Archive | October

315

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October 1, 2007
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Maintaining Wastewater Treatment Systems

Continuous vibration monitoring of pump stations at a major wastewater treatment plant pays off for the City of Tampa.

The Howard F. Curren Advanced Wastewater Treatment Plant (HFCAWTP) is a state-of-the-art facility that treats all wastewater discharged from the City of Tampa, fl, system from approximately 100,000 accounts. The plant has a license capacity of 96 million gallons per day (MGD), with an average daily flow of 60 MGD. The final product, or effluent water, is discharged to Hillsborough Bay or used as reclaimed water for cooling and irrigation. This high-quality water meets all state and federal requirements.

1007_wastewater1The plant has developed and is currently executing an optimization program that includes automation of processes and procedures when possible, and reducing scheduled vs. unscheduled downtime and maintenance, transitioning from a reactive to proactive organization ready to address issues and problems. Because the Howard F. Curren facility is the City of Tampa’s (COT) only wastewater treatment facility, it is imperative to minimize flow interruptions, unscheduled downtime and overflows.

The use of reliable pumps to transport wastewater from various locations in the city is critical for maximizing flows and maintaining biological efficiencies by producing a constant flow. When the pumps fail, backup pumps are used to keep the flow going. Failures often can be very damaging to the pumps and auxiliary equipment. Installing a protection system that monitors the vibration levels and can be integrated to a shutdown circuit can minimize flow interruptions and the amount of costly damage to that equipment. The price of a new pump motor can be as high as $450,000; the cost to repair an existing unit can approach $175,000 after a catastrophic failure. In an effort to help prevent these types of failures, the HFCAWTP and Connection Technology Center, Inc., a vibration analysis hardware and process equipment manufacturer, investigated different equipment and system options for monitoring this crucial application.

The application
There are eight major pump stations that collect the wastewater and deliver it to the treatment plant. Each major pump station has many smaller stations that will feed it—either through pump systems or gravity feed. There are approximately 224 pump stations within this system.

Three types of pumps setups are typical of these stations: Direct coupled, submersible and vertical shaft. The direct coupled stations will have the motor and the pump on the same floor, with the motor in an overhung position and supported over the pump. The vertical shaft stations will have the motor and clutch or VFD-controlled motor typically two stories above the pump, with the shaft coupled in one or two places.

Each major lift station has three or more motor-pump systems, with one pump typically running at a time to ensure system redundancy. Major failures can cause overflow issues, not to mention extensive damage or complete failure with auxiliary equipment such as valves, VFDs and wiring.

PROTECTING CRITICAL SYSTEMS IN FLORIDA

The City of Tampa’s Howard F. Curren Advanced Wastewater Treatment Plant (HFCAWTP) uses vibration analysis hardware and process controller equipment to protect critical machinery against damage due to mechanical failures or environmental changes. This system helps protect critical equipment with relays to trigger alarms or shutdowns, while integrating to the main plant’s Supervisory Control And Data Acquisition (SCADA) system for continuous monitoring. This helps ensure survivability and prevent unscheduled downtime and costs.

For the purposes of determining where to install a protective system, the major stations were identified as the areas to have the critical equipment monitored.

Vibration considerations
The general vibration considerations that are periodically monitored in the pumping systems at this plant include cavitation, mechanical failure and mis-alignment. Cavitations often will accelerate the mechanical failures of the pump, such as discharge valve failures and impeller wear. Faults due to mechanical issues also are accelerated due to increased flow. Possible mechanical failures include breaking or dropping the impeller or impeller shaft and/or bearing failures.

Other unique vibration considerations at this plant are associated with the alignment of the vertical shafts to pumps, requiring coupling shafts up to 20 feet in length, and accessibility of the equipment, which is often very difficult.

1007_wastewater01The application is made even more challenging by the fact that these remote pump stations are not manned, and the periodic monitoring may not be sufficient to capture any transient type of faults that could lead to failures.

Process/protection considerations
Periodic monitoring may be sufficient to identify general, long-term machinery conditions, but to capture transient conditions that can cause catastrophic failures, continual monitoring is required. Because the pump stations are unmanned, a system is in place to alert a technician at the plant that there is an issue with the pump station equipment. If there is an issue, corrective actions may be necessary in order to prevent the premature failure of the equipment and overflows.

Ensuring this capability required integration of the vibration system with the plant SCADA system. The output parameters of the vibration system, in this case 4-20mA output proportional to the overall vibration levels of the equipment, will feed into the SCADA system and allow the technician to observe a “status” of the equipment at the stations. This is an ideal situation, as many issues can be identified quickly before the effects of a catastrophic failure occur. However, this integration is often difficult based on the available resources of both the SCADA system and the plant personnel to integrate this.

1007_wastewater02Another solution that can be implemented as a stand-alone or integrated with the SCADA system is to provide a local relay or shutdown system that can be tied into the motor control circuit to shut down the pump system in the event of a catastrophic failure. Such a solution can limit the extent of the damage to the pump and limit/prevent the damage to auxiliary equipment, as well as minimize interruptions of the flow to the plant.

Equipment & system selection considerations
For the initial unit, a system of low-cost accelerometers mounted to mounting targets connected to a remotely mounted process controller enclosure was specified, with integration to the main plant SCADA system. The equipment was selected based on the following considerations.

Accelerometer selection…
To select the proper accelerometer for the monitoring of components, the following vibration frequency criteria was taken into consideration:

  • Pump vane frequencies
  • Pump cavitations frequencies
  • Motor fault frequencies
  • No clearance issues that would require low-profile sensors
  • Historical vibration data and experience with the equipment

Frequencies for detecting vibration faults should be within the frequency response of the selected accelerometer. For accelerometer specification, the motor and pump vane frequencies did not require a special frequency response, and a standard, 100 mV/g accelerometer, with a frequency response between 0.5 – 15000 Hz, was selected for this application.

Mounting hardware selection…
To provide the optimum vibration transfer between the machine surface and the accelerometer, a mounting system that utilizes the full frequency span of the accelerometer needed to be considered. A mounting target attached to the prepared machine surface (prepared with an installation tool kit [MH117-1B] that can be resharpened for multiple installations) with an adhesive was selected. The adhesive-mounted target facilitates excellent vibration transfer, and the full frequency range of the sensor can be utilized. Another advantage to the adhesive-mounted target is that the machine surface does not need to be drilled and tapped. A flat mounting target with a ¼-28 threaded hole was selected for this function.

Cable selection…
In light of the environment, the cable connecting the accelerometer to the enclosure needed to be robust, chemical resistant, water resistant and reliable in caustic conditions. A Teflon-jacketed cable with molded connector and stainless steel locking ring was chosen.

Signal conditioner selection…
Because of the required inputs into the process controller, a field-configurable signal conditioner with a display that can be easily seen in a variety of lighting conditions was chosen, as each pump that is monitored can have unique vibration levels. The signal conditioner also needed to be able to re-transmit the 4-20mA outputs in order to eventually integrate with another process control system and SCADA. Power for the signal conditioner(s) and the sensors are provided by the internal process controller.

Process controller selection…
The selected process controller allowed for field configuration, incorporated a display that permitted visual identifi- cation of the vibration level and included a power supply for the signal conditioners.

The ability to set up two different alarm levels, as well as a time delay to prevent “nuisance alarms” that might occur if a spike in vibration levels due to a transient event also was determined to be important for this system. The controllers are powered from 120 VAC input into the enclosure, which was provided by the facility.

1007_watewater_fig1Enclosure selection…
The selected enclosure allowed for easy wiring into and out of it. This enclosure also has proven to be unaffected in a highly corrosive atmosphere. The process controllers and the signal conditioners were factory-wired. The wiring of the sensors into the enclosure, any re-transmitted signals out of the enclosure and 120 VAC power into the enclosure were done through pre-defined cable entry and exit cord grips/conduit. The wiring was attached at a termination block that was clearly identified for the type of connection required. (See Fig. 1 for an example of the termination identification.)

The easy wiring minimized the time required to install sensor cables and integrate the components of the system into the enclosure, and ensured that the system was completely integrated prior to delivery.

Financial analysis
Justification for the Howard F. Curren Advanced Wastewater Treatment Plant project was determined based on a review of the approximate cost of a pump station motor repair versus the price of a typical two-channel monitoring system. The repair cost for an 800 hp motor could go as high as $175,000. The price of the monitoring system was approximately $2500—or roughly $1500 per measurement point.

The initial approval to outfit one major lift station was decided in 2006, and a unit has been in service since that time. The project justification was further underscored by a subsequent motor failure at another pump station. The estimated cost of that motor repair was close to $160,000—a fact that renewed interest in the relatively low-cost 24 hour protection device.

Approved monitoring setup
The approved system was to be used as a monitor to notify the plant of problems with the pump or motor, especially during off-hour operation. As shown in Fig. 2, this system consists of two permanently mounted sensors, with cable from the sensor wired to the enclosure. Mounted inside are: two process controllers, two signal conditioners, and two transmitters (for the 4-20 mA output process signals). The box also has a window to permit viewing of the process controller displays for overall vibration level readings.

  • The signal conditioner was scaled to less than 0.51.0 IPS, with a frequency range between 5 and 50 Hz.
  • Two relay outputs were configured based on experience in required alarm settings. The baseline vibration on the machine was observed to be 0.2 IPS, peak. From there, relay/alarm settings were set at 0.35 IPS, peak for the first level, and 0.65 IPS, peak for the second alarm level, with time delays of approximately 30 seconds for each level. If the vibration does not maintain that amplitude (or greater) for that length of time continuously, the relay does not activate. The levels, time delays and relay action (latching, latching with clear, manual reset) can be adjusted on the process controllers.
  • The system was mounted at a lift station with a flow capacity of approximately 35 MGD and connected to the main plant SCADA system. Relays are in place to shut down the pump/motor if there is an event that could cause serious damage to the equipment. Sensor location selection The sensor mounting locations were selected based on historical data and accessibility of the measurement location point. In order to monitor the pump and motor, for the direct driven system, a sensor was placed on both pump and motor. Enclosure mounting location selection The cable was routed from the pump and motor to the enclosure, which was mounted on a fixed wall. This is located near the shut-off switch, which was installed to protect the pump and motor equipment. Major benefits of the system can be seen in the following features and capabilities:
  • A turn-key system solution
  • Easy wiring terminations
  • Field-configurable signal conditioners and process controllers
  • Allows for re-transmission of the process signal
  • Allows for integration into a SCADA system
  • Allows for settings to shut down the equipment
  • Two relays with independent input levels with latching options
  • User-friendly components
  • Permits access to “live” data to hard to inaccessible points
  • Offers multi-functions vibration and temperature

Results
The installed system has identified possible pump cavitations occurring in the early morning hours during low-flow periods. These types of cavitations can escalate rapidly, putting a pump and motor in danger. For example, another station at this plant that did not have the approved system in place subsequently failed—possibly due to cavitation—requiring repairs to the equipment and costly unscheduled downtime.

Conclusion
The following factors were critical in convincing management that vibration monitoring has benefits to the Predictive Maintenance Program and City of Tampa (COT) and could be considered for expansion into other pump stations:

  1. Cost of the equipment is much less than the cost of repair or replacement of pump and motor
  2. The system protects critical equipment with relays to trigger alarms or shutdown
  3. 4-20mA outputs feed into SCADA system for continuous, online monitoring.
  4. Continuous monitoring can identify possible issues that would not have been observed otherwise.
  5. Protecting pump and motor systems during increasedflow events can reduce unscheduled maintenance or repair by alerting the plant of issues before they become catastrophic.
  6. The system permits easy access of dynamic data for route collection and/or detailed analysis.
  7. Required maintenance will be identified more precisely and accurately, thus reducing unscheduled downtime, repair cost and overflow issues.

Tom LaRocque is the engineering manager for Connection Technology Center, Inc., in Victor, NY. A Certified Vibration Analyst: Category III, he holds a B.S. in Engineering from Clarkson University. LaRocque is a member of the Central New York Chapter of the Vibration Institute. Telephone: (585) 924-5900 ext. 817; e-mail: tlarocque@ctconline.com

Gary Kaiser is a senior application engineer for Connection Technology Center, Inc. A Certified Vibration Analyst: Category III, he previously worked for Eastman Kodak for 23 years. While at Kodak, Kaiser spent 9 years in the vibration analysis group. He also is a member of the Central New York Chapter of the Vibration Institute. E-mail: kaiserg@ctconline.com

Joe Spencer is a mechanical specialist with the City of Tampa, fl. A Certified Vibration Analyst, he has 30 years of field maintenance experience.

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131

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October 1, 2007
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Viewpoint: Notice Anything New?

jane_alexander

Jane Alexander, Editor-In_Chief

Now that you’ve read through this month’s magazine, it’s fair to ask if you’ve noticed anything new on our cover and in our pages. You should have. That’s because we’ve made changes in some wording and visual elements to support a sharpening of our focus. With this issue of Maintenance Technology, we formally have become “your source for capacity assurance solutions.” We trust that you will find value in this move.

Capacity assurance is not a new term—it’s been around for many years. Those of you in the maintenance and reliability community are no doubt quite familiar with it, since it’s all about maximizing uptime, minimizing downtime, running safely, cleanly, efficiently and profitably.

The task of keeping modern plants running at peak capacity, however, goes well beyond the area of traditional maintenance and reliability (although those elements are more important than ever as key capacity assurance components). It encompasses all activities necessary for ensuring that your equipment and systems are capable of operating at prescribed output and quality levels whenever scheduled or needed. In other words, capacity assurance is the “fat rabbit” everyone in a company is chasing 24/7/365—and we do mean everyone. Therefore, being successful in this chase requires a “holistic,” integrated approach to maintenance, operations and management.

We at Maintenance Technology have long recognized how critical it is for you in industry to be able to catch the capacity assurance rabbit quickly—continuously. In fact, we’ve been championing the types of integrated approaches and solutions that help you get the job done for more than 20 years. Today, though, and into the future, with so much riding on a company’s ability to assure capacity, we feel compelled to be more specific in our own approach.

Time has marched on. Technologies, applications, operating parameters and business environments have changed. So have your jobs, your time constraints and your information needs. What has not changed is the importance of capacity assurance across your operations—and the fact that countless organizations are pushed to get more, more, more of it with less, less, less.

Putting our editorial spotlight on “capacity assurance” as opposed to “plant equipment reliability, maintenance and asset management” will allow us to better serve you and other busy readers. You’ve been seeing us move in that direction for some time, placing increased emphasis on failure avoidance and the operating equipment and systems where preventive and predictive maintenance technologies are applied than we have in the past. Our quarterly supplements, “Utilities Manager” (focusing on successful demand-side energy solutions for plants and facilities) and “The Fundamentals” (taking a back-to-basics approach to maintenance and reliability), are two other prime examples of our sharpened focus. Now, going forward, you can expect even more great “new” things from us.

You know it and we know it… Excellence in capacity assurance is vital to industrial profit and world-class quality. In our view, it’s one of the fattest rabbits out there. Maintenance Technology is proud to be your partner in this noble and exciting chase.

 

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6:00 am
October 1, 2007
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Uptime: Cheaper Is Not Always Better

bob_williamson

Bob Williamson, Contributing Editor

Now that you’ve read through this month’s magazine, it’s fair to ask if you’ve noticed anything new on our cover and in our pages. You should have. That’s because we’ve made changes in some wording and visual elements to support a sharpening of our focus. With this issue of Maintenance Technology, we formally have become “your source for capacity assurance solutions.” We trust that you will find value in this move.

Capacity assurance is not a new term—it’s been around for many years. Those of you in the maintenance and reliability community are no doubt quite familiar with it, since it’s all about maximizing uptime, minimizing downtime, running safely, cleanly, efficiently and profitably.

The task of keeping modern plants running at peak capacity, however, goes well beyond the area of traditional maintenance and reliability (although those elements are more important than ever as key capacity assurance components). It encompasses all activities necessary for ensuring that your equipment and systems are capable of operating at prescribed output and quality levels whenever scheduled or needed. In other words, capacity assurance is the “fat rabbit” everyone in a company is chasing 24/7/365—and we do mean everyone. Therefore, being successful in this chase requires a “holistic,” integrated approach to maintenance, operations and management.

We at Maintenance Technology have long recognized how critical it is for you in industry to be able to catch the capacity assurance rabbit quickly—continuously. In fact, we’ve been championing the types of integrated approaches and solutions that help you get the job done for more than 20 years. Today, though, and into the future, with so much riding on a company’s ability to assure capacity, we feel compelled to be more specific in our own approach.

Time has marched on. Technologies, applications, operating parameters and business environments have changed. So have your jobs, your time constraints and your information needs. What has not changed is the importance of capacity assurance across your operations—and the fact that countless organizations are pushed to get more, more, more of it with less, less, less.

Putting our editorial spotlight on “capacity assurance” as opposed to “plant equipment reliability, maintenance and asset management” will allow us to better serve you and other busy readers. You’ve been seeing us move in that direction for some time, placing increased emphasis on failure avoidance and the operating equipment and systems where preventive and predictive maintenance technologies are applied than we have in the past. Our quarterly supplements, “Utilities Manager” (focusing on successful demand-side energy solutions for plants and facilities) and “The Fundamentals” (taking a back-to-basics approach to maintenance and reliability), are two other prime examples of our sharpened focus. Now, going forward, you can expect even more great “new” things from us.

You know it and we know it… Excellence in capacity assurance is vital to industrial profit and world-class quality. In our view, it’s one of the fattest rabbits out there. Maintenance Technology is proud to be your partner in this noble and exciting chase.

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255

6:00 am
October 1, 2007
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Ultrasonic Showcase

Keep the following information in mind as you seek out the best product for your specific needs.

Ultrasonic technology can be one of the most valuable items in a predictive maintenance “toolbox.” This equipment can locate unwanted leaks, arcing, bearing noise and other problems in your mechanical and electrical equipment. Used effectively, ultrasonic technology can help eliminate unscheduled downtime, save valuable resources and lead to increased energy efficiency. The following pages highlight some of the leading manufacturers of ultrasonic equipment and their products.

1007_exxair1EXAIR CORPORATION
Established in 1983, EXAIR Corporation is a manufacturer of compressed air products for industrial applications including cooling, drying, conveying, housekeeping and static control. The company’s Ultrasonic Leak Detector (ULD) is a handheld instrument that can locate costly leaks in a compressed air system by converting high frequency turbulent flow into an audible tone. Background plant noise is filtered out using X1, X10 and X100 sensitivity settings, along with an “on/off” thumbwheel for fine sensitivity adjustment. The Model 9061 ULD comes complete with a hard-shell plastic case, headphones, parabola, tubular adaptor, tubular extension and 9-volt battery.
EXAIR Corporation, Cincinnati, OH
www.exair.com

COLE-PARMER
Since 1955, Cole-Parmer has been a leading global source of laboratory and industrial fluid handling products, instrumentation, equipment and supplies. Cole-Parmer presents ultrasonic leak detectors that “listen” for leaks and alert you to their presence, giving a distinct advantage over conventional leak detectors. Model 86417-00 includes leak detector headphones, tubular extension with adapter and a soft carrying case. An ultrasonic transmitter to amplify leaks in insufficiently pressurized applications is also available.
Cole-Parmer, Vernon Hills, IL
www.coleparmer.com

1007_monarch1MONARCH INSTRUMENT
Founded in 1977, Monarch Instrument has grown to be one of the world’s largest suppliers of portable speed measurement products, as well as an ISO 9001- 2000 registered manufacturer of precision electronics. The company’s UltraPro AG500 is a powerful ultrasonic leak detector and electronic stethoscope. It features an Automatic Gain Control that automatically filters the signal to provide the best signal-to-noise ratio, suppressing background noise and pinpointing leaks.
Monarch Instrument, Amherst, NH
www.monarchinstrument.com

1007_sdt1SDT NORTH AMERICA SDT
North America is a world leader in airborne ultrasonic detection equipment and training. The company’s main focus is to insure that the customer understands the components of a world-class ultrasound program. The cornerstone of the SDT product line is the SDT 170 Ultrasonic Detector. The 170 enables users to hear more about the condition of their factory’s production equipment. This instrument represents a milestone for ultrasonic technology, incorporating solid-state electronics and adaptable firmware. The product also measures non-contact temperature, contact temperature, RPM, noise (dBA) and air flow (SCFM).
SDT North America, Cobourg, ON
www.sdtnorthamerica.com

1007_uesys1UE SYSTEMS, INC.
UE Systems produces portable and online ultrasonic instruments for leak detection, mechanical analysis and electrical inspection. The company’s Ultraprobe is engineered to meet the unique demands of the many applications and programs in which it is used. A wide range of devices is available, including analog and digital Ultraprobes, some with basic functions and others with powerful features such as frequency tuning, on-board data logging and on-board sound recording. UE Systems also hosts Ultrasound World, a four-day conference providing information on energy conservation, inspection techniques and condition monitoring. The Ultrasound World IV “TOP GUN” Program is scheduled for January 27-30, 2008 in Clearwater Beach, FL.
UE Systems, Inc., Elmsford, NY
www.uesystems.com

1007_amprobe1AMPROBE TEST TOOLS
Amprobe® Test Tools offers a wide range of devices for testing and measuring electrical properties in various field applications. The Amprobe ULD-300 tests bearing problems, engine seals and compressed air leaks quickly and easily. In areas where leaking gases are not sufficiently pressurized, the area can be pressurized with the ultrasonic sound waves created by Amprobe’s UT- 300 Ultrasonic Transmitter. This allows the detection of cracks, which would not normally be possible.
Amprobe Test Tools, Everett, WA
www.amprobe.com

ANSONICS, INC.
Ansonics, Inc. has built quality ultrasonic detectors since 1963. Their ultrasonic detector, the Son-Tector, is a simple industrial maintenance tool used to inspect equipment to find leaks and mechanical malfunctions. The tool requires no complicated calibrations and has no unnecessary bells or whistles. Ansonics, Inc. has incorporated feedback from the field over the years in order to keep the Son-Tector dependable and easy to use. The product comes with a lifetime warranty.
Ansonics, Inc., El Prado, NM
www.ansonics.com

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147

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October 1, 2007
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Enhancing safety and productivity…Is There Voltage?

With the help of new pre-verification devices, coming up with the right answer has gotten safer, easier and much quicker for one Arkansas paper mill.

Electrical safety demands that we know the right answer to one question: “Is there voltage?” Since a wrong answer can have life-threatening consequences— like arc flash, for example—it’s important for personnel working with electrical equipment to be capable of answering this question with unerring certainty.

1007_solspot1When the NFPA published its Standard for Electrical Safety in the Workplace in 2000, the document generated essential changes in the way both electrical and mechanical maintenance is performed across today’s industrial and commercial facilities. There is no doubt these changes have been positive since injuries and deaths caused by electrical accidents have been significantly reduced.

As with many new regulations, productivity in some cases may have been adversely affected. Consequently, some companies have been asking another question: “Can we retain the reduction in injuries and deaths we witnessed because of NFPA 70e while regaining the level of productivity we experienced prior to NFPA 70e?” Grace Engineered Products says “yes.” As one paper mill in Arkansas discovered, pre-verifying electrical isolation is an excellent way to safely have your cake and eat it too. In an effort to boost employee safety during its Lock-out Tag-out procedures (LOTO), the mill ordered several of Grace’s ChekVolt™ Non-Contact Voltage Portals from a local electrical distributor. When installed in the door of an electrical panel, ChekVolt provides maintenance personnel with a no-touch voltage portal on the outside of a grounded metallic electrical enclosure. The device’s interface allows for the use of any non-contact voltage detector pen to pre-verify electrical isolation before opening an electrical panel. This pre-verifying capability affords an additional safety barrier between the maintenance person and hazardous voltage. Moreover, as this Arkansas facility discovered, the Chekvolt also helped increase productivity—significantly.

Prior to installing the ChekVolt portals, maintenance personnel noted that the mill’s mechanical LOTO procedures took 45 minutes for each MCC room. However, after installing the device portals in each bucket of two MCC rooms, the time required for the LOTO procedure was reduced from 45 minutes to 12 minutes in the first room, and from 45 minutes to 15 minutes in the second. This 70% reduction was possible because using the ChekVolt allowed personnel to combine and even eliminate some procedures.

In the past, when maintenance work was performed on an electrical enclosure at the mill, an electrician would have to be called to verify from where power was coming. Next, the electrician would have to throw the disconnect switch, put on PPE, and open the panel door to verify electrical isolation with a voltmeter. By pre-verifying electrical isolation with ChekVolt, these steps now are performed in seconds rather than minutes—and the panel door is never opened.

According to Grace Engineered Products, any company that routinely performs mechanical LOTO procedures can enjoy these same types of time-saving benefits with the help of ChekVolt. Being able to correctly answer that all-important “Is there voltage?” question without sacrificing safety for productivity, or vice versa, is something everyone can live with.

Grace Engineered Products, Inc.
Davenport, IA

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221

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October 1, 2007
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Boosting Your Bottom Line: Optimizing Motor-Driven Systems Can Save Big

Your company can achieve signifi cant energy and bottom-line savings by implementing an effective motor management plan. With a welldefi ned, proactive plan in place, you are in position to optimize the benefi ts of NEMA Premium™ motors and best practice repair. But, the savings don’t stop there.

Examining and optimizing motors as part of an overall system can elevate benefi ts to the next level. Savvy facility managers realize that the savings and productivity gains that can be achieved by optimizing motor-driven systems can be greater than the combined savings of upgrading individual components.

Our July column highlighted the benefi ts of adjustable speed drives in appropriate applications. This was a fi rst step in looking at motors as part of a larger system. A logical next step might be to identify motor systems that are common to a variety of industrial processes and commercial applications, e.g. compressed air, pump and fan systems.

According to the Department of Energy (DOE), motor-driven systems account for 64% of the electricity consumed in the U.S. industrial sector. Furthermore, signifi cant reductions are possible through the use of proven equipment and technologies.

Compressed air systems, for example
Compressed air, a utility that is generated inhouse, serves a variety of applications. While a majority of industrial facilities have compressed air systems, few realize that compressed air generation accounts for a signifi cant portion of their facility’s energy consumption or that these systems can be notoriously ineffi cient—as low as 10-20%.

System optimization measures include identifying systems that are leaking or poorly confi gured for end use, and reducing system air pressure or running times. Both the Compressed Air Challenge Website and DOE’s BestPractices Website offer a wide array of resources to help facility managers understand and capture these benefi ts.

Optimization resources are available
The Department of Energy’s Website provides optimization resources for other motor-driven systems as well. These include sourcebooks, software tools, tip sheets, technical fact sheets, handbooks and even market assessments for the following areas: steam, process heating, motors, pumps and fans. The Environmental Protection Agency is yet another valuable resource. This agency’s Web site, www.energystar.gov/, provides information and tools to help facility managers who are interested in generating energy and cost savings. (Tune in next month to learn more about the EPA’s energy management strategies for achieving continuous improvement and its benchmarking tools for commercial and industrial facilities.) The Motor Decisions MatterSM Web site provides links to additional optimization resources and information about funding sources for energy effi ciency across the U.S. and Canada. Visit www.motorsmatter.org, and click on Helpful Resources. MT


The Motor Decisions Matter campaign is managed by the Consortium for Energy Efficiency, a North American nonprofi t organization that promotes energy-saving products, equipment and technologies. For further information about MDM, contact Ilene Mason at imason@cee1.org or (617) 589-3949, ext. 225.

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243

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October 1, 2007
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Real-World Learnin

1007_inputoutput1We’ve said it before: We are always interested in reader feedback, no matter how it reaches us. Letters sent directly to our contributors in response to their respective columns or features can be especially helpful in that they often allow us to draw conclusions on the state-of-the-art, the mood of the industry, etc. That, in turn, lets us better serve you, the reader. An example of this process can be seen in a round of communications between Heinz Bloch and an unnamed Plant Manager. Focusing on “learning” out in the real world (an important topic in both MAINTENANCE TECHNOLOGY and our sister publication, LUBRICATION MANAGEMENT & TECHNOLOGY), we probably could have used this thoughtful exchange as a springboard to a stand-alone article in either magazine. Instead, we’ve chosen to share parts of it here, along with some additional insight from Heinz…

Dear Heinz:
I have enjoyed and learned much from your articles over the past two years since I discovered them. I particularly enjoyed your recent articles with implied (yet justified) comments about management not acting on rotating equipment advice—it brought a smile to my face. In my first stint and first year as a Process Manager, I was guilty of trying to be too clever. However, I soon came to appreciate the value of a first-class rotating equipment engineer and his advice.

At this time, I am about to re-enter a Plant Manager role in a refinery and wish to buy a text covering rotating equipment. My earlier experience has taught me how critical machinery issues really are. I’m aware of the importance of understanding the advice I am being given; certainly, a manager needs to know enough to ask the right questions.

That said, I recall that in one of your articles you quoted several texts as essential and am wondering if you would mind advising which of two or three of your books would be best for me.

Please keep the articles coming. I am bringing them to the attention of my colleagues here to make us Chemical Engineers more knowledgeable about rotating equipment.

Name withheld by request
Via e-mail

Heinz promptly replied to the Plant Manager…
The (referenced) listing was actually published in the May-June 2006 issue of our sister publication, Lubrication Management & Technology (formerly Lubrication & Fluid Power). The first three books in our “Essential Machinery Reliability Library” should be of value and are recommended in answer to your request. However, the following three-step plan should be of general interest when training professional employees:

1. Technical book(s) should be read in stages and must be assimilated or digested in stages. A stage of development builds on the previous stage. As an example, issues of pump specification should be learned after having observed pump repairs.

2. The technical reader will have to understand when, where and how best-of-class actions or procedures described in the “Essential Reliability Library” (and representing Best Practices) differ from the way things are done at the reader’s facility.

3. Equipment Reliability Professionals have to justify to their management why one should use Best Practices and what would be the safety and reliability implications of deviating from Best Practices.

Heinz P. Bloch, P.E.

We can assume that the Plant Manager who penned the letter (and prompted the above response) realizes there is more to training than meets the eye. As so many of our contributors continue to point out in our pages, there is. Most importantly, there is no progress without training. Heinz elaborates…

Indeed, the frequent restructuring that took place and continues to go on in industry has affected the training of both professional and craft employees. In some locations, entire training departments have been dissolved and little or nothing has replaced them.

The challenge, though, is the implementation of meaningful and technically sound replacement training for those who accept the premise that people versed in stateof- the-art capacity assurance methods are a real asset. In response to this at some plants, a loosely defined and sporadically executed self-teaching routine has moved into the void. But, there is a better way.

The beginning of training should be a well-focused, written role statement that explains to both manager and managed their respective perceptions of the technical employee’s role. Is he or she a parts changer or innovator? A fixer or an improver? A person who is expected to react to problems or anticipate problems? The role statement must, at least, allude to a training plan. The technical person and his or her supervisor should discuss both role statement and training plan initially and, of course, during scheduled future performance reviews.

A detailed training plan should probably be a separate document. Such a plan will give firm guidance and yet leave lots of room for individual initiative. Its aim will be the achievement of proficiency in a technical skill or craft. As an example, here’s how technical training for a young engineer could be structured:

Let’s say your facility employs four maintenance or reliability engineers or senior reliability technicians. You could get them to engage in worthwhile self-training by obtaining subscriptions to trade journals like Maintenance Technology and Lubrication Management & Technology, among others. (As you may already know, these types of subscriptions often are provided at no cost to qualified subscribers based on job title and responsibilities.)

If you find value in having your own personal copy of a publication month after month, others around your operations probably will, too—particularly those who work in large organizations or who travel extensively. Many publishers would be happy to ensure that a reasonable number of additional copies find their way to key technical and management personnel at a company or site. (In the case of the publications referenced here, one of the easiest ways to do this is to encourage your associates to qualify for their own subscriptions by filling out the required forms on www.MT-online.com and/or www.LMTinfo.com. Keep in mind that these periodicals are sent to qualified subscribers in the U.S. and Canada free of charge.)

All technical personnel should have access to the information in the publications that are deemed to be important to your operations. The name of each technical person should be at the top of the in-plant routing sheet of two or three of these periodicals and he/she would be required to screen the content of the periodical(s) for relevant material. The employee would not have to read the various articles, but would be expected to recognize from headings or abstracts the present or possible future usefulness of the write-up. Electronic copies would have to be made of these writeups and sent to the other “Professionals-in-Training” on the “PIT” distribution form. One copy would be filed in the plant’s central computer under appropriate headings that might follow a simple, but logical identifier system to enable easy retrieval via a straightforward, well crossreferenced PC-based software program. Remember, before making copies and distributing copyrighted articles, it is a matter of professional courtesy to contact the editor to request permission to do so.

The second phase of training might be called the “dig-upthe- facts” phase. Each “PIT” would be asked to present periodically scheduled briefings or information sharing sessions to mechanical workforce personnel assigned to shop or field (e.g. millwright) tasks. Tacked on to the ubiquitous safety meetings, these 7-10 minute briefings or information sharing sessions might deal with topics such as:

  • How to Install Rolling Element Bearings in Our Large Mixers
  • Proper Lubrication Procedures for Our Pumps and Motors
  • Why Four Different Types of Couplings Are Used at Our Plant
  • When to Use Bellows Seals Instead of Pusher Seals in Our Plant’s XYZ Process Unit

There are literally hundreds of worthwhile topics to research and discuss and disseminate. The process would compel the presenter to do some homework instead of guesswork, communicating with vendors and manufacturers instead of reinventing the wheel, and perhaps even rediscovering one or more of the many good technical textbooks which are generally available at a fraction of the cost of making a single mistake. The researcher also would be educating himself/ herself and contributing to the development of team spirit and the enhancement of mutual respect and cooperation among the many job functions in the plant.

From here, the phased approach to training could move to in-plant courses by competent presenters with both analytical and practical knowledge in machinery maintenance and reliability improvement procedures, and then progress to welldefined, known-to-be-relevant outside seminars or symposia. If someone in your company or at your site suggests that training is expensive, just let them try to calculate what your costs would be without proper training.

Which takes us back to the original reader’s request for an updated list of books that we have most often consulted in the past 25 years… For the “Essential Machinery Reliability Library” list, e-mail jalexander@atpnetwork.com. Be sure to put “Requesting Essential Library” in your subject line. On the other hand, you also can compile your own list through a Google Search or by entering Amazon.com and looking for either the author’s name or the approximate title. The terms “RELIABILITY” or “UPTIME EXTENSION” usually appear in any such search.

E-mail questions or comments to: jalexander@atpnetwork.com Or post them on: www.mt-online.com We reserve the right to edit letters for clarity and brevity.

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6:00 am
October 1, 2007
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Going for the gold…Part II

In the first installment of this series, the author discussed overcoming some common misconceptions to help you on your way to becoming an Elegant Maintenance Manager. This month, he deals with bringing corrective maintenance under control and extending it to preventive maintenance work to achieve efficiencies consistent with the assigned budget.

If one could get the right mix of preventive maintenance (PM) and corrective maintenance (CM), things might not be so bad. If CM could be reduced to zero, that would be grand, but that is not going to happen. Amid the propositions of RCM, TPM, RCA, the Pareto rule, best laid plans, etc., one still must contend with randomness. When our programs result in high levels of performance, the limiting factor is often randomness. Using the concept of randomness in analyzing equipment failure events is helpful in establishing the realistic limiting factors in PM and CM program development and management.

Small changes, big results
Before getting enthused about understanding the technical milieu of equipment failure modes and causes, failure intervals and maintenance task development in recovering a dysfunctional maintenance program, first look for an opportunity of a large reward for a small resource expenditure. One large reward, for example, could be a 50% reduction in corrective maintenance resulting from a program developed and implemented in-house (small resource expenditure). That 50% number is not unrealistic. A high incidence of maintenance induced failures in the CM arena result from poorly designed and implemented management strategy and systems. These “activity control failures” are commonly referred to as “personnel errors, miscellaneous, or unknown cause.”

If managers are not providing the maintenance staff with sufficient training, procedures, resources, time, leadership and competent supervision, they are their own worst enemy. One of the first and biggest values in maintenance program development is ensuring that you have a competent staff and that your management systems are effective. Only then can one proceed to implement a maintenance strategy in such a way that the maintenance staff does much more good than harm. Table I summarizes the analyses of hundreds of events at a variety of industrial facilities.

In addition to the categories shown in Table I, modification work (such as replacement of obsolete equipment, increasing capacity of an existing system, or meeting new regulatory requirements) can also be a significant cause of failures. In such instances engineering work is unavoidable, but sufficient engineering resources are often unavailable to complete all the requirements of installation, operation and performance qualification. In these cases the maintenance department is left with a classic, serious maintenance management problem, because the complexity of these seemingly simple facility events is not recognized. These failures are also “activity control failures,” even though most people think they are making desired improvements.

Let’s see if there is an elegant approach to addressing these serious problem areas in a maintenance program that is in a hole. Is there an elegant way for maintenance managers to stop digging, and then develop a strategy to lift their organization out of the hole they find themselves in?

Stop digging, start climbing
First, develop a “maintenance process” for doing your maintenance business. The maintenance process describes the conduct of maintenance at your facility. It becomes one of the key components of your strategy. It tells your staff how you want them to conduct the business of your department. Administrative aspects of the process probably already exist simply because of government regulations for doing business in general. The Elegant Maintenance Manager now must add the technical aspects and describe how the average maintenance technician and his supervisor should be conducting maintenance business and ensuring the operability and reliability of systems and equipment.

For example, does the maintenance technician know where to find the source documents for working on equipment? Are there source documents? How does he know what post-maintenance testing to conduct and what the acceptance criteria are? How does the supervisor interact to ensure communication and implementation of the maintenance process?

In a later article we will see that the maintenance process is a critical training document. That’s because if the maintenance manager specifies the conduct of maintenance, there will be goals and objectives for the maintenance technicians and supervisors to achieve on a consistent basis. If this is not done, work orders can become adventures being directed by a loose cannon or two. Maintenance process knowledge is as important as technical skills—do your people know how to work?

Second, take a look at your CM work load. Based on failure cause determination in hundreds of analyses covering thousands of mechanical, electrical, and instrumentation and control components, I discovered eight causes of failure for use in front end development of maintenance programs. These causes are:

  • Vibration
  • Degradation
  • Corrosion
  • Wear
  • Maintenance activity
  • Environment
  • Installation anomalies
  • Operations and testing

Coupled with the foregoing focus on irregular failure causes, this also is a great opportunity to apply the thinking inherent in RCM to address the CM problem.

Choose specific maintenance tasks on the basis of the actual failure characteristics for the equipment under study as evidenced by the CM history. All these tasks can be described in terms of the four basic forms of maintenance tasks, each of which is applicable under a unique set of circumstances. The four forms of maintenance tasks are well defined in the RCM literature.

Earlier, we discussed the problems associated with things like obsolescence and modifications that are not maintenance problems but become defacto maintenance problems due to a lack of an engineering function. Applied RCM thinking will help Elegant Maintenance Managers identify this trap before it gets sprung on them. Getting CM under control this way is cleverly apt and simple and obvious. Even in RCM program applications, this approach works when the specified RCM task doesn’t meet expectations for whatever reason, and CM is occurring on an “RCM’ed” unit.

There is even a concept in RCM that goes something like this for overhaul tasks: In the case of overhaul tasks, the question of applicability as well as effectiveness requires an analysis of operating data. Unless the age-reliability characteristics of the item are known from prior experience with a similar item exposed to a similar operating environment, the assumption in an initial program is that an item will not benefit from scheduled overhaul. The implication of these concepts is “make good use of CM data in specifying applicable and effective tasks.”

Let’s see where we are at this time after completing the previous actions. We stopped digging the hole we were in by managing. That produced the strategy that materialized in a maintenance process statement that the maintenance supervisors communicated to the work force, then implemented in the field as the staff conducted the business of maintenance. If supervisors cannot be counted on to communicate the strategy and see to implementation, then coaching and counseling are in order followed by getting competent supervisors in place if the incumbents cannot adapt to change. The reactive component of the maintenance business came under control with the conversion of CM work to PM work. That’s a good start on being effective. By managing, one attacks 50% of the CM cause, and by applying RCM thinking, one can attack just about all the remaining CM problem(s).

In the opening paragraph, randomness was put forth as a limiting factor in the maintenance business. This is where randomness comes in to help the maintenance manager understand what the PM/CM ratios are expected to be. Empirical determination shows that the reasonable values of the PM/CM ratios (computed as PM work orders divided by PM+CM work orders) are approximately as follows:

  • Mechanical Systems—80%. Due to physically harsh service environments and the interplay of many uncontrolled variables, there is a significant impact from random events in these systems. These systems also generally are associated with energy transport and conversion through physical system interaction.
  • Electrical Systems—90%. These systems are generally better controlled regarding environmental conditions, thus minimizing uncontrolled variables and random events. Also, the energy transport and conversion is in many cases by means of an electromagnetic wave, thus taking less of a physical toll on equipment.
  • Measurement and Control Systems—>90%. High CM in these systems is generally due to poor heat management or poor design. These systems should be among the easiest to maintain through a PM program and have a minimum impact from random events.
  • Overall—85%. This overall performance level accounts for about a 15% random failure level that will show up as the CM workload in effective PM programs.

Within a year of instituting the management and CM changes, the Elegant Maintenance Manager should be able to achieve the PM/CM ratios listed in this bulleted list.

Save some, get more resource efficiency
Now would be a good time to take an initial shot at bringing efficiency into the PM program. It is important to be effective first, then efficient, so that’s where the Elegant Maintenance Manager would be at this point in the maintenance program recovery. There are obvious savings from reducing the number of PMs, so the PM intervals should be examined to ensure the maintenance staff is not overdoing the PM thing.

1007_elegantmaint1Examining the PM results versus the interval of performance and effectiveness of the PM process is the first step in adjusting the PM schedule. For a start, consider the following:

  • Eliminate, within reason, all “tear down and inspect”-type PMs. This is the pointless “tear up the plants to check the roots” mindset that seems to make sense but in reality is one of the main causes of maintenanceinduced failures.
  • For scheduled replacement tasks, examine closely the item being replaced and make a determination as to condition. If it is not that bad, consider extending the PM interval by 50%. If you and your staff do not know how to make this judgment call, learn how to do this as soon as possible.
  • For all equipment in low-energy or low-duty-cycle applications, consider doubling the PM interval. Examples of low-energy parameters include temperatures less than 300 F, flow rates less than 100 gpm, operating pressures less than about 100 psi air or water or low-pressure steam systems, and duty cycles of eight hours per day or less.
  • For all changes made per the recommendations listed here, revisit the interval question at the next performance of the PM to again extend the PM interval as possible.
  • For non-critical, low-cost components with no collateral damage potential, consider a run-to-failure maintenance strategy and eliminate the unit from the PM program except for routine monitoring for deficiency identification.
  • Evaluate all skid-mounted instrumentation and control components for usefulness compared to remote process monitoring instrumentation and control systems. Remove redundant or not-used devices from the PM and calibration programs.
  • Design special tools, jigs, and fixtures to support maintenance on certain equipment as necessary and place these items under inventory control to ensure availability when needed.
  • Consolidate PMs. Ensure that subinterval PMs are embedded in longer interval PMs and that as many PMs as possible are included in work packages to minimize equipment downtime and minimize PM logistics.
  • Supply each supervisor, as practical, with a set of specialty tools and measuring and test equipment for their controlled use on their shifts.
  • Remove all barriers in the procurement process from the requisition phase to the receipt and staging of parts to support PMs. This will likely require some “just in time” (JIT) procurement tactics, vendor partnering, and removal of enterprise asset management system (EAMS)-type roadblocks.

Two elegant programs to implement
There are two must-have programs that will provide some of the important information details for the maintenance information flow network. These details are important inputs to the feedback networks that the maintenance department needs to ensure awareness of what is going on. These programs are the “CM Backlog Measure Program” and the “Material Condition Inspection Program.”

A CM work order is generally designed to process work within the constraints imposed by the facility organizational structure. The constraints are in the form of assigned responsibilities and authorizations for completing the specified tasks including appropriate paperwork closeout. If this system is run efficiently and adequate staff is available, experience has shown that an optimal CM backlog can be defined such that there are sufficient manpower resources to address other tasks besides CM or handle a reasonable, sudden increase in the CM workload.

What does this really mean and what does it have to do with a maintenance department’s backlog measure? It means that backlog is something that occurs due to a maintenance organization’s ability to respond to an increased workload in such a fashion that the increased workload is still manageable as part of the organization’s day-to-day business activities. The essence of this concept is that the organization should have the inherent characteristic of a system that responds to how much work there is to do.

Historically, CM backlog has been presented as a trended plot of total backlogged man-hours or total open work requests. While this type of measure does provide some useful information on the CM backlog, it does not tell much about the effectiveness of the organization or why the backlog exists as it is. This is really what we would like to know as opposed to knowing how much CM work has not been done. We are more interested in what caused the alarm than the alarm itself. In order to make use of a CM backlog measure consider this measure to be an indicator of how time-dependent work is addressed by the maintenance organization’s work order processing system. The key item for understanding what backlog really means is the phrase “time dependent.”

The material condition of the facility should be maintained to support safe and reliable operations. It should be everyone’s business to identify and correct deficiencies and prevent the deficiency culture that comes from complacency. The basic approach to developing the facility material condition inspection program (MCIP) is as follows:

  1. Develop and implement an inspection program to define responsibilities for conducting inspection, identifying and correcting deficiencies, and assuring cleanliness, safety and good material condition. Establish inspection areas so that the entire facility is inspected, including areas with difficult access.
  2. Establish inspection guidelines and criteria to assist inspectors in performing their inspections.
  3. Develop a training program for appropriate station personnel, including operations personnel, facility managers, and facility supervisors, to receive inspection techniques training.
  4. Establish a means to report, track, and correct, identified deficiencies in a timely manner. Document each deficiency on a work order. (See Fig. 1 for a simple reporting document that is extremely effective for use by anyone.)
  5. Include recommendation of operation and maintenance good practices in this reporting program as a means of identifying areas for improvement.

A significant side benefit of this program is the equipment monitoring and diagnostic results of these inspections—a sort of informal predictive maintenance. But this predictive maintenance program is a real bargain, since the cost is simply the cost of using available resources.

Conclusion
This installment of the Elegant Maintenance Management series deals with the fundamental mission of the maintenance department. We all know that a lot of CM comes from poor judgment, and that good judgment comes from the experience of bringing a lot of CM under control. Next, that control must be maintained and extended to PM work to achieve efficiencies consistent with the assigned budget. Only then can there be sufficient success to ask for more resources. Remember, only you as the maintenance manager can stop digging. Empower your talented staff to do the climbing.

Dr. Huzdovich is the service contract manager for Raven Services Corporation at the Bureau of Engraving and Printing’s Western Currency Facility in Ft. Worth, TX. He directs the O&M and engineering work performed by the Raven staff of 58 employees, which is responsible for the 24/7 operation and maintenance of all stationary and production support equipment in these operations, including their 850-ton chilled water units, 800-hp low-pressure steam boilers, 3600 KW of diesel generator capacity, the environmental management system and currency mutilation destruction equipment. He also is the principal engineer and consultant providing maintenance and reliability services and expert witness services for Forensic Action Services, LLC, in Denton, TX. Huzdovich serves as an adjunct instructor with the University of North Texas, MBA Program. E-mail: jhuzdovich@verizon.net; telephone: (817) 847-3674.

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