... tank, it could be worked in -35C degree. Heat pipe solar collector: Specification:Manifold material and thicknessA, Black or silver ... thickness 2.0mmB, Stainless steel 304 2B, thickness 0.8mmHeader pipe material and thicknessDiameter:32mm, thickness 1.0mm copper pipeHeat ... pipe material and thicknessDiameter:14mm, thickness 0.5mm copper ...