Product Name: Factory Supply Attractive Price Vacuum Tubes Solar Water Heater Model NO.: SPR Certification: CE, ISO9001 Composition: Tank, Insulation, Bracket, Glass Vacuum Tube Collector Components: Glass Vacuum Tube Interior Material: Stainless Steel Pressure: Unpressurized Structure: Compact Type Max. Capacity: 330L Installation: Freestanding Circulation Type: Direct / Open Loop (Active) Trademark: SUNPOWER / OEM Transport Package: Carton Specification: 10tubes-36tubes Origin: China HS Code: 841919 Product Description TypeSPR(Integrated Low Pressure System)Outer Tank MaterialGalvanized plateOuter Tank Diameter460mm,470mm,500mmInner Tank MaterialFood grade SUS304 2B stainless steel plate or316Lstainless steelInner Tank Diameter360mm,380mmTube MaterialHigh quality borosilicate glassVacuum Tube Size(mm)58/1800 (diameter/length)Tube Number8/10/12/15/18/20/24/30/32/36/40frames (Stand Parts)Galvanized plateInsulation LayerHigh quality polyurethane foam made by advanced high pressure foam machineInsulation Thickness50mm,(outer tank 460mm),55mm(outer tank470mm),60mm(outer tank500mm)Hail Resistance25mmOperation Pressure0.05MpaStandard QualifiedCE, CCC,Solar Keymark EN12976, SABSOur advantages:Our products process: