Induction Heating vs. Conventional Methods to Properly Mount Bearings and other Workpieces

October 17, 2017

It seems that every maintenance department has a hard time installing bearings because of the problems inherent in conventional heating methods.

Applying care, good technique and heating methods is better. Over 90% of rotating equipment has defects at startup that can result in equipment failure.

One reason bearing installation is often a herculean task is not using proper heating methods. Excessive heat applied to the bearing during installation can introduce defects that lead to premature equipment failure.  Instead, heating a bearing up on an induction heater, automatically demagnetizing it, and then slipping it on the shaft free of stresses is the way it should be done. The results of overheating a bearing are increased maintenance cost, increased safety risks, and more equipment downtime.

Proper heating methods and best practices should be applied to correctly install bearings.  Induction heaters such as SURETHERM can help eliminate induced bearing defects due to poor fitting and improper mounting techniques.  Induction bearing heaters provide increased safety, increased efficiency and reduce the risk of bearing contamination and damage that can result from using brute strength, oil baths, blow torches or other improper methods of heating bearings for proper installation.

Here are some conventional methods that are used in Industry and why they are not the way to install bearings:

Blow Torch
 – No temperature control
– Risk of over heating
– Grease leaks out of bearing
– Tension in material

 

Hot Plate
– No temperature control
– Risk of over heating
– Grease leaks out of bearing
– Tension in material
– Dangerous (plate stays hot)

Oil Bath
– Slow heating process
– New grease cooks out of bearing
– Dangerous (hot oil)
– Environmentally unfriendly

Oven
– Slow heating process
– High energy consumption
– Grease leaks out of bearing

0

How Often Should Condition Monitoring Measurements Be Taken?

October 10, 2017

Condition Monitoring Expert Tip #2 by Mobius Institute

This tip is sponsored by IMVAC (International Machine Vibration Analysis Conference)

How do you decide how often measurements should be taken?

Regardless of the condition monitoring technology, you must decide how often measurements will be taken. At one extreme, it could be a permanent monitoring system that takes measurements every split second of every day. At the other extreme, it may be infrared analysis that is performed once a year. But how do you make that decision?

The most common answer we receive is that it is based on the criticality of the equipment. More frequent measurements are taken on the more critical equipment. The next most common answer is that it is based on reliability. If you have been monitoring a machine with vibration analysis every 30 days and have not detected a fault for a year you may decide to test it every 60 days, or 90 days. Now, it is true that you have to decide how best to use your precious time. But the one factor often forgotten is the “PF interval”.

The PF interval, also known as the “lead time to failure”, is the time between when you can detect the fault condition and when the equipment will have “functionally failed” – i.e. it can no longer be used. If we use the right technologies with the correct settings and we take frequent measurements, then we will get the earliest warning, and therefore we have the greatest lead time to act. However, if the PF interval is short, then it is possible that if you have extended the measurement period to 90 days, the equipment may develop a fault and fail before you take the next measurement.

There is a lot more that could be said on this topic but suffice to say that it is essential that you understand the PF interval and continue to monitor equipment so that you take at least two measurements between the time the fault is detectable and when the asset will have functionally failed.

Special thanks to Mobius Institute for allowing us to share this condition monitoring expert tip with you!

0

Don’t let Hercules install your equipment bearings!

October 3, 2017

It seems that every maintenance department has at least one Hercules that uses more muscle than technique to complete maintenance activities.  Brute force and strength are occasionally required to complete a task.  Having Hercules around is important when those moments arise.

However,  applying care and good technique are usually better. Over 90% of rotating equipment has defects at startup that result in equipment failure.  One of the reasons arises from making bearing installation a herculean task and not using proper technique.  Excessive force applied during bearing installation can introduce defects that lead to premature equipment failure.  Instead of beating the bearing on with a sledge hammer, gently heat it up on an induction heater, automatically demagnetize it, and then slip it on. If Hercules did the job, then the bearing and equipment are doomed to failure from the moment of startup.  This results in increased maintenance cost, increased risks, increased equipment downtime.

Installing equipment bearings should not be a herculean task.  Instead, proper technique and best practice should be applied to correctly install bearings.  Induction bearing heaters like SURETHERM can help eliminate induced bearing defects due to poor fitting and improper mounting techniques.  Induction bearing heaters provide increased safety, increased efficiency and reduce the risk of bearing contamination and damage that can result from using brute strength, oil baths, blow torches or other improper methods to heat bearings for proper installation.

Comments Off on Don’t let Hercules install your equipment bearings!

Is your Application FIT for Ultrasound?

September 26, 2017

I often hear the question, “what can I detect with ultrasound?”. The fact is, ultrasound is such a versatile condition monitoring technology we tend to ask it to do things beyond its capabilities. And that’s fine because I firmly believe every technology should be pushed beyond its limits. It’s how we get better.

But to help answer the question, “what can I detect?”, I ask a simple question in return. Is your application FIT?

Now you’re asking “what does he mean by is it FIT”?

Let me explain. FIT is an acronym for Friction, Impacting, and Turbulence. Basically, if the defect you are searching for generates any of these three phenomena, then ultrasound is a solution FIT to solve your problem.

Let’s try a super easy example. You are tasked with finding compressed air leaks in your factory. Air lines run every which way throughout your deafeningly noisy plant so you can’t hear the leaks. You could run your hand along all the pipes and anywhere you feel cool air rushing out you’d know you found a leak. Or you could spray soapy water on the pipe joints and look for bubbles. A third solution could be to wait for a plant shutdown and listen for the turbulent flow of air leaks when everything is quiet.

The BEST solution is to ask, “do compressed air leaks produce Friction, Impacting, or Turbulence?”. That’s it! Due to the difference in pressure on either side of the compressed air line, anywhere there is a leak there is turbulent flow. Ultrasound detectors are really good at detecting turbulent flow in high noise environments. There’s no need to run your hand along the pipe, reach for the bubble solution, or wait for a shutdown. Go grab your SDT Detector and start tagging leaks today.

Comments Off on Is your Application FIT for Ultrasound?

Rotor Balancing Expert Tip

September 20, 2017

Guest Post by Bob Dunn from I&E Central, Inc.

A customer was having difficulty balancing the rotor shown above. They had made multiple corrections, some contradictory, and were worse than when they started. In that this is on a shop stand and controlled conditions, something was not right. Looking at the photo, I saw a couple of likely issues.

  1. The shaft is pretty reflective itself, it is doubtful that they were getting a good or consistent phase reading. I recommended they put a ring of black tape on the shaft, with the reflective tape on the black.
  2. The tach sensor is pointing at the shaft at about a 90 degree angle. Optical sensors and reflective tape works better if the sensor is aimed at an angle – 30 degrees or so.
  3. The tach sensor is pretty close to the rotor. In this case it is not too close, but you can be too close. A sensor like this will work from several feet away, if you are having problems, try moving the speed sensor further away.

The customer applied the tape and adjusted the tach position. The rotor was balanced in a single run.

Comments Off on Rotor Balancing Expert Tip