Feed water allows a boiler system to generate steam or hot water for power generation, chemical processing, brewing and other industrial applications. It consists of make-up water from the feed system and return or condensate water.
Generally, common boiler feed issues originate from water quality, which can affect heating efficiency, operations and equipment. Other issues can come from valve and pump failure. This guide shows you how to fix boiler feed challenges.
Boiler Feed Issues and How to Troubleshoot Them
You can troubleshoot boiler feed issues easily if you understand their root cause. This knowledge can help you perform targeted inspections and implement fitting solutions. Here are some common boiler feed challenges you may encounter and how to fix them.
High Levels of Sludge
High amounts of sludge could indicate poor filtration of solids upstream and water softening issues. Sludge comprises soft solid or oil deposits that can harden when exposed to heat. Sludge typically hardens when water levels decrease during drainage.
When hard sludge builds an insulation layer on pipes, it can constrain water flow, increase temperatures and eventually damage boiler components. These conditions can affect boiler efficiency and industrial processes.
Failing to filtrate and soften boiler feed water can lead to sludge. Consider testing the water for oil, grease and suspended solids against boiler manufacturer specifications.
Next, take these steps:
- If the boiler feed water has higher-than-recommended impurity levels, consider investing in ultrafiltration, reverse osmosis (RO) and other superior filtration technologies. These methods can eliminate fine deposits in your feed water.
- Clean and drain the entire system before installing the new water treatment equipment.
Scale Buildup
Scale forms when dissolved salts from heated water settle on the hot surfaces of boilers and pipes. As the water evaporates, the solids remain behind, building up over time and forming hard deposits. The scale creates an insulating layer on the surfaces, decreasing heat transfer.
This reduced heat exchange can prevent water in the boiler from reaching the required temperature. It also increases energy costs and affects production results.
Here's how to troubleshoot this issue:
- Test the feed water quality for magnesium, iron, silica, aluminum and calcium, and then compare the results against the boiler manufacturer's specs. If the mineral deposits exceed recommended levels, you may need water treatment upgrades.
- Acid clean the system to remove scale and replace components showing irreparable damage. When considering boiler feed replacements, it's best to engage a professional.
Higher-pressure boilers require higher water quality than their low-pressure counterparts. So, if your plant uses a high-pressure boiler, consider advanced filtration systems like RO and electro-deionization (EDI) to boost feed water integrity. In contrast, you can reduce impurities for a low-pressure boiler with a simple solution such as purchasing sodium cycle water softeners.
After cleaning the system, repairing components and upgrading the water treatment methods, you can resume boiler operations.
Foam in the Boiler
When a boiler generates steam, the water impurities foam and evaporate with the steam. This action reduces steam quality and efficiency, affecting the industrial process.
The foaming carryover can degrade downstream equipment, reducing its life span. For instance, the impurities can adhere to turbines and superheaters in power generation applications, minimizing optimal functionality. Foaming is a persistent process that's difficult to break. It results from impurities like oil, which decrease water's surface tension.
Assess the quality of your boiler water to check its alkalinity. If it falls higher or lower than 11, consider investing in an internal chemical treatment to maintain boiler water at this pH, as the National Board of Boiler and Pressure Vessel Inspectors (NBBI) recommends.
Other actions you can perform include:
- Cleaning and draining the system
- Upgrading external feed water treatment
- Replacing damaged components
- Installing a pH sensor to monitor alkaline levels
Boiler Corrosion or Leaks
Corrosion can occur due to a chemical reaction between the water and tank or pipe material. You could notice equipment cracking if the water contains dissolved carbon dioxide and oxygen. This type of corrosion worsens in high-pressure boilers and elevated temperature areas.
Significant levels of chlorides, incorrect pH and dissolved solids can also cause system corrosion, which affects the equipment's integrity and causes leaks. Broken seals or valves can also cause leaks, so check these components to rule them out.
Here's how to determine the type of chemical corrosion you're experiencing:
- If you notice localized corrosion and small holes in areas carrying hot water, your water may contain high oxygen levels. You can invest in a deaerator and quality oxygen scavengers to remove the dissolved gas. Also, hire a professional to repair the holes in the metal and the corrosion to avoid further damage.
- Thinning boiler metal indicates high water acidity due to carbon dioxide. Rusty water in the boiler gauge is another sign of acid corrosion. To resolve this issue, dealkalize and soften the water and invest in advanced filtration methods. You can also perform external and internal chemical treatments to remove solids, which are carbon dioxide sources.
- An uneven gouging pattern signifies highly basic water. This chemical corrosion type occurs under scale, meaning you can use the same methods for eliminating scale buildup. Also, administer pH-regulating chemicals to maintain the water at slightly alkaline levels.
Besides deaeration and pH-adjusting chemicals, consider using corrosion inhibitors to create a protective film on equipment surfaces.
Rotten Egg Smell
A rotten egg smell from your boiler system could signal bacterial growth. Anaerobic bacteria thrive in stagnant or low-quality water and produce hydrogen sulfide, which generates a smell similar to rotten eggs. They typically grow in the aluminum and magnesium parts of your boiler system.
To confirm that water quality is the cause, test for elevated sulfur or hydrogen sulfide levels. If the check comes out positive, consider acquiring top-quality filtration systems. You can also carry out these tasks:
- Deep-cleaning the entire system
- Chlorinating feed water
- Investing in a deaerator
- Installing pH monitors
Temperature and Pressure Imbalances
Boiler feed systems can also experience temperature and pressure imbalances due to trapped air, faulty pressure relief valves, scale deposits, leaks or overfilling.
Maintaining the optimal boiler pressure and temperature promotes efficiency, equipment longevity, proper system functionality and employee safety. Otherwise, fluctuations can fatigue pipe and boiler metal, resulting in structural damage.
A pressure gauge can help you identify this issue early and prevent it from escalating. Turn off the boiler to get an accurate reading. Also, inspect the system for leaks and fix them if present. Heating inefficiency, which could indicate trapped air, is another warning sign to look out for. Bleed the radiator to fix this issue.
Other actions you can take include:
- Testing the water pH for calcium and other minerals to determine if scale is the culprit. You can fix this issue through water softening, filtration and acid cleaning the boiler system to remove the deposits.
- Checking the pressure relief valve to ensure it's working properly. If it's not, replace it with a new one. All boilers must have automatic pressure relief valves approved by the American Society of Mechanical Engineers (ASME) for safety.
- Inspecting the check valve to confirm it's functioning well. When this component breaks, it can cause overfilling, raising the pressure beyond the recommended level. If broken, replace the valve before resuming operations.
Besides implementing these actions, consider preheating the feed water before it reaches the boiler to avoid pressure and temperature variations.
Pump Failure
Sometimes, boiler feed water pumps can fail and affect plant operations. When this happens, get an expert to inspect the entire system to identify the issue. If they find sediments at the bottom of the boiler tank, they can clean the whole system and add a strainer to the condensate pipe. Also, schedule regular cleaning to prevent the pump from pulling sediments and failing.
Motor overheating is another cause of pump failure. You can check the motor power supply to confirm whether the electrical system provides the required voltage. If the voltage exceeds the recommended amount, have a professional restore a stable power supply within a suitable range. Also, plan for routine inspections to ensure optimal performance.
Broken Probes and Sensors
If your facility's boiler probes and sensors break down or fail, you may have a scale buildup issue. These tools, which measure water levels, pH, temperature and other elements, can create scale buildup when submerged. These deposits can then affect measurement accuracy, affecting boiler efficiency.
They can also cause sensors to fail, preventing the boiler from shutting down when the pressure exceeds the recommended amount.
If you discover scale on probes and sensors, check the boiler water pH, which may have risen or dropped below 11. Next, execute these steps:
- Remove the scale deposits from the equipment.
- Schedule their routine cleaning.
- Integrate automated chemical controllers to adjust pH as required.
Tips for Preventing Boiler Feed Water Issues
While this guide provides valuable details on how to fix boiler feed issues, it's better to prevent them from occurring in the first place. Here's how:
- Understand your treatment needs: Determine the state of the water your plant will use and invest in the right filtration and softening methods to remove all impurities. You want to avoid under-treating the feed water to optimize boiler functionality. Engage the help of experts to identify the correct treatment methods for the water you use.
- Schedule routine maintenance and inspections: To avoid frequently repairing boiler feed components, arrange regular boiler blowdowns and blowoffs. You should also have a professional regularly inspect the entire boiler system to identify potential issues early.
- Monitor vital functions: Track pH, temperature, pressure and other important elements to ensure optimal operations.
- Invest in high-quality treatment methods: Acquire reliable treatment systems to maintain superior water quality. Also, integrate both external and internal water treatment to optimize boiler efficiency.
- Prioritize boiler feed replacements: Replace the boiler feed's components as soon as they break to prevent issues from escalating.
- Conduct frequent water quality tests: Regular tests inform you about your water's state and empower you to take action if you notice increased impurities.
- Switch to a boiler feed unit: If using a condensate unit, consider switching to a boiler feed option, which offers better water-feeding control. This system can prevent your boiler from overfilling and eliminate manual draining of excess water.
Frequently Asked Questions Relating to Boiler Feed Water
Explore answers to several topics related to boiler feed water:
What Is the Difference Between Filtration and Softeners?
Filtration removes water contaminants, with advanced methods eliminating bacteria, waste, viruses, per- and poly-fluoroalkyl substances (PFAS) and other chemical compounds. It ensures that process water meets quality and safety standards. In comparison, softeners minimize hard minerals in water, such as magnesium and calcium, to protect pipes and equipment from buildup.
What Is a Superheater in a Boiler?
A superheater is a device used in thermal power generation systems. It increases the steam temperature from a boiler by converting it from wet to dry steam.
What Is the Difference Between Internal and External Boiler Feed Water Treatment?
External treatment involves removing impurities from the water outside the boiler. It ensures that the boiler only uses high-quality water to generate steam or hot water. Examples of external water treatment methods include softening, filtering, deaerating and dealkalize .
In contrast, internal treatment purifies water within the boiler system. It entails chemically treating the boiler and condensate water to remove gases and solids and maintain the correct pH.
Incorporating the two methods in your plant can help you comply with industry standards, extend equipment life, ensure operator safety, cut energy costs, and support the proper processing conditions.
What Is the Relationship Between Water pH and Solids?
Some solids are less soluble in high-pH water, but their solubility increases with decreasing pH. For this reason, the NBBI recommends maintaining boiler water at a pH of 11, which is basic enough to discourage solubility. These solids can then settle at the bottom or top of the boiler, making them easy to eliminate through blowoff and blowdown.
What Is the Ideal pH for Condensate?
According to the NBBI, the proper pH for condensate water ranges between 7.5 and 8.5. Your plant can maintain this range by implementing a chemical treatment to neutralize carbonic acid. Internal treatment of condensate water is essential because carbon dioxide can easily dissolve in the cooling steam, forming carbonic acid, which can corrode steel pipes.
Condensate water forms when steam from a boiler condenses in the pipe. It combines with make-up water from the feed water unit and returns to the boiler to undergo the hydrological cycle or steam generation process.
Choose ePumps for Reliable Boiler Feed Units
Consider ePumps if you want a high-quality boiler feed replacement or a first purchase for your industrial plant. We can customize the product by adding optional features to meet your unique application needs and maximize the potential of achieving your production goals.
Our units come in various gallon capacities to suit operations of different sizes. You'll also enjoy a warranty to protect your investment, free shipping on less-than-truckload (LTL) orders, hassle-free returns and a 110% price match guarantee.
We're a reputable distributor of boiler feeds, pumps, compressors and seals. Our leadership team has over 40 years of experience in this industry and understands the best products for your needs.
Place your order online to purchase your desired boiler feed unit. If you have questions, contact our 24/7 customer service team for assistance.
