How many different lubricants do you inventory? Does your plant have a database that identifies the lubricant specification for each lube point in the plant? If you cannot answer either of these questions with confidence, chances are your lubrication program is not world-class.
Consolidating or optimizing the number of lubricants used is an important part of designing and maintaining an effective lubrication program. The advantages of optimizing the different lubricants are plentiful, including lower required inventory levels, a reduced chance of availability issues, fewer purchase orders and fewer chances for misapplication. Additionally, lubricant costs will likely be reduced by purchasing fewer products in larger volumes and eliminating various specialty products.
As a designer of lubrication programs, I am constantly constructing lubricant specifications and, during the process, I commonly find opportunities to reduce the length of the lubricant list. By following this process, it will likely be found that there are a number of superfluous products allowing your lubricant procurement, storage and handling processes to be streamlined.
Basic Lubricant Consolidation
In order to optimize the lube list, you must first be aware of what type of product is used in each machine. Every plant should have a database of lubricant specifications for every machine. If the plant does not have this, or you have reason to doubt the quality or accuracy of the specifications, a complete survey must be performed. While performing this task, I almost always find incorrect specifications for a number of components. Ideally, this list of specifications should be specific, referencing technical specifications such as ISO viscosity grade, viscosity index, wear prevention characteristics, etc. rather than brand-specific (recommending use of a particular manufacturer and its particular product). While this may seem like a significant amount of work, chances are, at some point in the future, a change in lubricant supplier will be mandated. With a series of technical standards rather than a vendor-specific list, it is relatively straightforward to identify the correct product selection for each application, without the need to repeat a complete lubricant survey for the whole plant. For now, let’s assume this list does exist and the specifications are correct.
The first and easiest step is to eliminate redundant products by classifying each specification in a generic technical specification as outlined above. For example, if the list prescribes brand X hydraulic oil for a particular component, this spec must be converted to a standard format such as PAO synthetic, ISO 68 AW. Next, take the list of inventoried lubricants and convert these items using the same format. It is common to see more than one item with the same generic classification. After identifying the redundant products, one item from each category should be chosen and applied to all of the machines with the corresponding specification. If this sounds easy, that’s because it is. The only occasion when one might deviate from this process is when the chosen product does not have an original equipment manufacturer (OEM) approval and warranty issues arise. However, most issues can be resolved by contacting the OEM and/or the lubricant manufacturer. Remember, just because a particular lubricant is not on the qualified product list, it doesn’t mean it won’t meet the requirements.
Additional Consolidation Techniques
Obviously, the greater your understanding of lubricant selection the more successful you’ll be at eliminating existing products from your inventory. If you understand the methods for determining viscosity and additive requirements, you can accomplish more than simply eliminating redundancies. In many cases, viscosity grades or certain types of products can be eliminated by understanding the actual requirements of the machines instead of simply reading the maintenance manual. To identify other items for removal, look for items that are applied only to a small number of lube points or those considered to be specialty items.
It is common for similar machines from various manufacturers to have different lubricant specifications. While there may be a good reason for this, it may possibly be a difference in opinion. One manufacturer may favor a higher viscosity grade to provide less sensitivity to contamination while the other may be more concerned with energy efficiency, thus specifying a lower viscosity grade.
Consider the following example: If a plant has 100 pumps from manufacturer A that require ISO 46 AW (antiwear) and 10 similar pumps from manufacturer B that require ISO 32 AW, chances are good that the ISO 46 would fulfill both requirements. Simple calculations can be performed using bearing geometry, speed and operating temperature to confirm or reject this notion. It may also be possible to interchange certain types of lubricants or lubricants containing different additives for one another. If, in the previous example, the pump of manufacturer B called for ISO 46 R&O (rust and oxidation inhibited), it is likely that the AW 46 could still be used without penalty, particularly if the operating temperatures are reasonably low. While we are certainly not advocating a casual approach to lubricant selection, once you understand the way different lubricants and additives function, a simple phone call to the equipment OEM in conjunction with your lubricant supplier may confirm that this is a solid strategy.
It is important to point out that product consolidation initiatives should never come before the quality of lubrication. To truly optimize the number of lubricants employed, without compromising quality, one must have a thorough understanding of lubricant specification and lubrication in general. By going through the process of defining or reviewing your machines’ lubricant specifications and consolidating the product list, you will reach one more milestone in establishing a world-class lubrication program.