... .7mm &=1.6mm, Φ=70±0.7mm &=2.0mm Internal pipe diameter and thickness Φ=37±0.7mm &=1.6mm, ... 7mm &=1.6mm Pipe length 800mm, 1200mm, 1500mm, 1600mm, 1800mm, 1900mm, 2000mm, 2100mm Absorbing coating propertyStructure Cu/SS ... is heated with solar energy absorbed by the coating outside of inner vacuum tube, the solar ... will be absorbed efficiently by the coating with little loss of heat because of the ...