Commercial Building Boilers

How do I chemically treat a commercial "Hot Water" recirculating boiler?
These commercial boilers are really easy to treat and to monitor. The best chemical you need is a closed loop chemical blend of nitrite, silicate, tolytrizole, and borate. The main chemical component is nitrite. Nitrite will passivate the metals within the hot water boiler systems. This passivation will minimize the corrosion on all iron within the boiler water system. The other components will protect the other metals such as low grades of stainless steel, aluminum, and bronze metals against corrosion.

How to inject the hot water chemical.
Often newly installed hot water boilers are installed with no water treatment consideration in mind. This is very common in small and large buildings. If this is your case, consider using an industrial chemical pot feeder. A chemical feeder is an easy and safe way to inject the chemical into the hot water loop. There are three common models to choose from.

If you have an existing commercial hot water system and have no chemical treatment, you most likely have a lot of corrosion and debris within the hot water system. Consider purchasing a chemical filter feeder. A chemical filter feeder can be used to clean the existing debris and may be used to inject the chemical safely into the system. Failure to remove this debris may cause erosion within the hot water loop which may lead to leaks occurring at the pipe elbows.

How to test you "Hot Water" Boiler system chemicals.
Testing a hot water boiler requires monitoring the conductivity (for reference) and measuring the sodium nitrite residual. This test can be performed with a nitrite test kit or with nitrite test strips. ChemWorld closed loop chemical comes in clear and with a pink "P" Inhibitor. The advange of the "P" Indicator product is no testing needs to be performed. Just monitoring the color of the water clarity.

How do I chemically treat a commercial "Steam Boiler"?
Before discussing the chemicals, if all possible install a softener system on all steam boilers. Chemicals are used as a polisher to remove trace hardness in boiler feedwater, they are not designed to remove high amounts of feed water hardness.

Commercial "Steam boilers" are much different to treat then commercial "Hot Boiler" and sometimes they can be tricky if they have a low duty cycle.

First, for really low generating steam boilers that make up very minimal water, you may consider chemically treating it as a closed loop hot water recirculating boiler. Low makeup water system introduce minimal dissolved oxygen within the makeup water.

For hot water boilers, passivation is the most important part of treating a hot water boiler. For steam boilers, removing the dissolved oxygen from the makeup water is the most important part of treating a commercial steam boiler. For this reason, the product of choice is an "All in One" boiler chemical. For systems that require condensate treatment, you may consider using an "All in One" boiler chemical with amine to increase the condensate pH. If you have severe boiler scale within your existing boiler system, consider using an acidic polymer "All in One" boiler chemical that is designed to gradually dissolve existing boiler scale (you need to install a softener prior to implementing this chemical).

How to inject your "Steam Boiler" chemical.
This chemical should be feed as far back into the feed water system as possible with chemical metering pumps. The chemical metering pumps should turn on when the boiler calls for additional water. The chemical should be injected through chemical injection quills, preferably into a feed water tank or before the boiler feed water pump to ensure a good mixture of the chemical.

How to sample and test your "Steam Boiler" chemical residual.
A boiler sample cooler should be installed from the surface blowdown to ensure a good representative sample is obtained and for safety reasons. Use a conductivity meter, a sulfite test, pH test strips, and hardness test kits.