Split pressurized Heat pipe solar collector heating System 1.SOLAR KEYMARK,SRCC,CE 2.Antifreezing -40 degree 3.OEM provide Split pressurized Heat pipe solar collector heating System1,Size:58/1800,47 ... as your requirement.Copper pipe: material purple copper,Glass tube: high borosilicate 3.3, thickness: 2.0mm, Three target type.Insulation: rock ...