Reliance Water Controls

Reliance Water Controls Potable Expansion Vessels

Reliance supply Aquasystem expansion vessels for both potable hot water systems and heating systems

In the case of expansion vessels for potable hot water they are manufactured to comply with UK water regulations and are tested and certified by WRAS.

All Aquasystem expansion vessels are supplied with a replaceable membrane, which separates the water and air, to prevent contamination of the water system, corrosion of the expansion vessel or pressure loss in the water system.

The main purpose of an expansion vessel is to compensate for the increase in volume of water due to the varying water temperatures in hot water or heating systems. When water is heated it expands and as water is not compressible this increased volume will create a rise in pressure within the system. As an example, water being heated from 0°C-100°C will increase by approx 4.5%.

The expansion vessel allows for this extra space, as when water temperature increases the membrane inside the vessel inflates to allow the water to fill the vessel. The membrane will continue to expand until the system reaches its maximum temperature. Once this has been reached the membrane will be fully inflated and takes up the capacity of the vessel shell. Gradually the temperature will drop, which will in turn decrease the volume of water. Due to the pressure from the pressurised air surrounding the membrane, water will start to exit the vessel until the membrane is deflated.

1–12 of 49 items

  • Advance Appliances - 2 Litre Expansion Vessel AA 0001

    Advance Appliances – 2 Litre Potable Expansion Vessel AA001

    SKU: UN-7-3
    EXCL. TAX £20.39 INCL. TAX £24.47
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  • Aquasystem Potable Expansion Vessels 2,8,12,18,24,35L +Sealed System Kit+Bracket

    Aquasystem Potable Expansion Vessels 2,8,12,18,24,35L +Sealed System Kit+Bracket

    SKU: RE-M-1
    EXCL. TAX £3.91 INCL. TAX £4.69
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  • 8 Litre Flow Through Expansion Vessel Anti Legionella

    Aquasystems 8 Litre Flow Through Expansion Vessel with Reliance – 3/4″ Anti-Legionella valve ANTI100001

    SKU: RE-B-212
    EXCL. TAX £99.75 INCL. TAX £119.70
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  • 4 x Reliance Aquasystem 24 Litre Potable Expansion Vessel XVES050060

    SKU: RE-B-98
    Sale! EXCL. TAX £116.39 INCL. TAX £139.67
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  • Warmflow Expansion Vessel Bracket - 2 - 24 Litres

    Expansion Vessel Bracket – 2 – 24 Litres

    SKU: TE-31-3
    EXCL. TAX £2.69 INCL. TAX £3.23
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  • Keston - Bracket

    Keston – Expansion Vessel Bracket

    SKU: KE-31-3
    EXCL. TAX £2.69 INCL. TAX £3.23
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  • Reliance - Aquasystem 100 Litre Potable Expansion Vessel XVES050110

    Reliance – Aquasystem 100 Litre Potable Expansion Vessel XVES050110

    SKU: RE-23-8
    EXCL. TAX £204.56 INCL. TAX £245.47
    Out of Stock
  • Reliance - Aquasystem 1000 Litre Potable Expansion Vessel XVES050170

    Reliance – Aquasystem 1000 Litre Potable Expansion Vessel XVES050170

    SKU: RE-D-1700
    EXCL. TAX £2,572.82 INCL. TAX £3,087.38
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  • Reliance - Aquasystem 12 Litre Potable Expansion Vessel & Bracket XVES050040

    Reliance – Aquasystem 12 Litre Potable Expansion Vessel & Bracket XVES050040

    SKU: RE-B-92
    EXCL. TAX £32.48 INCL. TAX £38.97
    Out of Stock
  • Reliance - Aquasystem 12 Litre Potable Expansion Vessel & Sealed System Kit XVES050040

    Reliance – Aquasystem 12 Litre Potable Expansion Vessel & Sealed System Kit XVES050040

    SKU: RE-B-93
    EXCL. TAX £52.06 INCL. TAX £62.47
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  • Reliance - Aquasystem 12 Litre Potable Expansion Vessel C/W Bracket XVES050045

    Reliance – Aquasystem 12 Litre Potable Expansion Vessel 3 bar C/W Bracket XVES050045

    SKU: RE-19-2
    EXCL. TAX £28.31 INCL. TAX £33.97
    Out of Stock
  • Reliance - Aquasystem 12 Litre Potable Expansion Vessel C/W Bracket XVES050045

    Reliance – Aquasystem 12 Litre Potable Expansion Vessel 3.5 bar C/W Bracket XVES050046

    SKU: RE-19-3
    EXCL. TAX £34.56 INCL. TAX £41.47
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