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One of the problems we can encounter while performing an alignment is the re-use of old washers. Sometimes it isn’t enough to replace all the used bolts, nuts, and shims. You need to replace old washers too.

They are just as simple to replace and as inexpensive as the bolts and nuts you are also replacing. Dished washers will try to center themselves in the bolt hole of the foot and will pull your machine out of alignment, even if you are very careful in your torquing procedure. This effect is virtually impossible to overcome and at times even to detect (unless you are using the live move function on a ROTALIGN® laser alignment system), resulting in a difficult alignment to finish properly, even if you have followed every step correctly. Make sure to discard all damaged or inappropriate washers on the movable machine and replace them with thick, good quality Grade 8 new washers.

Another issue is the use of lock washers. Generally, a good flat washer under a bolt head with a good washer seat that has been correctly tightened to the proper torque does not need additional security; however, if your application requires a lock washer due to severe vibration, or because the join needs to be allowed to expand while still maintaining the required amount of axial force on the closure, then a high-quality lock washer may be the right solution. Avoid the use of cheap, one-time-use split-ring lock washers, and use a high-quality Belleville washer (a conical disc spring washer) instead. A split ring lock washer exerts 90% of its force in the first 20% of its travel range, therefore it is a very ineffective solution to the problem attempting to be solved; a Belleville washer, on the other hand, exerts 100% of its locking force over 100% of its travel range, and moreover also serves the functions of a flat washer. In addition, they can be stacked in parallel to increase the axial locking force, or in series to increase both the locking force and the travel range.

Thank you for joining us for our Webinar Detecting Misalignment through Vibration Analysis. We hope you found the presentation to be valuable and very informative. If you missed our Webinar, you can view the recorded version at any time. Watch now!

Here are the answers to your questions:

Q: How do you account for thermal growth when installing new or repaired equipment?
A: If you already know that the machines will move as you run them, you must misalignment them ‘cold’ to compensate, so they grow into alignment as you run them. The trick, of course, is to know exactly how much! There are various methods to ascertain this precisely, the best being to perform a live monitoring job with PERMALIGN® or ROTALIGN® ULTRA Live Trend. To fully answer your question, I’d suggest that you take a peek at our Webinar “Thermal Growth and Machinery Alignment”

Q: If using a dual-channel phase without tacho, do you recommend orientating accels axially for angular misalignment detection and orientating accels radially for parallel misalignment? Is this relative to using 2 channel cross-channel phase to determine angular or parallel phase?
A: Both types of phase measurements are easy to take. The relative phase is the most convenient way to measure phase on a machine because the machine does not need to be stopped to install reflective tape on the shaft. Phase can be measured at any frequency. Most single-channel vibration analyzers can measure the absolute phase. Multi-channel vibration analyzers like the VIBXPERT have standard functions for measuring both absolute and relative phase. See below section “When to use Phase Analysis”

Q: Can’t you only find imbalance from phase?
A: Phase data can be used to verify a lot of vibration issues including imbalance, but it is not only for imbalance itself. I have included a few examples of what issues can be detected below by using phase. Both types of phase measurements are easy to take. Relative phase is the most convenient way to measure phase on a machine because the machine does not need to be stopped to install reflective tape on the shaft. Phase can be measured at any frequency. Most single-channel vibration analyzers can measure absolute phase. Multi-channel vibration analyzers like the VIBXPERT have standard functions for measuring both absolute and relative phase. See below section “When to use Phase Analysis”

When to use Phase Analysis

Everyone needs phase analysis. A phase study should be made on problem machines when the source of the vibration is not clear or when it is necessary to confirm suspected sources of vibration. A phase study might include points measured only on the machine bearings or it can include points over the entire machine from the foundation up to the bearings. The following are examples of how phase can help analyze vibration.

Soft Foot

The term soft foot is used to describe machine frame distortion. It can be caused by a condition where the foot of a motor, pump, or other component is not flat, square and tight to its mounting, or many other things, such as machining errors, bent or twisted feet and non-flat mounting surfaces. Soft foot increases vibration and puts undue stress on bearings, seals and couplings. Soft foot on a motor distorts the stator housing creating a non-uniform rotor to stator air gap resulting in vibration at two times line frequency. A good laser shaft alignment system should be used to verify soft foot by loosening the machine feet one at a time. I’d suggest that you take a peek at our Webinar “Soft Foot”
Phase can be used to identify soft foot while the machine is in operation. Measure the vertical phase between the foot and its mounting surface. If the joint is tight, the phase angle is the same between surfaces. If the phase angle is different by more than 20 degrees, the foot is loose or the machine frame is cracked or flimsy.

Cocked Bearings and Bent Shafts

Phase is used to detect cocked bearings and bent shafts. Measure phase at four axial locations around the bearing housing. If the bearing is cocked or the shaft is bent through the bearing, the phase will be different at each location. If the shaft is straight and the bearing is not twisting, the phase will be the same at each location.

Confirm Imbalance

A once-per-revolution radial vibration usually means rotor unbalance. Use phase to prove imbalance is the problem. To confirm imbalance, measure the horizontal and vertical phase on a shaft or bearing housing. If the difference between the phase values is approximately 90 degrees, the problem is rotor unbalance. If the phase difference is closer to zero or 180 degrees, the vibration is caused by a reaction force. An eccentric pulley and shaft misalignment are examples of reaction forces.

Looseness, Bending, or Twisting

Phase is used to detect loose joints on structures and bending or twisting due to weakness or resonance. To check for looseness, measure the vertical phase at each mechanical joint. When joints are loose, there will be a phase shift of approximately 180 degrees. The phase angle will not change across a tight joint.

Shaft Misalignment

Shaft misalignment is easily verified with phase. Measure each bearing in the horizontal, vertical, and axial directions. Record the values in a table or bubble. Compare the horizontal phase from bearing to bearing on each component and across the coupling. Repeat the comparison using vertical then axial data. A good alignment will show no substantial phase shift between bearings or across the coupling.

Operational Deflection Shapes

Instead of comparing the phase and magnitude numbers from a table or bubble diagram, operational deflection shape software (ODS) can be used to animate a machine drawing. An ODS is a measurement technique used to analyze the motion of rotating equipment and structures during normal operation. An ODS is an extension of phase analysis where a computer-generated model of the machine is animated with phase and magnitude data or simultaneously measured time waveforms. The animation is visually analyzed to diagnose problems. ODS testing is able to identify a wide variety of mechanical faults and resonance issues such as looseness, soft foot, broken welds, misalignment, unbalance, bending or twisting from resonance, structural weakness, and foundation problems.
Phase and magnitude were measured from permanently mounted X and Y displacement probes on a turbine generator. The values listed in the table were used in ODS software to animate a stick figure drawing of the high- and low-pressure turbine shafts and the generator shaft. The picture to the right of the table is a capture from the ODS animation showing the vibration pattern of each shaft and the relative motion between shafts at 3,600 cycles per minute (turning speed).
Many machines vibrate due to deteriorated foundations, looseness, the resonance of the support structure, and other problems that occur below the machine bearings. A phase study might include hundreds of test points measured all over the machine and foundation. Good ODS software can make it easier to analyze phase and magnitude data from a large number of test points. Analysis of an ODS involves observation and interpretation of the machine in motion.

Q: Will coupled drive and belt drive systems show up the same on the spectra?
A: Yes, vibration data on a belt drive system will look different from a coupled drive but not when looking at the common defects of a machine. For example, the vibration data on a belt drive motor will show additional vibration below turning speed due to the belts. The common defects such as imbalance, looseness, and misalignment (to name a few) will show up the same on a belt drive system or a coupled drive system.

Q: In the below spectrum we see a looseness, do we need to correct first the looseness before the misalignment?

A: When looking at vibration data there is always more than one issue showing within the vibration data. I suggest correcting the highest amplitude vibration issue first and the second issue will usually decrease in amplitude. For example, on this vibration spectra, I would suggest correcting the misalignment issue first. The misalignment is the root cause affect of the looseness. Once the misalignment issue is corrected the looseness issue will not be seen on the spectra data.

Q: Will this show up in both horizontal and vertical or is it predominately just one or the other?
A: The answer is that an alignment issue will show up in both the horizontal and vertical orientation when collecting vibration data. Of course, depending on the type of misalignment the horizontal or vertical orientation could be higher. Once a single orientation has a high amplitude level of misalignment it will cross over into the other orientation as well. Of course, if the alignment issue has a small amplitude level it might only be noticed in a certain orientation and again that depends on the type of misalignment that is present.

Q: How can vibration analysis instrumentation be integrated into a building’s BAS computer system?
A: There are generally two different vibration programs that exist in a plant. One would be walk around data collection. This is where a person goes out and places a sensor on a machine to collect the vibration data and then transfers that vibration data in a database. The second would be continuous monitoring where sensors are permanently mounted to a machine. Vibration data is collected every minute or less depending on the need. The walk-around vibration database does have a SAP export feature that would allow you to export certain data from the database over into your system.
In most cases continuous monitoring is best to feed data into another system. We have customers that use our continuous monitoring devices (online systems) to feed into their SCADA systems. This allows for an overall value of 4-20 MA signal to be sent across into another system. Now the other system, like the SCADA, can now alert if certain levels have been reached.

Q: What vibration is typically associated with a damaged impeller or damaged fan blade?
A: The vibration associated with a damaged impeller or fan blades is called vane pass frequency. When looking at the spectra vibration data you would be interested in the number of vanes or impellers that are on the machine. For example, if you had six vanes the vibration data would show a peak in the spectra data at 6 times turning speed, 12 times turning speed, 18 times turning speed, 24 times turning speed, and 30 times turning speed. Depending on the frequency maximum for your spectra would determine how far out the vane pass frequency would occur or be seen.

Q: When we laser align our mechanics say they can’t keep their coupling gap correct. What is a good method to laser align and maintain the coupling gap at the same time?
A: There are two kinds of coupling gaps we have to keep in mind when aligning a machine. The first is the simple gap difference between the coupling faces arising out of any angular misalignment between the shafts, and the second is the axial installation gap specification and tolerance that is demanded by the manufacturer of the coupling.
Typically, you rough align the machines and then set the installation gap of the coupling before you completely tighten it down. If the hubs are shrunk fit, then you guide yourself by the position of the hub on the shaft ends and hope your holes in the base are drilled in the right place when your machines are set down. The correction of any misalignment (angular and offset) typically will never affect the installation gap by enough to make any difference, since we are talking about changes to angularity in thousandths of an inch, whereas the installation gap may have a tolerance of as much as a quarter-inch in or out. So I’m not exactly sure what your mechanics are concerned about. With a good laser alignment system, you perform both angular and offset corrections simultaneously, and the axial gap between the couplings is not a concern.

What if you could reduce machinery alignment time from 4 hours to 2 hours? What if you could improve the average alignment from 9 mils to 3 mils? What if your Meantime Between Failure (MTBF) could be increased from 30 to 34 months, 13% (very conservative)?

Consider this: A plant with 200 machines at an average of 30 HP and a Mean Time Between Failure (MTBF) of 30 months are aligned using dial indicators. With the same conditions and a ROTALIGN® ULTRA or OPTALIGN® SMART laser alignment tool, the following savings could be expected to occur:

• Power: $7, 125
• Repair Costs: $18,823
• Labor: $15,040

A total of over $40,000 per year!!!

Contact us today to see how Laser Alignment can increase reliability and productivity at your shop or to request your Return On Investment Study.

You have invested in a high-precision laser shaft alignment system or vibration data collector/analyzer. Why? Because you want more accurate alignments and vibration measurements, done in less time.

But, what if some incident rendered your tool less accurate, or even wrong altogether? If accurate measurement and tight tolerances are key to your vital processes, this would be a grave concern. Proper operation of your critical machinery or safety systems depends on excellent alignment with low vibration under running conditions.

Perhaps your tool was subjected to temperature extremes, or you dropped your laser or sensor, and even though they are shockproof to the IP-65 standard and didn’t break, they are now out of calibration? What if you are trending data for preventive or planned maintenance, and two different tools used for the same measurement significantly disagree? Only a NIST traceable and certified calibration verification can ensure that your systems are working as designed and within tolerances.

Our highly accurate NIST-certified calibration verifications are performed within a 48-hour turnaround time under tightly controlled conditions to NIST standards in a climate-controlled laboratory. For our laser alignment systems, a biennial check (every two years) is recommended. For vibration data collectors and analyzers, a biennial check is recommended also, or whenever the instrument informs you that one is due.

PLANT SERVICES • JULY 2011

Misaligned pumps can affect energy efficiency
Align pumps with laser accuracy.
By Heinz P. Bloch, P.E., Process Machinery Consulting

In brief:

• Intern approaches pump laser alignment with laser accuracy.
• Tips to compare the energy wasted by a hot coupling to the energy loss.
• Misalignment affects bearing load and excessive bearing load causes exponential decreases in bearing life.

In the summer of 1994, Jack Lambley, an intern at Imperial Chemical Industries’ (ICI) Rocksavage site in the United Kingdom, was quantifying the effect of misaligned process pumps on power consumption. He arranged to have a surplus pump overhauled and fitted with new bearings. He then had the pump installed in a suitably instrumented closed-loop arrangement operating on the water. Prüftechnik loaned Lambley a laser-optic alignment instrument.

As an undergraduate student, Lambley had learned that misalignment affects bearing load and that excessive bearing load causes exponential decreases in bearing life. His supervisor, Steve Moore, had asked Lambley to read the engineering sections of SKF’s general catalog, which stated that a 25% increase in bearing load cut its rated life in half.

Continue reading “Misaligned pumps can affect energy efficiency”

Hot alignment checks are often unsuccessful because of delays in installing measuring devices on the equipment which has just been shut down.

Even when good planning and organization allowed you to take readings within minutes of the shutdown, these readings only address the so-called “Thermal Growth”. Often the effects of thermal growth on alignment had been calculated fairly accurately and the “hot alignment” check confirmed them, but still, excessive vibration persists and continues to be traceable to misalignment.

The problem is that machinery moves during operation for reasons unrelated to thermal effects.

Dynamic rather than thermally induced movements may cause machinery to operate misaligned. Since these dynamic effects disappear before the machinery stops rotating, hot alignment checks cannot measure them.

The non-thermal moves, both vertical and horizontal, are often as large or larger than the thermal moves but much more difficult to calculate. In our experience, dynamic moves are usually ignored.

These movements can be caused by foundation problems, pipe strains, and stresses, loose anchor bolts or changes in the load, etc. Whatever the cause or causes, almost the only way to determine the movements is through continuous computerized monitoring of the alignment.

When coordinated with records from the control room it often becomes clear why and how the machinery changed position. Proper “cold” alignment targeting thus becomes feasible and significant operational improvements are usually achieved.

Aside from the well-known consequences of less wear on bearings, seals, couplings, etc., it is sometimes possible to increase the load for the equipment, and last but not least, power consumption will reduce and result in savings which are a multiple of the cost of the monitoring equipment.

Several monitoring systems have been on the market for many years using dial indicators or proximity probes, etc. and now, fully automatic laser systems like the PERMALIGN® and the new Rotalign® Ultra LIVE TREND are available with suitably large measuring range.

Every asset-intensive organization understands that the greater the uptime of machines, the more efficient and cost-effective operations will be. Keeping your assets in optimal working order is easier and more cost-efficient when advanced technology such as laser shaft alignment is used to increase machine reliability.

The Machine Maintenance Goal

One of the goals of every production-oriented operation is to keep its machines operating at the lowest cost yet highest productivity levels. In order to do so, proper maintenance must be performed on machines. The level of maintenance care of machines can be broken down into four major categories:

1. Purely reactive or run to failure
2. Basic preventive maintenance and inspections
3. Combination of predictive maintenance methodologies and preventive maintenance
4. Organizations making use of preventive and predictive maintenance as well as advanced technologies such as laser shaft alignment, vibration analysis, infrared thermography, etc.

At the heart of most good maintenance operations is a CMMS system that records and tracks all asset detail and maintenance work information. The premise of a CMMS is that the more asset and historical work information you have, the more efficient and effective your maintenance planning will be.

Why Shaft Alignment Technology is Necessary?

A natural extension to using a CMMS is the use of advanced shaft alignment technology because it adds valuable information regarding the condition of the machines that might otherwise go undetected until machine failure occurs.

Typical signs of misalignment include:

• Abnormally hot components, the smell of burning insulation
• Bearing issues or grinding noises
• Higher energy usage
• Load imbalances
• Rotor bar problems
• Excessive vibration

One proven method for machinery alignment is laser shaft alignment. With up to 50% of damage to rotating machinery directly related to misalignment, correcting this problem in machines is critical to production as well as operating budgets. But these are not the only reasons:

Top 7 Reasons to use Laser Shaft Alignment

Laser shaft alignment can lower your operating costs through:

1. Early identification of problems enables machine maintenance to be proactive.
2. Reduced maintenance cost as a result of sharp reductions in bearing, seal, shaft, and coupling failures.
3. Reduced vibration lengthens the useful lifecycle of the machine as well as increases the quality of output.
4. Less unplanned downtime so production can be optimized.
5. Fewer emergency repairs lowering labor costs.
6. Error-free and accurate measurements to 0.0001″.
7. Reduced energy consumption. Poorly aligned machines require more energy to achieve the same results as a well-aligned asset.

Who Can Benefit from Laser Shaft Alignment

Laser shaft alignment can be used in any industry ranging from manufacturing to the wind power industry that depends on machinery to function. Machinery alignment is a cost-effective solution whenever critical functions are at risk. Some examples include, but are not limited to:

• Processing and centrifugal pumps used by the petrochemical industry
• Boiler feed pumps are found in every power plant and also in general industry
• Vertical turbine pumps found at water treatment plants
• Refrigeration compressors used for food processing and cold storage

Protecting your machines through precision shaft alignment is not an option, it is a must in today’s competitive environment. Old dial indicator technology may have too low a resolution to measure accurately enough and are subject to reading errors and hysteresis or sticking dial hands. On the other hand, laser shaft alignment is error-free with reports generated directly from the instrument in conformity with ISO 9001 requirements.

“7 Reasons Why Machines Need Laser Shaft Alignment” was written for us by Stuart Smith, MBA, MS. He is an avid writer about CMMS and EAM software solutions for Mintek Mobile Data Solutions. Stuart has over 25 years of experience running operations in multiple industries.

Have you ever been forced to check for soft foot when your brackets were less than 10 inches apart and the MTBM’s supports were several feet distant? If you answer yes to that question or if you have ever made foot corrections under similar circumstances, then resolution matters to you.

Resolution: The smallest detectable increment of measurement.
Synonyms: sensitivity, fineness

For laser shaft alignment systems mounted on a pair of shafts, the resolution is the smallest movement between the two shafts that the electronics can detect. On all systems LUDECA sells, this value is 1 micron (.00004″) or better. Typically, for any measurement system to be accurate, it must have a resolution at least four times better than the minimum increment of value it is designed to display, and for a “precision” measurement instrument, this ratio should be ten times or better.

Linearity: The closeness of a calibration curve to a straight line. Having output directly proportional to the input.
Synonyms: Straightness, direct proportion.

For a laser shaft alignment system, linearity is easy to evaluate. A graph of the known position versus the displayed value should be a straight line. If it is, we say the system is linear. Our products are linear to one percent.

Repeatability: The ability of an instrument to reproduce displayed values when the same input is applied to it consecutively under the same conditions. Repeatability is expressed as the difference between two or more sets of measured values when given identical input positions of the sensor(s).

Reproducibility: The ability of the experimenter (user) to reproduce or duplicate the conditions of an experiment or measurement.  Reproducibility and Repeatability are not the same, but Repeatability (of measurement results) depends on Reproducibility. For instance, if the anchor bolts are loose and the machine moves on you as you are turning the shafts to take alignment readings, your readings will not be repeatable, although they may be accurate for the conditions extant at each reading.

Accuracy: The ratio of the error in measurement to the ideal, or expected, value. How close a result is to the true value of the parameter being measured.
Synonyms: deviation, error, how close a value is to be correct or true.
Accuracy is how close a measuring system comes to measuring the truth. For specific measurements or specifications, the term error is used and is expressed either as a percent of full scale or as an absolute value. Accuracy is adversely affected by non-linearity, non-repeatability, poor reproducibility, and poor resolution.

This question is of importance because there are now a number of alignment systems on the market, using different methods. To answer, ask yourself the question: What do I want to accomplish? You want to bring offset and angularity within tolerance.

Rim & Face measures the offset through the RIM reading and measures the angularity through a face reading which can easily be inaccurate if the diameter at which it is measured is small such as 8″ or less, or even wrong if the shaft floats in or out during the measurement.

The reverse Indicator takes two rim readings which establish the offset and compute angularity from the difference in these offsets. It is not affected by moderate shaft float but is only accurate if the distance between the measuring devices exceeds 8″. Also, accuracy is dependent on measuring resolution which in the case of laser systems should be at least 5 microns if you expect to see improvements over normal dial indicator readings.

Offset & Direct Angle: Since offset and angularity are what you were out to measure, obviously a system measuring the RIM and DIRECT ANGLE is best, particularly if it also has a measuring resolution of 1 micron (.00004″) like our SHAFTALIGN®, OPTALIGN® SMART, ROTALIGN® ULTRA laser alignment tools.

June 2011 • TPO Magazine

ACING IT IN OKLAHOMA

Strong skills, preventive maintenance and good planning lead to success at the Coffee Creek Treatment Plant in Edmond.

The Coffee Creek Wastewater Treatment plant in Edmond, Okla., has had near-perfect compliance for 38 years and has won several awards, most recently 2010 Large Wastewater Plant of the Year from the Oklahoma Water and Pollution Control Association (OWPCA).

It all has happened with a staff of five, despite rapid population growth, several upgrades, and various episodes with collection system inflow and infiltration. “When you have only five staff, you have to focus on working smarter, not harder,” says Fred Rice, water resources superintendent for the city. This means preventive maintenance, SCADA monitoring of critical alarms, and ongoing equipment and safety training.

It’s also a matter of teamwork. Kris Neifing, chief plant operator, hired in 2004, supervises two operators, a maintenance specialist, and a lab technician, and is also responsible for one lift station at the plant and nine lift stations located throughout the collection system.

Rice credits Neifing and his staff for the plant’s track record. “Kris has really pulled everyone together as a team,” he says. “All the credit for what we’ve achieved in the last six years is due to Kris and his staff. My role is like coaching a sports team. You can coach them, but the team executes the plays.”
Says Neifing, “What makes us successful is that everybody has different skills that collectively make us the best we can be. Some are better at maintenance while others prefer operations. We believe that no one knows how to do their jobs better than the ones who do it every day.”

Continuous improvement

The plant’s compliance and safety record do not mean the staff is complacent. “We strive to continuously improve,” says Rice. “There is no process out there that can’t be improved, especially on the maintenance side.”
Rice and Neifing frequently attend the WEFTEC conference and other trade shows to check out the latest equipment. This has led to several innovations, such as vibration analysis and laser alignment equipment to help ensure that pumps and motors operate normally with the lowest possible maintenance. Rice and Neifing also read trade journals and network with others in the wastewater treatment business to glean ideas.

“The staff comes to us with ideas, like getting air compressors for maintenance, and suggesting better equipment or ways of doing things,” Neifing says. “We empower them to make suggestions, and we listen.” Adds Rice, “The city started a program based on the general concepts in the Good to Great book because we believe that organizations that excel are successful from the ground up. We give our employees responsibility and then hold them accountable.”

Read the entire article Acing it in Oklahoma

When craftsmen are given the task of laser alignment, quite a few assumptions are made. One very common assumption is that now that a laser system is being used, anyone can do an alignment. Another is that since a laser is being used, everything is alignable. Put a laser system on an unalignable machine and you will still have an unalignable machine, only with an expensive laser alignment system attached to it. A laser alignment system does NOT guarantee that a machine is alignable!!! (Actually, all machines are ultimately alignable, if only you throw enough time and resources at them- perhaps an entirely new base or foundation is needed, and/or redoing the entire piping. The question is, is it worth it in some cases? The point is, that just because you put a laser on a machine, that does not make it instantly alignable, vanishing all other problems.)

However, a laser alignment system, combined with a skilled and trained craftsman and a good alignment procedure, will greatly expedite alignments and help determine if a piece of equipment is alignable at all. The following is a tried and true procedure that will greatly expedite alignments.

Pre-alignment checks are critical in ensuring successful alignment. All surfaces should be clean and burr-free with metal-to-metal contact between the feet and shims, and the shims and base. Shim packs should be consolidated to three or four shims per foot. Jackscrews should be installed. A concentricity and runout check should also be done on the coupling and shaft. It is also a good practice to check the base for flatness.

The next step is to accomplish a rough alignment. Use whatever method that you prefer to get the machines reasonably close, or “eyeball” clean. A straightedge will work on some couplings in short-coupled machines. On machines with spacer couplings, the laser and a tape measure can be used very effectively. The purpose of this step is to remove gross misalignment and ensure that the laser and detector are in line enough to take readings. (Note that the best laser systems offer range extension so even rough alignment can easily be done with the laser.)

After your rough alignment has been accomplished, a rough soft foot check is in order. Eliminate any obvious rocking and fill any obvious gaps. This should be done with all hold-down bolts loose. Now it is time to use your laser alignment system. Make sure that all required dimensions are entered accurately and that initial alignment measurements are repeatable. Assuming you still have a rough alignment, a final soft foot check is in order.

Follow your laser system’s recommendations for this. The ROTALIGN® ULTRA even features a comprehensive soft foot wizard that guides you through the entire process, diagnoses the condition, and suggests a solution. After any corrections are made, retighten all hold-down bolts, then recheck each foot individually with all the others tight.

We recommend a tolerance of 2.0 mils or less. Now for the final alignment: The first correction that should be made is getting the vertical plane in tolerance. When making shim corrections, monitor the horizontal plane to make sure your machine does not move laterally too much. Once you are satisfied the vertical alignment is in tolerance, proceed to final horizontal corrections. Leave the hold-down bolts snug (not tight). They do not need to be all the way loose to make effective horizontal moves. This is where good jackscrews become invaluable, Try to avoid hitting machines with hammers. When the machine is within tolerance alignment is complete. Save the alignment file for documentation and future reference.

Many years of involvement with machinery alignment reveal that this is the best and fastest procedure for precision alignment. Each step is necessary and important in accomplishing the next step. Take your time and be diligent and you will succeed in your alignment.

May 2011 • MAINTENANCE TECHNOLOGY

Cardan Shaft Alignment: These applications aren’t as straightforward as others. Their special considerations call for special tools and approaches.

A Cardan shaft is, in the simplest terms, a spacer shaft with a universal joint coupling on each end. (Its name comes from a 16th-century Italian mathematician, Girolamo Cardano.) This type of arrangement allows power to be transferred between two machines that are offset from each other.
Widely used in industry, Cardan shafts have proven practical in applications where space is limited—as well as in situations where an element in the machine train (e.g. paper roll) may need to be actuated (dynamically positioned) to an alternate position when the machines are not running. The universal joint allows for limited movement without uncoupling. To ensure sufficient lubrication circulation, which in turn prevents the universal joints from seizing, Cardan shafts are normally installed with an angle from 4 to 6 degrees at the universal joints. Experience, though, has shown that the angle between the shafts of the driver and driven unit should be kept to a minimum, preferably less than 4.36 mrads (0.25 degrees). Ideally, the angles between the driver and driven shafts and the Cardan shaft, shown as ?₁ and ?₂ in Fig. 1, would be equal. Geometrically, this would equate to zero angularity existing between the driver and driven unit: In other words, the shafts of the driver and the driven machine would be parallel to each other.

Read the entire article Cardan Shaft Alignment featuring the ROTALIGN ULTRA laser alignment tool suited for cardan-shaft applications.

Some coupling manufacturers will sell couplings claiming that the coupling can take shaft misalignment. While this is true for most flexible couplings, it can be easily misinterpreted. Flexible couplings are designed to withstand, without damage, some shaft misalignment. Sometimes it is perceived that, since the coupling can take the misalignment, the machines can run under this condition without any consequences. When running machinery with significant shaft misalignment, bearing and seal life may decrease immensely, and other damage results. Therefore, for longer machinery life, it is always recommended to have equipment laser aligned to standard industry tolerances for shaft alignment, and not to the looser alignment tolerances allowed by the coupling itself.

Learn about Shaft Alignment Tools with Built-in Tolerances. 

As the Project Manager for the Millwright Competition and a member of the 2011 ABC Craft Championship Committee, I want to thank you and your company for your support for the Millwright competition.

Even though I have never used that particular laser, it was very easy to use and only took about five minutes to become very comfortable with it. None of the competitors had used the SHAFTALIGN® prior to the competition, which was great. It only took about twenty minutes to show them how it operated, including thermal growth, soft foot, and static feet selection. Even though the competition required an 1800 rpm alignment with thermal growth, one of the competitors did a 7200 rpm alignment within the time limitation, which would never have been achievable with dial indicators.

I am proud to say that with your help and equipment this competition has finally evolved into a modern competition. Your alignment equipment is easy to install, easy to use, and accurate. It is the best alignment equipment that I have ever seen.

Again thank you for your support.

Ed LePage
Mechanical Craft Training Coordinator
CIANBRO Institute
Congratulations to Joseph Ducharme, the first-place winner.

March 2011 • IMPO MAGAZINE, iPurchase Supplement

As the American economy recovers, how aware, or active, are manufacturers concerning predictive maintenance?

Most manufacturers never lost the desire to increase their overall reliability and predictive maintenance efforts during the recent economic slowdown.  Some companies did postpone purchases of predictive maintenance-related products.  However, a lot of companies realize that an investment in predictive maintenance technologies is a viable means to decrease overall maintenance expenses, so they do it the right way.  A lot of manufacturers, as a result of this understanding, continued to invest in predictive maintenance-related technologies during the recent economic slowdown.  This allowed them to reduce overall maintenance costs and place their company in a more competitive position once the economy recovers. Interest in these products is higher this year as companies continue to invest in vibration- and alignment-related products to reduce their costs. increase competitive advantages, and manufacture equipment reliability.

Read the entire interview Q&A Roundtable from iPurchase, a supplement from IMPO Magazine including:
Are there any interesting trends occurring in the maintenance market?
Why do you think laser alignment is important to a manufacturer’s maintenance strategy?
How would you recommend a manufacturer approach the creation of a more robust maintenance plan?

WaterWorld Magazine • February 2011

A Florida water treatment plant recently discovered that having full-flex (double engagement) gear couplings at either end of a spacer shaft connecting a Lufkin gearbox to a 13, 000 GPM Worthington water pump caused self-exacerbating vibration that eventually destroyed the gearbox twice within 3 months, requiring a full rebuild each time. After the second rebuild and re-installation, LUDECA was called in to monitor positional changes between the stopped and running conditions of the entire diesel engine-driven machine train with its PERMALIGN® system to derive true target specifications for the “cold” condition. Thereafter, a laser re-alignment to exact tolerances would be performed to the new targets…

Read the entire case study and view photos

Problem: Exhaust fans
The exhaust fans at two of our process buildings kept having the same common faults (failed bearings, failed motors, and running hot.). We spent over $4, 400.00 on one fan from 2008 to 2010 and over $5, 600.00 on the other fan on parts alone.

Solution: Purchased an OPTALIGN® SMART EX laser alignment system
In July 2010, we received our new OPTALIGN SMART EX and had LUDECA come in and give us an introduction introductory training course. After a few trials on using the laser alignment tool on a motor and pump that we set up in the shop, we were ready to take it out in the field. We went and set the tool up on our two exhaust fans and found out there were way out of alignment. After a few tries, we had smiley faces on both machines in the horizontal and vertical directions. Since the alignment, we haven’t had any more problems with either fan. The OPTALIGN SMART EX is very user-friendly and well worth the money.

Now we have incorporated the OPTALIGN SMART into to our PM program to check the alignment on all rotating equipment as they come up for a PM. In the last few months we have been using it, we are getting good feedback from the maintenance department on how easy it is to use and how much time is saved, instead of doing it the old way (dial indicators). —Bryan Brown, PM Technician with MARTEK Biosciences in Kingstree, SC.

1. Functionality: Do the Predictive Maintenance (PdM) tools you are considering have the ability to make all the measurements required by your physical asset management strategy? Are displays easy to see and interpret? Are the tools easy to learn and easy to use? Learn about our PdM tools. For Software, can it interface with your CMMS system? Can you import data from other systems such as oil data? Learn about our OMNITREND software.
2. Durability: Will the tools hold up to your plant’s environment? Are they rugged enough for multiple users? IP ratings such as water–, dust– and shockproof are very important when dealing with industrial tools.
3. Service: Will your vendor be available to answer questions or address problems should they arise? What is the vendor’s reputation for customer service? If you have a problem with a tool how soon can you expect a “loaner” until yours is repaired? Are the tools repaired and/or calibrated locally? Learn about LUDECA Repair and Calibration.
4. Training: What are the training costs associated with learning how to use the tools? Is training included with the purchase? What training resources are available? Learn about LUDECA Training.
5. Support: What level of support do you need? Does the vendor have a call-in tech support center, is it free or paid? Will the yearly costs of maintenance agreements make the tools considerably more expensive than competitors’ tools having similar capabilities? Do they offer free updates? Learn about LUDECA Technical Support.

Pumps & Systems • January 2011

Aligning an electric motor coupled to a large air blower required multiple measurements.
Around 18 years ago, a client needed assistance aligning an electric motor (more than 1, 000 horsepower) coupled to a large air blower. This was a critical piece of equipment that was routinely shut down for preventive maintenance at regular intervals to ensure trouble-free operation. The mechanical contractor used for this alignment was reputable, and the customer had used him several times in the past for this task with satisfactory results.

Vibration Problems
Upon startup, vibration levels were so high that the package tripped and shut down before reaching full rpm, preventing any meaningful collection of vibration data to help identify the problem. This continued for two days. Convinced that the problem was alignment-related, the contractor made multiple corrections with the same results. Every time the package was started, vibration levels were high, and the package shut down before reaching full rpm.

Laser Shaft Alignment Assessment
The client requested that a shaft laser alignment system be used to ensure correct alignment. The motor and the blower were uncoupled, and all the hold-down bolts were at spec. Initial readings were taken. Remember, this was more than 18 years ago, so the alignment system was a much less sophisticated system than those available today.

Read the entire article Measure Twice, Cut Once!

Machinery Lubrication, September • October 2010

In his book “Machinery Vibration: Alignment”, noted author and expert on precision alignment Victor Wowk illustrates the relationship between misalignment and loss of machine life. Of course, some equipment is more or less tolerant to misalignment depending on bearing type and coupling type. Likewise, the effects of misalignment are magnified as a function of speed.

Read the entire article Shaft Alignment has a Bearing on Lubrication Excellence