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More about Water Boiler Treatment & Powder Inhibitors

Corrosion Inhibitor Additives for Water Boilers

Author: Thomas Yoon explains about water boilers in his article...
....scales are very damaging to the boiler because they interfere with the heat transfer and can lead to overheating and eventually, boiler rupture...click here to read the entire article at his blog

By using one of the corrosion inhibitor powders we discussed in our last post, the build up of sediment deposits and damaging corrosion of water boilers is greatly reduced. Most users apply VCI-1 powder to working water boilers at a rate of 0.5 to 1.0 percent of the weight of water in the system. This amounts to 4 up to 8 pounds of powder corrosion inhibitor in 100 gallons of water.

The make-up water entering the system is also treated either by metering of a solution of corrosion inhibitor or by "topping up" the water reservoir on a regular basis.

To avoid bacteria or other uninvited contamination into the water system, the pH of the boiler water is often targetted around 10. Caustic soda or other material high in its basic pH is used for this purpose. This also helps to reduce corrosion and scaling in the system. By using the appropriate water additives, maintaining a basic pH, incorporating a scheduled "blow down" of the system and good maintenance procedures one can attain a long boiler life and the benefits of an efficient heat/power source.

When laying up the equipment for seasonal shutdown always clean it out thoroughly and treat with corrosion inhibitor powders to ensure a maintenance free start up next season. This will reduce yearly maintenance and extend the life of the equipment.

There are a few common methods of boiler lay up involving nitrogen purge, oil based chemicals, hazardous chemicals and recently biodegradable water soluble VCI powder products. Nitrogen purge involves special handling equipment and procedures to preserve the equipment. Oil based products are messy and require clean up and disposal prior to putting the equipment back into service. With the availability of the new VCI powder products there is no good reason to work with hazardous materials.


The easiest and cleanest method for in use operation or water boiler seasonal lay-up. It is also used for the short or long term corrosion protection of tanks, pipe, cooling towers, chillers, silos and any enclosure made of metals.

For water boilers, VCI-1 powder is often used because of the lower cost, biodegradabiity and its effectiveness for cast iron, steel and aluminum metals. The VCI anti-corrosion powder does not require removal for most applications. It is non-hazardous and biodegradable. When putting the boiler back into service, after a seasonal shut-down, simply fill with water and the normal additives then fire up the equipment.

Where non-ferrous metals are present V-848 or VCI-841 is used instead of the VCI-1 powder. V-841 is especially suited for closed loop systems, such as chillers where multi-metal materials are present and the process water system in use requires a high solubility of the inhibitor. For help with your industrial process water treatment or storage of equipment use this corrosion control help form.

Boiler Seasonal Shutdown Maintenance VCI Powder Corrosion Inhibitors VCI-1 Boiler Water Treatment