February 09, 2006
Maintenance Tip
EAM-2006/RCM-2006 Maintenance-Tips Challenge 3rd Place Winner
After the failure of the operating mechanism on a very large air operated, air blast circuit breaker, reassembly during repair became a real challenge. The operating pistons were about 6 inches in diameter and less than an inch thick. The trick was to somehow compress the single piston ring and slide the cylinder over the piston. At this remote location, we had few tools and no ready access to a tool supplier. Plus, finishing the circuit breaker repair would restore a 155 Megawatt generator to service.
After an hour of finger pinching and screw driver prying, it occurred to me that a couple of large hose clamps put together around the piston could compress the ring very nicely and come back off easily. Using a little lube oil to ease the way and clamping the ring on its very edge, the cylinder slid on with little difficulty.
Tip provided by: Larry Walker, Maintenance Specialist, US Army Corps of Engineers, Walla Walla, Washington USA
February 09, 2006
vbOnline Condition Monitoring
Commtest has developed a revolutionary concept in online systems. The vbOnline now features a standard 32 channel chassis, and our starter units include 4 active channels. As your requirements change and additional channels are required, it is as simple as downloading a file and Proflash® it into your online system to activate additional channels.
February 09, 2006
Ultrasound Tip
Air Leak Surveyors Play the Bounce
While performing a quarterly ultrasonic leak inspection on the plant’s compressed air system, our inspector picked up what sounded like a leak coming from a brick wall. He was miffed. How could a brick wall have a compressed air leak?
The Answer… Play the bounce.
Ultrasound is a low energy wave that is partially absorbed when it contacts a surface. The composite of a surface determines the amount of absorption. A carpeted floor will absorb most of an ultrasonic wave while a harder surface such as steel or brick will absorb less and reflect more of the wave. What appeared to be a leak coming from a brick wall was in fact ultrasonic energy from a pipe leak around the corner, reflecting off the brick wall.
When faced with our inspector’s dilemma, play the bounce as though it were a billiard shot.
1. Walk your ultrasonic detector toward the brick wall where the leak sound is detected.
2. Now turn the detector away from the brick wall on angles that would represent a reflection or “ricochet”. Do this until the leak sound is heard again.
3. Like a billiards shot, the angle toward the source will be equal to the angle of reflection off the brick wall.
4. If you are on the right path to the source of the leak, the ultrasound in the headphones should be more intense as you’ve just eliminated absorption from the brick wall and additional attenuation through the medium of transport.
5. If your detector has digital readout the intensity can be confirmed by taking a dBuV measurement before and after the ricochet.
6. Adjust the amplification of the detector to a comfortable level in the headset.
7. Follow the directional nature of the ultrasound until you pinpoint the leak.
This tip supplied by SDT North America
http://www.sdtnorthamerica.com
1-800-667-LEAK (5325)
Find a Predictive Maintenance for the Masses workshop near you
February 09, 2006
Balancing Tip
Pre-Balance Procedure
Before you jump right into a balancing job to correct a reported vibration issue, begin your analysis by taking an overall vibration reading and comparing the results to the ISO 10816 specifications (in./sec. rms). Next, collect spectral data to ensure that you can verify a major contribution at 1X running speed. Also collect phase readings to reinforce that balancing is the key contributor. Phase is the determining factor on the type of unbalance and whether or not it can be addressed by the one-plane or two-plane method.
As other faults might be present, correct any mechanical looseness that might create high 1X, 2X, 7X. Address any misalignment that creates high 1X, 2X,3X. Also be sure to address any structural resonance at running speed that will cause unstable phase readings.
Tip provided by Commtest Inc.
http://www.commtest.com
Tel: 865-588-2946
February 02, 2006
Vibration Analysis Tip
To help justify your vibration analysis program, try providing your machinery’ health in a report.
Print out a statistical report showing how many pieces of equipment are within acceptable limits versus how many are outside acceptable limits. Often, you think management only wants to see the bad equipment, but one of the major benefits is showing a problem in its infancy, before the failure.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
Request Condition Monitoring Return On Investment Study for your facility
February 02, 2006
Motor Testing Testing
Is it the motor, or is it the load that is causing the problem?
Sometimes, when everything is said and done, more is said than done. This happens, if the motor-load application shows behavior that “is not right”, but the mechanical and electrical team are scratching their heads on the true root cause.
How to stop the finger pointing from the mechanical team pointing at the motor team and the electrical team pointing at the load?
The motor’s job is to deliver whatever torque the load is requesting. The job of every motor is very simple. Either it manages to spin at close to synchronous speed, or it dies trying. The motor has to deliver whatever is requested by the load. The load defines how much torque, and what type of torque is used by the mechanical system (steady State, oscillating, showing cavitations, etc).
So, how do you separate motor problems from load problems? Just check the signature of the torque. If it looks ok (example: smooth for pumps and fans), then the load is ok, and the culprit has to be the motor. If it shows some unexplained behavior – too high or a strange signature – then the problems must be on the load side.
Tip provided by Baker Instrument
Tel: (800) 752-8272
http://www.bakerinst.com
February 02, 2006
Save Dirt and Water For Playtime
Keep your equipment clean and dry with Des-Case fluid handling systems.
Des-Case’s FlowGuard™ hand cart makes fluid handling a simple task, requiring less equipment and labor while reducing system contamination.
Our filtration products, with the use of our quick
connect adaptors, make your job safer, easier,
and cleaner. By prohibiting entry of dirt and moisture,
your equipment and lubricants can run longer and harder.
email:
Tel: 615.672.8800
February 02, 2006
Oil Analysis Tip
EAM-2006/RCM-2006 Maintenance-Tip Challenge 3rd Place Winner
EGR Engines, is there a solution?
For those of you that don’t quite understand what an EGR diesel engine is.
EGR stands for Exhaust Gas Recirculation.
These engines are now being used in many late models, over the road applications including. Caterpillar, Cummins and Detroit.
Their primary function is to reduce emissions by recirculating exhaust gases one more pass through the combustion cycle.
However, this also has a major impact on soot levels.
Higher than normal soot readings are now becoming a factor, as many oil analysis labs are recommending to drain crankcase oils at much shorter intervals. LubeTrak is all about solutions for lubrication, and this particular problem is no exception. Because this is a growing epidemic for larger fleets, and in the end, may cost all of us more to get our goods delivered, we have compiled some recommendations to reduce expensive oil changes and help the environment at the same time. These suggestions also apply to construction fleet managers as well.
First, we recommend the use of HIGH quality motor oil. Not just oil that you ‘get a good deal’ on. Using oils not designed for increased soot loads will cost you more in the long run than an oil with a higher TBN that meets or exceeds (API) CD CDII, CE, CF4, CG4, SD, SE, MIL-L-2104B, CID AA 52039.
There are many quality oils to choose from. Be sure to choose one that fits your needs and application. Buyer beware, many diesel oils DO NOT meet ALL the (API) codes listed above.
Second, Your oil must have a superior viscosity index. One that will handle the higher temperatures. When we tested (ASTM D-446) viscosity @ 210 degrees F, some oils come in at 80.0. This was very acceptable for larger diesel applications, however some of the oils tested were much higher because of the soot buildup from the new style EGR engine. We noticed this oil DID NOT have the CID-AA or CE rating. Your viscosity rating @ 100 degrees C, cSt, typically should run between 14.4 and 15.6 on oils for this application.
Third, Quality diesel fuel is a BIG factor when running a diesel engine. It approximately takes 18,200 Btu’s (British Thermal Units) to burn a pound of diesel. Anything less. and your engine does not get a complete burn through its compression stroke. This leaves behind carbon that affects the engine components and the engine oil creating an increasing buildup of soot. Our tests concluded, that running a combustion catalyst in the fuel, increased the Btu’s to between 18,200 and 19,400 per pound. This has a major impact on reducing soot levels by getting a more complete burn. Also, water is your worse enemy when it comes to diesel fuel. Water will make a sulfuric acid when mixed with diesel fuel causing catastrophic failure to any diesel engine.
Last of all, purchasing quality filters of at least 20 micron or lower will cause the, now larger soot particulates, to adhere to the filtering media.
When getting into the lower number micron filters, it may be possible to run an off-line filtration system to reduce fuel soot build up and keep the contaminates to a minimum. This will allow oil to be ‘double filtered’ and strip out any of the smaller contaminates.
So in conclusion, this will also allow you to reach the longer oil drain intervals that you were once used to with the older style engines. The added benefit is longer engine and equipment life. These 4 steps above have been proven to help enterprises running EGR engines reach their maintenance goals.
Winning tip provided by Brett Winberg
LubeTrak
Tel: 866-582-3872
February 02, 2006
Ultrasonic Tip
SCAN 360° WHEN SCANNING OVERHEAD ELECTRICAL LINES FOR ELECTRICAL DISCHARGE
Do a 360° walk around the tower or power pole, when scanning overhead lines for electrical discharge.
Wind direction can play a role as to whether or not electrical discharge can be heard. Standing downwind and pointing the parabolic dish or long range cone upwind towards the apparatus, transformer or switch typically yields higher dB’s or sound by which to diagnose a problem.
Tip provided by Jim Hall
Ultra-Sound Technologies
Tel: (770) 517-8747
February 02, 2006
National Plant Engineering & Maintenance Show and Conference
Reliabilityweb.com is pleased to again sponsor the Reliability Pavilion March 21-23 at the Rosemont Convention Center in Chicago as part of the National Plant Engineering & Maintenance Show.
The 58th National Plant Engineering & Maintenance Show and Conference is the only event for MRO professionals and operations executives from across the country responsible for the maintenance, reliability and compliance of industrial and institutional facilities through new ideas and products for HVAC, material handling, software & computers, safety & security, tools, paints/coatings, lighting, flooring, cleaning technologies, environmental technologies and maintenance. Thousands from the US manufacturing community, especially small to mid-size manufacturers, come together for in-depth education and exhibits which provide the knowledge and insight necessary to innovate, grow and compete in the global marketplace.
Connects with the leading suppliers, focused product pavilions, and a leading application oriented conference with more than 250 all new sessions and workshops – all engineered to help you innovate, work smarter and excel.
