... WATER HEATERPRICE, SOLAR WATER HEATING, EVACUATED TUBES, VACUUM TUBES, HEAT PIPE SOLARWATER HEATER, HEAT PIPE SOLAR COLLECTOR, SOLAR PANELS, SOLAR COLLECTOR, ... heated by the heat pipe rapidly.2.There is no water in the vacuum tube ,so the tube will not ... vacuum tubes ALN/SS/CUHeat pipe material:TU1 Tube quantity: 12pcs.15pcs.20pcs.25pcs.30pcs, 40pcsTube hail resistance:≤25mm Certificate for Heat pipe ...