In Charge Of The Maintenance Of Boilers? Here’s What You Need To Know
The industrial revolution was built on boilers, and they are used for various applications to this day. You will be hard pressed to find a facility without a single boiler somewhere on its premises.
In industrial settings, boilers operate around the clock and play an important role in ensuring that the facility runs smoothly. Due to these reasons, boiler maintenance requires a disciplined approach.
If you are in charge of the maintenance of boilers, we have many important information to share.
The dangers of poor boiler maintenance
Boilers are one of the most commonly used pieces of equipment in the industrial setting. They are also among the more dangerous ones. When you are dealing with combustible fuel, hot water, and steam held at very high pressure – you really need to know what you are doing.
A boiler failure can cause a large catastrophe, harming both life and property in its vicinity.
On May 7th, 2020, there was an explosion in the NLC India Ltd thermal power plant in Neyveli, in the state of Tamil Nadu in India. This accident caused the death of 6 workers and injured 17 more. A fire that broke out in the boiler was the cause of the explosion.
Because of the aforementioned dangers, designers and engineers have made sure that boilers are built well. They are unlikely to suffer a failure after skipping one or two maintenance appointments. Unfortunately, this can lead to complacency in the maintenance team’s attitude towards boilers – and such behavior can compound equipment inefficiencies, eventually resulting in a large blowout.
Other reasons for neglecting boiler maintenance include cost-cutting measures, lack of resources, and indifference.
Conclusion? Boiler maintenance needs to be carried out with discipline, by sufficiently trained technicians.
Types of boilers
As mentioned earlier, boilers have been in use for centuries. The initial concept was based on applying heat to water. Over the years, the development of new technologies, materials, and principles led to the creation of different types of boilers.
Here is a quick breakdown of the more common types of boilers based on energy sources, tube contents, tube numbers, furnace positions, and circulation methods.
Boilers vary according to their energy source. Some of the most commonly used energy sources for boilers are:
Contents in tubes
Water in the boiler shell is heated using hot fluid circulating through boiler tubes. Based on the type of fluid flowing through their tubes we can differentiate between:
Fire-tube boilers: Hot gases and fumes generated through combustion are passed through the boiler tubes to heat up the water.
Water-tube boilers: Here the water that needs to be heated passes through the tubes. The tubes are surrounded by hot gases, fire, and heat from the combustion chamber.
Boilers can also be classified depending on the number of tubes in the boiler shell:
Single tube boilers: This type of boiler has a single tube in its design. The single tube can be either a fire tube or a water tube. Single tube boilers generally have a low capacity.
Multi-tubular boilers: As the name suggests, multi-tubular boilers have more than one tube. Such designs enable heating a larger quantity of water in a shorter time, at a higher efficiency.
Another way to classify boilers is based on the position of the combustion chamber (or furnace):
Internally fired boilers: Fuel combustion takes place inside the boiler shell, in a separate chamber within the shell.
Externally fired boilers: Fuel combustion happens outside the boiler shell.
Of course, some boiler designs do not include a furnace. For example, electric boilers do not burn any type of fuel, and therefore don’t need to have a combustion chamber.
The water to the boiler, hot water from the boiler, and steam can all be circulated using different methods:
Natural circulation boilers: Convection currents and gravity are used to move fluids.
Forced circulation boilers: The fluid is moved using centrifugal pumps or other external forces.
Common issues with industrial boilers
Despite all of these types and variations, there are some common problems that plague almost any boiler. If not explored and addressed in time, these problems will compound, until you are forced to pay attention.
Watch out for:
Leaks: Leaks are one of the most common boiler troubles. Leaks can happen at various transport components, as well as the boiler shell itself. Whenever the water is dripping, it is time for an inspection.
Corrosion: Corrosion is another universal problem with boilers. Since the metallic parts and components interact with water, they are prone to corrosion. This damages various boiler components, and can cause them to fail if preventive steps are not taken.
Scaling: Water used in the boiler contains minerals and other impurities. These impurities can form scaly deposits on different boiler parts. Their appearance is similar to fish scales – hence the name.
Foaming: When water is heated, solid impurities can rise up and foam up over the boiling water. This causes a drop in boiler efficiency. The solid waste can also get carried further with steam, and form deposits on other boiler parts.
Low pressure: Low water or steam pressure is another common problem. This is generally an indication of other problems within the boiler.
Priming: In steam boilers, water molecules can get carried along with steam. The result is called wet steam. This is called priming, and can cause many other problems down the line. Priming happens due to improper boiler design, high water levels, water contaminants, and improper usage.
Unusual noises: If you have been around them for a while, you know how a boiler sounds under normal operation. Loud bangs and whistling noises are usually not part of normal operations. Such symptoms clearly indicate underlying problems.
Different problems affect different boiler components. Understanding critical boiler components is essential for effective troubleshooting and maintenance. Let’s go over that next.
Critical boiler components
As with any compley equipment, boilers consist of many components with unique functions. Each of the components has distinct maintenance requirements. Let’s quickly go through the different components and their respective maintenance considerations.
This is the part where the combustion happens. Fuel, air, and sparks meet at the burner to create the energy used to heat water. Inefficient combustion leads to a loss in efficiency and fuel wastage. Clogged burners lead to fuel leakage, which can cause uncontrolled fire and explosions.
Conduct periodic burner inspections, including its electrical and mechanical connections. Ensure there are no fuel leakages. Also, check for corrosion: the surface, the fuel pipes, and other fittings. Regularly check for debris blocking the fuel source or the fresh supply of air for combustion.
The combustion chamber is a safe and isolated space for fuel combustion. This is one of the critical boiler areas, generating energy that is used to heat the water. Naturally, it can also generate many hazards if maintenance is not up to par.
Clean up the combustion chamber periodically. Soot and other debris in the combustion chamber can lead to a drop in efficiency. Unwanted objects in the combustion chamber are also a cause for fire hazards. Ensure air intake is not blocked. Check periodically for cracks or corrosion on the materials lining the combustion chamber.
The heat exchanger is where the combustion-generated heat gets transferred to the water. In most boiler designs, the heat exchanger basically consists of fire/water tubes that carry fluids.
The surface of the heat exchanger is in contact with fluids of different temperatures. This can cause various material distortions. Check for cracks or other physical changes in materials. On top of that, you can perform various non-destructive testing methods – like ultrasonic testing and eddy current testing – to check tube health.
The switches, knobs, sensors, and other components for monitoring and controlling the operations can also be considered as critical components of the boiler. Control failure can lead to catastrophic results.
Check the electrical connections of the control elements periodically. If software is used in control systems, make sure the latest update is installed. Additionally, make sure to follow proper cyber security protocols. Replace hardware components according to the schedule provided by the OEMs.
Boiler water, hot water, and steam are all transported using pipes, tubes, or other mechanical contraptions. They form boiler transport lines.
Regularly check the transport lines for corrosion and cracks. Ensure there is no pressure loss in the pipes and tubes. On top of that, make sure that there are no blocks hindering fluid flow.
The exhaust stack consists of chimneys and associated equipment used to remove the gases and fumes produced by fuel combustion. The exhaust stack is designed so that no poisonous gases remain in the plant.
Broken exhaust pipes and chimneys can cause exhaust gas leakage. Check the pipes and tubes in the exhaust stack for faults. Periodically check for poisonous gases to ensure that the exhaust stack is working properly. Schedule clean ups regularly, as soot and other accumulated debris can decrease exhaust efficiency – and, consequently, boiler efficiency as well.
Maintenance schedule for industrial boilers
Boilers have to be regularly maintained to ensure they are operating safely and within the desired operational efficiency. Creating a preventive maintenance schedule for boilers used in industry is critical in avoiding boiler failure.
The boiler manufacturer will provide a standard maintenance schedule that needs to be adhered to.
However, that is just a baseline – the schedule must be adjusted based on the condition of the boiler and its day-to-day usage.
Water hardness, pH levels, and water impurities can play a huge factor. Many other environmental factors – like the variations in humidity and temperature at the boiler’s location – also play a part in determining the exact maintenance schedule. This is even before considering factors like spillage or debris from other plant equipment!
In order to factor in all the various considerations, the boiler maintenance schedule has to be created by experienced professionals. This includes engineers from the boiler manufacturer, operations technicians, reliability engineers, and maintenance technicians.
All the experts have to come together and determine the different tasks that have to be done on a daily, weekly, and monthly basis.
Maintenance tasks have to be done routinely and meticulously. Skipping steps in the maintenance process is not advisable. Checklists are helpful in following rigorous maintenance procedures. They help to prevent mistakes caused by negligence or complacency.
Each boiler will have its own set of maintenance checklists. The following sections cover a common set of steps to be taken at different time intervals.
Perform the following tasks on a daily basis.
Open the drainage and blow out water from the pipes when the boiler is not in use.
Keep track of boiler parameters such as fuel consumed, temperature, and pressure. This is to make sure that the boiler is operating within its operational characteristics.
Regularly check output steam pressure. Also, check the pressure of the water inlet.
Observe the furnace periodically through the sight port. Look for flame abnormalities. Also, look out for sooting.
Check the various venting systems and drainage for blockages and obstruction.
The characteristics of water used in the boiler. Take samples and check water hardness, the minerals present, etc.
Some checks to be done on a weekly basis are given below:
Check the fuel supply, pipes, tubes, and valves associated with the fuel supply valve.
Perform evaporation tests to ensure proper operation.
Check the boiler for leakages – including water, steam, and exhaust gases.
Check whether the controls are performing normally.
Check whether the indicators and safety features are working properly.
Check for unusual noises and vibrations in the equipment.
Follow the following checks on a monthly schedule:
Check boiler components for visible cracks and other damages.
Clean up the combustion chamber, chimney, and exhaust stack.
Check the boiler’s ignition system.
Check for hotspots on the boiler’s exterior.
Some maintenance tasks need to be done in six-month intervals, including:
Checking for scaling inside the boiler components.
Assessing corrosion levels in the boiler and transport tubes.
Checking the operational characteristics of various boiler pumps.
Performing non-destructive testing to test boiler components materials.
Checking the condition of wires, switches, and other electrical components.
It is important to reiterate that the exact maintenance schedule should be based on the boiler type, OEM guidelines, maintenance history, and the conditions the boiler is currently operating in.
Take charge of service and maintenance of boilers
Boilers are one of the most critical pieces of equipment used in industrial operations. At best, boiler failure will cause capital losses and operational disruptions. At worst, it will result in catastrophic damage, taking life and destroying property.
As such, boiler maintenance should not be on the agenda for cost-cutting measures. Quite the contrary.
You should create comprehensive maintenance schedules and meticulous plans for executing them. If needed, follow that up with maintenance checklists and SOPs to ensure that all the maintenance tasks are performed in time and with due discipline.
If you need help organizing and tracking maintenance work, give Limble CMMS a try. It is simple to use and has all the features you will need to take charge of boiler maintenance.
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Valley Salt LLC
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I spent a long time evaluating systems I'm so glad I chose Limble
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"I can track my inventory and it sends me emails when I'm running low on an item. Also that I can track how much time I'm spending on certain jobs over an extended period of time."
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