Steam and Condensate systems - What is Condensate?

Properties of Condensate

Steam that has been condensed back into water by either raising its pressure or lowering its temperature. Not to be confused with demineralized, de-ionized, make up, or softened water. When the condensate enters the boiler feed pump additional chemicals are added and the product is now called boiler feed water.

Where does condensate come from?

We want to keep dissolved oxygen out of condensate. Why?

It will contribute to corrosion problems in the system. Especially the boiler.

Temp °F. Temp °C. PPM
Dissolved Oxygen
30 1 10 ppm
90 32 5 ppm
120 50 4 ppm
150 65 3 ppm
180 82 2 ppm
210 100 0 ppm
Temp °F. Temp °C. PPM
Dissolved Oxygen

The average level detected in condensate receivers is three parts per million.
This is almost one thousand times greater than the five parts per billion level that can induce pitting corrosion.

How does oxygen get into the condensate system?

How do you get rid of the dissolved oxygen?

Why are we concerned about carbon dioxide in condenste systems?

Where does the CO2 come from?

Mammals exhale CO2 it enters condensate and feed water:

Why do we have to use so much "Make Up" water in our boiler?

Because we lose so much of it.

What are some methods for conserving condensate?

Reference(s): Mc Nally Institute

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