... Solar Water Heater Features: 1,The pipeline is made of red copper and conducted by heat transfer medium liquid. Water can ... grade stainless steelModule: PVDFManifold: aluminum alloy our casing & red copper flow passageGlass tube: New trivalent element heat tubeVacuum tube: ... tank 5L-8L, manometer, flow-meter, pressure relief valve, Copper fittings etc.Water capacity: 150L / 200L / 250L /300L/400L ...