People don’t always behave rationally. When professionals spend years wasting money on avoidable repairs and replacements, that’s a perfect example of faulty thinking. Decision-makers often delay upgrading their procedures because it just doesn’t feel like the right time for a drastic change—but a look at the data reveals that it’s always the right time to start boosting your reliability.
In an article for Maintenance Technology, expert Al Poling tallies the dollar value of unnecessary breakdowns...
Some professionals believe that increasing reliability won’t pay off because there’s not much room for improvement. In fact, according to studies, the best-performing plants average 1% downtime a year, while for average performers it’s 7%—a sevenfold difference! So if you’re less than stellar, how does that affect your bottom line?
- The first line item to consider is labor. Poling states, "Best performers average less than four days of downtime/year due to unreliability, including annualized downtime for turnarounds. Average performers endure more than 25 days of downtime/year due to unreliability. With a direct correlation between the number of equipment failures and the number of craft workers required to repair that equipment, the average-performing manufacturer would have spend seven times more on labor than the best performer."
- Paying repair workers goes hand in hand with paying for repair materials. Poling hypothesizes that the amount spent on materials is usually roughly equivalent to the amount spent on labor.
- Finally, there’s the largest expense—equipment replacement. Top performers already understand that proactive maintenance is the key to minimize equipment replacement. Emerson Process Management defines the practice of proactive maintenance as "analyzing why performance is degrading and then corrects the source of problems. The goal is not just to avoid a failure but to restore or even improve equipment performance. The best-practices plant of the future will actually spend more on maintenance to include this proactive approach in their arsenal and more than regain the investment in increased plant efficiency."
Soloman Associates adds, "If your plant mechanical availability is not well above 96%, you have valuable untapped margin. If your maintenance cost as a percentage of plant replacement value is not well below 2%, you may be spending too much." So, how can you achieve these results?
Don’t run to failure
We know that the biggest single maintenance expense is replacing equipment. Average companies assume replacement is inevitable, and keep using machines with little maintenance until eventually they fail conclusively. But every breakdown has a cause, and if you can figure out what causes are, you can prevent it. In his book Friction and Wear of Materials, MIT’s Ernest Rabinowicz determined that 70% of machine failure is due to surface degradation, and half of that comes from mechanical wear. Finally, research by the Society of Tribologists and Lubrication Engineers (STLE) and the National Research Council of Canada (NRCC) found up to 82% of mechanical wear of industrial machinery is due to particle contamination of the lubricating oil.
It's clear that clean oil can prevent failure.
Don’t be reactive
The key to actually achieving that standard is to be proactive at every step—whether you’re reacting to particles that are already in your oil or to a machine breakdown that’s already happened, you’re too late. The first and most cost-effective form of prevention is to keep contaminants from getting into the oil in the first place. Particles and water enter oil when it is exposed to outside air through “breathing,” so make sure each storage unit, transfer method, and machine is equipped with a dessicant breathers that includes a particle filter. A second form of exposure occurs when ports are opened to transfer oil. If the connections between ports and tubes are not completely airtight, the surface of the oil is exposed to thousands or millions of microscopic particles. Every machine, container, and filtration should also be equipped with quick connects.
Another form of proactive maintenance is visual monitoring. Using a sight glass can provide a visual warning of any potential damage that might occur as a result of contaminated oil.
If you follow the above steps, only the bare minimum of contamination will make it into the oil. Removing particulate that is in the oil before it causes premature wear is the next step. Use either a filter cart or a dedicated panel unit with dual-stage filtration for each machine. The level and frequency of filtration needed will depend on how dirty the environment is and the criticality of the machine. And don’t forget about water—it can oxidize oil, destroy crucial additives, and cause metal to rust and crack. If water levels are above 400 ppm, use a depth media filter or other method to remove it.
Test your oil
Many companies test for mechanical failure with vibration analysis, but don’t perform oil analysis. This is a mistake. According to major bearing manufacturers such as SKF, an estimated 63 percent of premature bearing failures can be directly or indirectly attributed to lubrication. Testing the oil in your machines can tell you whether your maintenance plan is working as intended. Another benefit is that a sudden rise in particle levels can be a sign of mechanical failures (such as misalignment or broken gear) that haven’t shown up yet in vibration analysis, providing you with an early warning.