October 20, 2005 Data Analysis Tip
Data Analysis Tip Part 2 – Create a Vibration Test and Analysis Guide
Archived at
http://maintenancetalk.com/blog.php/tipsblog
A vibration test and analysis guide is a simple book or electronic document that contains a variety of information about the machine. Information should include: A simple schematic of the machine with test points identified, instructions for testing the machine (especially if loads and speeds must be manipulated or verified), name plate information and a simple schematic of internal components. This information is invaluable for conducting a proper diagnosis of the machine.
Access to testing instructions may lead the analyst to recognize bad data caused by improper test conditions. Test location information allows the analyst to determine what graphs to consult when looking for particular faults. A simple internal schematic of the machine is invaluable as one wouldn’t want to diagnose ball bearing wear in a machine with only sleeve bearings! (Believe me, it happens!) Additionally, faults present themselves differently depending on how the machine is configured. A common example is that unbalance in a fan with a supported rotor looks different from unbalance in a fan with an overhung rotor. It is essential to have this information visually in front of you when conducting data analysis.
Tip provided by DLI Engineering
http://www.dliengineering.com
Tel: 206-842-7656
October 20, 2005 Contamination Control In Hydraulic and Lubricating Systems Short Course
LubricationWorld - Co-located with
The 20th International Maintenance Conference
December 6-9
Tampa Florida
Short Course led by Leonard E. Bensch, Ph.D., P.E., Vice President, Pall Corporation
Contamination in hydraulic and lubricating system fluids is generally recognized as the single most important factor in reducing the reliability and longevity of the equipment. The decrease in reliability because of fluid contamination has a major impact on maintenance costs as well as machine productivity. In order to increase system reliability, a program should be established for cleanliness control. Such a program involves machine design to exclude built-in and ingressed contaminants, proper filter selection to maintain the operating cleanliness, and good practices to ensure minimal contamination is introduced or remains after maintenance is performed.
This short course provides a fundamental understanding of contamination control principles, starting with particulate contamination, including how to measure and report contamination levels. Typical damage caused by contamination is presented as well as benefits achieved by controlling contamination to desired levels. Fundamentals of filtration for contamination control are discussed, including a review of historic and modern filter rating methods. Finally, guidelines are given for determining cleanliness requirements, filter selection, and filter location.
Contamination control is much more a science than several years ago. Through proper implementation of a total cleanliness management program, the goal should be to reduce or eliminate contaminated related failures. With technology available today there is no reason to continue to allow dirt to be the major machine life limiter.
Attend this subject plus 50+ other short courses and learning zone sessions at LubricationWorld. Discount hotel rooms at the Tampa Marriott are available till November 1 so please book today.
To register or to request a brochure please call toll free (888) 575-1245 or…
October 20, 2005 The Best Offense Is A Good Defense
We offer the contamination control solution that helps you optimize your fluid power, cut back on your maintenance costs & meet your most vigorous production demands. The Des-Case breathers simply replace your standard filler/breather caps to defend your systems against opposing contaminants.
Des-Case offers a full line of disposable, steel, & specialty breathers to meet the needs of any industrial application.”
Please call Des-Case at 615.672.8800 or…
October 20, 2005 Maintenance Tip: Mounting Resonance
A sensor’s high frequency usable limit is a function of the resonance of the accelerometer. Sensors with a higher resonance will generally be small, light weight, and specially designed. These transducers will then be usable to read high frequency vibration signals.
However, the mounting method of the sensor will have a significant impact on its “as installed” resonance and high frequency limit. Each mounting method has an associated resonance. If the mounting resonance is less than the sensor resonance, the high frequency limit of the sensor will be compromised.
In general, the more intimate contact between the sensor and machine surface, the better chance the “as installed” resonance and high end response will be in line with the sensor specifications.
For more information on vibration sensor mounting, including the specific capabilities of 6 different mounting methods, read Wilcoxon’s Technical Note 21: “Mounting Considerations,” in Wilcoxon’s extensive online Knowledge Desk.
October 20, 2005 Family Analysis Alarming Methodology White Paper
Insight Services has developed a white paper on their family analysis alarming methodology that they are offering free of charge for Reliabilityweb.com visitors.
Insight Services’ white paper on their family analysis alarming technology in oil analysis explains how they are uncovering machine problems sooner. This method has been in proven use for over a year and a half and customers are really starting to understand the importance of dynamic alarm levels.
October 20, 2005 Reliability Centered Maintenance (RCM) Tip
How to Select RCM Facilitators
One of the most important phases in starting a successful RCM effort, is selecting the right people to facilitate the analyses. Your RCM facilitators will provide several key functions that will determine the future success of your RCM effort. As a result you should take some time and consider the following traits displayed by the best RCM facilitators.
1. Most important, your RCM facilitators should be driven and likable. A good personality combined will keep people on task and in the room. It should be a must that these people have shown the ability to facilitate an orderly meeting.
2. Your facilitators should be highly motivated self starters who have a vision for what the future of maintenance should look like. Your RCM analyses will take some time to complete and implement so your facilitators will need the strength and patience to continue to push forward towards that future vision.
3. Your facilitators should have a good knowledge of several trades, electrical, mechanical, instrument, and pipe. While it’s not required to be an expert in each, the more you know of each the better off you are as a facilitator.
4. Your RCM Facilitators should have a thorough understanding of Reliability and the use of different Reliability Tools.
5. Your RCM Facilitators should be highly respected by their peers. If you can select your facilitators from within the organization they will have credibility from the start and won’t have to spend time building it.
Companies with successful RCM efforts take the time to use a process for selecting their RCM Facilitators.
Tip provided by Doug Plucknette
Reliability Solutions
Tel: 585-349-7245
http://www.reliabilitysolution.com
October 20, 2005 Motor Testing Tips
Finding Broken Rotor Bars
Broken rotor bars and cracked end rings are issues every predictive maintenance technician faces at some time. There are several sophisticated technologies that can be employed to diagnose rotor bar issues including dynamic testing and vibration analysis, but there is a simple technique anyone can use that works quite well (assuming the rotor is not “skewed”).
Apply a single-phase voltage equal to approximately 25 percent of the nameplate voltage and monitor the current of one phase as you slowly turn the rotor. The current will remain reasonably steady as the rotor passes through the magnetic field until it passes the broken bar. At that time, the current will drop decisively since that bar is not capable of conducting current. Once the broken rotor bar has passed through the magnetic field, the current will quickly return to the same level it was tracking.
Tip provided by Baker Instrument
Tel: (800) 752-8272
http://www.bakerinst.com
October 20, 2005 Vibration Analysis Tip
If there is a dramatic change in the amplitude of your vibration readings, a rotor rub could be the suspect. A rubbing rotor may change the stiffness of the rotor, thereby changing the natural frequency. The equipment may now be running in a resonant condition due to this change in natural frequency.
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
