Chemical water treatment: the essential vitamins required for a “healthy” steam and condensate loop

A steam and condensate loop acts like a living breathing organism; taking in water to produce steam and utilizing that steam for work, then returning a portion of the used steam as condensate to be reutilized.

By Spirax Sarco October 29, 2014

A steam and condensate loop acts like a living breathing organism; taking in water to produce steam and utilizing that steam for work, then returning a portion of the used steam as condensate to be reutilized.

From a chemical perspective, the steam loop requires specific control over chemical constituents and nutrients by a water treatment chemical program that is specifically relevant to each plant.

There are 3 key areas of the steam and condensate loop that require a regular “health check-up”:

1. Feedwater: The Life Blood

One needs to check for hardness and silica to prevent scaling as well as oxygen control and pH to prevent corrosion. It all starts with the feed water quality. It needs to be controlled if the boiler is expected to last and produce high quality steam over the long term.

2. Boiler: The Heart Of The Steam Loop

The “heart” of the steam loop is the boiler. Its ability to continue to efficiently produce high quality steam is what is important. In order to accomplish this, a preventative mechanical and chemical maintenance program is vital to implement. Most prominently, checking to ensure dosing of the correct scale and corrosion inhibitor chemicals in the right quantity and in the right place is imperative. Controlling alkalinity and TDS levels will minimize carryover, and sometimes specialty anti-carryover. As such, foaming chemicals may need to be used. If the boiler is not under control, the steam it produces will struggle to meet requirements both in quantity and quality.

3. Condensate: Feedback On The Body

A lot can be learned about the state of a steam distribution system by testing the condensate. Checking pH can point to evidence of condensate line corrosion or carryover. Checking conductivity will often disclose a level of product contamination. Measuring iron levels in condensate is an essential indicator of both carryover and condensate line corrosion. As a consequence, it is a good indicator of the performance of your condensate protection chemical program.

Constant monitoring of the condensate is critical in assessing the overall performance of one’s water treatment program. Taking action to ensure you get the most from your steam plant is the real key to gains in productivity.

Content provided by Spirax Sarco, originally published in Steam News. Edited by Anisa Samarxhiu, Digital Project Manager, CFE Media, asamarxhiu@cfemedia.com