Boil-Out Chemical

Purchasing a new boiler entails a lot of preparation to ensure proper functioning and longevity. Its internal surface usually contains deposits of residual oil, grease, and protective coating which are post-production remains. These deposits should be removed, since contamination lowers the heat transfer rate and can possibly overheat pressure vessel metal. A boil-out chemical will effectively clean these off.

Boil-out chemical is a concentrated mixture of alkaline cleaners and detergents, chelating agents, and inhibitors designed specifically for the cleaning preoperation of industrial boilers and certain water systems. The product is formulated to precondition the exposed metal surfaces, thereby minimizing flash rusting before treatment program starts. 

Features and Benefits:

• Assures boiler reliability and cleanliness upon commission
• Effectively removes oil, dirt, and grease
• Assists in loosening mill scales typically found in new equipment

Feed and Control:

Product is usually pumped into the boiler through one of the vents while the unit is being filled with water. Manufacturer’s procedure should then be followed.

Feedrates: 1 to 4 gallons per 100 gallons. 

Handling and Storage:

Boil-out chemical is highly caustic, and can produce a violent flash if introduced too rapidly into the water. Protective equipment like goggles, gloves, and laboratory gowns should be worn before handling it. 

Store product in a tightly-closed container, away from sunlight. Recommended storage temperature range is 10°C-40°C (50°F-105°F). After chemical is consumed, do not reuse container. Dispose empty container properly, in compliance with federal, state/provincial, and local laws and regulations.

Reference - http://www.banksengineering.com/boilout.htm

Corrosion in Boilers

To solve corrosion in boilers, you must first determine the type of the system. Boilers are either steam-producers or hot water recirculators. Then appropriate chemical solution can be applied to address the problem.

Corrosion in Hot Water Recirculating Boilers

For hot water boilers, corrosion is typically distributed and spread across the system. Most, if not all metal tubes, are rusted. The reason is that the rate of mild steel corrosion greatly increases in low to mid pH range at elevated temperatures. Nitrite is the most suitable chemical to control corrosion in this type of boiler. Nitrite will passivate either mild or inexpensive version of stainless steel. Typically, nitrite is blended with silicates and tolytriazoles (TT) and is boosted with a pH buffer. Silicates and TT provide protection on aluminum and copper.

Innovation in technology now offers P indicator in chemical solutions. P indicator calculates the hydroxide alkalinity of water. Add it to the system and when water turns into a pink lemonade color, you have enough of the chemical. This eliminates the need to perform other tedious chemical testing. Just verify the color every other week and you know you have a good corrosion protection. Our anti-corrosion chemical for recirculating boilers is Boiler Chemical 2388D.

Corrosion in Steam Boilers

Corrosion in steam boilers is more complicated. You have two types: either dispersed on all tubes, or localized as small corrosion pits.

For dispersed corrosion, water pH should be boosted. At low pH ranges, mild steel is exponentially more corrosive. Water pH should be maintained above 10.5 to minimize the rate of metal breakdown and to keep polymers in good working condition -- preventing any hardness in the solution. Typically, sodium hydroxide or potassium hydroxide is used to boost boiler water pH. Our alkalinity product is Boiler Chemical 2425.

If there are corrosion pits, there is not enough sulfite in the feedwater tank. Sulfite is used to remove the water’s dissolved oxygen (which will make mild steel vulnerable for corrosion at elevated temperature). You should maintain a minimum residual of sulfite to ensure you have no dissolved oxygen and provide additional protection against oxygen spikes entering the system. Our sulfite-based product available is OS1537LF.

Boiler Water Treatment

You must treat steam boilers different then hot water boilers.  Steam boilers are boiler that produce steam.  Hot water boilers do not product steam, rather they recirculate hot water. This is important in selecting a proper boiler water treatment program.

Steam Boilers Chemicals: Boiler Water Treatment

Sulfites, Alkalinity, Amines, and Phosphates or polymers are used essential to maximize the life of a low pressure boiler.

Alkalinity is used to increase the boiler water pH to above 10.5. This serves three purposes. pH above 10.5 will decrease your overall corrosion rates, it will keep a 3:1 ratio of total alkalinity to silica, and it allows the polymer to react with calcium. A 3:1ratio keeps silica from plating in the boiler. A low pH will result in an over general corrosion appearance on your boiler tubes.

Sulfites are used to remove any dissolved oxygen from the water. Dissolved oxygen enters the boiler in make up water or as air is sucked into the system. Dissolved oxygen is extremely corrosive to your tubes and localized pits will form, ultimately resulting in premature tube failure. Maintain a 20 to 40 ppm residual of sulfite in your boiler water.

Amines are used to increase the condensate pH to a range of 7.8 to 8.7. When generating steam, carbonic acid forms and as a result your steam pH is low. Amines are volatile and when introduced into the steam header or boiler water, amines will increase the condensate pH. A low pH will lead to excessive condensate pipe corrosion.

Phosphates and polymers are used to react with any calcium in the water. The polymer attaches itself to the calcium. The polymer and calcium then is able to exit the boiler through the surface or bottom blowdown. Phosphate reacts with the calcium and sinks the calcium to the bottom of the boiler. When using phosphates you must perform boiler blowdown daily to release the phosphate and calcium. Failure to use a polymer or phosphate will result in calcium build up on the tubes or as some call it boiler scale. This will decrease the over boiler efficiency and will drastically increase your fuel cost.

Remember water expands 100,000 times when changing from a liquid to vapor phase. A typical home water boiler 30 gallon system has enough energy to throw a 2,000 pound car over 100 feet in the air if catastrophically failed. Every year people die from not implementing a basic water treatment program.

That is boiler water treatment made simple for less then 200 psi boilers.