... ,CE,ISO 3.Deliver time:Within 3days 4.Manufacturer copper heat pipe DescriptionVacuum tube58-1800mm co-axial structure high borosilicate 3.3 ... tank ,and the cold water sink to bottom,then heat by solar collector.so the whole system is always circulatingcontinuously.3,The electromagnetism ... water is full,it will close the valve automatically copper heat pipe for solar collector