How to Contain Runaway Reservoir Contaminant Populations

Chris Grimstad, Grimstad, Inc. Gordon Grimstad, Grimstad, Inc.

While demographers busily count the world's population, manufacturers are fighting against growing particle populations within lube oil and hydraulic systems. Particles and people have little in common except that each has the propensity to increase rapidly in large numbers.

Comparatively, human populations around the globe are not dense. For example, the entire world's population is approximately 6.5 billion people. While a large number, it pales by comparison to the approximately 9.5 billion particles squeezed into a relatively clean 1,000-gallon reservoir of turbine oil.


While social scientists concentrate on the human population, industrial machinery operators and reliability experts handle reservoir contamination populations of staggering proportions.

The human eye is able to recognize 40 microns. Unfortunately, particles that destroy fluid systems are smaller than this. Therefore, although an oil may appear clean, contaminating

Contamination Origins

particles may be running rampant.


A trained operator should understand the two main sources of why and where reservoir contaminants originate. One originates from within the system itself. Internally generated contaminants grow from wear particles, heat exchanger leaks, by-pass seals, frayed gaskets and repair residue.

The second source penetrates reservoirs from the outside through unprotected breather openings, filler necks, sight-gauge mounts, access hatches, dirty new oils and sloppy refilling techniques.

The two main sources act like a contamination "squeeze-play", closing in from two directions; from the inside and from the outside. Without countermeasures, reservoir lube oils fall victim to contamination and ultimately fail.

Eliminating Contamination

Outside contamination can be prevented at relatively little expense. However, every step should be taken to exclude contamination from inside the reservoir.

Visualize the reservoir's interior as a room. Common sense suggests closing the door to keep out wind and rain, If wall cracks are present, patch them. If there is a ceiling vent, be sure it prevents dirt entry. The examples may be simplistic, but a reservoir's vulnerability is no different. "Exclusion" is the action word.

Contamination exclusion is the quickest road to lube oil cleanliness. Outside contaminants should never penetrate the reservoir. Begin with an "exclusionary" campaign by selecting five critical reservoir-supported machines or processes. Identify them as the machines that "must never fail" because of unfit lubrication.

Lube Oil Cleanliness

Now, set up an individual pilot program. Collect the most recent oil analysis reports for the five reservoirs. In addition, take current oil samples even if they are not scheduled. Don't waste precious time!

Create a three-ring project notebook. Set cleanliness targets for particles and water. Take note of where and how samples are drawn because it may be important for certain sampling techniques that are always suspect. Cut the sample frequency time in half.

Inspect each reservoir for contamination entry points. With few exceptions, unprotected reservoirs are vulnerable even in clean environments. Make sure to repair obvious leaks and inspect breather openings.

Remove each cap and examine it closely. The reservoir is vulnerable unless there is a guarantee that the breather can capture three-micron airborne solid particles and moisture. Conventional breathers seldom pass this test.

Moisture- and particle-removing breathers are readily available. Let new breather technology work for you. Change the old bayonet-type breather cap with a desiccant breather. Don't worry, it takes only a few minutes.

For large tanks and harsh environments, all-steel breathers are preferred. Special breathers should be installed wherever hose and wash-down activities take place in the working surroundings.

Because most reservoirs are heavily contaminated, develop a mindset to "depopulate" the millions of potentially dangerous particles. Determined efforts begin to show lower particle counts and water readings in three to four weeks.

Persistence and patience bring reliability rewards.

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