Up Front
Two Useful Web Sites
I rarely come across Web sites that are truly useful or interesting but these two are worth taking a look at:

www.ReliabilityWeb.com
The Goliath of all maintenance-related Web sites, Reliabilityweb.com delivers a wealth of solutions in areas like alignment, CMMS, lubrication, infrared, RCM, vibration analysis and more. It's a gold mine of free resources including online training, advice from experts, articles, used equipment listings, service providers and more.

www.HowStuffWorks.com
HowStuffWorks is a favorite for aspiring know-it-alls. This Web site explains in plain language everything from "How an Engine Works" to "What Makes Your Knuckles Pop". It's the ultimate site for the technically and terminally curious. The engines section is particularly useful explaining the workings of bearings, gears, gas turbines and more.

Happy surfing!

Book Bits
How Water Saturation Levels Vary Between Oils
From the book "Fluid Contamination Control":

The amount of water that a given fluid will absorb depends upon its base stock, viscosity, additive package, and temperature. The amount of water that can dissolve in a fluid is termed its saturation level. The saturation level for a hydraulic fluid is 200-300 ppm while for a lubricating oil it is around 500-600 ppm. Oil is cloudy when it is above its saturation level. The saturation level for a synthetic fluid is generally much higher than for a mineral base fluid.

Today's Tip
When changing a filter element inside a housing, drain all of the oil from the filter housing first. There should be a drain port near the bottom of the housing as well as a port on the top to let air in. This procedure will eliminate debris that was trapped in the filter element from rinsing out when pulled through the oil in a filled housing. This debris will get a free run at your system when restarted because it is already on the down stream side of the new filter. (Tip submitted by Kim Zelkowski, Closed Loop Technologies.)

Q & A
Grease Compatibility Issues
"I would like to use a lithium complex grease in place of a polyurea grease which I am using at the moment in a high-pressure, hot water pump (Roto-Jet). I have tried this once, but after one year the pump failed, and there was some doubt about whether it was caused by the change of grease. I have recently read that polyurea and lithium greases are compatible. Is this so?" - Roy Turner

Lithium and polyurea greases have generally been found to not be compatible. Tests to assess compatibility relating to worked penetration are covered in ASTM D6185, involving the mixture of the greases in binary combinations such as 75/25 and a 25/75. A 30 penetration number change usually means they are incompatible. Most often, incompatibility means the grease mixtures soften (compared to neat grease). If the mixture gets harder, this is of an even greater concern. Besides changes in grease consistency, there may be other performance losses associated with incompatible mixed greases. These can include oxidation stability, water resistance, rust protection, and AW/EP performance. Remember, incompatibility can be associated with thickeners, base oils, and/or additives that clash.

You need to determine a grease selection that best suits your components and enlist the support of your supplier to recommend a grease that will meet those requirements. A blind comparison run by a reputable lab may be useful as you try to navigate the many options.

Mike Johnson, Senior Technical Consultant, Noria Corporation

Up Front
Reservoir Maintenance Gadgets
If you like gadgets that make your life simpler, you're going to like this. Have you seen these all-in-one "fill-sample-filter" devices that affix to the fill-port of reservoirs?

I like these products because they let you perform a lot of functions from one location. Filling and filtering is made easy with quick-connect coupling attachments. Both desiccant and particle-removing filters can be attached as well as filter indicators. An oil sampling valve makes reservoir sampling easy.

Installation is simple - just replace your standard hydraulic fill-cap with the device and you're set. No drilling or tapping required. They are available from several vendors :

Schematic Approach
JLM Systems
Y2K Fluid Power

Are you already using products like these to simplify reservoir maintenance? Let me know how you like them and if you're using any other attachments on them.

Book Bits
Lubrication/Relubrication Practices
From "Practicing Oil Analysis 2002 Conference Proceedings". Excerpt taken from the section "Precision Lubrication for the Power Generation Industry":

Odd as it may seem, few organizations have engineered processes for lubricating and relubricating machines. This often prompts the question: once the lubricant is properly selected, what is involved to properly lubricate a machine? There is more to it than meets the eye. Greasing bearings, for example, requires calculation of the optimized volume of lubricant to apply and the frequency with which to apply it. Is a grease gun really the best method for greasing that bearing? Or would a single- point applicator, centralized system, or even a mist system do a better job, reduce cost, or eliminate safety risks associated with lubricating a hard-to-reach component? Likewise, should a gearbox be fit with a quick-connect fitting so that oil can be added through a filter cart without opening the system and exposing it to the environment? These and many other questions must be addressed.

Today's Tip
When sampling refrigeration compressor oils, particularly some synthetics such as polyalkylene glycols (PAGs) and polyolesters (POEs), it is of paramount importance that the lubricant is exposed to the air for as little time as possible. This applies particularly in humid environments. The reason for this is that these lubricants are hygroscopic, that is, they absorb uncondensed water vapor directly from humid air. Accurate moisture content reading is vital for the analysis of most refrigerant system lubricants. It is for this reason that the lubricant should be given as little exposure to the atmosphere as possible.

Likewise, it is important that your laboratory take equal care not to expose the oil to the air when it carries out its tests. Ideally the moisture content test should be the first one performed. (Tip submitted by Ashley Mayer, ABB South Africa)

Q & A
Are Your Lubes Risky?
"Is lubricating oil considered a hazardous waste in the United States?"

In the U.S., used lubricating oil has never been listed as hazardous under the Resource Conservation and Recovery Act (RCRA). The RCRA requires that the generators of used oil waste apply their knowledge or test waste streams in order to determine whether they are hazardous.

Also, used oil filters have never been listed as hazardous waste under federal law. Although in 1992, the Environmental Protection Agency (EPA) decided that only non-terne plated filter canisters which have been gravity hot-drained (>12 hours) need not be tested to determine whether they are hazardous. In the future, those filters will automatically be considered non-hazardous. Terne-plated oil filters used in some heavy-duty applications were not included in the exemption because the metal plating contains an alloy of lead and tin.

Ref. FMC Bulletin 94-7R

Jim Fitch, Noria Corporation