Any equipment or machinery that has metallic components is prone to corrosion over time. This is highly likely in equipment like boiler which has both metallic component and also water. Corrosion happens when iron or steel are exposed to water and oxygen. A boiler is always in constant contact with both water and oxygen and hence the probability of corrosion is high. Corrosion leads to the disintegration of metallic pieces and eventually a complete system failure. With consistent monitoring and proper maintenance corrosion in boilers can be prevented or kept to minimal levels.
Corrosion causes and types
In a boiler, the primary cause of corrosion is the dissolved oxygen in the feed water. The feed water if untreated will have both dissolved oxygen and metallic impurities which will corrode the inner walls of the boiler. As time passes by corrosion creates tiny holes in the boiler which leads to water leakage which can be a serious threat. Another type of corrosion is caustic corrosion which happens when concentrated caustic substances start dissolving the magnetite layer in the boiler. When the boilers are cleaned, various chemicals are used which can be harmful if handled improperly. If the chemicals are mishandled during cleaning, it will lead to acidic corrosion which is equally harmful. Most of the corrosion types can be prevented with careful handling and maintenance.
Though 100% corrosion prevention is not possible, we can try to minimize corrosion with a cautious approach. As stated above dissolved oxygen and metallic impurities are the primary causes of corrosion. One of the most effective preventive measures is to treat the feed water before it enters the boiler. When proper additives are added to the feed water it will absorb any excess oxygen and send in clean water. Corrosion is not possible without oxygen and hence removal of oxygen is the best solution. If the feed water is treated with proper chemicals which can remove all the impurities then corrosion can be further reduced.
Maintaining a strict schedule for proper boiler service is the best preventive measure for corrosion. Periodical checks are required to ensure that there are no nicks in the connections which will let in oxygen. Another simple hack to ensure your boiler remains corrosion-free is to do periodic tests on the water sample. If the water sample tests positive for chemicals or impurities then there is a chance of corrosion happening. Highly disciplined documentation and reporting are required to prevent or detect corrosion early and treat it.
Prevention is the best option for corrosion but there is no need to panic when corrosion has already happened. If you can detect corrosion early, it can be treated. Corrosion, if left untreated for a while, will wreak havoc and destroy your boiler completely. There are various cleaning chemicals available in the market which can reduce the damage caused by corrosion. The first thing to do is to hire a treatment expert to assess the level of corrosion and its damage zone. Once this has been established it can be treated with various chemicals like corrosion and scale inhibitors, alkalinity and dispersing agents, and condensate line protection.
Preventing or minimizing boiler corrosion should a top priority for companies as it could lead to an unexpected shutdown and expensive repair or replacement of the boiler.