Ltd- the solar vacuum tube technology initiator in the world. The newly established company has the world's most advanced solar vacuum tube production lines. Strategic Partnership Packaging & Shipping Our products have been widely exported to many countries, like Vietnam, India, Mexico, Syria, Korea, Dubai, Etc. we are serving the top brands in solar water heaters for each country. Our yearly export quantity is 600 containers. Certifications