... , solar water heater, split solar water heater,CE,EN12975,KEYMARK Product Description Solar Collector Features: Evacuated tubes convert solar energy into ... insulation with integrated polyurethane foam.. Technical data: Number of Tubes 10, 15, 20, 22, 25, 30 ,Length of Tube 1800 mm ... Tube Thickness 1.6 mm Tube Thermal Expansion 3.3 X 10 -6 oC Tube Material Borosilicate Glass 3.3 Absorptive Coating ...