Water treatment

Feed water pre-heating is used to pre-heat the feed water in the feed water container. Because heating it up allows gases (oxygen and carbon dioxide) which are harmful to the steam system to escape. The feed water is heated by introducing steam produced by the steam boiler into the feed water container. The temperature of the feed water is measured constantly. When the temperature falls below the target value, a steam valve opens and the water is heated. When the temperature rises above the target value, the steam valve closes again.

The patented priority circuit is a special feature of JUMAG feed water pre-heating. At higher steam consumption through the steam consumers, the feed water pre-heating should not put any more stress on the steam consumption. In this case, the supply of fresh, cold water is suppressed until enough steam is available again. If, however, a defined water level in the feed water container is undercut, fresh water is topped up. To avoid stress on the steam system, a second, lower target temperature is aimed for temporarily.

Feed water pre-heating is always recommended to protect the steam system from corrosion. It is absolutely necessary, however, if no or minimal condensate return flow is available. Heating 100 kg/h of fresh water from 15°C to 95°C requires approx. 10 kW or 14 kg/h of steam. This corresponds to approx. 14% of the steam output at 0% condensation return flow.

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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