Applying a new layer of coating is one of the feasible ways to improve your boiler’s performance and lifespan. Fine particles (slag) can accumulate inside your boiler, causing erosion and corrosion. Slag can restrict airflow inside the boiler, causing interference with fuel combustion, corrosion, erosion, leaks, and failures. You can optimize your boiler’s performance and longevity through regular boiler maintenance. You might also need to repair or replace some parts. A new coating may be all you need to prevent slag build-up and restore your boiler’s first performance. Here are five things to remember when coating your boiler.
1. Always use a coating & process suited for your boiler
There are different types of boilers, and each coat fits a category. You should determine the best coating for your boiler. Most boiler installation and repair companies have this information at hand so it shouldn’t be a problem. anti-erosion coatings might also work for anti-corrosion.
However, there are different types of coatings explicitly offered for each category. It is also important to note the type of fuel your boiler uses and the corrosion it faces. Both HVOF and HVAF chromium carbide coatings can work for boilers that use fuel that have a sulfur yield. If the boiler wears more at the cold end of the boiler (dew point corrosion), HVOF offers an ideal solution. HVAF provides higher density and excellent hot-corrosion resistance.
2. Different boiler parts may need different coating
Various factors influence boiler wear and tear. Even unexpected factors like boiler design and type of fuel used to determine areas that will wear sooner than others. It is essential to know precisely where the wear is occurring. Boiler coatings also come in a wide variety of options that target specific parts and types of corrosion.
For instance, the water wall area and screen tube will work better with the arc spray system. Tank and vessel, on the other hand, may require conventional HVOF thermal spray. The best coating should offer protection against the specific wear conditions your boiler experience. Parts that experience more wear will naturally require more protection. You should contact your boiler installers or manufacturers to take care of coating services. If they are unreachable, make sure you pick reputable professionals licensed to offer such services.
3. Never coat the unprepared surface
It is essential to prepare the surfaces you will be coating before you apply the new layer. General cleaning may entail opening valves and flush with running water. You should also check for cracks and leaks. If you notice any, make sure you repair them before coating.
Boiler coating is slightly technical, so it is recommendable to involve a professional with experience in the area. Whether you need brazing or actual replacement, call an expert to take care of repairs with brazing equipment before cleaning and coating. Preparing the surface improves the bond between the boiler’s surface and its new coat. It also removes slag build-up and ensures your boiler is in the best condition even before adding the extra armor.
4. Coat one layer at a time
Every boiler is different and may require a different approach to coating. It also depends on the scale of corrosion and what you want to protect it from. However, it is recommendable to coat one layer at a time until you achieve the desired thickness. Some parts will need more coating than others.
Each layer of coating should be left to settle and dry before you apply another. The length of time will depend on the type of coating and method used. Whether you are employing a hard-facing coat or using high-velocity arc spray on a boiler tube, do not forget to let each layer of coating settle before adding another. In most cases, it only takes a few minutes.
5. Test for porosity and screen particles
Boiler coating will improve your boiler’s lifespan by up to 2 or 3 times. However, you need to ensure the coat has consistent metallic powder without any screen particle. You can use a powder de-duster to screen for fine particles and ensure you have the right blend. It is also recommendable to have a gas-permeability tester for on-site porosity checks. Additional equipment that you may need includes a grit feeder and more varieties of HVAF AK spray guns.
A boiler will make your home more comfortable by supplying hot water when you need it. They are also quite expensive, so you should choose reputable durable brands and designs.
However, like other mechanical parts, your boiler will gradually succumb to the daily wear and tear as well as hot water corrosion. Adding a new coating can give your boiler more service years and save you the money needed to buy new parts. Make sure you choose an ideal coating for your boiler. You should also work with professional boiler companies and liaise with the manufacturer’s recommendations.