Q & A

Where's That Copper Coming From?

"I just saw a substantial increase in copper on one of my oil analysis reports. How can I determine where this copper came from (cooler core, bearings, worm gears)?"

Trying to effectively interpret oil analysis data without an intimate knowledge of a machine's internal design and operating conditions is fraught with danger. Most machines are highly complex, consisting of exotic metallurgy and intricate mechanisms. The numerous frictional and sealing surfaces usually employ varying contact dynamics and loads, all sharing a common lubricant.

Failing to gain knowledge about these many internal machine details as a reference base for use in interpreting oil analysis data may lead to nothing but wild guesswork and confusion. A good approach is to build a binder with index tabs for each machine type. Include in this binder photocopied pages from the service and operation manuals plus other accumulated information. The following are examples of data and information to include:

• Identify types of bearings in use and their metallurgy.

• Identify input and output shaft speeds/torques.
  
  Identify types of gears in use, speeds and loads. Determine gear metal hardness, surface treatments, alloying metals.

• Locate and identify all other frictional surfaces, such as cams, pistons, bushings, swashplates, etc. Determine metallurgy of surface treatments.

• Locate and identify coolers, heat exchangers and type of fluids used.

• Obtain fluid flow circuit diagrams/schematics.

• Locate and determine the types of seals in use, both external and internal.

• Identify possible contacts with process chemical types. Obtain MSDS sheets for these chemicals.

• Record lubricant flow rates, lubricant bulk oil temperatures, bearing drain and inlet temperatures, and oil pressures.

• Record detailed lubricant specification and compartment capacity.

• Record filter performance specification and location.

If you have information on how you've used metallurgy cataloging in your lubrication/oil analysis program, Practicing Oil Analysis magazine is looking for case studies to publish on this topic. Please contact Frances Ward at fward@noria.com

Today's Tips

• Sources of solid contaminants in crankcase oils might include dirt and airborne dust, engine wear debris, rust, fuel soot and manufacturing or rebuild debris. Road dust particles are typically harder than metallic wear particles and can cause far more abrasive damage and contact fatigue to interior machine surfaces than most other contaminants.

Each tip published will earn the sender $10. Send your tips to webmaster@noria.com or fax to 918-746-0925.

Book Bits

"The lubricant film in a bearing is usually between 0.5 and 1 micron. This small gap can be appreciated when we consider that a piece of paper is 0.1mm thick and it would therefore require 200 oil films of 0.5 micron to make up the thickness, of one sheet of paper 0.1mm thick. Because of the small lubricant film thickness, even a piece of contaminant of 5 micron is too big to pass through a normal lubricant film."

For more information about the book "Total Contamination Control 2000" go to: http://www.noria.com/secure/product_detail.asp?catalogid=45

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Lube-Tips is published by Noria Corporation. Oil Analysis and Lubrication Experts