CAS DataLoggers recently provided the data acquisition solution for a hydropower plant setting up hydro turbine condition monitoring for preventative maintenance.

Personnel worked without any clear indications of the hydro turbine’s status for detection of developing equipment problems that could help safeguard against critical damage. Therefore management needed to monitor and analyze various plant parameters including shaft vibration measurement, bearing vibration measurement, generator air gap measurement and plant process signals including mV, mA, RTD, TC, pulse, PLC communication data, etc. Maintenance and commissioning engineers needed a single integrated system to process all these measurements, setup alarm functions, and perform diagnostic analysis. This system would also have to easily integrate into the existing company network via an Ethernet connection to give easy accessibility to any department depending on the access rights. With this in mind, management began searching for an efficient, cost-effective and reliable solution.

The hydropower plant installed a modular and scalable Delphin TopMessage data acquisition system in an industrial enclosure which was then DIN rail-mounted and fitted to a control cabinet. The TopMessage was then connected to a wide range of sensors and began monitoring the plant’s machinery for vibration, temperature, humidity, electrical power, etc. An adjacent bearing block shaft was connected to vibration sensors at each of its 2 ends, where 2 ICP converters were connected to the sensors and to the TopMessage. Sensor inputs were true differential and consequently ensured a high level of accuracy, while the Delphin system’s integrated AMDT/V2 module enabled vibration analysis and monitoring and acquired vibration/process signals and PLC communication data synchronously. The TopMessage was connected to the plant’s network using its Ethernet connection and sent all the data remotely to an office PC while also recording onto its internal 1GB data storage capacity.

Additionally, Delphin ProfiSignal software provided users with a full development environment to easily configure their individual HMI screens and control panels, giving the control room operator a maximum overview of equipment status. The TopMessage’s powerful software channels were used to configure several alarm functions with the ability to switch outputs, to regulate the equipment, and to initiate emergency shutdowns when necessary. The system’s integrated event channels reported any limit violations through SMS and email messages, and users also configured an alarm table giving them a consolidated overview of the plant’s status. ProfiSignal provided a convenient analysis through a seamless transition between online and historical offline data, also enabling online trend plotting and evaluation.

The hydropower benefited significantly following installation of the Delphin TopMessage DAQ system. The main advantage of the TopMessage was that this one solution performed all measurement, monitoring and alarm management functions, and could also be easily adapted to the plant’s individual applications using any number of inputs. The Delphin system’s powerful diagnostic analysis functions gave users a clear indication of the hydro turbine’s status and immediately pinpointed any area developing a problem. This early detection system prevented the plant’s equipment from sustaining major damage and also gave personnel an indication where to focus during the next maintenance stop. Additionally, the TopMessage’s Ethernet connection gave plant departments instant data accessibility and transparency. The plant has since been operating continuously and reliably with very little downtime.
www.dataloggerinc.com

Pumps, fans, compressors and other motor-driven rotating equipment are essential to manufacturing, commercial and institutional enterprise, from fluid handling systems in petrochemical plants to large air comfort systems in shopping malls.

Many facilities monitor this type of equipment on a regular basis, because often a simple problem like lubrication can be spotted and fixed inexpensively, before the entire unit burns out. Such strategies fall under the general heading of predictive maintenance (PdM).

Thermal imaging is especially useful for monitoring rotating equipment since many impending failures are accompanied by overheating. This predictive technique uses a handheld thermal imager to capture two-dimensional images representing the apparent* surface temperatures of equipment.

What to check?
While it is in operation and under load, monitor rotating equipment that is critical to your operations, i.e., equipment whose failure would threaten people, property or production. Be sure to scan the equipment’s drives — electric motors and gearboxes (if any). Also, on pumps and fans, get thermal profiles of the housings—scans that are likely to reveal any problems with bearings or seals — as well as scans of shaft couplings or drive belts and sheaves.

What to look for?
In general, look for hot spots and pay special attention to differences in temperature between similar units operating under similar conditions. For example, if a bearing in one fan in a bank of similar fans is running hotter than rest, the hotter one may be trending toward premature failure.

On a pump, a difference in temperature along a seal or gasket is the “signature” of a failure. A hot spot on the housing adjacent to a bearing may signal an impending bearing failure, although the root cause probably will not be ascertainable from a thermal image alone.

What represents a “red alert”?
Equipment conditions that pose a safety risk should take the highest repair priority. However, the imminent failure of any critical pump, fan or compressor represents a red alert. Consider using key safety, maintenance and operations personnel to quantify “warning” and “alarm” levels for these assets.

What’s the potential cost of failure?
Because pumps, fans and compressors are key to productivity in so many industries, it is difficult to speak generally about the cost to a company from the failure of a critical unit. However, a failed pump at one automotive facility cost more than US$15,000 to repair while lost labor costs totaled US$600 per minute and lost production opportunities amounted to US$30,000 per minute.

Follow-up actions
Whenever you use a thermal imager and find a problem, use the associated software to document your findings in a report that includes a digital photograph as well as a thermal image. That’s the best way to communicate the problems you find and to suggest repairs. If a catastrophic failure appears imminent, the equipment must either be removed from service or repaired immediately.

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For more information, visit www.flukecanada.ca.

An automatic lubrication system (ALS) helps eliminate unplanned and unnecessary expenses. Whether you know it as an automatic lubrication system, an “auto greaser” or a centralized grease or oil lubrication system, an ALS automatically lubricates multiple points on a machine from a centralized pump/control unit mounted in an easily accessible location. A system dispenses small measured amounts of lubricant at frequent intervals, while your machine is operating, maintaining a uniform supply of grease in the bearing at all times and a consistent lubricant seal to prevent dirt and contaminants from migrating into bearings.

In talking with people who don’t currently use ALS, we often hear statements like, “Even if I use an auto lube system, I still have to do a regular machine inspection on the system.” This is correct. An ALS will not replace your regular machine maintenance inspection. What an ALS does is take the grease gun or oilcan out of your hand and replace it with a wrench, making any necessary adjustments or repairs as you conduct your regular inspection.

There are eight reasons why an ALS may be right for you:

1. Safety: An ALS helps reduce or eliminate climbing over and under machinery or into difficult-to-reach areas — and in today’s workplaces, safety is always a key consideration.

2. Efficient Lubrication: An ALS applies lubricant while the machine is operating so you don’t have to stop what you’re doing or set aside time to lubricate it. As well, since the bearing is turning when it receives the lubricant, you get much better grease or oil coverage on the bearing.

3. Consistency: Applying grease or oil is most effective when dispensed in small, measured amounts over short, frequent intervals. Unfortunately, tight deadlines and manpower constraints often make this method impossible. Machinery gets lubed when it’s available and when we have time and somebody available to do it. An ALS makes this problem go away.

4. Better Housekeeping: How much is too much? If you’re old school, you keep pumping it in until you see it oozing out of the bearing. This is what we like to call over lubrication. As previously stated, frequent and small, measured amounts will give your bearings the best protection. This also means that you get less leakage. The end results are less wastage and less mess on your equipment and floor. Appearance aside, safety (danger of slipping) and environmental issues are even more important.

5. Being Preventative: The preventative maintenance provided by an ALS is key to reducing maintenance costs and minimizing downtime by extending the life of the many pivots, bearings, bushings and other components on the machine. There are also fewer replacement parts to stock.

6. Increasing Productivity: This results from an increase in machine availability and a reduction in downtime due to breakdowns or general maintenance.

7. Extending Machine Life: Because bearing areas are consistently protected and your machinery in general is better maintained.

8. Helping the Environment: For the environment, less premature wear of bearings and other components means less landfill. Also, since you’re not over lubricating, you’re depleting fewer resources from the environment.

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Mike Deckert is vice-president and Gabriel Lopez is the marketing specialist with FLO Components in Mississauga, Ont. For more information, visit www.flocomponents.com.

For many modern open-pit mines, shovels are one of the most critical components in the production process. These multi-million-dollar machines are the first to handle the material before transporting and processing begins. Because of this, the shovel must be closely monitored to avoid any unnecessary downtime and to ensure it is in peak operating condition. Any unnecessary downtime can cost a mine thousands of dollars per hour in lost production time.

One of the common causes of shovel downtime for many mines is worn or missing shovel teeth or adaptors. Operating with worn teeth reduces the performance of the shovel, resulting in increased energy usage, slower operation and an increased likelihood of missing teeth or adaptors.

Replacing the worn teeth must be carefully planned as an unplanned change-out can result in up to two hours of unexpected downtime. When factoring in the opportunity cost of lost production, a 2009 case study of an American copper mine determined that the total cost of an unplanned change-out is US$41,368 — compared to US$3,000 for a planned change-out.

In hard-rock mining, such as iron or copper ore mining, it is not uncommon for the shovel teeth to go missing in normal operation. During the digging cycle, the extreme forces can cause the teeth to break off completely and become mixed with the loaded material. Big problems occur when a load with a shovel tooth accidentally makes its way to the crusher. Because the shovel teeth are made of a very durable metal, when a tooth enters the crusher, it jams the crusher and can disable it for hours or even days at a time. If the mine has no other primary crushers or has little or no stockpile of crushed ore to feed the next stages of production at the time, the mine production could be put to a complete halt, which can result in millions of dollars in lost production time for every occurrence.

To address issues with worn or missing shovel teeth or adaptors, a Canadian company, Motion Metrics International Corp., has developed two innovative tooth monitoring solutions: ToothMetrics and WearMetrics. The ToothMetrics system constantly monitors the shovel teeth with advanced image processing techniques and artificial intelligence algorithms, and alerts the shovel operator when a shovel tooth or adaptor is missing. Once detected, the tooth or adaptor can be located and prevented from reaching the crusher. The WearMetrics system automatically monitors the shovel tooth-wear and provides the status of each shovel tooth by displaying the remaining length of the tooth expressed as a percentage of the original length. This assists the mine engineers in planning teeth replacements, and helps avoid any unplanned change-outs. Both solutions share the same rugged embedded CPU platform and hardware components, reducing the total cost of ownership for any mine.

The system works by installing a rugged camera mounted on the boom of an electric rope shovel or on the stick of a hydraulic face shovel. The high-sensitivity, monochrome camera provides a clear view of the shovel teeth directly to the embedded CPU, which is installed in the shovel operator’s cab. Due to intense shock and vibration experienced by the shovel during operation, Motion Metrics has designed shock-absorbing camera brackets specifically for each different type of shovel, including P&H and Bucyrus/CAT electric rope shovels, as well as Komatsu, Liebherr, Terex/CAT, Hitachi and other makes of hydraulic shovels.

The open-pit mining environment is also subject to a number of environmental conditions such as dirt, dust and varying lighting conditions, a key challenge for any mining system to deliver consistent results. To counter lighting variations, a heavy-duty, high-intensity LED light is installed alongside the camera to illuminate the shovel teeth during night operations. Advanced artificial intelligence algorithms continuously monitor the incoming video to exclude images when the view of the teeth is blocked by dirt, dust or shadows and select only optimal images for tooth analysis.

Building on this successful shovel-monitoring platform, Motion Metrics has added the optional safety and collision avoidance components: ViewMetrics and RadarMetrics. Due to the sheer size and vast blind spots of mining shovels, the frequent and swift swinging action of the shovel is a common concern for open-pit shovel operations as there is always a risk of collision with other equipment or personnel working in close proximity.

The ViewMetrics addition provides the shovel operator with three additional wide-angle surveillance views around the shovel blind spots in the left, right, and rear of the shovel for greater visibility. RadarMetrics enhances the operator’s awareness even more by providing intelligent proximity sensing and active feedback to the operator. This addition seamlessly combines a strategically placed array of heavy-duty pulsed radar sensors with the three surveillance views from ViewMetrics to provide visual and audible alerts to the operator when an object enters the shovel’s swing radius. Optional warning lights can also be installed around the shovel to extend the warning to any nearby equipment or personnel, providing an extra level of safety. This unique patent-pending approach, according to Motion Metrics, is the “only collision avoidance system for mining shovels [that] takes into account the swing radius of the shovel when alerting the shovel operator.” This additional level of intelligence helps eliminate unnecessary alarms that would otherwise be distracting to the operator.

As real estate in the operator’s cab is limited, the company has managed to integrate all five of the shovel monitoring solutions mentioned above into a single embedded CPU platform and a 12-inch touchscreen display installed in the cab.

The operator-oriented interface displays the shovel bucket camera view from the ToothMetrics and WearMetrics systems, along with the three surveillance views from the ViewMetrics systems. As an object enters the shovel’s swing radius, RadarMetrics displays a graphical bird’s-eye view of the shovel to indicate the direction and proximity of the object, and also makes an audible alarm to grab the shovel operator’s attention.

Motion Metrics is also a provider of payload monitoring systems for large hydraulic mining shovels, such as the Terex/CAT RH340/400 and the Komatsu PC8000. Many mines only have weighing systems on their haul trucks, but this makes it difficult for the shovel operator to know when a truck is being overloaded, since the weight will not be known before the load is in the truck. Furthermore, many truck scales require the truck to be in motion before the weighing system is able to provide an accurate measurement. To prevent voiding the manufacturer’s warranty, overloaded trucks must dump their load immediately, resulting in a significant loss of productivity, as the same load will need to be reworked and loaded a second time. On the other hand, underloaded trucks requires the truck to make more trips, thereby increasing the mine’s haulage cost per ton.

One of the key features of the LoadMetrics system is to provide the bucket-by-bucket payload information directly to the shovel operator, allowing the operator to determine whether dumping the current load will overload or underload the haul truck. The system also provides helpful warnings to the operator when the shovel is reaching its cylinder extension or retraction limits. Repeated over-extending or retracting of the shovel’s hydraulic cylinders can cause the cylinders to burst, thus requiring premature replacements.

As a crucial element in open-pit mining operations, shovels should be closely monitored to maximize productivity and minimize downtime. The cost of any unnecessary downtime can easily cost the mine thousands or millions of dollars in lost production time. To address many of these challenges, Motion Metrics has developed a unique collection of shovel monitoring solutions. Their proven systems have been installed in various combinations in over 150 mining shovels and in over 30 mines around the world since 2003.

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Enoch Chow is the marketing manager with Motion Metrics International Corp. For more information, visit www.motionmetrics.com.

To the savvy maintenance professional, industrial machinery almost “talks” to reveal its condition. But the real key to success is in understanding what the machine is saying. To detect potential machine problems, the professional “listens” in many ways:

• With thermometers and thermal imagers, to detect overheating, poor electrical connections or failing bearings;
• With digital multimeters and power analyzers, to diagnose electrical problems; and
• Using techniques like lubricant analysis, to gauge machine condition over time.

Today, the maintenance professional has a new way not just to listen but to find mechanical problems and fixes: the Fluke 810 vibration tester is engineered to detect and evaluate machine vibration and recommend any needed repairs.

In one case study, a major oil company had to keep 40 electric motors on the job, pumping crude oil, propane and other petroleum products down the pipeline. That task is now easier for one 35-year industry veteran, the area logistics manager for the company. For the past year, he’s been using the vibration tester to diagnose issues in pumps, blowers, and motors up to 3,500 horsepower that pump 8,000 barrels an hour.

“This is something I’ve been waiting on for quite some time,” he said. “The ones we’ve used in the past give you the vibration signature, but you had to interpret the signature. The problem with that is you need to get that in the hands of a technician who knows how to read your signature. The neat thing about it is the Fluke will give you its idea of what it thinks is wrong. But it also gives you that signature you can give to the engineers.”

 “We went down to our transport station — we’ve got eight mainline units there — and were able to find some bearing problems on one of our units,” the logistics manager said. “Once we got the pump into the shop we found out the shaft was out of round, which took the bearing out.

“We went to our number eight pump, and it said ‘motor-pump misalignment.’ The coupling has a shim pack — it’s kind of a flex coupling. That was on a 400 horsepower. We thought we might have a misalignment on the motor but it turned out we had a broken shim pack. We fixed it and it’s still running today, with no problem. It really surprised me how it picked that one up. I don’t know how it did that.”

Ease of use is another advantage. “You can give this thing to just about anybody, and they can learn how to use it in a matter of a few minutes. You can log all your equipment, you can pair it up with Fluke’s infrared camera and it will give you a full picture.”

Today, the Fluke 810 delivers results fundamental to the company maintenance program. “With the big motors, we do the vibration analysis, we look everything over on an annual basis with the Fluke imager so we can see if there’s any heat rise, and we use it on all the switch gear. I call it shoot-fix-move on.

“A lot of companies like to bring people in who actually do the vibration analysis and thermal imaging for ’em,” he said. “The problem is they’ll send you a report but it’s three months down the road, and here you’ve been running this piece of equipment that’s had an issue for over three months.” But with the new tester, “once you’ve got your technicians trained you just shoot, fix and move on.”

With a typical vibration program, he added, “I was spending probably $16,000 just to do the first pass. I can put this $8,000 piece of equipment in their hands and get the same performance.”

In the world of mechanical maintenance, vibration remains one of the earliest indicators of a machine’s health. Mechanical equipment is typically evaluated by comparing its condition over time to an established baseline condition. Vibration analyzers are designed specifically for maintenance professionals who need to troubleshoot mechanical problems and quickly understand the root cause of equipment condition.

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Colin Plastow is industrial product manager for Fluke Electronics Canada. He may be contacted at This e-mail address is being protected from spambots. You need JavaScript enabled to view it . For more information, visit www.flukecanada.ca.

PEM is providing maintenance and facility managers the opportunity to tell their success stories. Don't be intimidated: we accept applications from facilities large and small!

So get started! Please tell us a little about your maintenance team by completing our online submission form:


Fill out the online form


Now is your chance to step into the industry spotlight. As a winner, your team gets a plaque and is featured on the cover of the February 2012 issue of PEM. Now is your chance to step into the industry spotlight.

The PEM Maintenance Awards were first introduced in 1999 and through this program. The mandate of the award is to acknowledge and reward maintenance excellence and asset management professionalism. Past ward winners include CN Tower, Goodrich Landing Gear, EnCana Corporation, Grant Forest Products Inc., Canadian Tire, City of Mississauga, ArcelorMittal Dofasco, City of Toronto (Toronto Wastewater), Purolator Courier Ltd. and Gennum Corp.

Preventive maintenance is a key component in maximizing a pump’s lifespan, not to mention cost savings, increased profitability, increased pump availability, improved productivity and decreased repair costs. Thus, it makes sense for pump owners and users to implement a comprehensive service and maintenance program.

To yield maximum profit, equipment must be operated properly. Effective service and maintenance keeps equipment working at peak efficiency; so service and maintenance should not be viewed as a strain on income. Rather, they should be considered a contribution to output. The key to a good service and maintenance program is preventive maintenance. This includes adjusting and tuning up equipment and detecting and correcting small problems before they become major problems.

Scheduled preventive maintenance is typically viewed as oil, fuel and air filter changes every 200 to 250 operating hours, as recommended by the manufacturer. While this is necessary, it also provides an excellent opportunity to perform a general machine audit that includes inspection of all wear components and to make replacements or adjustments as needed.

Good equipment maintenance requires that everyone shares the responsibility. Field operators and mechanics must make sure the equipment is operated properly and that required maintenance intervals are performed. The supervisors must ensure that the proper maintenance schedule and procedures are completed by the mechanics. Finally, the purchasing or parts department must procure necessary parts, in advance, to avoid delays and downtime.

Having a manufacturer’s trained service technician perform these tasks may increase the initial cost of the service when compared to using on-staff personnel. However, a trained technician will do the job correctly and also identify components that are susceptible to failure, which avoids downtime and damage to other parts. This will reduce repair costs throughout the life of the equipment and result in savings much more than the initial cost of a service call.

More Specifically, For Aggregates
During visual inspection of the pump, all areas of material buildup should be noted and removed after the unit is shut down. Look for and remove dust especially around the alternator, radiator and control panel. Especially with aggregates, dust can create waterways and channels affecting electronic and non-electronic components. An air hose is the most effective tool to remove the dust buildup.

Often with the aggregates market, the substance being pumped has varying pH levels. These high or low pH levels can cause extra wear on the pump. Thus, some pump manufacturers offer pumps with special materials such as bronze or stainless steel or with special coatings to prevent added wear, depending on the application. Hardened impellers, wear plates and volute rings can also be helpful to lengthen the life of the pump.

For pit dewatering, always be sure to use a strainer. This keeps unwanted foreign materials out of the pump. Some of the most common pumps used in pit dewatering are high head, high-pressure pumps (such as the Thompson Pump JSC series). Hydraulic submersible pumps also provide pumping power for common aggregate applications.

Please dispose of used oil in a manner that is compatible with the environment. We suggest you take used oil in a sealed container to your local recycling center or service station for reclamation. Do not throw it in the trash; pour it on the ground, or down a drain as oil can be harmful to the environment.

Items to Monitor
To perform general maintenance properly, it is important to pay close attention to the pump while it is running. The following are items to monitor: heat, pressure, vibration, noise, flow, speed, strain, liquid level, power consumption, product contamination, leakage and emissions.

Serious items to watch for — cavitation and water hammer — occur frequently in the aggregates market. To prevent cavitation, run the pump at the proper speed or provide a larger suction hose to handle the fluid. Water hammer, which is a spike in discharge pressure and often the cause of blown seals, can be prevented by starting the pump and slowly throttling up to recommended max speed. Multiple check valves in the discharge line can also provide relief to water hammer.

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Kirsten Petersen Stroud is the marketing manager for Thompson Pump. For more information, visit www.thompsonpump.com.

Compressed air can comprise up to 20 percent of the costs of underground mining, according to the Ontario Mining Association (OMA), and 20 to 40 percent of energy costs at mines can be attributed to compressed air systems. Given that up to 70 percent of that air is wasted through leaks, the problem of leaks in compressed air lines is one of the most costly and inefficient draws on the bottom line.

The numbers are staggering. The OMA’s compressed air leak management program report, “Implementing a Sustainable Compressed Air Leak Program,” demonstrates just how costly leaks can be: a single 1/2-inch-diameter leak, assuming energy costs of $0.10/kWh, can total to $12,820 throughout the course of a year for a one-shift operation and as much as $47,850 for a three-shift operation. Even the tiniest of leaks can add up: a single 1/16-inch-diameter leak can cost up to $200 over a year for a one-shift operation and up to $750 for a three-shift operation.

In a typical mining operation, leaks in compressed air lines can number into the hundreds, resulting in wasted energy costs upwards of $100,000 a year. The costs alone should be enough to consider a leak management program, but leaks also create other problems. Fluctuating system pressure can lead to inconsistent performance of the tools and equipment that operate on compressed air. Operation time may need to be increased to make up for the lower pressure, which can increase maintenance costs and reduce the service life of compressors due to excess load.

Problem Areas
Leaks can occur at any point in a compressed air system and are blamed on a number of factors. Through regular mining activities, compressed air piping is exposed to vibration, impact and harsh materials, all of which could lead to leaks. Compressed air lines in the mining industry are typically joined using grooved mechanical piping due to the joining method’s ease of installation and maintenance, strength and ability to quickly adapt to changing mine geography. If the joints of a grooved system aren’t properly assembled, however, the gasket contained within the coupling housings can be a leak source. During its study, the OMA determined that pipe couplings are the most common source of leaks; approximately 60 to 80 percent of the air loss can be attributed to couplings.

Fortunately, the solution isn’t as drastic as replacing grooved piping systems, which mines rely upon to decrease installation and maintenance downtime and reduce total installed costs. The two primary causes of couplings as a leak source, pinched gaskets and incompatible gasket material, are easily fixed.

During coupling installation, a gasket can pinch, creating a leak path, if it’s not properly lubricated. Lubricating a gasket takes only a few seconds, but this step is often skipped to save time. If coupling gaskets are not pre-lubricated, personnel should take the time to lubricate the gaskets prior to installation, and managers should educate pipe installers as to the importance of doing so and the economic ramifications that result from leaks.

Mine maintenance personnel will try just about anything to save time, so adding a step to the pipe installation process may not be a welcomed idea. Installation-ready couplings, an alternative to traditional couplings, require fewer installation steps and decrease installation time compared to traditional couplings; they also reduce the chances of pinching a gasket upon assembly. Installation-ready couplings do not require disassembly prior to installation. The pre-assembled coupling is simply “stabbed” onto the pipe ends, and the bolts are tightened, like typical couplings, until the housing bolt pads meet metal-to-metal. Installation-ready couplings are offered in flexible and rigid styles in sizes up to 8 inches/200 millimeters.

The benefit of installation-ready couplings is twofold. First, they can reduce pinched gaskets during installation because the coupling is kept assembled and installed as a single unit, rather than piece-by-piece. Second, they can be installed in as little as half the time it would take to install traditional pipe couplings. As a result, installation-ready couplings meet owners’ goal to reduce costs and miners’ goal to save time.

Another cause of leaks at pipe couplings is gasket deterioration, which can occur when the gasket material is incompatible with, and not approved for the piping service. For example, when grade “E,” or EPDM, gaskets are used on compressed air lines, oil vapors present in the system can degrade the compound, eventually leading to a leak. EPDM is a commonly specified gasket grade, and is suitable for water services, but using this grade on air services can be problematic.

Oil separating filters are generally not used on compressed air systems, so the lines may carry oil vapors. As a result, grade “T,” or nitrile, gaskets should be used. This gasket grade is designed to stand up to air with oil vapors and will not degrade with exposure over time. Nitrile gaskets should not be used on water services, however, so mines will need to use two types of gaskets: EPDM for water services and nitrile for air services.

Replacing EPDM gaskets with nitrile gaskets on compressed air lines is not a quick maintenance procedure, but the cost savings that can be achieved through this method is significant. The OMA suggests conducting gasket replacement during maintenance to repair existing gasket leaks, and during installation of new compressed air systems.

Study Outcome
Three mines participated in the OMA’s air leak management project as pilot sites. The mines saw almost immediate results in energy savings. In fact, two of the mines saved about $100,000 in annual operating costs just by fixing major air leaks. The project report, which includes lessons learned and best practices, is a must-read for every mine.

Fixing leaks attributed to gaskets within pipe couplings will not solve all challenges involving compressed air systems. After all, leaks can occur at multiple points along the line, and a big-picture leak management program is necessary to ensure long-term commitment to locating and repairing leaks. Such a plan, according to the OMA, should include recognition of the role of people and leadership, uses of equipment and instrumentation, and the development of new procedures and processes.

Nevertheless, proper selection and installation of pipe couplings play a major role in reducing downtime associated with leaks. Repairing leaks can reduce air loss to less than 10 percent of the mine’s compressed air output, resulting in immediate and significant cost savings.

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Marc Carrière is the global mining market manager with Victaulic, a producer of mechanical pipe joining systems. For more information, visit www.victaulic.com.