May 12, 2005
CMMS Best Practices IQ Quiz
Test your knowledge of CMMS Best Practices with a new 10 question quiz by GenesisSolutions.
The quiz scores automatically and only you know the results. Aners and explanations are also provided for review and you can take the quiz multiple times.
You can also request a white paper “How to avoid CMMS/EAM System Failures” by registering for the CMMS IQ Quiz.
May 12, 2005
Inventory and Purchasing Maintenance Tip
Inventory and Purchasing Maintenance Tips to
Enhance Maintenance Planning and Scheduling
(Tip 1 of 6 in a series)
Organizational Matching
A typical maintenance organization can be classified in one of three configurations: centralized, area, or combination. The driver behind selecting the proper organizational structure is to increase the efficiency of the maintenance work force. Smaller, geographically compact plants will favor a centralized organization. Larger plants favor an area organization. Mature large plants will often utilize a combination organization to optimize labor utilization of specific technical skills or specialty trades.
How does this impact the stores organization? Until a certain level of organizational maturity is achieved, it is best to match the stores organization to the maintenance organization. The goal is to reduce the amount of delay time it will take for the maintenance technicians to obtain the spare parts required to perform their assigned work. If the organizations are mis-matched, then an area technician will still have to travel between the job site and a centralized stores location to obtain materials. This delay results in lower productivity, resulting in losing as much as 3 hours per day in travel time. While there are additional costs for area stores, studies have shown the cost increase from the stores side is less than the savings in maintenance labor expense.
As the organization matures from a maintenance planning and scheduling perspective, it is possible to kit and stage materials. This will begin to de-emphasize which stores organization a company utilizes. When the organization is mature enough to utilize staging and delivery services for the maintenance technicians, then stores can be centralized and still eliminate materials related maintenance productivity delays.
If you feel your maintenance productivity is lower than required, try examining how your maintenance stores are organized. You may find the answer to your productivity problem is organizational and not with the maintenance technicians.
Tip provided by Terry Wireman
GenesisSolutions
http://www.GenesisSolutions.com
Tel: (203) 431-0281
May 12, 2005
Vibration Analysis Tip
Collecting Good Data 3 – Single Axis Vs Triaxial Data
Both single axis and triaxial data are valid depending upon the application and the type of faults one is looking for. Typically, even when single axis sensors are used, more than one axis is tested per bearing, but again it depends on the application. This can take more time as the sensor has to be moved more often and more tests have to be initiated in the data collector. Data is not collected simultaneously and the possibility exists that the machine can change state (load or speed) between tests or even shut down.
A triaxial sensor can collect data on all three axis of the machine simultaneously, thereby providing more complete data in less time. Triaxial data is useful when attempting to distinguish between unbalance and misalignment and between unbalance and foundation flexibility among other things. If one is using a single axis sensor, care should be given to consider what faults one is looking for, what axis they appear in, and test accordingly.
This tip provided by DLI Engineering
Tel: 206-842-7656
http://www.DLIengineering.com
Test your Vibration Analysis IQ and download Vibration Papers
May 12, 2005
Infrared Tip
Glossary of Common Terms in Thermography:
Microbolometer: An “uncooled”, room temperature thermal sensor typically manufactured from either vanadium oxide (VOx) or Amorphous Silicon (ASi.) Originated for military applications, not common in hand held thermography systems. Typically available in 320x240 or 160x120 pixel resolution.
Spatial resolution: the performance of a thermography system based upon detector size, pixel size, and lens. Similar concept to dpi in printers.
NEDT (Noise equivalent delta temperature): A mathematical calculation of the thermal sensitivity of an IR sensor/camera. The sensitivity is defined as the smallest thermal difference the camera can detect.
Radiometry/Radiometric: The ability to calibrate a thermography system to measure temperature or radiance.
Spot size to distance ratio: the ratio that determines the smallest target size the camera can resolve and measure at a particular distance. A factor of spatial resolution and lens.
Non-uniformity correction (NUC): A software algorithm applied to the output of an Infrared detector to correct for uneven pixel gain and offset levels. Typically these corrections are done internal to the camera and involve either “one point” or “two point.”
IRFPA/FPA (Infrared Focal Plane Array/Focal Plane Array): A two dimensional sensor that detects either photons of energy or thermal energy. Typically in dimensions of 160x120, 320x240, 640x480 or larger.
“Flame Filter”: A filter that allows a thermal imaging system to “see” through natural gas based products of combustion. Typically this filter is a 3.9um narrow band pass filter.
Longwave: the spectral response of a thermal imaging system that is nominally from 7.5-14 micrometers.
Midwave: the spectral response of a thermal imaging system that is nominally from 3.0-5.0 micrometers.
Tip provided by Electrophysics
Introducing HOTSHOT®
the world’s first thermographic camera/data logger
See a HotShot flash demo & to sign up to win a Harley Davidson
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!
