... 20 / 25 / 30 Vacuum Tube Borosilicate glass, red copper heat pipe, aluminum fin Manifold Copper flow passage, PU insulation, Aluminium alloy ... workstation system, accessories and interconnecting pieces.Heat Pipe Solar Collector:1) Heat pipe solar collector for thermal collection, with a ... P valve, Stainless bolts & nuts, anti-aging rubber seal, pipe holder make their life as long as other parts of the ...