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As stated by Daniel Keys Moran, “You can have data without information, but you cannot have information without data.” The driving factor for any reliability program is data; but how do you gather and record the right data to achieve your maintenance and reliability goals? By documenting and generating clear reports with the necessary data. This will permit statistical trends to be developed that can improve uptime and productivity as well as justify repair or replace decisions.

First, let us look at what information should be gathered and documented, followed by how and where you should store the data so that you can use this data over time to develop trends and Key Performance Indicators (KPI’s) to drive your reliability program forward. Harness the data coming out of your maintenance operations and turn it into actionable information that will make a difference in the way you work and what you accomplish.

What data should be captured?

The following list describes the equipment and information that is necessary to make informed decisions and drive the improvement process forward in a maintenance program:

  • Instruments used for measurement
  • Person(s) completing the task(s)
  • Description of the asset
  • Date and time
  • Tolerance requirements
  • As-Found and As-Left measurements
  • Reference to the standard used
  • Appropriate signatures

 

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Where should my data be stored?

Now that we’ve assembled the needed information, we need to store this data in a way that we can easily access it and refer back to it to identify problems and develop solutions. The preferred storage location should be within your company’s CMMS (Computerized Maintenance Management System.) If your CMMS is configured properly, you may be able to store the As-Found and As-Left measurements directly in the work orders to trend them, thereby allowing the CMMS to automatically create work orders when an asset is out of tolerance. The next alternative is to link the report to a work order and/or asset, allowing the information to be easily accessed within your company. If you don’t have a CMMS, another option is to create a folder structure on a shared drive where the reports can be saved. Keep in mind that there should be a consistent naming structure that is followed by everyone with access to the shared drive so the reports can be ordered correctly and easily located. This will require some training.

What are the Key Benefits?

The goal of any maintenance organization should be asset management with the equipment operated and maintained in a cost-effective manner. Creating detailed reports starting from when the equipment is first installed and continuing throughout the life of the asset allows you to predict when failures may occur so that you can effectively plan and correct the issue in the most efficient manner, in advance of an unplanned failure. With the right data gathered and properly stored, organizations can analyze and develop maintenance strategies to ultimately increase equipment availability, decrease production downtime and generate greater profits for the company. These detailed reports allow communication between operations and maintenance and drive continual improvement throughout the organization by identifying, mitigating, or preventing losses. Ludeca provides a wide range of reliability technologies that generate detailed reports that can be easily shared within an organization to help you Keep it Running.

Visit our Knowledge Center for resources and tools to help you succeed when implementing and using our maintenance technologies! Watch our video tutorials, download infographics, plus explore other helpful information to reduce equipment failures and downtime. 

by Diana Pereda

Belt Pulley Alignment

Belt-driven rotating equipment is commonly found in all types of facilities. Typical applications include rolls, fans, motors, shafts, and blowers. It is important to maintain that equipment in order to increase its reliability. Maintenance is essential in today’s industrial environment to ensure assets and equipment are running as reliably as they should.

Like any part that can wear over time, belt-driven equipment should be periodically inspected.  This includes the inspection of the pulleys, sheaves, and belts. Worn belts and sheaves should be replaced. Belts should be properly tensioned and the equipment aligned.

It is important to have quantitative values so that the condition of the machine can be evaluated and monitored over time. One way this can be accomplished is through ultrasound and vibration readings. Another value that can be quantified is alignment and belt tension. Belt tension is commonly quantified by force and deflection and determined during the installation of a new belt.

Pulleys and sheaves be should be properly aligned. However, the most common methods rely on pass/fail methods.  This includes straight edge and visual laser guides. While they are better than not performing an alignment check, how does one quantify the degree to which the alignment is accomplished?  In the same way that it is important to quantify shaft alignment, belt alignment should be quantified as well. This supplies numerical information which the reliability engineer can trend and decide the condition of, in order to plan, rather than react to a maintenance operation.

Our Easy-Laser XT190 belt alignment tool can carry out this task and supply numerical values for the current belt alignment condition. A laser transmitter and receiver are placed on the sheaves and pulleys to be aligned. The results are instantaneously projected through the iOS and Android app to supply the current alignment condition in real-time as well as the required corrections. An added benefit is that the users typically only need to access each pulley without having to pull the entire coupling guard off (provided proper lock-out and tag-out procedures are followed). With this advantage, one does not need to visually figure out the alignment as it is all displayed in the app.

The result is that alignments take less time and the reliability engineer can have quantitative data to decide the current and trending alignment condition. This one tool can help move belt-driven rotating equipment from the reactive maintenance stage to the planned and eventually to the precision domain.

Download our Pulley Alignment Guide Plus 5-Step Procedure for information on the implementation of good pulley alignment of belt-driven equipment including terminology, alignment methods, belt maintenance, storage, and tensioning as well as a 5-Step Sheave/Pulley Alignment Procedure.

by Diana Pereda

We previously discussed in our series of soft foot, Types of Soft Foot: Part 3 Squishy Foot. In this follow-up blog, we will discuss Induced Soft Foot.

What is induced soft foot?

Induced Soft Foot: Occurs when stress-induced external forces such as pipe strain, electrical connections, or severe misalignment combined with a stiff coupling pull or push on the machine creating a distortion of the frame.

The precise alignment of rotating machinery is affected by many factors and components. From the very foundation the equipment is mounted upon to the equipment itself, and extending to anything connected to the machine. Because of the tightness of the tolerances that are aimed for during these alignments, it takes little to put stress on a machine.

In rotating equipment, the internal alignment of the bearings that hold the shaft in place is very precise. As we’ve seen in this series the mating between the feet and mounting surface can stress these internal components and clearances. What else can cause internal misalignment of the bearings?

Condition 4: Induced Soft Foot

  • Caused by external forces such as pipe stress, coupling strain and strain from conduits and braces.
  • Correct by removing any external forces on the machine.

Soft Foot - Induced Picture

Download our Soft Foot Find-and-Fix Infographic which outlines the of types of Soft Foot including causes and corrections.

by Diana Pereda

When performing shaft alignment, the best way to accomplish the horizontal (side-to-side) corrections is using jack bolts. You do not want to hit your machines with a hammer in order to move them. Always remember to back off the jack bolts on the opposite side. Remember that once you are done with your side-to-side correction, we recommend that you always back off all jack bolts after the alignment is completed and the anchor bolts are tight.

Where to put the jack bolts on your machine?

Place the jack bolts in such a way that they do not interfere with the shimming and allow you to pivot the machine you are moving. See figures 1 and 2 below.

Correct positions of jack bolts

Picture1-jack bolts
Figure 1
Figure 2

The picture below shows the jack bolt “not in a good position”—it will interfere with the shimming.

by Diana Pereda

Belt Alignment job on Motor & Pump

Belt driven machines are the Rodney Dangerfield of the maintenance industry – “they don’t get no respect!” For example, look at the image below. Belt driven machines do need a little bit more TLC than they currently get. I want to show you two innovations that will greatly improve your maintenance efforts on these highly efficient drives. I also want to show you why the general way in which we work with belt drives is a good example of what keeps reliability unachievable for many.

Belt Alignment

First let me say that there are some individuals/organizations who really understand the value of doing this work right. I am reminded of a gentleman called Gary Burger who wrote a very good article on improving the efficiency of belt drives.  He says that he “expects to get three to five years from a belt that is running 24/7.” And I believe he gets that, and you can too. Keep in mind that this is not a roof fan that will spin forever, this is a working machine that needs sizable horsepower to turn it over.

The reason I say these drives do not get the respect they need is experience. Like many of you, I have seen belts pried off, then a new set pried on. I have seen large sheaves installed with air guns and never checked for runout, so they vibrate in the axial plane. I have seen string used for alignment or a length of angle iron from the steel rack used as a straightedge for alignment. I have seen air guns used to tension a belt so tight that the belt would not defect, even if you walked on it. And belt dressing, which was used a can at a time to try and stop the belt from squealing. All of these are not acceptable if you had planned on doing the job right. The first time.

What is Belt Misalignment?

The number one reason why belts fail prematurely is heat. Heat dries the belt out which leads to cracking and slippage and the end is not far off after that. The heat is from friction caused by misalignment. To correct misalignment, we must correct the offset and angle errors in both the Horizontal and Vertical planes.

Belt Misalignment

The first belt shows angular misalignment in the horizontal plane (toe-out and toe-in). The second belt shows parallel (offset) misalignment in the horizontal and vertical planes. The third belt shows a combination of angular and parallel (offset) misalignment in both planes. This is what we are normally trying to correct.

One of the reasons why it is difficult to correct this misalignment is because you are constantly correcting the alignment as you tension the belt. If you have ever worked with an adjustable motor base that has one central adjusting bolt allowing the motor to pivot as you tighten it, it is a challenge, to say the least. These bases are lightweight, flexible, and cheap. The inexpensiveness is why they are used but there is a hidden cost. You do a lot more maintenance work with this type of base so there is no saving.  The frustration comes from the fact that you are unaware the bases are flexing until it’s too late. This is because it is not something you can see by eye when using a straightedge to align the sheaves. You still must compensate or adjust the alignment as you tension the belt. Download our 5-Step Sheave Pulley Alignment Procedure which provides a simple and effective procedure for sheave pulley alignment of belt-driven equipment. 

Click here to read the entire case study: “It’s About Time We Treat Our Belts & Sheaves With More Respect”

Thank you John Lambert with Benchmark PDM for sharing this educational article with us!

by Diana Pereda

We previously discussed in our series of soft foot, Types of Soft Foot: Part 2 Bent Foot. In this follow-up blog, we will discuss Squishy Foot.

What is squishy foot?

Squishy foot: also known as spring foot, occurs when the gap between the foot and base has already been filled with an excess of shims to correct a soft foot problem.

Proper preparation for a shaft alignment job is essential to success. Inspect the machine components and hardware and ensure the environment is free of any rust, dirt, debris or paint. The above steps are part of the pre-alignment check detailed in our 5-Step Shaft Alignment Procedure and should not be overlooked.

Condition 3: Squishy Foot

  • Caused by compressible material under the feet of the machine.
  • Too many shims can also be the culprit. Try to have four or fewer shims under each foot.
  • Proper cleaning of the environment and use of new crush resistant shims will eliminate this condition.

 

 

Soft Foot - Squishy Figure 3C

Watch our Shaft Alignment Know-How: Soft Foot video to learn about the effects and importance of measuring and correcting Soft Foot when performing shaft alignment.

by Diana Pereda

A few things that should always be inspected during belt PM’s are:

  1. Inspect grooves for V-belts for wear using a sheave gauge following supplier recommendations.
  2. Rusted or pitted sheaves should be replaced. Otherwise, belt damage/wear and premature failure can easily result.
  3. Shiny grooves should not be overlooked and can indicate heavy wear.
  4. Corrosion on the sheave and especially in the grooves will build up and rapidly wear the belt and result in premature failure. Sheaves should be replaced if corrosion is found.
  5. Bent sides can introduce wear and damage.
  6. Replace all belts and never a single belt. Mixing old and new belts results in the load not being shared evenly and could easily lead to damage, premature belt failure and sheave wear.
  7. The same manufacturer should always be used. In other words, do not mix and match belts from different manufacturers on the same drive.
  8. Noisy belts can be identified using a squirt bottle with soapy water. Spray the belt during operation with the soapy water. If the noise level changes, then the belt is part of the problem. It should be inspected for damage, proper tension, etc. If the noise remains, then most likely the belt is not part of the problem.
  9. Ensure that the sheaves are properly aligned. Misalignment will result in premature wear and damage.
Alignment-Belt-Driven-Equipment
Photo courtesy of Brian Franks with JetTech Mechanical LLC

Download our Belt & Chain Storage Best Practices which has some basics things to prevent belt and chain damage and contamination thus maximize parts life and performance.

by Diana Pereda

From a reliability perspective, commissioning a machine requires precision shaft alignment to the correct tolerances and proper documentation. Ideally, these alignments should be performed using a laser system with built-in ANSI alignment tolerances such as the Easy-Laser XT770 and with the ability to generate a detailed graph report of the alignment, both as found and as left. But what if the technician could do a little more than just the shaft alignment, like checking the overall vibration levels of the machine before and after the work? Pre- and post-vibration checks will reassure you and your supervisor or customer that the job was done correctly.

XT280 Measuring Vibration Overalls

A tool such as the Easy-Laser XT280 makes collecting vibration data from assets like pumps, motors, fans and bearings simple and fast. It displays 1×, 2×, and 3× RPM, total level, as well as bearing condition, providing necessary information for the installation and alignment job.

The XT280 interfaces with all Easy-Laser XT alignment systems but can stand alone if connected to a smartphone or tablet using the Easy-Laser XT Alignment App to generate PDF reports with photos of each measurement point to support acceptance checks after installation and alignment.

XT280 Vibration Overall Values

 

by Diana Pereda

We previously discussed types of soft foot in Types of Soft Foot: Part 1 Parallel Air Gap. In this follow-up blog, we will discuss Bent Foot.

What is Bent Foot?

Bent foot: Occurs when a foot of the machine is deflected or in an angle with regard to the base. However, this also applies to when the base is in an angle with respect to the foot.

When a machine has a soft foot condition, the act of tightening the hold-down bolts will put stress on and distort the frame. This will cause the bearings that hold the shaft to misalign internally, which can cause vibration, out-of-roundness in the bearings and stress on the shaft. Minimizing the effect of soft foot will increase your machine’s reliability.

This condition in our soft foot series is a common one.

Condition 2: Bent Foot

  • Caused by one (or more) machine feet that are bent or angled to the mounting surface. Can also be caused by a deflected base.
  • Feet that are not parallel to the surface will stress the machine when tightened down.
  • To correct, re-machine the feet, base or both.
  • Step-shimming is also an acceptable solution when pressed for time.

Soft Foot - Bent Figure 2B

 

Download our Soft Foot Find-and-Fix Infographic which outlines the of types of Soft Foot including causes and corrections.

by Diana Pereda

The Easy-Laser E970 alignment system makes roll parallel alignment accurate and easy to accomplish.  This application requires that the rolls be parallel to each other in term of skew and level.  In addition, and very important to the application, is to make sure the slitters and guides are aligned to each other axially on the rolls.

Sheet Metal Roll Slitter - Pic1

Should they not be aligned, they will cause forces on the guides, causing the product to be affected during the process.  The E970 system was set up so that the laser was exactly parallel and level to the reference slitter roll, a process that took about 10 minutes.  The laser transmitter was then deflected a perfect 90 degrees for a vertical sweeping laser plane that could be projected down the line.

Sheet Metal Roll Slitter - Pic2

The finding was that the guides were off at some places by as much as 3/8″!  Corrections were made live and the appropriate spacers were installed in order to make sure the guides were in perfect alignment with the slitters.

Sheet Metal Roll Slitter - Pic3

The outcome was that the product produced was of a high quality that had not been experienced on the machine before.  A report was generated directly from the Easy-Laser E970 in PDF for documentation.

by Diana Pereda

What is soft foot?

Soft foot is a common term used for machine frame distortion. The distortion is caused when one or more foot of a machine differ in height from the others.

Soft foot can be frustrating and bad for the health of rotating machinery and the sanity of the technician performing the alignment. Soft foot needs to be corrected in order to achieve a good alignment. When attempting to correct soft foot it is helpful to identify the type of soft foot condition(s) present in the machines. This will allow you to more intelligently approach correcting the defect and get you moving on your way to the rest of the alignment.

In this series we will cover the types of soft foot conditions likely to be encountered during any given shaft alignment job.

Condition 1: Parallel Air Gap

  • Caused by one machine leg that is too short or a base that is not coplanar at all four mounting points.
  • Produces a “rocking” effect as the leg that is located diagonally from the “short” leg is also affected.
  • To correct, simply add shims to take up the gap and remove any rocking effect.
  • Correction is usually made at only one foot, or in rare cases, at both diagonally opposed feet.

Soft Foot - Parallel Air Gap Figure 1

 

 

 

Watch our Shaft Alignment Know-How: Soft Foot video to learn about the effects and importance of measuring and correcting Soft Foot when performing shaft alignment.

by Diana Pereda

When a failure occurs, one of two things happen:

  1. A Failure Analysis program kicks in to figure out what truly caused the failure in order to eliminate the condition that caused that specific failure. Or…
  2. The easiest thing to see gets blamed. That “blame game” can be influenced by factors that have nothing to do with that specific failure, like past experiences, mechanical prejudices (preferring one brand over another), personal differences (doubting another’s workmanship), and even possibly looking to sweep the whole problem “under the rug” to distance someone from that blame.

When it comes to the failure of a crankshaft, or any other component of a rotating assembly, alignment is one of the things often brought up, like a “low hanging fruit”. This is why having a proper procedure, such as our 5-Step Shaft Alignment Procedure is so important. Going through each step of that procedure will help spot and eliminate the defects that could cause the equipment to experience that failure. And once the work is completed, the documentation portion becomes a record of how the job was done in order to help with any Failure Analysis.

Let’s take a look at some failure modes and see what could have caused the issue instead of just saying, “must have been a bad alignment.”

High Bearing wear at the front of an engine with Oil Analysis showing Tin, Aluminum, and Copper

Since this is nowhere near the coupling, alignment would be hard to blame, but there are other things to consider when looking for causes. Do the belts have too much tension? Was Soft Foot or Base Deflection overlooked? Has the Harmonic Balancer failed? Has the engine been reconfigured to run faster than originally rated and not have the supporting parts replaced to accommodate that increase in RPM? The bearings are coming apart and the cause must be found. Download an outline of types of Soft Foot including causes and corrections.

High Bearing wear at the front of an engine

High Bearing wear in the middle of an engine with Oil Analysis showing Tin, Aluminum, and Copper

The problem is getting closer to the coupling so it cannot be ruled out, but it would need to be a large amount of misalignment to cause the bending of the shaft and a proper alignment procedure with proper tools and training would help eliminate that. What else would cause this condition? How about web deflection? Are the middle feet of the engine properly mounted and torqued?

High Bearing wear in the middle of an engine

 

High Bearing wear at the rear of an engine with Oil Analysis showing Tin, Aluminum, and Copper

Now we are talking a lot more about the alignment. Since the coupling is right next door, we have to be very aware of what that alignment looks like. How was the equipment aligned before, and what does the report show for an “As Left” condition? Has the equipment shifted or is the base and foundation degrading to the point that it can no longer support the weight and power delivery on this package? Was Thermal Growth calculated correctly and properly compensated for? All of these factors should be addressed with the application of a proper alignment procedure. Download an overview of 4 common thermal growth methods including advantages and disadvantages.

These are just some of the issues that have been discussed when a failure occurs, and in a lot of those cases, alignment got an unfair amount of the blame. If a procedure is in place to perform alignments correctly, and documentation has been properly archived, Failure Analysis should go much smoother to find the actual cause of the failure, instead of just going for the “low hanging fruit”.

by Diana Pereda

Marine propulsion alignment consists of ensuring that all bearings and rotational centerlines are set into a straight line as per the installation requirements. Depending on the vessel size, this means the machine, gearbox, clutch, support bearings, stern tube and struts should all make a straight line when the vessel is at sea. Proper propulsion alignment prevents unnecessary loads to the bores and prevents vibration due to back and forth bending cycles of the propeller shaft due to misalignment.

Ensuring this alignment is correct in dry dock is a physically demanding task!  Ask anyone that has been tasked to perform such measurements and they will probably have stories of climbing in and out of the stern tube and though cramped spots—“Propulsion Alignment Yoga”.

With all the components that will need to be checked and re-checked after corrections, it is imperative that the alignment system be accurate and easy to use. Traditional marine propulsion alignments involve the use of a tight-wire that is stretched down the length of the propulsion line.  While simple in concept, it is not without its woes.  If a component needs to be removed, the line must be broken and reset.  The wire can bounce due to wind and vibration.  Finally, the operator must physically avoid coming in contact with the wire.  In many cases, this is physically impossible and dangerous. It is dangerous because if the user was in a stern tube taking a measurement and the line broke, that high tension wire could seriously injure the person in the stern tube!

Propulsion Alignment Results using the E950

Fortunately, this task is made both safer easier with the Easy-Laser E950B laser marine propulsion alignment system.  The concept is simple: the laser beam replaces the tight wire.  The high accuracy laser sensor replaces the inside micrometer.  The system digitally records the position of the sensor and touch probe with respect to the laser with a high accuracy (0.02mm).  The result is quick and easy measurements of marine propulsion alignment.  After the alignment is finished, the system creates a report for documentation showing that any alignment defects have been eliminated.

by Diana Pereda

I recently participated in an alignment check done on a fracking rig. The misalignment between the diesel engine and the gearbox causes excessive vibration and damage to the u-joint. The goal for this particular alignment was parallelism between the gearbox and the engine.

The Challenges:

  • The offset between the gearbox and engine was a little over 1 inch.
  • Checking alignment between the engine and the transmission with and without the u-joint in place.
  • Alignment is difficult because it has to be done on the rig which basically a tractor trailer, which means conditions can vary as the job is being performed.

The Solution:

Fracking Rig Alignment
Figure 1
  • Using the Easy Laser XT770 alignment system with the cardan bracket set, we measure without the u-joint in place, which allows mounting the components even in very tight spaces. See Figure 2.
XT770 Multipoint Measurement Mode
Figure 2

Using the Multipoint measurement mode allows measuring accurately even with the flexible frame of the tractor trailer. This measure mode allows us to increase the number of points collected at each arbitrary measurement position.

Benefits:

Accurate data can be easily collected even under challenging conditions in less time, allowing for better decision-making and corrective solutions to be implemented more efficiently.

by Diana Pereda

Motion Amplification is a camera-based full-field vibration technology that turns every pixel in the camera into a displacement sensor enabling you to see and visualize motion across the entire video. This opens up opportunities in visualizing an asset or system holistically instead of location by location often revealing information that would otherwise remain hidden. By combining this technology with other precision maintenance tools in the reliability toolbox you can better position yourself to address underlying issues and bring your equipment into a more sustainable operation. It is common for problems with machinery such as motor and pump installations to remain hidden or go undiagnosed.

For example, an improper or insufficient base installation can lead to excessive stress or looseness that ultimately leads to further faults or degradation in operating conditions. High vibration levels can be observed through contact sensors, but the problem persists even after the most common repairs are made, or perhaps the problems soon return. Often these issues are longstanding and go unmonitored and undiagnosed. These persistent issues can make it impossible to align a machine to the specified tolerances. Detecting issues through Motion Amplification can expedite the determination of the root cause issue. Once detected and repaired the equipment can then be precision aligned to bring it into the proper operating conditions and make it better suited to stay in that condition. By leveraging motion amplification and precision alignment technologies together, you can achieve a broader approach to diagnosing equipment and achieve more sustainable alignment conditions knowing the equipment you just aligned is not being affected by a fault still existing in the system. One size doesn’t always fit all and combining multiple tools in your reliability program to achieve superior reliability is just another way you can #keepitrunning.

Discover Misalignment with Motion Amplification

Motion Amplification showing Misalignment – Equipment setup: motor (left) and blower (right). The data on the screen is showing a measurement on either side of the coupling made from the video (red box corresponds to the red plot and blue box corresponds to the blue box) indicating the motion is 180 degrees out of phase in the vertical direction. This is also seen in the Motion Amplification video as one side goes up while the other side goes down.

Motion Amplification can be utilized in a multitude of use cases and to detect a broad number of faults. Among them are:

Thank you Jeff Hay with RDI Technologies for expanding our knowledge about motion amplification technology with us!

by Diana Pereda

Marine applications often involve cramped locations and dirty environments which require that measurement systems be compact in order to be installed inside the vessel, but also be rugged and dependable enough to perform in these environments.

The application below shows the Easy-Laser equipment is being used in such an environment.  Both the E-series and XT-series systems feature multi-role capability to handle the diverse needs of marine rotating equipment commissioning and maintenance such as flatness, straightness, squareness, level, and shaft alignment.  They are used extensively in marine applications.

Marine-Vessel-Baseplate-Flatness-Measurement

Measuring a baseplate in this environment is a challenge for some methods such as level or theodolite optics because these methods require consistent level, which is difficult on a floating vessel.  With optical theodolite measurements, the scope itself can move due to the operator having to physically look through the scope and his or her weight potentially causing movement.

The ideal solution chosen for this application was the Easy-Laser E920.  The issue of drift was removed by rigidly mounting the D22 laser to the most ideal location, the baseplate itself.  The D22 rotating laser component projects a perfectly flat laser beam.  A sensor is placed at the points of interest and can be measured remotely, removing the issue external factors causing any movement of the baseplate or laser.

Marine-rotating-equipment-commissioning-and-maintenance

The result was a fast and accurate measurement of the baseplate.  A report was then generated to confirm that the alignment defects of base twist and distortion were removed from the installation.  With this confirmed, the rest of the alignment could continue with the assurance that this step of the alignment process will not cause issues in the future.

Application photos provided courtesy of Ozan Onur Okumus, Energy Systems Engineer and Energy Manager of D.M.T. Makina.  Bursa, Turkey

by Diana Pereda

As part of our laser shaft alignment troubleshooting series, we have discussed Laser Shaft Alignment Troubleshooting: Part 1 Repeatability and Laser Shaft Alignment Troubleshooting: Part 2 Response to Corrections. In this final part of the series, we will discuss The Pipe Test.

In this series, we’ve examined some of the causes of errors in laser alignment measurements that can be encountered and how to remedy them. If you’ve gone through each of the possible sources of error and are still experiencing problems, there is a simple field test you can perform to ensure the laser alignment system’s functionality.

Laser-Troubleshooting_870x460

THE PIPE TEST:

  • Mount the measurement heads 6 – 10” apart on to a piece of pipe of a diameter no less than two inches.
  • Start the horizontal shaft alignment program and enter the dimensions for the laser heads. Foot dimensions are not needed.
  • If V-blocks are not used, take measurements by rotating the pipe with your hands.
  • Take at least two separate measurements turning the shaft 360 degrees.
  • The coupling results should be zero or very close to it if the system is performing correctly

Laser shaft alignment systems are reliable tools that produce highly repeatable results and simplify shaft alignment. That being said, technicians need to know that the measurements they’ve taken have minimal uncertainty and errors. That is where calibration comes in. Sending your unit out for periodic calibration checks will ensure the reliability of your system.

 

by Diana Pereda

We previously discussed misaligned couplings and how to reduce failures when ultrasound and alignment meet in “Ultrasound and Alignment Meet at the Coupling to Reduce Failures.” In this follow-up blog, we will discuss how ultrasound and alignment come together to improve belt-driven performance.

Misalignment in belt-driven equipment is one of the leading causes of failures throughout the industry. It breaks down machines and often costs your company thousands upon thousands of dollars in repair expenses and unplanned downtime. Imagine if you could combine two technologies you may already be using to prevent some of these failures. Ultrasound and precision laser alignment will make your maintenance department ever more proactive than ever before.

Ultrasonic-time-signal-of-slapping-drive-belts
Figure 1

Belts can be too loose, too tight, or be running on misaligned pulleys. Loose belts will slap and produce a noise similar to whiplash. Tight belts and misaligned belts will generate additional friction which will again be audible ultrasonically. Figure 1 is a sample time signal of slapping belts.

An easy way to detect and prevent failures is to add your belt driven machines to your ultrasound routes. It will require a few extra measurements on each route and some trending. However, the benefits will far outweigh the costs. By being able to tell when a belt system needs to be aligned and properly tensioned before it breaks down, we can be more proactive and less reactive.

Belt-drive-alignment-with-Easy-Laser-XT190

Once the imminent failure is being detected, we can address it with a realignment of the belt drive unit using our Easy-Laser XT190 pulley alignment system. It is easy to use and it will provide the user with a PDF report for documentation and accountability.

 

This blog was inspired by Uptime Magazine’s article, “There’s Something in the Air”, July 2009, pp. 48-53, written by Thomas J Murphy with SDT Ultrasound Solutions.

Download our 5-Step Sheave Pulley Alignment Procedure which provides a simple and effective procedure for sheave pulley alignment of belt-driven equipment. 

by Diana Pereda

We previously discussed a lack of repeatability and identified some of the most common and easy-to-correct culprits in Laser Shaft Alignment Troubleshooting: Part 1 Repeatability. In this follow-up blog, we will discuss Response to Corrections.

Along with measurement repeatability, the laser alignment system’s ability to display the correct moves to bring the machines into alignment is crucial. If the machines do not respond to these corrections, you’ll be chasing moves throughout the alignment process – which isn’t fun!

Response-to-Corrections-XT-Move-Screen_870x460

WHAT IS RESPONSE TO CORRECTIONS?

Response to corrections is how the moves given by the alignment system work out.

If the results don’t reflect the moves made, the following can be the causes:

  • Incorrect dimensions entered for the machinery. The alignment system relies on the correct dimensions being entered in order to predict the correct move amounts.
  • Coupling strain can cause small deflections in the machine shafts that can misreport the correct shaft centerlines to the alignment system. Precise measurements of the rotational centerlines is crucial in determining the misalignment between them.
  • Soft foot amongst other negative effects can hinder adjustment attempts.

In addition to the above considerations, environmental vibration, external stresses on the machines, and thermal effects can cause a lack of response to corrections. Identifying and accounting for these causes will make your alignment easier overall and help you get it done faster.

Watch our Shaft Alignment Know-How: Thermal Growth video to learn the importance of accounting for thermal growth on rotating equipment.

 

by Diana Pereda

Sometimes I will assist a customer on-site for shaft alignment.  The first thing I will ask is, “what is the tolerance you wish to achieve?” Many times I would be given a specification, but sometimes I would be told “we need it aligned to 1 thou.” 1 thou I would ask, where?  The answer would be “at the coupling and feet.”  I would then reply, “Well that depends…”

Assuming soft foot will be addressed and that correct targets (deliberate misalignment, if needed) are given, there is just one thing that needs to be aligned. That is both shafts. They should be set for a proper offset and angle at the coupling point.

Watch our Shaft Alignment Know-How: Offset & Angularity and learn about the concepts of Offset & Angularity as they relate to aligning rotating equipment.

Feet adjustments are what you move the machine to align it to achieve tolerance at the coupling, therefore, feet moves have no tolerance.  Feet adjustments vary depending on how far away or near they are to the coupling and to each other.  Think of a laser pointer. If you aim it at a wall close to you and slightly angle it, the beam will slightly move.  Should you aim in 20 feet away and slightly angle it, it moves much more.  Depending on the feet positions, the precision of the adjustments will be generally more critical if they are closer together than if they are farther apart.

Regarding the coupling, the most important part of the alignment, you should consult your alignment tolerance table. For example, see the Easy-Laser XT’s built-in ANSI tolerance table below:

Easy-Laser-XT-built-in-ANSI-alignment-tolerance-table

To achieve excellent (***) tolerance for coupling offset, you need to be within +/- 1.6 thou.  Being within +/-1 thou can mean achieving either -1.0 thou or +1.0 thou, which is still within the excellent tolerance of +/- 1.6 thou.  Being within +/- 1 thou offset at the coupling also means that you are within acceptable (**) and minimal tolerance (*) standards.

It is an entirely different case for the angle.  The excellent tolerance is 0.4 thou/in, the acceptable is 0.7thou/in and the minimal is 1.3 thou/inch.  1 thou of variation can throw the alignment angle at the coupling completely out of alignment!  Now is the spec unreasonably tight?  Absolutely not!  It is expressed in thou/in.  If you had a typical 10” coupling, 1 thou out is equivalent to a coupling gap of 10 thou out, and this gets magnified for large couplings!

In conclusion, be careful about following the dogma of “1 thou” being acceptable.  It is important to follow your required tolerance specifications.

Request your complimentary copy of our Shaft Alignment Fundamentals Wall Chart which highlights the ANSI/ASA Shaft Alignment Tolerances as well as information and guidelines for the implementation of good shaft alignment of rotating machinery, best practices, soft foot, tolerances, thermal growth, and much more!

by Diana Pereda

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