Expansion Vessels

Aquaflex Expansion Vessels incorporate a diaphragm/bladder arrangement which provides a flexible barrier between the system fluid and the precharged air in the vessel. As the system water expands, the bladder also expands, pushing against the precharged air cushion. This is how the expansion is accommodated in a closed-loop system. The NR vessels are fitted with a relief valve preset to 3 Bar. The F and R series vessel’s are not fitted with relief valves. Pressure setting must be specified when ordering.

Other Features

  • Threaded connections.
  • Non-replaceable diaphragm. For replaceable diaphragm type vessels refer to “R” series on back page.
  • Pre-set pressure 150KPa (Nitrogen) - variable.
  • Wall mount bracket available for 8-25 litres.
  • Also available in stainless steel.


Sizing for Expansion Vessels

In order to select a suitably sized expansion vessel, the following information is required:

  • Total system water volume in litres.
  • Temperature of water when system is filled (in oC) and average maximum operating temperature (in oC).
  • Minimum operating pressure in kPa and maximum operating pressure (10% below relief valve, in kPa).
  • Which level of the building it will be installed and number of levels there are above it?

We look forward to the opportunity of assisting you.

Please contact us with your requirements; we are always ready to listen.