Water treatment

In most steam systems, the condensate is completely relieved and returned into a depressurised feed water container. Relaxation steam is released in relaxation of the condensate. The energy contained in this will be lost depending on operating mode. This may make up as much as 15% of the total energy demand. Because of the relaxation steam, water is lost from the steam circuit on the same scale.

In closed systems, however, the condensate is not or is only partially relieved and is routed into a pressurised condensate pressure vessel. This minimises the relief loss and the water loss.

Advantages of the JUMAG high-pressure feed water container

  • Significant cost savings due to closed system
  • High fresh water savings potential as relaxation steam is eliminated

How it works

Structure of closed systems from JUMAG

The JUMAG condensate pressure vessel has all functions of the JUMAG feed water container for steam boilers (e.g. water level control for fresh water supply and steam pre-heating for degassing).

Furthermore, the JUMAG condensate pressure vessel contains an overflow valve in addition to a relief valve. This prevents frequent opening of the relief valve at excess pressure increase. Degassing of the fresh water can be controlled in this way as well.

As the feed water is routed into the steam boiler at a much higher temperature, the temperature-resistant boiler feed pump is used.

Because this is a pressure vessel, it is subject to TÜV approval and regular monitoring.

Possible uses of closed systems

Closed systems are particularly worthwhile for steam systems:

  • with a high share of condensate return flow (if possible 100%). The higher the share of condensate return flow, the higher also the savings as compared to a depressurised feed water container.
  • with steam consumers, all of which emit condensate at a high pressure (at least >1bar, if possible >4bar). As the condensate pressure vessel may at most have the pressure of the lowest condensate return flow, there should be no consumers with low pressure.
  • with high condensate temperatures (if possible in excess of 110°C). The higher the condensate temperature, the higher also the savings as compared to a depressurised feed water container.
  • with long operating times. At regular use of the steam system, the pressure in the condensate pressure vessel can be maintained and the system will run stably.

Do you have questions?

Your JUMAG team is happy to assist you!

About us

For more than 40 years, we have been developing, producing and selling oil and gas-fired steam boilers.

JUMAG steam systems represent efficiency and user-friendliness.


Jumag Dampferzeuger GmbH
Badener Str. 8a
69493 Hirschberg

+49 6201 84603-0



We are happy to advise you