... 4.Factory only, not trading company. low price and high quality solar water heaters How it worksThe design of this type ... ² / H=3.7-4.2MJ/m²Vacuum tightness3.0×10¯³ PaIdle sunning property parameters220-260 m².C/KW / 260 ... angle:0,18,22,38,45 optional, pitched roof, flat roof optional.Fastening pieces:Made of zinc-coated stainless ... )8.Punching(Outer tank processing)9.Pressing(device)10.Foaming11.Packing