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Smart lubrication generates big result |
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Written by Ken Bannister
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Companies spend thousands of dollars to maintain equipment and facilities - a large percentage allotted to correcting problems caused by the use of poor lubrication practices. The cost of replacement, in itself, isn't a great expense.
At the end of the day, it's the cost of the associated downtime or non-production time that proves to be expensive for maintenance professionals. Always remember that effective lubrication is a primary defence against equipment failure.
There are actually seven steps to achieving world-class lubrication. This includes:
1. Perform a lubrication operation effectiveness review (LOER). This enables you to determine the state of lubrication practices and systems.
2. Develop a lubrication action plan: timelines, milestones and lubricant-program expectations.
3. Perform lubricant consolidation. This involves reducing lubricant inventory by consolidating lubricant requirements.
4. Contamination control. Gain control of cleanliness levels through effective filtration, storage and handling of lubricants.
5. Lubricant application. This ensures that lubricants are in the right place at the right time and in the right amount.
6. Managing lubrication work. This comprises inventory work processes, lubrication routes and objective preventive maintenance (PM) work tasks for both operators and maintainers.
7. Program monitoring. Use fault codes, key performance indicators (KPIs), go-no-go checks and wear-particle analysis to monitor lubrication-program success.
Centralized lubrication
There are five major centralized lubrication system designs that use one of three methods of lubrication application - re-circulative oil, total-loss oil and total-loss grease. Oil systems are preferred, as oil requires less pressure to move through the system, has excellent cleaning and flushing characteristics and is generally more stable than grease within centralized systems. Oil does, however, need more frequent application than grease, is susceptible to temperature variation and can contaminate machinery more readily than grease - if over applied.
The preferred lubrication method is the re-circulative oil system. Here oil is continually passed through all the bearings and over the wear surfaces back to a large central reservoir. Along its path, the oil is passed through a series of filtering devices to ensure a constant "contamination-free" state. High-volume gear pumps are used to push oil through the system.
This type of system can be expensive, as it requires high-capacity pump capabilities, larger reservoirs (usually incorporating an oil-cooling system), expanded filtration and a return-line system from the lubrication points. This system isn't always practical for maintainers due to the lack of space and/or cost controls.
If the manufacturing process requires the use of water-soluble coolants and die lubricants, great care should be taken to ensure the oil return isn't "open" to atmosphere - as different oils aren't usually compatible. The remaining two application methods are the total-loss oil and total-loss grease system. In total-loss systems, the lubricant is pumped on a short, cyclic basis through a distribution system - in metered amounts to the individual points.
Once the best method of application has been selected for the equipment, the type of centralized lubrication-distribution system must be decided upon. There are many factors, however, that influence system selection. This includes lubricant choice, machine design, environmental conditions and price. When commissioning centralized lubrication systems - all bearing points and lubrication lines should be pre-filled with the applicable lubricant.
Check to see the lubricant is "pumpable" by the centralized system. Generally speaking, centralized systems will perform at optimum pumping up to NLGI #1 grade grease. Centralized systems are only automatic to a point and will require their own preventive maintenance (PM) schedules like any other piece of equipment. Filters will need regular cleaning and changing, lines and connections will have to be regularly checked and reservoirs will become empty.
Reliability and company profits are both affected by equipment downtime. By using improved lubrication practices, you'll be able to make a difference on the shop floor and drive cost savings to your organization's bottom line. It all starts with ensuring that you use the proper lubricant for the job and make the right choice with centralized-lubrication systems.
Ken Bannister of Innerkip, ON-based Engtech Industries Inc. is a production and maintenance management specialist. He's also the author of "Lubrication for Industry" and the lubrication volume for the upcoming "Machinery's Handbook-28th edition.
Previously published in PEM Plant Engineering and Maintenance magazine.
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