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Tag Archive: Heat Exchanger Maintenance

  1. Chiller Tube Maintenance Step-by-Step Guide

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    Chiller tube maintenance is likely not on the top of facility managers’ minds during cold months. But just because they may not be in use, doesn’t mean you shouldn’t give them some attention during the winter season. In fact, this extended period of time when chillers are not a critical component of your building’s HVAC efforts is the perfect opportunity to address any chiller tube maintenance concerns.

    Of the many components of a chiller, the tubes are one of the most impactful in terms of overall energy efficiency, according to The NEWS. Chiller tubes and coils can become dirty or coated with scale over time, which decreases their heat transfer capabilities. As a condenser’s heat transfer ability goes down, its energy consumption goes up – sometimes by 30 percent or more, according to the U.S. Department of Energy. A well-maintained system, therefore, can save energy and money. If your condenser was struggling to reach a full refrigeration load or was reaching higher pressures than expected, it’s likely you have buildup that’s increasing your energy spend.

    Begin Your Chiller Tube Maintenance with Clean Tubes

    An initial water cleanse is a good step toward cleaner tubes, but it shouldn’t be your only means to achieve greater energy efficiency. There will likely still be scaling left clinging to the tube walls after the cleanse is finished, especially considering that most chiller tubes have ridges in them.

    A rotary tube cleaner, like the Goodway Ram-Pro sold by Enerquip, includes a brush that rotates to get into those grooves and can help immensely. Newer models of rotary tube cleaning systems also allow you to add antimicrobials and corrosion inhibitors onto the surface of the tubes to minimize future scaling.

    Choose the brush you use with the rotary tube cleaner carefully, as different models are designed to clean specific types of fouling. There’s a big difference between removing softer fouling like algae and mud compared to tougher scaling and mineral deposits.

    You may also consider using chemical descalers to tackle more difficult forms of buildup like calcium, rust and lime. However, before you choose chemicals to insert into your tubes, make sure they’re compatible with the equipment’s materials of construction. If your tubes were fabricated with an alloy that’s highly resistant to corrosion, such as stainless steel, this may be less of a concern.

    Cleaning your tubes should be at least an annual or biannual task, and doing so during the colder months can give you ample time to address any issues before the weather warms up again.

    Do an Eddy Current Test

    Many chillers go through eddy current testing after fabrication and installation to test for any damage that may have occurred before the unit is fully operational, Process Cooling explained. It’s also a good method to test for issues that may arise during the lifetime of the chiller.

    An eddy current test may be able to detect small defects that can lead to leaks, but it shouldn’t be confused with an actual leak test, Texas Eddy Current explained. An eddy current test, sometimes called a magnetic field test, can highlight corrosion, erosion, mechanical damage and more. It can also indicate whether your tube walls have lost thickness over the years, Facilities Net reported. To conduct this test, a metal probe that creates a full-circle magnetic field is inserted into the tube. As the tester moves the probe through the tube, the magnetic field will either remain stable or show signs of a disturbance. Those signals indicate an issue at that location.

    You don’t necessarily need to do an eddy current test each time you clean your tubes. Once every two or three years for your chiller or three to five years for your evaporator should be sufficient.

    Treat Your Water

    The quality of the water that enters and flows from your chiller plays a big role in determining how often you should perform chiller tube maintenance and cleaning. When you know the water quality in your area, you can take proactive measures to prevent scaling and fouling in your tubes.

    “When you know the water quality in your area, you can take proactive measures to prevent scaling.”

    Closed-loop systems, which are most common in chillers, generally require a one-time chemical treatment to reduce the risk of fouling. If you have an open-loop system, which may be found in condenser systems or atmospheric cooling towers, you’ll likely need to arrange for continuous chemical treatment. In any case, water treatment should be tailored to the unique qualities of the local water source. A water treatment specialist in your area is the best resource to consult.

    Though keeping the risk of fouling at a minimum may be your highest priority, you should also keep in mind other conditions of the water, such as the temperature and flow rate, Contractor Business explained. Colder water is generally more efficient to use in chillers. In fact, if your chiller isn’t running optimally and you aren’t prepared to clean the tubes just yet, lowering the temperature may be a good temporary solution for improving efficiency. Don’t mistake this as a long-term fix, though – if you’re looking for sustained improvement, it’s critical to remove scale and other buildup in the tubes.

    The flow rate should generally be between 3 and 12 feet per second. Fall below this range and you’ll get laminar flow that reduces the efficiency of the chiller. Higher flow rates can cause the equipment to vibrate and shake, and increases the risk of damage to the tubes.

    Create a Prevention Plan for Your Chiller Tube Maintenance

    Setting aside enough time to conduct thorough chiller tube maintenance and inspection is a great first step toward lasting energy efficiency, but it’s important to plan for the future, too. Every system is different, so you should create a plan to keep your unit running well for years to come.

    Creating a daily operating log will help you visualize small day-to-day changes in the chiller’s performance, which will indicate how often you should repeat the cleaning process. It will also clue you into small issues that occur. Identifying and addressing these before they escalate into larger problems can help you maintain a functioning chiller for longer.

    In time, you may start to notice patterns in your chiller’s performance. This will help you create a schedule for inspections and maintenance.

    Know When to Replace Your Chiller

    Every chiller will be replaced sooner or later. Though these units can generally be relied upon for several decades, they’ll eventually become more costly to maintain than it would be to install a newer, more updated model. If your chiller is presenting frequent issues and is close to 25 or 30 years old, it’s likely ready to be retired, Facilities Net explained.

    When choosing your next model, seek out a manufacturer that can provide reliable, high-quality equipment. The engineers at Enerquip are here to help identify shell and tube requirements for a wide range of assets, including chillers. Request a quote.

  2. Five Important Qualities to Look for in Pharmaceutical Process Equipment

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    Condensers are key components for pharmaceutical production. Increased regulations and oversight of pharmaceutical manufacturers over the past few decades have created a need for specifically designed for their intended purpose.

    Shell and tube heat exchangers used for pharmaceutical condensers should be easily cleaned, compatible with the appropriate heat transfer fluids, resistant to contamination and corrosion and reliable. Here’s what you need to know about choosing a heat exchanger that works for your pharmaceutical operation:

    1. Easily Cleaned

    Pharmaceutical products must be as pure as possible, and one step in achieving maximum purity is using clean equipment. Residue remaining from the previous batch or product type can taint the next round of product.

    Any amount of product left behind that could feasibly be removed through normal cleaning methods should not be present in equipment before production begins, according to the U.S. Food & Drug Administration’s Current Good Manufacturing Practices.

    Instruments that test for cleanliness today are highly accurate, able to detect even tiny amounts of residue. As such, it’s not always feasible to clean equipment to the point where absolutely no amount of previous product is detected. However, it’s always best to clean as thoroughly as possible.

    Choosing equipment that’s easily cleaned is a good step toward ensuring product batches are as pure as possible. Certain configurations of shell and tube heat exchangers are more easily cleaned than others. For example, straight tube exchangers are often easier to clean than U-tube style exchangers because there are no bends to maneuver around.

    Drainability can affect how easy it is to clean a shell and tube heat exchanger. If it’s hard to get the last ounces of liquid out of an exchanger, it’s harder to rid the equipment of all traces of the fluids. Exchangers that are designed to promote drainability, such as those offered by Enerquip, are best for this purpose. By being able to completely empty the equipment of all fluids (either by free-draining or with air-assist), the cleaning process is more effective, and the next batch won’t be affected by traces of previous product.

    2. Silicone Heat Transfer Fluid Compatible

    Your equipment needs to be compatible with the substances that will pass through it – both on the tubeside and the shellside. The heat transfer fluid used plays a large role in how effective the heating or cooling process is, as well as how well the equipment will hold up in time.

    Fluids that aren’t effective for heat transfer will require a longer process time and more energy to run. Additionally, fluids that can be corrosive can cause equipment to wear out faster. Some fluids are flammable, creating potential risks in the work environment if products or equipment are mishandled.

    Silicone is becoming a more popular heat transfer fluid for a number of reasons. It is known for their thermal stability, an important quality of heat transfer fluid. Silicone fluids are ideal for temperatures above 350 degrees Fahrenheit, according to an article from The Dow Chemical Company originally published in Process Heating Magazine. While silicone is effective at high temperatures, it also has good pumpability at low temperatures, making it a versatile heat transfer fluid.

    They also are long-lasting and aren’t likely to cause chemical abrasion, even when exposed to high temperatures. For these reasons, more than 375,000 tons are expected to be generated by 2024, according to a press release from Global Market Insights.

    Silicone has a low risk of flammability, making it an attractive fluid for many manufacturers, Chemical Processing pointed out.

    3. Leak-Free

    No manufacturer or equipment operator wants to have leaks. But for pharmaceutical processing equipment, leaks are particularly troublesome. Leaks create the possibility of product contamination, as well as corrosion or other chemical reactions that may occur when process and utility fluids mix.

    One way to reduce the risk of leaks is with a fully welded tubesheet. Another method to minimize the risk of leaks – or at least the negative impacts of them – is to design an external leak path to prevent any possible leakage from interacting with the fluid on the opposite side of the exchanger.

    Shell and tube heat exchangers constructed with double tube sheets are designed to drain any leakage away from the exchanger to minimize the chances of cross-contamination. At the same time, the operator is alerted to the problem so he or she can address it promptly.

    4. Resistant to Contamination and Corrosion

    Equipment used to create any product should not pose any risk of contamination. However, avoiding contamination means different things for different industries, processes and products.

    To minimize the risk of contamination as much as possible, equipment used for pharmaceutical production should be pharma-grade. Enerquip’s high purity exchangers are ideal for this industry. Our knowledgeable heat exchanger experts have ample experience fabricating shell and tube heat exchangers for pharmaceutical purposes, and are even used by companies like Bristol-Myers Squibb, Pfizer and Unilever.

    Corrosion-resistant materials also help to lower the risk of product contamination. Corrosion can be caused by chemical or physical processes, and the residue that emerges through this process can be reactive or can put the purity of the product at risk. Stainless steel and stainless-steel alloys are highly resistant to corrosion, making them smart choices for pharmaceutical construction.

    5. Highly Dependable

    All manufacturers, regardless of industry, strive to reduce or eliminate downtime. Every minute of downtime has a real impact on the company’s bottom line.

    Choosing reliable equipment is one of the most effective ways to reduce downtime. The less frequently equipment requires maintenance or spare parts, the more often it’s contributing to your facility’s production.

    Enerquip prides itself on fabricating equipment that is long-lasting and can be counted on. To learn more about choosing the right pharmaceutical process equipment for your facility, reach out to the knowledgeable heat exchanger experts at Enerquip.

  3. Three Types of Mechanical Failures in Shell & Tube Heat Exchangers and How to Prevent Them

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    Shell and tube heat exchangers are well favored by plant engineers for their long life spans and minimal maintenance needs in addition to their ability to efficiently transfer heat. While stainless steel heat exchangers are reliable and durable for the most part, there are times when stress and extended use take their tolls on the equipment’s components.

    Mechanical failure can appear in several different forms, each with its own symptoms and consequences. When you know what to look for, you can work to prevent mechanical failure in your exchangers or identify an issue quickly so you can solve it promptly. Here are three types of mechanical failure that shell and tube heat exchangers can sustain in time:

    1. Fatigue

    Repeated thermal cycling can lead to fatigue in shell and tube heat exchangers. Fatigue can cause cracking in the tubes beginning with small, hard-to-see striations that can quickly grow larger. Eventually, fatigue cracks can span the diameter of the tube and completely sever it.

    There are several factors that can increase the risk of fatigue or cause it to escalate more quickly. A report on failure analysis of shell and tube heat exchangers from the College of Engineering Pune in Maharashtra, India, explained that the stress ratio can play a big role in contributing to thermal fatigue. As may be expected, when stress increases, so does the risk of failure due to fatigue.

    “Small weld defects can lead to fatigue and severe damage.”

    Another factor that can lead to fatigue faster is poor welding practices, as well as other fabrication shortcomings. In one failure analysis published in Case Studies in Engineering Failure Analysis, engineers determined that a faulty weld joint where the tube met the tubesheet was the catalyst that resulted in failure. After careful review, the team identified a small welding defect, just 0.4 millimeters long, which was the first crack that would eventually lead to dozens of small fractures throughout the tube. With use, the cracks grew and propagated.

    In addition to the welding defect, issues with thermal expansion also caused serious stress on the tube-tubesheet joint. The report noted that it’s best to have expansion positions 15 or more millimeters away from the tube end to lessen the stress expansion would have on the tubesheet. In the failed exchanger, the expansion position was very close to the tube end, which likely caused even greater stress on the already faulty weld joint.

    Avoiding fatigue must begin with fabrication. Even a tiny 0.4-millimeter mistake can lead to severe damage to the exchanger. Additionally, understanding how to adjust your process to reduce stress within the equipment can help.

    2. Metal erosion

    Metal erosion in stainless steel shell and tube heat exchangers negatively impacts the quality of the equipment in two ways. First, as metal erodes away from the tubes, they become weaker and more susceptible to damage. Second, as the protective outer layer of the tubes wears down, the tubes face a higher risk of corrosion. Any corrosion already forming will only get worse as metal erosion takes place, according to Plant Engineering.

    Metal erosion can be caused by excessive speed of flow within the exchanger and by abrasive solids suspended in slurry streams. When a high-velocity stream is divided into thin, sharp jets of fluid upon entering the heat exchanger, it can also lead to metal erosion. In cases like this, the erosion pattern is horseshoe shaped and very localized. Additionally, high temperatures, such as those that allow for flash steam to occur, can also increase the risk of metal erosion. Plant engineers are most likely to see metal erosion occur on the bends of U-tubes or at the tube entrances.

    To prevent metal erosion, it’s important to understand the maximum velocity fluid within the exchanger can reach without causing harm to the components. This largely depends on the materials of construction, the fluid type and temperature, among other factors. Stainless steel fabrication, for example, can handle much higher velocities than a copper shell and tube heat exchanger. Other alloys that contain steel, stainless steel and copper-nickel combinations are also sturdy and can handle higher flow speeds.

    3. Thermal expansion

    As the fluids within the shell and tube heat exchanger transfer heat, the tubes and shell begin to heat up. Depending on the materials of construction, the temperature change, how fast it occurs and other factors, either the tubes, the shell or both may swell, a process called thermal expansion.

    Thermal expansion is fine, as long as you know how to prepare for it. If your exchanger is not equipped or built to handle thermal pressures that cause the metal alloys to widen, it can sustain extensive damage. Plant engineers will most commonly see thermal expansion in exchangers where the cold fluid that’s being heated is valved off, most often in steam-heated exchangers.

    In fixed tube heat exchangers, thermal expansion of the tubes can cause them to grow too large for the tubesheet, causing pull out, warped tubes or a damaged tubesheet. A U-tube shell and tube heat exchanger is a popular deterrent for the potential damages of thermal expansion because the side of the tubes with the U-bend is expected to absorb the heat that leads to swelling, thus saving the fixed side from the stress. However, that doesn’t mean this is an infallible strategy, Mechanical Design of Heat Exchangers explained. In process dealing with very high temperature changes, it’s important to consider all possibilities of thermal expansion and ensure the tubes can handle it.

    Thermal expansion can also be a problem when the fabrication material for the tubes is subject to faster expansion than the fabrication material for the shell. When the tubes swell but the shell doesn’t, it can cause severe damage to both the tubes and the shell.

    Preventing damage due to thermal expansion must begin with the heat exchanger design. First, it’s important to understand the properties of various alloys and how they react in certain conditions. As such, engineers building the exchanger must have a thorough idea of how the exchanger will be used, including information about planned temperatures and the types of fluids that will be introduced to the equipment. If it’s determined that thermal expansion is highly likely, the exchanger can be built to include an expansion joint.

    When designing and fabricating shell and tube heat exchangers, it’s important to have a full idea of what types of mechanical failure the equipment will be at risk for, and to take measures to prevent it. The engineers at Enerquip are well-versed in the many different design options for heat exchangers and can construct a high-quality exchanger for your operation. If you’re looking for the right exchanger for your process, reach out to Enerquip.

  4. Freezing Fouling in Shell and Tube Heat Exchangers: What you need to know

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    Fouling is a natural part of heat exchange. However, not all fouling is alike. Some types are more common but less damaging, and many can be anticipated long before installing an exchanger.

    One type of fouling that is relatively less common but potentially very damaging is freezing fouling. It’s important to understand this phenomenon, what causes it, how to prevent it and which measures to take when it does happen.

    What is freezing fouling?

    Freezing fouling, also called solidification fouling, occurs when the fluid inside the shell and tube heat exchanger seizes up and creates a block of substance that is difficult to remove. There are a number of reasons why this might happen.

    Every fluid has a freezing point, and it’s critical that those who work with heat exchangers and the fluids that go inside understand at which temperatures materials will freeze. Intuitively enough, one primary cause of freezing fouling is when the heat transfer surface falls below a fluid’s freezing point, Thermodedia explained.

    This might be the case when using a shell and tube heat exchanger to chill water. If the heat exchanger surface that is in contact with the water (i.e. the tubes if the water was entered on the tubeside) falls below 32 degrees Fahrenheit, the water will begin to freeze. How much it will freeze depends largely on the temperature difference between the tubeside and shellside fluids, among other factors. It could be a matter of a thin sheet of ice on the surface of the tubes (or shell, if the water is on that side), or a thicker mass of ice.

    Moist air can also freeze when coming into contact with a cold surface. Keep this in mind if you’ll be working with low temperatures and anticipate evaporation or mist to result from your process.

    Freezing fouling doesn’t necessarily mean the entire fluid will solidify. When using a solution, there may be various components with differing freezing points. Those ingredients that have relatively higher melting points could be challenging to keep liquid in certain processes. The solution may separate as a result, resulting not only in a partially frozen slurry, but also a liquid with different proportions of components than expected.

    Freezing fouling and crystallization fouling

    Crystallization fouling occurs when some solutes within a solution solidify and begin to accumulate on the heat transfer surface, wrote InTechOpen, an open access science, medical and technology book publisher. Depending on the solute and the conditions, people who work with shell and tube heat exchangers may refer to this phenomena with different terms, like:

    • Scaling, one of the most common, describes solid deposits that are very difficult to remove.
    • Sludge, softscale or powdery deposit describe softer, more porous, mushy or slimy deposits.

    Crystallization fouling and freezing fouling are two different events, but they do have a Venn diagram-like overlap when it comes to waxy deposits. When waxy hydrocarbons from a hotstream come in contact with the cold surface, waxy deposits can form on the heat transfer surface. These types of deposits may technically be crystallization fouling, but many people identify it as freezing fouling.

    Paraffin is one substance in particular that commonly results in a waxy precipitate, according to the Society of Petroleum Engineers’ PetroWiki. Naphthenic hydrocarbons, which like paraffin are found in crude oil, also causes wax-like deposits, but are much softer and referred to as “microcrystalline wax,” often accumulating at the the bottom of the vessel in a sludge-like substance. Since waxes have a high melting point – paraffin’s is generally between 104 and 158 degrees Fahrenheit – these deposits are often seen at ambient temperatures.

    Preventing freezing fouling in a shell and tube heat exchanger

    To avoid freezing fouling in your shell and tube heat exchanger, you must begin with understanding the fluids you’re using and how they respond to different environmental conditions, including temperature and pressure levels. Additionally, when working with solutions that contain solutes with varying freezing points, it’s critical to understand the properties of all components.

    When you know which substances you’re working with, their properties and expected behaviors, you can prevent freezing fouling by not creating the conditions in which they’ll solidify.

    With more complex substances, like crude oil, it’ll be more difficult to determine exactly which conditions will lead to the formation of solid materials. In the case of paraffin, engineers need to know the wax appearance temperature, also called the “cloud point” or “WAT.” This depends on many factors, including the weight and size of paraffin molecules, the ratio of water to oil, the composition of the oil and the presence of other substances that aid in solidification, among others.

    In some cases, freezing fouling could result from a malfunctioning component or an incorrect setting, according to an article for Plant Engineering. This may be the case if your chiller, condenser or evaporator freezes up when it’s not supposed to. In these cases, you may be unprepared for the event, and the ice formation can cause considerable damage if allowed to continue. Much like a pipe bursting during a cold winter, your tubes or shell could pop open with the pressure of the expanding ice.

    If all components are set and behaving as they should, taking precautions ahead of time could prevent a freeze-up. If you’re using antifreeze to prevent it but ice forms anyway, you may need to readjust your concentration of antifreeze. A thermal protection device or control system can also be advantageous. Finally, if you’re preparing your equipment for a seasonal shut-down in the winter, not properly and thoroughly draining your equipment can lead to freezing.

    Responding to freezing fouling

    In some cases, a certain process requires engineers to use substances that may solidify, risking the occurrence of freezing fouling. In these instances, it’s important to be prepared for if and when freezing fouling occurs so you can prevent further damage to the equipment.

    If your freezing fluid is on the shellside, you may be able to warm up the equipment using electric tracing, Chemical Processing noted. Heat exchangers exposed to cold environmental conditions can also be insulated to help prevent damage from the elements.

    However, if you know the fluid is one that would be very challenging to remove in this way, it may be better to allocate it to the tubeside. If it permanently solidifies with little or no hope of rescuing it from the exchanger, you’ll at least be able to remove the tube bundle for replacement; if an unmovable substance sets on the shellside, on the other hand, it’d be nearly impossible to take out. You may wind up needing to invest in an entirely new exchanger.

    If your freezing fouling consists of waxy deposits, you can generally remove these by melting, using steam, hot water or hot oil, or using chemicals to dissolve the wax.

    Freezing fouling may be a constant risk in your operation, or it may be an outlier event. If your equipment has sustained damage due to freezing and need a replacement part or a new custom shell and tube heat exchanger, reach out to the helpful engineers at Enerquip.

  5. How often should you clean your shell and tube heat exchanger?

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    Keeping your shell and tube heat exchanger contaminant-free is critical to creating a high-quality final product. However, every company must face a hard (and sometimes calcified) reality: Fouling happens. When it does, the built-up matter needs to be removed, and the equipment sanitized.

    Of course, there are some downsides to cleaning your shell and tube heat exchanger. The process usually needs to be done offline, thus eliminating some production time. Reducing the number of hours your equipment is productive will have an impact on your company’s bottom line. Then again, so will fouled material if allowed to continue to build up in your equipment. Further, excessive buildup will reduce heat transfer efficiency, causing processes to increase in price and length of time.

    Thus, equipment operators must strike a balance between regular cleaning times and fouling accumulation. To make sure your shut-down day has as low an impact on your business as possible, take these factors into consideration when planning your cleaning schedule:

    Fouling allowance

    The Tubular Exchanger Manufacturers Association recommends that companies determine well in advance what they would consider an allowable amount of fouling and take these into consideration when calculating heat transfer resistance, as well as determining a cleaning schedule, according to Conoco Consulting Corp. When your level of fouling nears this level, you’ll know it’s time to plan your next shut-down day, though you’ll usually define a loose maintenance schedule when calculating your fouling allowance.

    Engineers typically determine the allowable amount of fouling during the design stage, according to InTechOpen, an open access science, medical and technology book publisher. This is an important factor to take into consideration when calculating the heat transfer coefficient. A higher fouling allowance will result in a lower coefficient, but may also result in fewer necessary cleaning days.

    Fouling allowance can be thought of in several different ways, including a percentage of fouled matter as compared to the overall surface area, how clean the equipment is or what the maximum fouling resistance should be.

    Cost of operation

    Keeping a close eye on the cost of your operations is a good indicator of efficiency and productiveness. As fouling builds up, so too will your cost of operations per hour. The increase in cost is due to greater energy needed to achieve the same heat transfer rate, a lower rate of production, or a combination of the two.

    Referencing a 1981 report, “Optimum Cycles for Falling Rate Processes,” published in The Canadian Journal of Chemical Engineering, Conoco Systems suggested determining when your process will reach its minimum value to the company. When calculating this, you’ll need to take several factors into consideration, including the cost of cleaning, the cost of the lost production time and any interest accumulated due to borrowed funds, if applicable. Compare all this to the cost of reduced efficiency of the heat exchanger.

    Your production cycle

    No one knows your production cycle better than you and the people at your company. You know when your busy seasons are and when business slows down, as well as when you’ll have three-day weekends. Use this knowledge when planning out your cleaning schedule.

    With this information, you’ll be able to choose a day or several days to shut down your plant for much-needed cleaning without taking away from a busy or usually productive day. Additionally, you know your staff won’t feel pressured to make up for lost production time when everything is shiny and new once more. If it makes sense to schedule cleaning over a three-day weekend, take advantage of the day off and turn it into a day offline.

    Every operation is different and will require different intervals between cleaning. Some plants may require multiple shut-down days each year; others might be able to hold off for a decade using effective fouling mitigation tactics and discretionary maintenance tasks. It’s important to decide what’s right for your company so you can ensure consistent quality at as low a cost of production as possible and with minimal disruption to normal business operations.

    If you’re in the market for a new shell and tube heat exchanger, reach out to the helpful engineers at Enerquip. When you explain your operation and needs, they’ll be able to work with you to design and fabricate a custom shell and tube solution that works.

  6. What you need to know about cleaning different tube configurations

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    When considering your options for a new shell and tube heat exchanger, one important factor is the tube configuration.

    Various options benefit different types of processes. For example, a floating head configuration is better suited to processes prone to significant thermal expansion because the tubes aren’t constrained by the tube sheet or the shell, and can therefore expand or vibrate without risking damage to the rest of the equipment.

    Beyond taking into account the intended use for the exchanger, and other elements like location of the exchanger or the product that will be introduced to it, it’s also a good idea to think about cleaning methods. Not all cleaning strategies are appropriate for all configurations, but all exchangers will need to be properly and thoroughly cleaned sooner or later. It’s best to know what cleaning capabilities you’ll have with a particular configuration beforehand so you can factor it into your decision, or at least prepare for new sanitation needs.

    How to clean fixed tubesheet shell and tube heat exchangers

    A fixed tubesheet is a popular shell and tube heat exchanger design for several reasons, including cost effectiveness and ease of cleaning. Since the tubes are straight and the tubesheet is welded straight to the shell, construction is relatively simple.

    “Shellside cleaning is a bit more complicated with fixed tubesheet designs.”

    To clean a fixed tubesheet shell and tube heat exchanger, the bonnet first needs to be removed. This is a relatively simple task with this configuration. The insides of the tubes can be cleaned mechanically, and the straight configuration makes it easy for brushes, hoses or other cleaning supplies to be fed into the bores. The tubes can also be cleaned chemically, and running the cleaning solution through the tubes is fairly easy, again, because of the straight design.

    While cleaning the tubeside is pretty straightforward, shellside cleaning is a bit more complicated with fixed tubesheet designs. Because the tubesheet is welded to the shell itself, it’s nearly impossible to mechanically clean the outsides of the tubes. Chemical cleaning must be done instead. However, it’s critical that operators are confident that the chemical cleaning agent can be thoroughly rinsed from the shellside before operation reconvenes. Leftover residue can damage the material of construction or contaminate the product.

    The bonnet type plays a role in how easy it is to reach the tubes. L-type and N-type bonnets, which have removable covers, grant easy access to the inside of the tubes without removing any piping. The M-type bonnet does not have this removable cover, which means the entire head needs to be taken off to access the tubes.

    The difficulty in shellside cleaning isn’t always a problem. If the shellside of this heat exchanger is only used for clean fluids rather than fouling services, there’s virtually no need for future cleaning.

    How to clean a U-tube shell and tube heat exchanger

    As the name suggests, the tube bundle of a U-tube exchanger is curved at the end and returns the fluid back to the same side it entered, rather than providing a point of exit on the opposite end of the exchanger. Thus, only one tubesheet is required, leaving the other end free to expand or vibrate without risking damage to the rest of the construction.

    While the U-shaped bend provides benefits in some ways, it becomes cumbersome when it comes time to clean the equipment. The curve at the end of the tube makes it challenging for mechanical cleaning, unless a flexible-end drill shaft is utilized. Chemical cleaning is possible, but certain types of fouling, make it challenging – particularly scaling that hardens to the sides of the tubes and is difficult to remove without physical force. Additionally, with scales forming at the point of the bend, it may be difficult to assess whether all fouling has been completely removed. The solution to this dilemma is to use clean fluids on the tubeside with this configuration, Thermopedia pointed out.

    An articulating brush is advantageous for cleaning U-tubes.

    While cleaning the interior of the tubes on U-tube exhchangers is a challenge, the shellside is very easy. Since there’s only one tubesheet, deconstruction is simple. Once removed, the shell and the outside of the tubes can be cleaned easily.

    How to clean a floating head shell and tube heat exchanger

    The floating head tube bundle configuration is the best of both worlds. Only one end of the two tubesheets is welded to the shell, allowing the other to expand as needed according to the process it’s engaging in, similar to the U-tube configuration. Meanwhile, the straight tube design makes cleaning easier, comparable to the fixed tubesheet configuration.

    These advantages make floating head shell and tube heat exchangers a favorite among operators who are concerned both about thermal expansion as well as fouling on both sides, such as petroleum refineries or kettle reboilers, for example.

    A number of methods can be employed to sanitize floating head shell and tube heat exchangers and remove fouling. Mechanical cleaning is a practical solution, as the straight tubes make it easy for brushes, bits and sprayers to reach all areas of the bores. The floating head configuration makes it easier to remove the tube bundle than with the fixed tubesheet design, so it’s easy to reach the outsides of the tubes and the interior of the shell.

    “The bonnet type plays a role in how easy a heat exchanger can be cleaned.”

    Chemical cleaning is also a possibility, especially because it’s easy to spot inconsistencies in the cleaning job. When insufficiently cleaned areas are identified, they can be mechanically or chemically cleaned again before the equipment is put back into operation.

    The bonnet type associated with a particular exchanger’s construction plays a role in how easy this configuration can be cleaned. A P-type rear header, which is an outside packed header, gives convenient access to the tubeside but does not allow the tube bundle to be removed so the shellside can be difficult to clean.

    The S-type header also allows the tube bundle to be removed, but it is hard to take apart for bundle pulling, which can cause some complications when it’s being cleaned, inspected or repaired. The T-type header is easier to dismantle and remove than the S-type, often making it a more desirable configuration, though it also tends to be a bit pricier. The W-type header is also easy to remove and is often the least expensive of the options for a floating head heat exchanger.

    No matter what type of shell and tube heat exchanger you have, it’s important to know how to properly clean it to prevent fouling and ensure deposits left behind won’t cause corrosion. To learn about the right configuration for your operation, reach out to the helpful engineers at Enerquip

  7. 3 possible causes for flange leaks and how to fix them

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    Shell and tube heat exchangers are integral pieces in a processing operation and must be fully operational at all times. However, there are a number of things that can go wrong when operating such highly pressurized equipment – such as leaks.

    Leaks are never OK in process equipment. Depending on the exchanger, where it is and what it’s used for, leaks can decrease productivity; impact a company’s bottom line; contaminate product or heat transfer fluid; create a safety or environmental hazard; or increase the risk of fire. As such, any leakage from a shell and tube heat exchanger must be addressed soon after it’s detected.

    One common area equipment operators observe leakage is around the flanges of a shell and tube heat exchanger. Flanges have three main components: a ring, a gasket and bolts to hold the flange together and secure it to the exchanger. When a flange leak occurs, it’s typically associated with the gasket – perhaps it’s not installed correctly or the wrong size is used – but that’s not always the case.

    When leaks happen, it’s important to identify them quickly, then determine the cause. Here are several possible causes of flange leaks in shell and tube heat exchangers:

    Thermal stress causing distortion

    The temperatures of product inside a shell and tube heat exchanger can vary dramatically; that was, after all, what the exchanger was designed for. However, distortion caused by the rapid change from hot to cool solutions is inevitable in some cases. If this is the case, it’s important to ensure all parts of the exchanger are designed to account for temperature distortion.

    “Take temperature fluctuations into account during the design phase to prevent future leaks.”

    Writing for Chemical Engineering Magazine, mechanical design engineer Pankaj Kumar Singla pointed out that American Petroleum Institute standard 660 outlines temperature limits and when they become a major factor to consider when designing shell and tube heat exchanger flanges; however, these standards are only a guideline. There are cases when an operation should take temperature fluctuations into account during the design phase, even when they have not met API 660.

    To determine if special consideration should be made regarding the flanges, Singla suggested first determining the temperature inlet and outlet for the tube side. Next, determine the temperature for a random area within the tube as well as a random area on the shell side. Then, calculate the difference between the tubeside inlet and outlet as well as the difference between the random area on the tubeside and that of the shellside. If either equation results in a temperature differential of more than 110 degrees Celsius, be sure to take this into account.

    Singla noted several strategies and design adaptations that may be beneficial in these cases:

    • Increasing the thickness of the flange and tubesheet.
    • Reduce the allowable flange rigidity index.
    • Reduce the allowable stresses for flanges and tubesheets.
    • Make the required bolt ratio 120 percent of design and perform full bolt-load calculations.

    The bolts aren’t secure anymore

    When your exchanger is in operation, there may be vibrations, temperature increases and high pressure, all of which can affect the security of your bolts. Over time, the bolts may loosen and cause the gasket to leak. Of course, the obvious answer is to tighten the bolts again and proceed with your operations. However, it’s important to consider the method by which you tighten the bolts, as well as how often you need to tighten them.

    Torquing is the typical method of tightening bolts when they become loose. Dennis Martens and Michael Porter wrote for Penn State that hot torquing and hydraulic tensioning are two methods that can be more effective in tightening bolts and keeping them secure.

    If you find that you’re tightening your bolts continuously with seemingly no effect on leakage, there could be another factor at play. The American Society of Mechanical Engineers pointed out that, when equipment has excessive paint over or around the bolts, this could reduce the bolt integrity. As the paint degrades, it can reduce the bolt load and cause leaks to occur, for example.

    Other times, the design of the shell and tube heat exchanger simply isn’t adequate for the stress within, and an addition to the equipment may be required to mitigate the problem.

    Additional hardware is needed

    Martens and Porter discussed in their report “Investigation and Repair of Heat Exchanger Flange Leak” a recurring problem in a shell and tube heat exchanger, whose bolts never seemed to stay secure, despite efforts to tighten them using proven techniques. Even after hot torquing and hydraulic tensioning, the bolts would loosen and cause problematic leaking in the plant.

    The researchers identified two problems: excessive bolt load and gasket scuffing. The excessive bolt load was caused by the temperature differential. To combat this issue, disc spring washers were installed before replacing the bolts. They found that these were more capable in handling the load to the bolts without allowing flange deformation.

    The second issue of gasket scuffing was likely due to movement during operation and caused enough damage to the gasket that, even with adequate bolt tightness, it would continue to leak. The gasket needed to be replaced, but the problem also needed to be addressed so the new gasket would not also fall into disrepair. To avoid this, a weld ring, which consists of two separate halves of the gasket ring being welded together to contain the gasket material and prevent deformation. This creates a sealed gasket.

    If you’re experiencing gasket leaks in your shell and tube heat exchangers, it could be an indication that something is amiss in your equipment. The engineers at Enerquip are happy to help you get to the bottom of the problem and help devise a solution for your process equipment.

    Contact us today.

  8. Heat Exchanger Routine Maintenance Tips

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    How do you tackle your shell and tube heat exchanger routine maintenance? When heat exchangers are an essential aspect of your operation, it’s important that they’re working at top efficiency. Dirty or fouled exchangers can slow down your processes, contaminate your product and lower your company’s overall efficiency. To avoid these negative consequences, it’s important to be vigilant about shell and tube heat exchanger routine maintenance and proper cleaning.

    Here are five factors to keep in mind to make your shell and tube heat exchanger routine maintenance as effective as possible:

    1. Create a Plan for your Heat Exchanger Routine Maintenance

    When it’s time to clean your shell and tube heat exchanger, there’s a good chance that you’ll need to shut down operations temporarily. This is lost production time, which translates to reduced output and efficiency. However, there are ways to minimize the effects of a plant shutdown. One of the most effective ways to lower the impact is to prepare for it.

    Have a dedicated datefor planned maintenance, Ethanol Producer Magazine suggested. This way, you can plan and prepare for the event, allowing you to choose an inconsequential day for the shutdown. Additionally, since contractors who specialize in equipment maintenance often have busy schedules, planning and preparing can help you choose the date and time that suits you best – not when the contractor has a free space in his schedule.

    Make sure that any spare gaskets or replacement tube bundles are ordered in plenty of time to arrive by your scheduled maintenance date. Without a predetermined date for planned maintenance, it’s all too easy to let this important task get pushed back. When this happens, your equipment is more likely to run into problems. Sooner or later, you’ll either have to shut down your operation yourself, or a piece of equipment will fail, and you’ll have to quickly schedule reactive maintenance. There’s no predicting if or when this will occur, and it may not always be in your favor.

    2. Inspect Your Equipment

    Excessive fouling is never a good thing for your heat exchanger. If not identified or addressed in a timely manner, it could result in several problems, including contaminated or unusable product, corrosion or leaks. Ethanol Producer Magazine pointed out that, in some cases, material buildup can become a fire hazard.

    To prevent these issues, it’s important to note when fouling begins to form and to remove it promptly. Check your tube bundles as well as the shell side for signs of material buildup or corrosion.

    3. Test your Heat Transfer Fluid

    Another area of concern is the heat transfer fluid. When using chemical-based HTFs, it’s inevitable that the material will eventually become degraded and less effective. When this happens, it can reduce the efficiency of the exchanger and, depending on the chosen fluid, can adhere to the surface of the tubes, become a more volatile solution or create a fire hazard, Processing Magazine reported.

    Regularly testing the HTF will tell operators where in the lifespan the fluid is. Take the fluid from several different places to get a more complete idea of how good the fluid still is. Additionally, be sure to test the fluid while it’s in operation; cooled HTF will display different properties than the HTF in action, making the reading of fluid from a shutdown machine a less informative sample. Additionally, shutting down a piece of equipment for the purpose of taking a sample will slow down operations, put undue stress on the equipment and HTF, and takes more time out of your workday.

    Test the fluid periodically; Processing Magazine noted that quarterly testing typically provides the best results.

    4. Collaborate with the Right People

    Shell and tube heat exchanger routine maintenance is no small task, so it’s important to include any and all relevant personnel in planning it. Work together to identify maintenance needs, a day that works best for the company and the right professionals to assist or carry out the job.

    “Approach your planned maintenance day with a checklist.”

    “The maintenance manager, the environmental health and safety coordinator, and I typically work together on scheduling and making sure we have the proper documentation, training records, etc.,” Tyler Edmundson, the plant manager at ethanol plant Mid-Missouri Energy, told Ethanol Producer Magazine. “Safety is the No. 1 priority – making sure contractors have proper credentials and understand our policies and expectations.”

    When you include people from different departments, such as your environmental health and safety team, you’ll be able to collaborate on smart decisions that are good for the company overall. Additionally, when you approach your planned maintenance day with a checklist, you’re more likely to have as productive a shutdown day as possible.

    Edmundson noted that working with different people to plan out the maintenance day also allows them to collect all the necessary documentation that any incoming professional would need to know. For example, Matt Werzyn, maintenance manager with Louis Dreyfus Commodities, Elkhorn Valley Ethanol LLC, told Ethanol Producer Magazine that he creates and sends an informational packet to any contractors that will work on their equipment. It includes the company’s safety rules and requests items from the contractor, like employee training records, to demonstrate their credentials. Then, after arriving on-site, but before they get their hands on the equipment, the team goes through a contractor orientation.

    Other information you may want to provide any contractor that will be working with your equipment is a maintenance log, documentation from the original equipment manufacturer or information about the products or fluids used in the equipment.

    5. Cleanup after your Heat Exchanger Routine Maintenance

    Depending on your cleaning method, there may still be necessary tasks to carry out once everything is all cleaned. Whether you used chemical or mechanical cleaners to remove fouling, there could be debris left over. This could contaminate your product if left unaddressed. Give your equipment a rinse to ensure there are no leftover chemicals or dirt.

    Your shell and tube heat exchanger is designed to be closed up tight most of the time. As such, opening it can sometimes cause damage to the gasket, Marine Insight explained. Be sure to double-check your gasket and gasket cover before wrapping up your heat exchanger maintenance. Make sure that you have spare gaskets on hand and replace them if necessary.

    Heat exchanger routine maintenance and cleaning can be a time-consuming task, but it’s not one that’s worth putting off. By being proactive, you can help your equipment perform more efficiently and last longer. When you have questions about proper care for your heat exchanger, need replacement parts, or when you’re ready for a replacement unit, reach out to the helpful heat exchanger experts at Enerquip. Clickhere to contact us today.

  9. New FSMA Guidelines for cGMP’s

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    According to the Centers for Disease Control and Prevention (CDC), about 48 million people in the U.S. (1 in 6) get sick, 128,000 are hospitalized, and 3,000 die each year from foodborne diseases. This is a significant public health burden that is largely preventable.

    In 2015, the FDA Food Safety Modernization Act (FSMA) was enacted to help prevent foodborne illness rather than simply responding to it. FDA has seven major rules in regards to FSMA for both human and animal food. The FSMA rules are designed to make clear specific actions to prevent contamination.

    CGMPs for animal food

    CGMPs for animal food production cover elements like personnel, sanitation, work environment, water quality, equipment and more. Jenny Murphy, a consumer safety officer at FDA’s Center for Veterinary Medicine, explained that CGMPs are typically actions manufacturers should already be making throughout the normal course of their business.

    “I would say the CGMPs establish a base to make sure you don’t contaminate the animal food and the preventive controls take it a step further by making you really concentrate on things that, if they’re found in animal food, could be a public health concern,” Murphy said, according to the Food & Drug Administration.

    For example, according to CGMPs, equipment used for food manufacture should be:

    • Adequately cleanable.
    • Made from nontoxic materials.
    • Properly maintained.
    • Protected against contamination.

    Preventative controls for animal food

    While CGMPs cover the basics of maintaining a sanitary work environment and can be applied to any facility, preventative controls are more individualized to unique plants and are designed to address more specific situations.

    “Preventative controls are more individualized to unique plants.”

    “Once you have CGMPs in place, you can see where you need extra layers of protection,” Murphy explained. “Preventive controls require a food safety plan that includes an analysis of potential biological, chemical or physical hazards and the steps needed to reduce or minimize that risk.”

    Joann Givens, the director of FDA’s Food and Feed Program in the Office of Regulatory Affairs and a co-chair of the FSMA Operations Team Steering Committee, explained that it’s OK – even advisable – to have some redundant processes in place. This way, when one procedure falls short, another can pick up the slack. It ensures all your bases are covered.

    Givens explained that preventative controls are important because, if a violation does occur, some of the first questions a facility manager might be asked include:

    • Could you have predicted this issue?
    • What did you do to prevent it?
    • Once it became a problem, what did you do?
    • Did you educate your employees about the issue or how to address it?

    Every animal food manufacturing plant will have different risks, and therefore each may have different preventative control requirements. Facilities should have preventative controls in place for:

    • Processes, like heating or refrigerating.
    • Sanitation, like the minimization of pathogens or biological hazards.
    • Supply chain.
    • Recalls, when they’re needed.
    • Any other aspects of the facility where a preventative control might make sense, such as hygiene training or reviews of CGMPs.

    Making sure your equipment is compliant

    Your process equipment is a large investment, which means you’ll want to make sure it’s compliant from the get-go.

    Stainless steel shell and tube heat exchangers are a common component to animal food manufacturing facilities because they meet many CGMP expectations. For example, stainless steel is a highly sanitary surface, which meets the requirement that materials that come in contact with the product should be nontoxic.

    Certain configurations also allow for easy cleaning. Tube bundles on u-tube exchangers are often easier to remove, giving easy access to the crevices of the exchanger when cleaning. On the other hand, straight-tube designs don’t have difficult curves to work around when cleaning.

    It’s also important to think about the wear and tear equipment sustains over time. Shell and tube heat exchanger processes that involve high-pressure differentials can create more stress on the tubes and tubesheet, making a leak or other form of damage more likely. When a tube springs a leak, the batch of product inside the equipment could become contaminated. This is especially true if the feedwater used is of lower quality than required for animal food production. The U.S. Food & Drug Administration pointed out that this is often the case, which means facility managers must always be aware of the state of their equipment.

    The first step in preventing leaks in exchangers – and thus fulfilling CGMPs relating to avoiding contamination – is to regularly inspect the equipment and identify when a problem emerges. Seeing the signs of wear and potential leakage should be enough to pursue repair or replacement of the weathered part or the piece of machinery as a whole.

    Understanding the many requirements included in the FSMA isn’t always easy, but it’s important that animal food manufacturers determine where their current weaknesses are and address them sooner rather than later. Murphy explained that the FDA won’t begin conducting inspections to make sure everything is up to code until 2018, but that doesn’t mean there’s time to waste.

    For animal food companies looking to upgrade their equipment in compliance with current CGMPs, the engineers at Enerquip can help.

  10. Rouging: What it is and how to avoid it

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    Pharmaceutical manufacturers carefully choose their process equipment to ensure a completely sanitary final product. Most commonly, manufacturers turn to stainless steel shell and tube heat exchangers and other equipment, Pharmtech.com explained. Not only is it affordable, but it’s very durable, stain resistant and has a low risk of corrosion.

    Though stainless steel is highly resistant to corrosion, it’s important to realize what risk there actually is for this equipment to wear down or become unsanitary. Though titled “stainless,” the reality is that steel of any kind can actually become stained. Stainless steel just wards off this reaction for longer than others.

    Stainless steel resists staining by forming a passive layer filled with oxides. The layer forms naturally when in the presence of oxygen, and it protects the stainless steel from reacting with any chemicals passing through the piece of equipment.

    Rouging in stainless steel equipment

    Passivation, or the formation of the passive layer, is only possible under specific circumstances. When the chromium-to-iron ratio begins to fall, passivation becomes more difficult and the all-important oxide-rich layer may not form.

    Rouging in stainless steel equipment

    Passivation, or the formation of the passive layer, is only possible under specific circumstances. When the chromium-to-iron ratio begins to fall, passivation becomes more difficult and the all-important oxide-rich layer may not form.

    “Stainless steel is highly resistant to corrosion, but rouging can still occur.”

    Eventually, the stainless steel may begin to corrode. The process usually produces a thin colorful layer with a red, orange or yellow hue. Sometimes it produces pink, purple or brown. This phenomenon is typically called “rouging” for the more commonly seen reddish colors.

    Rouging is not corrosion, but rather the symptom of it. If you see rouging, you know there’s likely an underlying problem of some sort.

    There’s no singular identified cause of rouging, the British Stainless Steel Association pointed out. It’s typically composed of iron oxides, though the exact chemical composition can change, leading to a rainbow of reactions that all fall under the category of rouging.

    Manufacturers who have noticed rouging in their stainless steel equipment often cite causes like poor welding or construction; vulnerabilities in the passive layer; high iron content in materials that come in contact with the equipment; and surface contamination, including small steel particles or dust that lands on the equipment, according to Pharmaceutical Engineering.

    The truth is, though, that no one really understands completely how to predict rouging or exactly what causes it, Michelle Gonzales explained in Pharmaceutical Engineering. Nonetheless, manufacturers can – and should – take steps to ward off this colorful phenomenon.

    Choose materials of construction carefully

    The most popular stainless steel to use for sanitary shell and tube heat exchangers is 316L because of its low carbon content and its ability to endure heat treatment, Gonzales pointed out. It’s an austenitic metal, which means it’s highly durable and resistant to corrosion.

    Duplex stainless steel is another material that’s highly resistant to rouging. This style of stainless steel is a combination of austenitic steel, like 316L, as well as ferritic steel, which gives it greater durability under heat applications.

    When having a new piece of equipment fabricated, be sure to bring up the subject of rouging with the manufacturer. Explain clearly what the conditions are in your facility and how the equipment will be used, including what products will come in contact with the metal and how you plan on cleaning. Be open to suggestions based on the engineer’s expertise.

    Purchase equipment from a trusted fabricator

    Pharmaceutical manufacturers have reported rouging occurring in pieces of equipment that have flawed welding or construction. The simple way to avoid this is by doing your research and choosing a fabricator that can be trusted to present you with a high-quality piece of equipment.

    Find out whether the fabricator has experience with the type of equipment you need. Also ask about their experience with relevant industry regulations, such as ASME-BPE, which is commonly referred to in pharmaceutical and other bioprocessing manufacturing.

    Understand common causes of rouging

    Though rouging is not always predictable, there are certain conditions that are more likely to cause it than others. For example, elevated temperatures above 140 degrees Fahrenheit for long periods of time are known to cause rouging. Additionally, extreme pH levels and surface damage are all common predecessors of rouging.

    “Rouging is not always predictable, and there’s no specific known cause.”

    In many cases, high temperatures and solutions with a specific pH are necessary for the processes in a manufacturing plant. In these situations, it’s important to periodically check the equipment for beginning signs of rouging or surface damage.

    Rough surfaces encourage rouging more than sleek ones. Electropolishing gives stainless steel a smooth surface where rouging is less likely to occur, according to BSSA. Electropolishing also provides an ideal environment for the passive layer to form and helps it maintain stability.

    Once you’ve experienced rouging once or twice, you will gain an understanding of the unique conditions under which the phenomenon occurs in your specific operation. When you know this, you can be on the lookout for the first signs of rouging.

    Learn how to react to rouging

    When you see rouging, you know that there could be unknown chemical compositions inside your process equipment. As such, it’s important to not use any chemical cleaners or treatments right away.

    Rather, manufacturers need to take the time to evaluate the rouging and determine what’s causing it, what chemicals are involved and whether it’s a danger to the final product. Gonzales pointed out that, sometimes, the rouging looks more worrisome than it really is.

    Correcting rouging can be a time-consuming project, PharmTech.com pointed out. A manufacturer may want to enlist the help of an expert who can identify the ultimate cause and practical solutions to fix it.

    If you’re in the market for a high-quality stainless steel shell and tube heat exchanger, reach out to the knowledgeable and helpful engineers at Enerquip. They have the knowledge and experience to help you select the appropriate material to combat rouging while meeting your codes and standards. They also can passivate your exchanger before shipping it to you.