... , antifreezing 3. endure high pressure U shape Vacuum Tube Solar collector Introduction:The pipeline is made of red copper ... liquid. There is no water in the tube, so the tube will never be broken in low temperature in ... winter. Specifications:1. Vacuum tube: 3-layer tube (AlN/Al-SS-Cu),58*1800mm, 47* ... 1500mm standard tube (Al-N-Al), 58*1800mm, 47*1500mm2. ...