May 05, 2005
16 Part Benchmarking Best Practices Maintenance Management
MaintenanceBenchmarking.com works with various subject matter experts and a network of over 50,000 maintenance & reliability professionals to uncover better practices that you can use to establish your own goals and measure your progress.
You can use this information to discover the gaps between your present practice and those of over 700 other sites from around the world.
The survey is 100% confidential and each section only requires a few minutes to complete. Survey participants get immediate survey results as well.
May 05, 2005
Motor Testing Tip
Before and After Repair Resistance Measurements
When performing quality assurance tests of rebuilt AC induction motors for acceptance, it is important to compare phase resistance readings from before and after the repair. Although smaller then original windings are easier to
rewind motors with, it increases the phase resistance and can significantly lower the operating efficiency. The end result could be a much higher utility cost, outweighing the money saved by rewinding instead of buying new. Larger motors exhibit very low values of phase resistance and will
require a 4-wire bridge type of measurement to accurately assess the winding resistance.
Tip provided by PdMA
http://www.pdma.com
Toll Free: 1-800-476-6463
Tel: 813-621-6463
May 05, 2005
(ADV) Infraspection Institute Distance Learning Infrared Thermography Classes
Now you can receive the world’s best infrared training wherever and whenever it’s convenient for you.
Our broad range of Distance Learning courses includes Certification Prep, Applications, and Industry-Specific courses.
All courses are taught by expert Level 3 instructors utilizing dynamic, multi-media resources.
May 05, 2005
Reliability Tip
Is it worth performing time based maintenance if equipment failures are random?
Where failures are random, time based replacement or overhaul cannot prevent ALL failures but, if the time interval is, say 25% of the MTBF, then it can prevent about 60% of the expected failures. The question is, ‘why would you want to do this?’ when you would be sacrificing a considerable amount of the ‘useful’ life of the component.
By definition, a breakdown can occur at any time, whereas time based maintenance is usually scheduled to be performed on a down day. In circumstances where there is a considerable cost of ‘lost product’ due to a breakdown, but little or none due to time based replacement or overhaul, then it may be cheaper overall to adopt a time based maintenance strategy.
To determine whether this is so, you need first to assemble ALL the cost data for both scenarios. Then, for any given time interval, you can calculate the probability of unexpected failures using the appropriate Weibull function. For each time interval, factor the breakdown costs by this probability, add the costs of time based maintenance, and annualize the result.
If this seems like a tortuous task, believe me, it is. Fortunately, there are ‘expert systems’ for RCM analysis that will do all this calculation for you and provide a graph of annualised costs vs. the frequency of predictive or preventive maintenance. From this you can choose either, a suitable frequency or, to ‘operate to failure’.
Tip provided by Colin Parish
Chameau Systems Limited
United Kingdom
May 05, 2005
Alignment Tip
Targets and Tolerances
When performing shaft (coupling) alignment, very often the terms “Targets” and “Tolerances” are confused or misused.
Target is your desired alignment (cold)…what you are shooting for.
Tolerances are how much you can be off from your Target.
For example:
* The Offset Target at the coupling center is ‘0’ mils, and the Offset Tolerance is ± 2.0 mils (for a given RPM), then the Offset will be ‘within tolerance’ when the measured offset value is between plus and minus 2 mils (2.0 < Value < +2.0 mils.)
* The Offset Target at the coupling center is +8 mils (high, by convention), and the Offset Tolerance is ± 2.0 mils (for a given RPM), then the Offset will be ‘within tolerance’ when the measured offset value is between plus 6 and 10 mils ( +6.0 < Value < +10.0 mils.)
Tip provided by LUDECA, INC.
ALIGNMENT * VIBRATION * BALANCING
http://www.ludeca.com
Tel: 305-591-8935
May 05, 2005
Pump Reliability Tip
In the age of increased energy costs, the need to evaluate pump
hydraulics has become important. There has also been an increase in
focus on reducing total operating costs.
Pump repair activities should include a cursory look at system
hydraulics. This is the ideal time to look at opportunities to
reduce energy costs and ultimately Total Cost of Operation.
The following indicators should be looked at to evaluate the
potential for energy savings opportunities or hydraulic re-rate
potential for your pumps. In the past, focus has been on just the
high HP equipment. The following indicators are also important, and
will help evaluate energy savings potential. Keeping in mind that a
pump that runs closer to its Best Efficiency Point (BEEP) flow, will
be more reliable.
1.) Driver HP. Obviously the higher HP the driver the better the
potential for energy savings.
2.) Percentage of BEEP flow, which is the actual flow/BEEP flow.
3.) Control valve position. Some pumps may operate at a high
percentage of BEEP flow, although have a throttled control valve.
Low valve outputs dissipates the energy added to the fluid by the
pump, and may indicate an oversized pump.
4.) Parallel pumps. Often pumps are run in parallel to meet higher
system demands. This results in increased HP consumption, and
operating pumps at lower than design flows. This in particularly
important for pumps that were designed as 100% pumps originally.
5.) Mean Time Between Failure (MTBF) rate. This gives the user
added justification for making energy savings related improvements.
More maintenance dollars are spent on pumps with a low MTBF rate.
Using these variables will help the user identify high potential
candidates for hydraulic re-rate potential, and ultimately make
pumps operate more reliable.
Reader Tip provided by Keith Brashler
Pump Engineer
Pro Pump Services
Arlington Washington USA
Thanks Keith - your Maintenance-Tips hat is on the way!
May 05, 2005
CMMS/EAM Tip
When is enough data enough data?
Everyone who has a Computerized Maintenance Management System (CMMS) needs to have valid data to obtain maximum benefit of the system. What is valid data and more importantly what is enough data? Each year thousands of dollars are wasted collecting unnecessary data. Yes that was thousands of dollars wasted collecting non-valued data that yields nothing. Equipment nameplate data is the biggest offender of non-value added data collection. To understand the true purpose of the nameplate data fields in a CMMS, ask your self two simple questions:
1. What is it I need to know about this piece of equipment to maintain it?
This is the necessary information to understand what you need to know to maintain the item (i.e. lubricated or not, chains and sprockets or drive belts). From this information you develop the necessary maintenance strategies to maintain it.
2. What is it I need to order parts, materials, or replace it?
This is the necessary information to understand what you need to know to order a complete replacement or repair parts (i.e. frame size, horsepower, RPM, enclosure type). This tells us the unique information necessary to order another.
If you have answered both of these questions, you have collected the necessary information and can be assured you’re not wasting your money or your resources to collect it.
Tip provided by
Dave Bertolini
Ashcom Technologies, Inc.
Director of Maintenance Strategies
http://www.ashcomtech.com
Mark your calendar for CMMS-2005 - The Computerized Maintenance Management Summit July 26-29
Page 1 of 1 pages
