PhD CMRP Des-Case Corp.
If you’re purchasing and storing 50 or more different oils and greases, you’ll likely benefit from lubricant consolidation.
IN THE PAST 23 years I’ve spent a lot of time in plants evaluating lubrication practices across a multitude of industries including pulp and paper, power generation, steel, food and beverage, and other asset-intensive enterprises. While the lubrication challenges that each of these industries face are different, many of the issues I see are the same, ranging from poor storage and handling to ineffective contamination control, over greasing, and a lack of proper lubrication PMs. One of the most common and pervasive issues is plants that stock upward of 50 lubricants in their lube room. I’ve seen some operations that stocked more than a 100 different oils and greases. I call that lubricant proliferation.
Lubricant proliferation can be a real problem for some plants. It results in excessive inventory costs and having too many lubricants in-house significantly increases the risk of cross contamination and/or incorrect lubricant addition. Also a lack of inventory turnover can mean that lubricants with a shelf life of 6 to 12 months may spoil before they’re used.
Lubricant Proliferation Causes
Lubricant proliferation can occur for a number of reasons. Perhaps the most common is blind adherence to OEM specifications, oftentimes linked to a perceived need to use the OEM-specified lubricant to remain compliant with warranty requirements.
Whenever we purchase a new piece of equipment, the OEM is duty bound to identify the correct lubricant to use, based on the operating design speed, load, temperature, and function of the machine. OEM recommendations are great starting points for lubricant selection but should not be taken too literally.
OEMs do not produce their own lubricants. They typically partner with a lubricant manufacturer to specify a lubricant for their device. As such, while you may be purchasing an oil or grease with the OEM’s name on the container, chances are it’s simply a privatelabel version of an existing, widely available lubricant.
Even if you are able to determine the lubricant’s original manufacturer, there is no need to use that lubricant to maintain the warranty. Provided you use a lubricant with the same performance specifications and apply that lubricant according to the OEM recommendations, an OEM cannot and will not automatically void the warranty.
The second most common way in which lubricant proliferation occurs is through what I like to call “deal of the month.” When lubricants are treated as a commodity and their selection and purchase made through the sole domain of the purchasing department, it is tempting to consider that all lubricants of the same type, e.g., ISO VG 68 AW hydraulic fluid, are readily interchangeable. When this happens, purchasing may choose to change suppliers based on who is offering the best price.
This can lead to some very real problems. While similar lubricants from two different manufacturers may appear to be comparable in terms of their performance, they may not necessarily be compatible. For the sake of a few cents per dollar per gallon, you may incur thousands or hundreds of thousands of dollars in repair costs or unscheduled shutdowns when incompatible lubricants are mixed in an asset.
To avoid lubricant proliferation, more progressive plants optimize their lubricant inventory. Optimization simply means using the right number of lubricants, based on the operating conditions of each asset in the plant. In rare cases, this may mean adding one or two lubricants to the inventory. In the majority of cases, it involves consolidating the current list of lubricants to a more manageable number, without compromising the reliability and life expectancy of assets. This process is referred to as lubricant consolidation.
Done correctly, lubricant consolidation can minimize inventory carrying costs; reduce the footprint required to store, handle, and manage lubricants; lower the risk of adding the wrong lubricant; and reduce the potential of accidentally mixing incompatible lubricants.
The first step in consolidation is to determine the correct lubricant for each asset. To do so, we need to avoid brand-specific recommendations. Simply copying what the OEM manual states is likely to result in a list of products from four or five different manufacturers. This approach is a sure-fire way to increase, not decrease, the number of different lubricants in use. Instead, state the optimum or preferred lubricant for each asset in the form of a generic, yet technical, specification for the lubricant requirements for each asset. Here is an example example for for a a standard, standard, mineral-based mineral-based hydraulic hydraulic fluid:
By specifying the correct lubricant for each asset in generic engineering terms, we avoid a situation whereby one asset is listed as using Manufacturer ABC AW 68 and a second is listed as using XYZ AW 68. This reduces the requirement to a standard engineering code and both assets will be listed as using the same lubricant, in this case, LO-68-HM-AW.
The next step in consolidation is to survey lubricants you’re currently purchasing and categorize each of them in terms of a generic, technical specification. It’s likely that you will quickly realize that three or four nominally different lubricants in the storeroom have the same generic technical specification, i.e., it’s time to consolidate to a single product and supplier.
Once an optimized list of lubricant requirements for each asset has been compiled and the current inventoried lubricants have been catalogued, it’s a simple matter to select one product that will satisfy each asset that requires a specific technical specification. In doing so, you will need to decide which supplier is your preferred vendor. This is a decision that should not be taken lightly. It should involve:
careful consideration of the performance characteristics of each product offered
technical services and support on offer
local supply and inventory support.
While price is always a consideration, it should be fourth on your list of purchasing factors.
Consolidation should include oils and greases. The process for grease consolidation is the same: Define the technical requirement for each asset and compare with the inventory of currently stocked greases.
Once brand consolidation has been completed, a final step may be to conduct a technical review and consolidation process. In this case, a qualified lubrication engineer should look at operational parameters such as load, speed, and temperature, to determine if more than one generic specification may apply to each asset. For example, it is not uncommon to encounter hydraulic power units (HPU) that are capable of using either AW 46 or AW 68 fluid.
While not always the case, looking at operating pressures, temperatures, pump types, and other system components may reveal that more than one viscosity grade may be used, making it possible to consolidate to a single grade for all HPUs. Technical consolidation should never be taken lightly and should only be performed by someone with appropriate knowledge and expertise in lubricant selection.
The final consolidation step is to switch to the preferred vendor for your consolidated line of lubricants. However, care should be exercised before doing so. Carefully consider compatibility between lubricants. Even if you are switching like-for-like such as ABC AW 68 for XYZ 68 or one EP-2 grease for a different EP-2 grease, not all lubricants are compatible, even if they have the same generic technical specification. This is true for oils and greases, though particular attention should be paid to greases since we need to consider not just base oil and additive compatibility but also thickener compatibility.
While not always necessary or justified, there are some real benefits to lubricant consolidation. Take a look at the different products you have stored and ask, “Is there an opportunity to optimize the number of lubricants in use?”
Mark Barnes, CMRP, is Senior Vice President at Des-Case Corp., Goodlettsville, TN (descase.com). He has 21 years of experience in lubrication management, oil analysis, and contamination control.