Steam boilers play a key role in a wide range of industries, from manufacturing to food processing, from chemical production to the medical field, and the heat they provide is an indispensable source of power for the production process. However, such an important piece of equipment can easily break down and affect the production process if it lacks effective maintenance. So we have to ask: why is preventative maintenance so critical for steam boilers? Next, let's delve deeper into this topic.
Reduced safety risks
Commercial boilers are large and powerful because they need to heat large spaces. A potentially significant safety risk in these systems is boiler explosions. While boiler explosions are uncommon, they are not impossible. In most cases, boiler explosions are caused by an excessive buildup of internal pressure. In the event of an explosion, not only can it cause serious property damage, but it can also jeopardize human life.
Improving efficiency
Simply put, regular boiler maintenance ensures that the system works as it was designed to. If regular cleaning, inspections and other maintenance tasks are neglected, there is a high risk that problems with the equipment will not be detected in time. Preventive maintenance is similar to regular maintenance in that it emphasizes proactive measures to prevent problems before they occur. The fewer problems that occur with the system, the less energy the boiler will have to use to heat the space, resulting in more efficient energy use.
Cost reduction
Ongoing follow-up on routine and preventative boiler maintenance prevents emergency repairs and prevents wasted energy due to system failures. Emergency repairs are often accompanied by high costs, and wasted energy increases operating costs. Through preventive maintenance, companies can reduce both of these expenses and achieve effective cost control.
Maintaining water quality
The efficiency of an industrial steam boiler is directly related to water quality. When a boiler converts water into steam, any impurities or oils in the water can degrade steam quality. Dirty water can also trigger short-cycling and the production of wet steam, both of which can lead to wasted energy and higher operating costs. Included in your routine steam boiler maintenance checklist should be a check of all relevant gauges to determine if the boiler water quality is good. If water is observed to be moving quickly and bouncing behind the glass tube in the water level gauge, the water contains oil; if water is dripping from the top of the gauge, the boiler is producing wet steam. Wet steam heats up faster and less efficiently, forcing the burner to run longer.
In addition, boiler maintenance includes chemical testing of the water by a professional to ensure that the treatment chemicals used, such as scale inhibitors, are mixed in the correct proportions and concentrations. The results of these tests, along with regular water quality monitoring, can indicate whether the water quality is sufficient to prevent premature corrosion, scale buildup, and other problems that could shorten the life of the boiler or affect its efficiency.
Ensure proper boiler sewage
Draining is the process of periodically removing some of the water from the boiler. This operation is critical because as the boiler discharges pure water in the form of steam, solids in the make-up water gradually dissolve within the boiler. The accumulation of solids can lead to poor water quality, increased energy consumption, increased corrosion and scale formation. The most sludge accumulates at the bottom of the boiler, and the skimmer drain valve is located slightly below the water level where the concentration of dissolved solids is highest. While skimming drains are effective and essential for controlling the thickening cycle, bottom drains are necessary to prevent dangerous sludge buildup. Proper drain operation is a core element of boiler maintenance, and an expert should be consulted to determine how often this maintenance task should be performed, depending on the particular system and application.
Equip with proper insulation
Insulation plays a key role in the safe and efficient operation of industrial steam boilers. It reduces the surface temperature of the boiler, preventing employees from being burned, while keeping the temperature more stable and increasing the energy efficiency of the heating cycle. The amount and material of insulation required varies widely, depending on the size of the piping and its operating temperature, and the thickness of the insulation may range from an inch to several inches. Steam boilers typically use the following insulation materials: fiberglass, mineral fiber, calcium silicate, and foam glass. Insulation maintenance includes inspecting the piping, boiler surfaces, and fittings. Inspections should look for wet or deteriorated insulation and for corrosion on boiler surfaces below damaged insulation. Post-maintenance inspections are also important to ensure that the insulation was not damaged during the maintenance process.
Water treatment test
It is critical to test the chemical treatment level of the boiler water, including indicators such as pH, hardness and dissolved solids. Maintaining proper water chemistry helps prevent scale buildup and corrosion. For example, improper pH levels may accelerate corrosion of metal parts, while excessive hardness tends to cause scale formation and reduce heat transfer efficiency.
Visual inspection
Carefully inspect water, steam and fuel piping for leaks or signs of damage. Also, check the water level in the boiler's steam bag to make sure it is within the recommended range. A low water level may cause the boiler to dry out and damage the equipment, while a high water level may affect the quality of the steam and put pressure on the pressure relief valve.
Record readings
Record important boiler operating data such as pressure, temperature and fuel consumption. Accurate records help identify operating trends and catch potential problems before they develop into major failures. By accumulating and analyzing data over time, it is possible to anticipate the maintenance needs of the equipment and schedule maintenance in advance to avoid unexpected breakdowns.
Testing safety devices
Safety valves should be tested weekly to ensure they open properly at the correct pressure setting to prevent excessive pressure inside the boiler. Also, check for blockages or leaks in the drain system; a poor drain system can affect water quality and, in turn, boiler performance.
Clean burner components
Over time, soot and debris can build up on the burner, which can affect combustion efficiency. Thorough cleaning of the burner components, air baffles and combustion chamber maintains optimum combustion performance. For example, a cleaned burner allows fuel to burn more fully, reducing fuel waste and pollutant emissions.
Check the refractory lining
Check the refractory lining inside the boiler for cracks or signs of deterioration. The condition of the refractory lining, which protects the metal surfaces of the boiler from high temperatures, has a direct impact on the efficiency and life of the boiler. If significant damage to the refractory lining is found, it should be scheduled for repair during the next maintenance shutdown.
Checking the water side
The water side of the boiler is inspected monthly for any buildup of scale or deposits. These substances can impede heat transfer and reduce boiler efficiency. For example, scale has a much lower thermal conductivity than metal, and its buildup on the water side is the equivalent of adding a layer of insulation to the heat transfer path, causing the boiler to use more energy to achieve the same heating effect.
Testing combustion controls
Test the operation of all flame safety controls, fuel/air ratio controls and combustion management systems to ensure a safe and proper combustion process. Accurate combustion control ensures that fuels are burned properly, reducing pollutants from incomplete combustion while improving energy efficiency.
Checking stack emissions
Checking stack emissions ensures that the boiler is operating within the permitted emission limits for pollutants such as NOx, CO and particulate matter. This not only helps to protect the environment, but also ensures that the business is complying with relevant regulatory requirements. If emissions exceed the limits, the boiler may need to be adjusted or repaired.
Lubricating equipment
Lubricate all motors, pumps, fans and other rotating equipment associated with the boiler to prevent premature wear and tear of the equipment. Good lubrication reduces friction between mechanical parts, reduces energy consumption, and extends equipment life. For example, pumps that are regularly lubricated run more smoothly and are less likely to break down.
Water pressure test
As a rule, an annual water pressure test of the boiler's water-side surfaces is required. During the test, water is filled into the boiler and the pressure is raised to check for leaks. This test identifies areas that need to be repaired before the boiler is put back into service, ensuring safe operation of the equipment.
Combustion system inspection
Disassemble and inspect burners, fuel lines, air baffles, and other combustion components, as well as check for deterioration of refractory insulation. The inspection allows worn components to be identified and replaced before the next operating cycle, ensuring proper operation of the combustion system.
Control testing
All combustion management controls, safety interlocks, flame monitors and gauges are tested and calibrated according to the manufacturer's specifications to ensure safe and efficient boiler operation. An accurately calibrated control system ensures that the boiler operates stably under all operating conditions, improving energy efficiency and reducing operational risk.
Maintenance planning
Maintenance plans are drawn up based on inspection results to address problems found during shutdowns. At the same time, replacement parts are ordered and maintenance work is rationalized to minimize future downtime. For example, if a critical component is found to have severe wear and tear, ordering new parts and scheduling repairs in a timely manner can prevent the component from suddenly breaking down during operation, resulting in a prolonged downtime.
Collecting preventive maintenance data
Decisions to develop a boiler preventive maintenance program should be based on actual data. Storing work order data in a computerized maintenance management system (CMMS) is a good place to start collecting usable data to optimize boiler maintenance. Specifically, the data collected should include information on the health of the boiler, frequency of breakdowns, time to complete repairs, and cost of repairs. Additionally, speaking with technicians is a way to obtain data that, while not precise enough, can provide insights into whether certain preventive maintenance tasks are irrelevant or ineffective, helping to identify specific maintenance tasks that need to be further analyzed.
Analyzing the data
After collecting boiler data over time, it needs to be analyzed to identify potential trends. The time interval for each preventive maintenance task should match the estimated wear rate of the component being maintained, which requires the use of data such as Mean Time Between Failures (MTBF). If the data shows a high number of corrective maintenance tasks on the boiler, it is important to look at whether current preventive maintenance practices are targeting these issues. If preventive maintenance is not targeting these issues, or if it is focusing too much on other areas, this is a signal that the maintenance program needs to be adjusted. Many professionals recommend that for every corrective maintenance task performed on an asset, six preventive maintenance tasks should be performed. If the ratio of corrective to preventive maintenance exceeds this standard, the preventive maintenance strategy may need to be adjusted.
Adjust the scheduling of repetitive tasks as needed
Some preventive maintenance tasks may be performed too frequently, while others are not frequent enough. Over-frequent maintenance can lead to over-maintenance and increased costs, while under-maintenance can leave holes in the boiler maintenance program and increase the risk of equipment failure. For example, if a boiler system is run less frequently than average, but still follows the calendar maintenance schedule in the equipment manual, the frequency of preventive maintenance may need to be adjusted based on actual hours of operation. Calculating when to perform preventive maintenance based on actual hours of operation saves maintenance costs and allows maintenance to be more targeted. On the other hand, if a preventive maintenance task is intended to deal with a certain failure mode that still occurs frequently, it may be necessary to increase the frequency with which the task is performed or to check that the task is performed correctly to accommodate normal wear and tear on the system.
Implementing Condition Monitoring
In some cases, it is worthwhile to implement condition monitoring. By using sensors to monitor vapor pack pressures, track temperatures, or check for leaks, it is possible to ensure that preventive maintenance is performed only when necessary. Real-time condition monitoring provides timely data, allowing organizations to address problems early, thereby saving on repair and maintenance costs and avoiding potentially significant safety hazards. In addition, condition monitoring provides the basis for upgrading to a predictive maintenance program, which can result in cost savings of 8% to 12% compared to traditional preventive maintenance.
Studying results and making improvements
After adjustments are made to a boiler system's preventive maintenance practices, data needs to be tracked on an ongoing basis. This data will help determine the impact of the changes made. Regularly reviewing data on the health of the boiler and seeing positive changes suggests that the adjustments may be in the right direction; however, if there are still unresolved issues, the data should provide clues for further improvements. Ultimately, preventive maintenance optimization (PMO) is an ongoing process with the goal of continuous improvement, so one-time solutions are unlikely to be the best approach.
Create checklists
Create a detailed checklist for each preventive maintenance task that specifies the exact steps and procedures for completing the task. Checklists ensure consistency and accuracy in maintenance and reduce the potential for human error. For example, when performing a burner cleaning task, a checklist could list the specific parts to be cleaned, the tools to be used, and the order in which they will be cleaned.
Include Time Estimates
Utilize Mean Time to Repair (MTR) data obtained from work orders to estimate the time required for each task. Proper time estimation helps to better organize the work of maintenance personnel and increase efficiency. For example, if it is estimated that a maintenance task will take two hours to complete, personnel can be scheduled and time allocated accordingly to avoid task delays or idle personnel.
Consider replacement parts and tools
When planning each maintenance task, give due consideration to the replacement parts and tools that will be required. Preparing these items in advance can minimize delays in the maintenance process and ensure that maintenance runs smoothly. For example, before an annual maintenance shutdown, order parts to be replaced based on inspection results and prepare the appropriate tools in advance to avoid extended downtime due to waiting for parts or tools.
Prioritize safety
Safety is an important factor in boiler maintenance planning. Safety must always be a priority when developing maintenance plans and performing maintenance tasks. For example, when performing any maintenance work involving high pressure, high temperature or electrical components, safety procedures should be strictly adhered to with the necessary personal protective equipment to ensure the personal safety of maintenance personnel.
Regular inspection
Steam boilers should be inspected regularly by trained and qualified technicians to ensure their safe and efficient operation. Inspections should include a visual inspection of the boiler, as well as testing of controls and safety equipment. Regular inspections allow potential problems, such as worn parts, leaks or malfunctioning safety devices, to be detected in time and repaired with appropriate measures.
Cleaning
Regular cleaning of the boiler to remove soot, scale and other buildup helps maintain boiler efficiency and reduces the likelihood of problems. Soot and scale buildup can reduce the efficiency of a boiler's heat transfer, causing it to use more energy to produce the same amount of steam. Regular cleaning keeps the inside of your boiler clean, improves energy efficiency and extends the life of your boiler.
Water treatment
The water used for steam boilers is treated to prevent the formation of scale and corrosion. Water treatment can be performed using chemicals or filtration systems. Common water treatment chemicals include pH regulators, corrosion inhibitors, and deaerators. For example, ChemREADY offers boiler water treatment chemicals and solutions that are customized for each system, with ultra-concentrated boiler water treatment chemical blends that have 90 - 98% active ingredients and are packaged in one-gallon containers to provide efficient water treatment without taking up too much space.
Monitor and adjust water levels
Regularly monitor the water level in your steam boiler to ensure it is at the proper level. A low water level can cause the boiler to dry out and damage the equipment, while a high water level can cause problems such as a malfunctioning pressure relief valve. By installing a water level monitoring device and regularly checking and adjusting the water level, you can ensure the safe operation of your boiler.
Testing safety devices
Regularly test steam boiler safety devices, such as pressure relief valves and low water cutoffs, to ensure they are working properly. Safety devices are the last line of defense for boiler operation, and regular testing ensures that these devices will activate in time to prevent accidents in the event of an emergency.
Checking and adjusting boiler components
Check and adjust boiler components as necessary to ensure that they are functioning properly, such as the burner should produce a clean and steady flame, the fuel supply should be able to deliver fuel to the burner on a constant and steady basis, and the air supply should be able to ensure sufficient airflow for the burner to function properly, as well as ensuring that there is sufficient ventilation to exhaust flue gases from the boiler. For example, if the burner flame is unstable, there may be a problem with the fuel supply or the air mixing ratio, which requires prompt adjustment.
Lubrication
Regularly lubricate the moving parts of your steam boiler, such as the pump and motor, to ensure they run smoothly and efficiently. Lubrication reduces friction between parts, reduces energy consumption and extends the life of the equipment. For example, adding regular lubrication to the bearings of a motor can reduce bearing wear and avoid motor failure.
In summary, preventive maintenance for steam boilers covers a wide range of levels from routine inspections to annual shutdown maintenance, and involves a variety of aspects such as water quality management, component maintenance, safety inspections, and optimization of maintenance schedules. By implementing a comprehensive preventive maintenance program, companies can significantly reduce safety risks, improve boiler operating efficiency, and reduce operating costs. In the long run, this not only helps to ensure production continuity, but also creates greater economic benefits for the enterprise. Therefore, it is highly recommended that all relevant companies take immediate action to review and improve their steam boiler preventive maintenance work to ensure that the equipment is always in the best operating condition.
