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

SKU: 473447
Availability: In stock

Free shipping

£5.58 EXCL. TAX

£6.69 INCL. TAX

Order before 4pm for next day delivery


Aquasystem Potable Expansion Vessels

Available in 2,8,12,18,24 or 35 Litres

Options include an EasiFit Sealed System Kit One and Mounting Bracket


Reliance Potable Expansion Vessels

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.


  • – Stainless steel bolted flange prevents corrosion.
  • – Extra wide membrane opening prevents noise caused by restricted flow.
  • – Internal membrane preventing water contact with the steel shell, stopping internal corrosion.
  • – Vessel can be serviced without being removed due to replaceable membrane.
  • – Vessel has pre-charged valve for topping up air pressure.
  • – System kit with one piece manifold – Requiring no assembly.
  • – Easy to read pressure gauge.
  • – Union type connection to the expansion vessel can be orientated easily.

Vessel Size Guide:

Vessel Capacity: Vessel Dimensions:
2 Litre Height: 265mm Diameter: 110mm
8 Litre Height: 310mm Diameter: 200mm
12 Litre Height: 295mm Diameter: 280mm
18 Litre Height: 465mm Diameter: 280mm
24 Litre Height: 492mm Diameter: 280mm
35 Litre Height: 440mm Diameter: 365mm

Additional information

Weight 1 kg
Manufacturers Code



Reliance Water Controls





SKU 473447


There are no reviews yet.

Be the first to review “Aquasystem Potable Expansion Vessels 2,8,12,18,24,35L +Sealed System Kit+Bracket”

Your email address will not be published. Required fields are marked *

Alternatives & Related Products