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  • Stiebel Eltron Solar Expansion Tank - 2 Gallons - ST117

    - 1/2 inch straight thread connection

    Product ID • ST1170000000

  • $65.95
  • Quantity:
  • Free Shipping Eligible


Stiebel Eltron Solar Expansion Tank 2 Gallons - ST117 is used for solar hot water heating systems using flat panels or Evacuated Tubes used up to 5 panels.

Modern solar heating systems can reach temperatures of up to 385°F during inactivity. The result is the vaporization of the solar liquid and extreme temperatures in the solar circuit, up to the solar station. This damages parts of the system, including pumps, connection joints and the diaphragm in the expansion tank. Furthermore, in the event of prolonged heat absorption, for example in the summer, when on vacation or if the electricity is out, the pressure of the solar systen can increase to the point of activating the safety relief valve. In order to support the highest possible inactivity temperatures, the special heat-resistant diaphragm in the Stiebel Eltron SolarPlus ST117 expansion tank can withstand temperatures up to 225 Degrees F.

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Technical Specs

Stiebel Eltron Solar Expansion Tank 2 Gallons - ST117 Techs and Specs

  • Capacity
    2 Gallons
  • Collectors
    Up to 5
  • Body
    Welded Steel
  • Connection
    1/2 inch Male Thread
  • Coating
    Epoxy paint
  • Diaphragm
  • Solutions Medium
    Water, Glycerine and Propylene Glycol solutions
  • System temperature range
    32 to 250°F
  • Maximum diaphragm temperature
  • Maximum working pressure
    150 psi
  • Pre-charged pressure
    25 psi
  • Size
    12 5/8 inches H by 8 Diameter
  • Weigth
    5 pounds

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