December 08, 2005
Vibration Analysis Tip
Sometimes the simplest things are overlooked. When taking vibration data, remember to always prepare the surface of your machinery before mounting the accelerometer. It is best to clean the surface; this may include sanding or wire brushing the surface to remove any paint that may interrupt the transmission of the vibration data. If the surface is curved, it is not recommended to attach an accelerometer with a flat magnet, try a curve surface magnet that has two legs (poles) that contact the surface.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
December 08, 2005
Enter the Maintenance-Tip Challenge!
Do you have great advice that will help other maintenance and reliability professionals do their jobs better?
Enter your tip into the EAM/RCM Tip Challenge and you may be a lucky winner!
Prizes:
1 Grand Prize EAM/CMMS Tip: Free EAM-2006 3 Day Conference Pass, 3 nights at the Orleans Hotel and Casino in Las Vegas, Tip Featured at EAM-2006 and in Maintenance-Tips Email newsletter
1 Grand Prize RCM Tip: Free RCM-2006 3 Day Conference Pass, 3 nights at the Orleans Hotel and Casino in Las Vegas, Tip Featured at RCM-2006 and in Maintenance-Tips Email newsletter
1 Runner Up EAM/CMMS Tip : Free EAM-2006 3 Day Conference Pass, Tip Featured at EAM-2006 in Maintenance-Tips Email newsletter
1 Runner Up RCM Tip : Free RCM-2006 3 Day Conference Pass, Tip Featured at RCM-2006in Maintenance-Tips Email newsletter
25 other tip submissions will be entered into a drawing for a Free Maintenance Tips hat, Conference proceedings and a free one year subscription to Reliability Magazine
The winners will be selected and notified on January 12, 2006 and must confirm acceptance within 3 business days or another winner will be selected.
December 01, 2005
Maintenance Tip: Sensor Selection: Sensitivity Tolerance
Is a wider sensitivity tolerance bad? Such as +15%?
Not necessarily! Vibration sensors with wider tolerances can provide adequate, cost-effective information for a successful monitoring program.
Nearly all data collection boxes, analyzers, and acquisition systems have the ability to enter the exact sensitivity of a sensor. In these cases, purchasing a sensor with a wide tolerance is acceptable as long as its sensitivity is appropriately noted.
However, if the user is unable to enter the exact sensitivity of a sensor, and the acquisition system assumes a nominal sensitivity, then a precise measure of the vibration level may not be possible. For example, if the acquisition system assumes the vibration signal is obtained from a 100mV/g sensor, and the actual sensor being used is 85mV/g, the vibration readings will be 15% low. In this case, a tighter tolerance (+5%) may be more appropriate.
If possible, enter the exact sensitivity of the sensor into the acquisition system to obtain the most precise measurements.
For more information on choosing vibration sensors, read Wilcoxon’s Technical Note 16: “Sensor Selection.” This Tech Note from Wilcoxon’s extensive online Knowledge Desk explains in detail the many considerations for maintenance professionals selecting vibration sensors.
December 01, 2005
Engine Cooling System Tip
Higher Engine Operating Temperatures Require Controlled Cooling System Maintenance Procedures
The new engines introduced by manufacturers in the last few years are designed to lower fuel consumption and meet impending federal emission laws. As a result, the cooling systems for these new designs must operate at much higher temperatures making careful cooling system maintenance necessary to avoid engine damage due to boiling, deposits or pitting.
The cooling system guidelines below are designed to help operators and fleet maintenance personnel maintain and control cooling system maintenance procedures.
BASIC RULE: 4-8-16
1. Every 15ºF to 17ºF (8.4ºC to 9.5ºC) increase in cooling system operating temperature above 160ºF (71.1ºC) can result in a potential doubling of deposits or acid pitting of metal for the same coolant problem, in the same amount of time, with the same rate of flow. See example below:
• 160ºF (71.1ºC) engine operating temperature: (Base Point)
• 190ºF (87.9ºC) engine operating temperature: Potential increase of pitting or deposit is 400%, but reduces ring and bearing wear by 40%.
• 205ºF (96.1ºC) engine operating temperature: Potential increase for pitting or deposit is 800%.
• 220ºF (132ºC) engine operating temperature: Potential increase for pitting or deposit is 1600%.
2. If a coolant is corrosive, doubling the rate of flow, at high temperatures, will double the rate of corrosion.
Tip provided by POLARIS Laboratories
Tel: (317) 808-3750
Click here to see an example that applies the Basic 4-8-16 Rule
December 01, 2005
Motor Testing Tip
Separations of Surge Waveforms
When doing the Surge Comparison Test, called by IEEE and IEC standards, as well as National Fire Standards, ANSI, and NEMA for motor windings and generators, it is important to have a good portion of the wave available for observation. We all know the characteristic pattern of the wave is several sine type waveforms. When we are looking for shorted turns, or to many or to few turns, it is critical to have on screen several cycles. This is because there may be separation on the trace at the end of the pattern – not at the beginning.
Lets not forget that the Surge test identifies two types of faults: Incipient and Set. Incipient faults are considered “weak insulation”. They will show up as we ramp up the voltage and are also why the surge test is considered predictive. Set faults are found with low voltage: shorted turns, wrong turn counts, etc.
Tip provided by Baker Instrument
Tel: (800) 752-8272
http://www.bakerinst.com
December 01, 2005
Documentation Tip
Documentation Tip Part 2 – Create a Brief Technical Case History
Archived at
http://maintenancetalk.com/blog.php/tipsblog
A technical case history is a brief summary of what the vibration looked like when the machine was in good condition what it looked like just before repair and what it looked like just after repair. If “as found” information or photos of damaged parts are available it is even more useful. Most vibration analysis software will allow you to cut and paste graphs, notes and images into MS Word. With this capability it is very quick easy to put together a brief case history.
The purpose of a technical case history is to educate yourself and others, promote your technology and justify your work. These reports should be posted in your office, public places in the plant and submitted to websites and magazines for publication. Many people in maintenance departments and management do not understand or appreciate the power of vibration analysis to detect specific machine faults. This is your chance to educate them. Make it short and simple, with annotated before and after graphs, a brief explanation and either a photo of or the actual damaged components. Do this for every repair action and create yourself a portfolio. A byproduct of this effort will be training materials for those who come after you and a reference guide for yourself.
Tip provided by DLI Engineering
http://www.dliengineering.com
Tel: 206-842-7656
December 01, 2005
Distance Learning: Change Management for Maintenance & Reliability Professionals
A Self Paced Distance Learning Course by Steve Thomas
Companies initiate change programs all of the time. Some succeed but many more fail to accomplish their stated goals. Previous failure can make future efforts even more difficult due the audience becoming skeptical.
Of all types of change, reliability focused efforts are perhaps the most difficult to initiate and conduct. These initiatives often meet significant resistance because there are always those who did well working in a reactive maintenance environment. Lukewarm support is often the most that can be expected from those changing to the new reliability based approach. How a manager manages the change will be the difference between success and failure.
This self guided course teaches the basic skills required to break down the barriers encountered by reliability focused change efforts. The course includes:
• Making your vision of a reliability focused future understandable and accepted
• Achieving the vision by use of the Goal Achievement Model
• Building your Roadmap of Change
• Becoming a non-linear thinker using spiral learning
• Understanding the role of teams
• Overcoming resistance
• Measuring your opportunities for improvement with the Web of Change
In addition you will learn about the Eight Elements of Change – leadership, work process, structure, group learning, technology, communication, interrelationships and rewards. You may have worked with one or more of these in the past, but this course shows you how to view and work with them as a global set of critical change elements.
Preview: Change Management for Maintenance & Reliability Professionals
December 01, 2005
Reliability Centered Maintenance (RCM) Tip
Using RCM as a Design Tool
While Reliability Centered Maintenance is most often used as a reliability tool to develop a complete maintenance strategy for a process or piece of equipment, it can also be used as a tool in the design phase to not only develop a complete maintenance strategy, but to also ensure greater inherent designed reliability for your new asset.
Some key elements to consider when using RCM in the design phase:
1. Use an experienced, skilled, and certified RCM facilitator.
2. Perform the RCM analysis following final design approval but prior to equipment installation.
3. Your Design RCM team should include design engineers, maintenance technicians & mechanics, experienced operating personnel.
Companies with successful RCM efforts understand the benefits of having a complete maintenance strategy prior to the delivery and accreditation of the asset.
Tip provided by Doug Plucknette
Reliability Solutions
Tel: 585-349-7245
http://www.reliabilitysolution.com
December 01, 2005
5 Days till IMC-2005
The 20th International Maintenance Conference™
“Mastering The Maintenance Process”
December 6-9, 2005 - Tampa Florida
The 20th International Maintenance Conference offers 4 days of focused maintenance and reliability learning through a series of informative learning sessions, short courses, discussion sessions, networking opportunities and a wide selection of full day workshops.
Please join us in beautiful Tampa Florida by calling toll free (888) 575-1245 or…
