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UPTIME • December 2013/January 2014

AES Southland provides power to Southern California from a multitude of power resources. In 1998,  AES Southland acquired the Alamitos natural gas power plant from Southern California Edison. Since that time,  AES has undertaken a number of programs to modernize the generating station and improve the reliability of the Alamitos facility.

In 2010, AES Alamitos’ Units 3 & 4 boiler circulating pumps and Units 5 & 6 exciters were identified as having reliability issues. These machines were never equipped with vibration probes and only the metal temperatures of the exciter pedestal bearing and common lube oil drains were monitored by the control room recorders. Due to the low cost of implementation and OMNITREND® software compatibility, it was decided to purchase and install a VIBNODE® monitoring system to improve the reliability of the AES Alamitos Units 3 & 4 boiler circulating pumps and the Units 5 & 6 exciters.

Download the entire article RETROFIT MONITORING WITH BIG PAYOFF RESULTS by Jim Cerda and Greg Lee.

Vibration data collection on plant equipment can be very problematic due to safety concerns,  time constraints, access difficulties, and other reasons.

Solution: The use of a termination switch box and vibration sensors can allow an analyst to safely collect vibration data away from conditions that could complicate or even prevent manual readings from being taken due to safety concerns or other reasons. In addition, this can speed the data collection process and increase time efficiency within the Condition Monitoring (CM) program. A capable data collector such as the VibXpert® II  allows a CM program to collect data remotely using methods like the one described above. This capability can greatly enhance safety and efficiency within your CM program.

The Finger as a Sensor and Other Things That Are Of Utmost Importance!

Toyota did a study to find out why some equipment failed prematurely. They found that something like 80% of premature equipment failures could all be traced to three rather simple causes; causes that could have been prevented or remediated before they led to equipment breakdown. What were the three culprits?
a. Looseness
b. Improper Lubrication
c. Contamination

All three of these can be addressed by the vibration analyst during collection and analysis.

Looseness can be detected with a vibration analyzer. When you see looseness,  use your finger as a sensor and run it around the interfaces of the bearing pedestals, housings, and foundations. It is surprising how sensitive one can be to the phase difference of shaking parts that have become loose. See that it is remedied before it causes catastrophic failure.

Inadequate lubrication can be detected by Shock Pulse. If you are taking high-frequency acceleration readings it will cause a raised noise floor. This one is best avoided altogether by a well-planned and supported lubrication program. Often, by the time-poor lubrication is detected, a considerable amount of damage has already been done. An electric motor’s winding insulation breakdown rate is doubled for every 18° F rise over 165° F. This is why motor cooling fins are actually for cooling and not for holding dust, grime, or whatever. Contamination is an important condition to monitor via a manual input point for each machine area. Add it to your route. Report equipment covered in whatever foreign matter your plant has lots of so it can be properly cleaned before damage is created.

Focusing attention on the three areas above will definitely create value for your company.

Triax transducers have three sensors within a single housing measuring all three vibration axes (X,  Y, and Z). There is an argument in favor of mounting a Triax sensor in the middle of a motor, asserting that it can provide all of the necessary data for defect analysis. Triax sensors are also beneficial when collecting large amounts of either Modal or Operational Deflection Shape (ODS) data. A special impact hammer can be used to measure all three axes of vibration data for Modal analysis, minimizing the number of impacts and effort required to collect this type of data.

However, certain disadvantages are associated with Triax sensors that also should be taken into consideration. For example, some defects can be missed until very late in the failure mode when the sensor is used at a single sensor location. This can reduce the amount of time available to take corrective action on the equipment being monitored. Triax sensors can be quite expensive when compared to standard vibration sensors. Additionally, the data collector being used must have the electronic capabilities to utilize these types of sensors.

For many vibration analysts,  a magnet is the point of contact between them,  with all of their sophisticated technology, and the rotating equipment they wish to monitor. This being the case, the magnet and its mounting characteristics occupy a very important position in the scheme of what they do every day, yet this crucial part of their occupation is most often taken for granted.

Check your magnets frequently! Make sure the sensor is securely bonded to the magnet so the least possible interface loss is experienced. If you have to help hold the magnet and sensor onto the equipment, it’s time to get a new magnet. The magnet should be strong enough to support the weight of your cable assembly without rocking at all when the cable is swinging. When your sensor and magnet are not in use, make sure the magnet has something to pull against like a washer or what many analysts have found to be very useful for magnet storage… the side of a metal file cabinet.

Cross channel phase is a process of using a two-channel instrument to determine the phase relationship between two measurement locations without using a fixed reference tachometer. The cross channel phase uses two-time waveform signals: Using channel “A” as a reference it takes one cycle in the time waveform as one revolution of the shaft and plots the “B” channel time waveform against channel “A” to determine the relative phase. This process is useful for confirming angular or offset misalignment,  unbalance,  loose parts, and problems such as soft foot (machine frame distortion), etc.

Cross channel phase cannot be used for performing a dynamic balance on a rotating component as it refers to the relative phase while dynamic balancing requires absolute phase data.

To appropriately determine monitoring intervals a couple of things must be known. First,  the point in time (P) that the potential failure becomes detectible must be known (detected with vibration monitoring,  etc.). Second, the time (F) at which the potential failure would degrade to a functional failure must be known. This difference in time (P-F Interval) is the window to take corrective action and avoid the negative consequences of the failure. This difference in time will determine how often conditional tasks such as vibration monitoring must be done to detect potential failures such as bearing issues, etc. Typically, the monitoring interval would be set to half of the P-F interval. This allows enough time for the technology to detect the problem and for corrective action to be taken. However, in certain circumstances, it may be necessary to collect data at shorter intervals than half of the P-F interval.

With the shift in technology over the last ten years,  it is easier to store pictures, music, and documents on a computer. The computer allows quick access to files and the ability to share them. Of course, with technology there are risks, but most can be minimized. One of the worst things that can happen is for the computer to crash or the hard drive to malfunction, rendering all your files unretrievable. A computer has a lot of ways to duplicate your files, but this is usually thought of too late. Once your computer crashes it is usually too late to make a copy or a backup of your files.

Creating a vibration database takes time and effort to make certain everything is entered correctly for your facility. Once everything is set up correctly, vibration data is collected and transferred into the vibration database. That vibration database is a health history of the machines for which vibration data was collected. Many additional items can also be stored within condition monitoring software such as machine photos, repair invoices, infrared images, and work orders to name just a few. How important is the data that is contained within your database? It is strongly advised that your vibration database be backed up on a regular basis. What constitutes a regular basis? It is suggested to back up your database after any major change. The rule of thumb for backing up a database should be related to how much additional effort would have to be expended in order to get the database back to its current state.

It is very easy to back up your condition monitoring database. A decision will need to be made as to how and where the database will be backed up. If you are running a network version of the condition monitoring software, then in most cases the IT department is backing up the server where this database resides. If you are a standalone user, then the responsibility of backing up the condition monitoring data rests on your shoulders. You should consider copying the database to a flash drive or creating a CD/DVD. Does your IT department have a shared network drive that is being backed up every night? That would also be an excellent place to copy your database.  It is fine to have multiple backups of your database but be certain that the backups are recent and not months or years old.

A regular backup policy can save time, effort, and protect your valuable data. The cost of external data storage is very inexpensive and allows for the vibration database to be backed up too many different media types such as CDs, DVDs, external hard drives, and USB flash drives as examples. Being proactive should not only apply to your maintenance program but should extend to the backing up of your vibration data!

As Published by BIC Magazine May 2013 issue

A relatively small investment in training is a win-win scenario for the plant with a huge return

LUDECA has trained its customers’ maintenance personnel for more than 25 years. The incidence of mistreated laser alignment systems coming back for repair drops dramatically when a plant’s millwrights are properly trained in the use and care of the system. A relatively small investment in training is a win-win scenario for the plant with a huge return.

Many plants cognizant of the benefits of good training invest in a separate fully funded training department with highly qualified instructors. If you do not have this,  do not hesitate to hire outside experts to come in and train your personnel, but ensure these experts really are qualified to train. Research credentials and follow-up on references.

Buy the best systems you can afford and really train your people to use them, or your equipment will be underutilized or mishandled. A well-equipped, dedicated training center provides a controlled environment where employees can learn undisturbed to their maximum potential. Equip it with good lighting, sanitary facilities, quality tables, comfortable chairs, a generous coffee pot, the latest SMARTboard™ technology, projectors, computers, and Internet access.

If you cannot provide a good training environment in-house, send employees away for training. Vendors who offer such services should have better facilities for this than you do. Ensure they do! We went out of our way to build and equip our own state-of-the-art training center and staff it with highly qualified people.

If you cannot afford to send away several employees at a time, send your most qualified employee or resident instructor for more in-depth training to have the knowledge brought back. We offer intensive “train the trainer” courses and in-depth courses for day-to-day users of our alignment and vibration systems. For us, it is a win-win proposition — well-trained users of our systems learn to love them, use them correctly and care for them properly. We offer an educational discount for systems purchased by training programs or educational institutions.

Six students per class is ideal (eight max) to allow the instructor to devote individual attention to each student, answer all questions and ensure each student gets hands-on practice. Each pair of students is assigned their own training simulator and complete laser shaft alignment system or vibration data collector and computer and necessary peripherals. Each student gets a complete set of training materials and an operator’s handbook for the system being learned to keep.

Vibration training is regarded as complex, and it can be at the more advanced levels. Yet a solid understanding of the basics of machine vibration and its underlying causes will benefit you greatly. Maintenance employees will be more attuned to spotting potential problems than they otherwise might and become more valuable, proactive members of your overall reliability program. Understanding what causes imbalance and its consequences, and what causes a bearing to fail prematurely is valuable knowledge for your employees, saving you money in the long run.

Most equipment failures are not age-related.  The equipment will provide some sign of impending failure if we have the right tools available to understand the change in condition.

A lot of facilities assign monitoring intervals based upon arbitrary schedules such as 30,  90, 180, or 365 days.

Often this is due to a lack of understanding of how equipment fails, misunderstanding of how conditional tasks such as vibration analysis work, available labor, and lack of importance placed upon Condition Monitoring (CM) efforts.  These arbitrary collection intervals can actually lead to failures that go undetected and a loss of value from the effort.  The equipment will tell you how often monitoring must be completed.  Not understanding this can lead to costly results!

How does your facility determine the correct monitoring intervals for CM efforts?  Is it based upon manpower, gut feel, P-F Interval, or what someone told you to do?

Combine vibration monitoring and ultrasound for more cost-effective predictive maintenance
The best overall machinery monitoring program is one that utilizes multiple,  integrated monitoring technologies.
In brief:

• The best overall machinery monitoring program is one that utilizes multiple, integrated monitoring technologies that are well-suited to detect expected failure modes.
• One goal of PdM is to determine how much time is left before a machine will fail, so plans can be made to minimize downtime and damage while still getting the most useful life from the machine.
• An application where ultrasound and vibration work well together is a mechanical inspection.

Reliability-centered maintenance programs are most effective and most profitable when a variety of appropriate technologies and tools are used to complement one another. Vibration analysis and ultrasound are as complementary as two sides of the same coin. Ultrasound is a useful monitoring tool, capable of detecting failing rolling element bearings and over-and under-lubrication conditions. The best overall machinery monitoring program is one that utilizes multiple, integrated monitoring technologies that are well-suited to detect expected failure modes. For low-risk machines, vibration analysis can be performed by a mechanic or operator using a vibration data collector or vibration meter. For machines of higher criticality, a certified vibration analyst should use advanced vibration data collection and analysis hardware and software.

Read my comments in this valuable PLANT SERVICES article.

If you are a vibration analyst or are responsible for managing a Condition Monitoring (CM) program or reliability effort,  you are probably keenly aware of the “what have you done for me lately” mentality. This is a mentality that may frustrate us somewhat, but if we think about it, it is only natural. In fact, if we are honest with ourselves, we will probably find we apply the same mentality to others at times.

This being the case, it is very important that we keep our management team apprised of the value they are getting from us, our tools, and our training. This is not a personal pride thing, but simply a part of business operations. Corporate management reports regularly to stockholders, showing the value of their management. Investors are willing to maintain their investment in a company, so long as they know they are getting a valuable return on their investment.  In the same way, management will be willing to sustain their investment in CM along with its practitioners and equipment, as long as they are aware they are getting ample value in return for their investment.

CM efforts provide direct and positive contributions to key indicators like reduced downtime, reduced repair costs, reduced parts inventory need, increased production capacity, etc.  If tracked correctly it will be clear to management that CM provides a big return on investment (ROI).  Do not hesitate to bring Management’s attention to the many ways that CM contributes to the business goals of your facility or corporation.

Many companies are so accustomed to the CM department detecting unbalance in fans and the like and then driving the remediation of the problem (via cleaning, repair, and field balancing) that they no longer appreciate the value of such things. If the CM manager is not careful, he may find himself wondering what happened, because he took it for granted everyone appreciated the value of the CM contribution to the bottom line, only to find out that some of his people (or even himself) are seen as expendable because the value of their work is not fully appreciated. In this era of downsizing and “leaning up”, this is a chance no one should take. Document the actual savings in parts, labor, lost production, and downtime that you generated with your CM successes by averting the potential failures that would have occurred without your efforts.

One thing that most field vibration analysts will become aware of is how the directional stiffness of a typical machine will manifest itself in vibration data. The typical horizontal machine train (driver and driven) is fastened down to a very rigid foundation,  having little to no freedom of movement in the vertical plane. Although the machine components are bolted and welded to one another in the horizontal plane, there is nothing like the rigidity of the foundation preventing the movement of the machine frame in the horizontal plane. This being the case for most horizontal machine trains the vibration amplitude in the horizontal direction is typically higher than in the vertical direction. How much higher depends on the structural make-up of the machine. This is a tipoff to the savvy analyst who may notice a rise in the ratio of the vertical amplitude to the horizontal. When this happens, it usually means the machine has lost some stiffness in the vertical direction. This can be due to loose fasteners, cracked welds, or even compromised foundations.

Is your equipment considered a slow-running speed machine?  If so,  what speed do you consider slow? Is it 30 RPM? 60 RPM? 100? 200? 600?

No matter what you consider slow speed,  the two most critical points to consider for slow running equipment are:

1) Does your vibration sensor (accelerometer) have the appropriate frequency range to measure low frequencies?

2) Does your vibration analyzer and/or online monitoring system measure down to those frequencies?
Unfortunately, some vibration analysis devices on the market are not truly capable of measuring slow-speed equipment and providing a true mechanical diagnostic analysis. These devices can actually create a reactive maintenance result that the device was supposed to prevent.

For example, a motor shop in South Texas had completed a rebuild of a 100 HP motor. The motor is used in the oil and gas industry. It has an average running speed of 30 RPM. The customer tested the motor on their motor test stand. As it was in its test cycle, the vibration was measured using a self-diagnostic vibration analyzer. The results and diagnostics the analyzer provided to the customer were “please replace bearing”. After several further tests running the motor on the test stand, the customer refused to accept those results and retested the motor using a VIBXPERT® II analyzer with machine templates designed for slow running machinery and a VIB 6.147 low-frequency accelerometer.

The final analysis revealed a high unbalance condition on the motor (11 mils peak-peak). The motor shop followed up with a balancing job (single plane) on the motor. The balancing was performed with the VIBXPERT II as well.  Subsequent tests showed that the unacceptable low-frequency amplitude that had been observed (11 mils pk-pk) prior to performing the balance job had now disappeared. Final mechanical diagnostics showed no problems and the bearings were in proper condition. A balance report was printed and the motor was ready to leave the shop.

If you want to increase your uptime and availability and reach your financial goals, proper investment in Condition Monitoring and reliability will provide a positive return on your investment.

In the Condition Monitoring (CM) world there are two types of instruments: toys and tools. A toy will be defined as an instrument that is used only a few times after it has been purchased. Perhaps it failed or is determined to be too inefficient or insufficient to do the job. The toy is then placed back on a shelf or forgotten in a drawer as it offers no worth to the end-user or the company. Sometimes that toy is traded in for a real tool or simply thrown away. On the other hand,  a tool is an instrument that is used extensively every month and offers a real return on its investment. Granted, a tool can be more expensive than a toy, but the amount of money spent on a quality tool should be recouped quickly. In today’s economy money is very tight and a lot of decisions must be made before purchasing a CM instrument. The Latin phrase “caveat emptor” comes to mind when making such a purchase.

The internet allows for research to be done quickly on different CM instruments. This allows a potential buyer to discover what is a tool and what is a toy. A few things to consider when purchasing a CM instrument are:
1) How long has the provider been in the industry?
2) What kind of support is offered?
3) Does this support require additional fees to be paid or is it provided free of charge?
4) What type of training is required and available from the provider?
5) Where are any needed repairs performed?
6) Is loaner equipment available when calibration and repairs are required?
7) Can the instrument’s capabilities grow to meet your needs?
8) Does the instrument help us determine the root cause of our equipment reliability issues?
9) What is the real cost of ownership over the life of the instrument?
10) Does the instrument provide the true analytical capabilities needed?

As Published by BIC Magazine March 2013 issue

LUDECA’s VIBXPERT® II is exemplary of the company’s line of products designed to ‘Keep It Running.’ The slogan is indicative of what LUDECA’s condition monitoring solutions are committed to doing — keeping U.S. manufacturing running and productive.
The VIBXPERT II is a portable vibration analyzer with a full-color display,  fast data acquisition, and powerful diagnostics tools. It combines the advantages of a rapid processor with a brilliant energy-efficient color VGA display. The diagnostic capabilities allow machinery reliability issues to be identified so corrective action can be taken to keep your equipment running and avoid unwanted downtime.
Ray Wonderly, the owner of Advanced Maintenance Technologies, purchased his first VIBXPERT from LUDECA in 2006 and upgraded to the VIBXPERT II in 2010 after being very satisfied with the company’s laser alignment systems (OPTALIGN PLUS) and customer service.

“Using the VIBXPERT II vibration system has substantially increased my business and customer base,” he explained. “It is a great selling point to my customers when I tell them I can take more vibration measurements and monitor more total equipment in less time because of the outstanding speed of the vibration analyzer itself without affecting the quality of vibration measurements.”

Wonderly found the “extras” LUDECA provides at no additional expense refreshing.

“Many vendors have it as a requirement that you purchase their additional and expensive maintenance support agreements in order to receive additional free firmware and software updates,” he explained. “LUDECA offers the highest quality system at the most affordable price — and with no additional support agreements — when compared to others.

“I have told many people if you just want a basic system at the absolute lowest price, LUDECA’s VIBXPERT may not be the best fit. But if you are looking for a top-of-the-line system at a fair price with many great features, the VIBXPERT is a great choice. You can buy it as more of a basic system and at a cheaper price and kind of grow into the many additional features as needed or required, such as the balancing or advanced diagnostics. The firmware is already built into the device and all you have to do after purchase is open it with the provided ID and password. You don’t have to send the system back for additional firmware features.

“In my personal opinion, LUDECA offers the highest quality system at the most affordable price and absolutely fantastic technical support. I truly feel you are getting more for your money as compared to some of the others.”

“At LUDECA, we maintain a high standard of ethics, service, and customer support by always striving to exceed customer expectations,” said Frank Seidenthal, president, LUDECA.

Every vibration analyst relies on accurate data to provide the necessary information to base a report or work order on that will set in motion the activities of the maintenance department. Therefore,  the analyst must resist sinking into bad data collection habits. When early detection of a fault or possible problem is important (it usually is),  the measurement contact point for a walk-around route should be clean down to the bare metal. A nice thick coat of paint is good at protecting against rust, but it’s not very good for transmitting vibration.

Trends are a very reliable tool for monitoring the condition of equipment IF the data points are taken exactly the same way time after time. The analyst must make sure that the amplitude and frequency changes are equipment-induced and not an analyst- or monitoring apparatus-induced. Sensor placement points should be clearly marked.

Many analysts take thousands of points each month and often don’t see the same discrete point again for at least a month. Don’t depend on memory to place your sensor.

Don’t play data roulette; force yourself into good data collection habits. The day will inevitably come when something seems to be wrong with your data and you will have to troubleshoot where the problem is. If you have disciplined yourself into meticulous habits, the troubleshooting will be much easier, and you can be much more confident in your day-to-day analysis.

This is Part 2 of a 2 part series,  see Part 1 here.

After the proper groundwork has been completed, it is time to build the database for your CM technology. Read my article in IMPO Magazine which includes the last 5 Steps to Successfully Implementing a Vibration Program:
#6: Database structure
#7: Interfacing with other plant systems
#8: Build a database
#9: Create standard reports
#10: Get help

This is Part 1 of a 2-part series. 
Selection of a condition monitoring (CM) technology is not an easy task and requires that many concerns be taken into consideration. Determination of what functionality is needed,  selection of a technology provider that can deliver the required technology, and an available budget are all critical considerations to think about before making a purchase. Otherwise, the intended results will not be found and the new CM technology will not provide value to the reliability efforts within your facility or corporation.

Management often fails to correctly consider how to successfully implement the CM technology once the selection has been made. The failure to consider beforehand how the CM technology should be implemented within their facility or corporation leads to:

• Increased labor
• Increased expense
• Living with the unsatisfactory results for a very long time
• Unsatisfactory results from the CM technology, including:

1. Missed technology findings
2. Lack of integration into the existing business process
3. Inability to create standards
4. Inability to generate meaningful reports

Read my article in IMPO Magazine which includes the first 5 Steps to Successfully Implementing a Vibration Program:
#1: Getting Started
#2: Do you already have a technology database available?
#3: Determine what equipment will be monitored
#4: Obtain required equipment information
#5: Create equipment templates

WATER/WASTE PROCESSING • December 2012

Production plant analyzes resonance anomaly; looks at condition monitoring program as a profit center

Sometimes in industry,  mechanical “circumstances” change. When it happens,  a machine train identical to other machine trains can suddenly become atypical. This was exactly the case for Process Water Supply Pump A, whose behavior was very similar to that of its sister pump trains until something changed. In this article we discuss a problem that was abruptly encountered, the methods used to investigate it and the solution devised.
One of four identical pump trains mounted to a common piping system experienced a catastrophic motor (75 hp, 4 poles) failure. The motor could not be saved, and a new motor was purchased and installed. After installation, the pump was started with the new motor. High vibration caused the installers to immediately shut it down. The new motor had been laser aligned to the pump; therefore the alignment was not suspect; therefore vibration data was taken.

Read the entire article “Where is that vibration coming from“.

Thanks to Roger Earley with LUBRIZOL for sharing this case study with us.