(1) The solar vacuum tubes used in domestic solar water heaters are divided into 37, 47, 58, 70mm, etc. according to the pipe diameter, and 1.2, 1.5, 1.6, 1.8, 2.1, 2.3m, etc. according to the length.
(2) According to the production process, it is divided into: solar ordinary clarinet, ordinary blue tube; three high blue tube, three high purple gold tube
