Pressurisation Systems

The correct pressure is a fundamental requirement for the proper operation of water based heating, solar, and cooling water systems, and pressure booster systems.  Like all other substances, the volume of water changes with its temperature, but unlike other liquids, water does not expand proportionately to the temperature.  As water cannot be compressed, this means the pressure increases significantly in closed systems as the temperature changes.

Pressure maintenance systems have to fulfil three fundamental tasks:

  • Compensate for fluctuations in the system volume due to temperature changes as the system cycles.

  • Maintain the pressure within permissible limits.  This means not only ensuring the permissible operating pressure is not exceeded but also maintaining a minimum pressure to avoid vacuum formation at system high points, cavitation, and evaporation.

  • Balance systemic water losses using a water reservoir.

Dynamic pressure maintenance stations (also known as pressurisation units) are the next generation improvement on conventional diaphragm expansion vessels (static pressure maintenance).  The difference in principle lies in the addition of a control unit that can be used to change the volume in a connected vessel and ensures highly efficient performance.

This approach produces three key advantages:

  1. Automated and monitored operation.

  2. Space Saving – With virtually the entire capacity of the expansion vessel used to accommodate expansion water, the vessel volume can be reduced by up to approximately 1/3 compared to a traditional diaphragm expansion vessel.

  3. Reliable pressure maintenance, with the minimum operating pressure is programmed on the controller and monitored to ensure reliable facility operation.

Reflex offer a broad portfolio of pressurisation stations to enable automated and precise pressure maintenance in systems with the broadest spectrum of different requirements:  Office buildings from 100kW heating capacity or more to power plants up to 300MW, water as hot as 250°C or cooling water with -10°C, low rise buildings 10m tall to high-rises up to 200m tall, as well as customised solutions for complex hydraulic systems such as data centres with safety-related cooling systems.

Reflex offer two different types of dynamic pressurisation maintenance systems:  compressor controlled (Reflexomat) and pump controlled (Variomat).


Variomat pump controlled pressure maintenance for operation up to 13.5bar system pressure.
Reflexomat compressor controlled dynamic pressure maintenance up to 8.5bar system pressure.

Related Products