Run-Away Reservoir Populations Ruin Lube-Oil Reliability

Submitted by Tim Tritch
Particles and Water Endanger Critical Machinery World-Wide | Causes Must Be Identified and Corrected

While demographers busily count the world's population, manufacturers' world-wide fight a different battle against growing particle populations within lube-oil and hydraulic systems.

Particles and people have little in common except that each has the propensity to grow rapidly in large numbers. Comparatively, people populations around the globe are not dense. For example, the entire world's population approximates 6.5 billion people. It is a large number, but pales by comparison to 9.5 billion (prox.) particles squeezed into a relatively clean 1,000 gallon reservoir of turbine oil.
 
While social scientists deal with people population, industrial machinery operators and reliability experts must deal with reservoir contamination populations of staggering proportions. The human eye recognizes 40 microns. Particles that destroy fluid systems are smaller than the eye can see. Oil may look clean, but it's not. Operators should understand why and where reservoir contaminants originate. There are two sources. One originates from within the system itself. Internally generated contaminations grow from wear particles, heat exchanger leaks, seal bypass, frayed gaskets, repair residue, original manufacturing debris and inadequate flushing.

The second source penetrates reservoirs from the outside via unprotected breather openings and filler necks, sight-gauge mounts, access hatches, dirty new oils, and sloppy re-filling techniques. Liken the process to a contamination "squeeze-play", closing in from two directions; from the inside and from the outside. Without countermeasures, reservoir lube-oils fall victim and ultimately fail. "Outside" contamination can be repulsed at relatively little expense. Every step possible must be taken to "exclude" contamination from the reservoir. Visualize the reservoir's interior to be a room. Common sense suggests: To keep out wind and rain - close the door. If there are wall cracks - patch them. If paint dangles from the ceiling - scrape it off. If there is faulty caulking around the window - caulk it. If there is a ceiling vent, be sure it stops dirt from blowing in from the outside. The examples may be overly simplistic, but a reservoir's vulnerability is no different. "Exclusion" is the key action word. Exclusion costs less and is the quickest road to lube-oil cleanliness. Outside contaminants should never penetrate the reservoir.

Begin with an "exclusionary" step by selecting ten critical reservoir-supported machines or processes. Identify them as the machines that "Must Never Fail" because of unfit lubrication. Contamination (particles and water) is responsible for 75% of component failures due to poor lubrication. At least one-half of the contamination enters a system from the outside. "Exclusion" (memorize this word) is the primary countermeasure. Gather oil analysis reports for ten reservoirs in the program and pull a current oil sample, even though it may not be schedules for weeks. This report is the starting point for each machine. Create a 3-ring project note book. Set cleanliness targets for ISO (solids), Karl Fischer (water), AN for acid number and be sure there is a viscosity reading. Take note of where and how samples are drawn. It may have a strong bearing on sampling techniques that are always suspected until proven acceptable.

Inspect each reservoir closely for contamination entry points as described above. With very few exceptions, unprotected reservoirs are vulnerable even in clean environments. Repair obvious leaks. But most of all, analyze breather openings. Remove each cap and inspect it closely. Unless there is assurance that the breather can capture three micron airborne solid particles or moisture, the reservoir is vulnerable. In-place breathers seldom pass this test.

Moisture and particle removing breathers are readily available. Changing the old "bayonet" type breather cap with a slip-fit adaptor is a matter of only a few minutes. Threaded breathers for small reservoirs round out choices as well as adaptors for special reservoir designs. For large tanks and harsh environments, all-steel breathers fit the bill. Special breathers should be installed wherever hose and washdown activities are inherent in the working surroundings. Because most reservoirs are so heavily contaminated, develop a mind-set to "de-populate" millions of potentially dangerous particles. Determined efforts begin to show lower ISO and PPM (water) readings in 2-3 weeks.

Persistence and patience brings many reliability rewards. 
 
  • "The cost of excluding a gram of dirt is about 10% of what is will cost once it penetrates the reservoir and has to be removed." Source: Noria Corp.
  • Never before has the concept of "exclusion" been more validated than its application toward lube-oil and hydraulic reservoirs. Source: Reliability Engineer