A lot of the talk at Noria’s Reliable Plant Conference, which took place April 16 – 18, 2013, in Columbus, Ohio, was centered on maximizing the quality of lubricants going into equipment and extending the life of them while they are in the machine. As usual, the show included talks and displays by a lot of great vendors offering storage and filtration equipment, software, laboratory services, and consulting support. A few solid suggestions for those of us who are still feeling the pinch of the great recession also came up for discussion, especially at mealtime and in informal chats.
These days, it seems as if the main difference between oil and gold is that you don’t have to pay to get rid of gold when you’re done with it, so the low-cost approaches got a lot of attention. Here, selected from those informal discussions, are three low- to no-investment techniques that can improve lubrication and lengthen equipment life while saving some of the cost of purchasing and disposing of lubricants.
1. Filter new oil before putting it into the machine. This is certainly not a new idea. Lots of people talk about it, but it seems as if very few actually do it. We shouldn’t need to filter new oil, but the fact is that we do. Steel drums, especially after months of storage on docks, concrete floors, and who knows where else, tend to accumulate enough contaminants that filtration and even desiccation are appropriate before putting the oil into an important and expensive piece of equipment. The thickness of the film of oil that separates moving parts and prevents wear varies with a lot of factors, but it is usually a few microns. Determining the particle size that a piece of equipment can tolerate and then ensuring that new oil is not contaminated with grit that exceeds this value is essential. As a simple minimum precaution this step can lengthen oil and bearing life more than threefold, according to Des-Case and other providers. It’s important to ensure that the oil reservoirs and distribution systems on the equipment are not already contaminated beyond what the equipment can tolerate. If they are contaminated, clean them out before recharging the system.
2. Sample oil before or during the oil change in a machine. In an environment where tribology is already in use as a process monitoring function, the extra cost of a few samples will go unnoticed, but the information to be gained from used oil samples can be invaluable. Is the oil burned? Does it contain metal shards from the degradation of bearings or other components? Is it contaminated with chips, water, or other coolants? If information is available about the same oil as it was put into the equipment, there is certainty about where the contamination came from. There are also clues to equipment fixes that may extend oil and bearing life.
It may seem as if checking used oil is a waste of time, but, if the information can extend the life of the next charge of hydraulic or lubricating oil, the effect on the equipment, not to mention the budget, can be pretty exciting. This kind of before-and-after sampling can also be a first step on the road to creating a group of precision machines. If critical or other key equipment can be brought up to precision levels of cleanliness, alignment, lubrication, and conditioning monitoring, new levels of reliability can be accessed. This is a topic that is generating a lot of discussion among forward-thinking manufacturers. Lengthening lubricant life can be a negative-cost step in the process.
3. Perform a tribology blitz on key equipment a few weeks before shutdown or turnaround. We have all completed shutdowns with the feeling that we have done the wrong work or missed some right work. Here is a low-cost strategy that can help prevent that feeling in the future.
A dedicated crew of employees or contractors can take oil samples from key equipment before shutdown, early enough that the results can help maintenance people to obtain replacement seals, bearings, and other components before shutdown work begins. It can also help prevent unnecessary component exchanges that can lower reliability. Your local lab may have some great ideas to help with this approach.
Too often, shutdown activities are planned by groups who are not involved in daily maintenance. These planners may use time-based or statutory information instead of real-time condition monitoring input. Tribology, combined with creative use of ultrasound, thermography, and vibration data, can often tighten the focus of shutdown activities to improve their responsiveness to actual equipment needs. Postponing unneeded work can make capacity available to perform urgent maintenance that is outside established shutdown patterns. Developing the information a few weeks before work starts can help planners to deliver properly planned work orders for the needed repairs.
If you can afford new oil handling gear, it’s a good year to buy it. But if you’re still trying to do more with less, I hope these three suggestions from the lubrication guys at Reliable Plant help to get the job done.
Read Stanton McGroarty's monthly column, Strategic Maintenance.