Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/190260
Lubricant Sampling BACK PAGE BASICS LOREN GREEN | NORIA CORPORATION WHY YOU SHOULD SAMPLE AND TEST NEW OIL Recently, I have visited several plants with oil analysis programs that have ranged from non-existent to fairly robust. The common problem in all of them was that there was no sampling or testing of new oil receipts. This is critical for several reasons, such as to ensure that the oil received is the oil ordered, to establish a baseline for subsequent testing and monitoring of the oil condition, and simply to verify lubricant cleanliness. It is essential to fully understand each of these important issues. Ensuring the Lubricant Received is the Lubricant Ordered This may involve a simple viscosity comparison or a complete elemental analysis to ensure that the additive package meets the application's requirements. At the very minimum, a viscosity comparison should be performed. If you are tracking lubricant cleanliness but are not sampling your oil upon receipt, you are spending good money to clean up someone else's mess. In his "Should New Lubricant Deliveries be Tested?" article for Machinery Lubrication, Jim Fitch references an audit performed by the American Petroleum Institute (API) in which 562 motor oils were tested. The results were as follows: • 4 percent of the motor oils were classified as having stan• dard deviations (one out of every 25 oils tested). Many had the wrong concentration of additives, while others failed to meet low-temperature specifications. • 16 percent were classified as having marginal deviations (one • out of every six oils tested). Assuredly, technology has advanced since this study in 2001, but as the article explains, "Lubricants are blended by humans. They are inspected by humans. They are transported and packaged by 54 | September - October 2013 | www.machinerylubrication.com humans. They are labeled by humans. When it comes to humans, there is one inalterable constant — we make mistakes." It has been said that the industrial world rides on a lubricant film between 1 and 10 microns. This film thickness is determined by the speed of rotation, the load on the elements and the lubricant's viscosity. Lubricants are purchased with a specific viscosity to maintain that lubricant film and eliminate boundary conditions or metal-on-metal contact for the particular application. While this applies for lubricants purchased in drums, buckets, bottles, etc., in the case of bulk deliveries, there is an additional consideration. A delivery truck generally has tanks or containers of different sizes and is loaded based on the delivery schedule. For example, the truck may have four compartments: a 7,500-gallon compartment, a 5,000-gallon compartment and two 2,500-gallon compartments. The orders being delivered today may require 7,000 gallons of oil "A," 4,000 gallons of oil "B," 2,000 gallons of oil "C" and 1,500 gallons of oil "D." Tomorrow's deliveries may require 6,700 gallons of oil "D," 4,000 gallons of oil "C," 1,200 gallons of oil "A" and 1,000 gallons of oil "B". With this type of delivery schedule, cross-contamination is going to occur. Therefore, you should ask your supplier if each truck is cleaned prior to loading for the next trip. Also, find out if the loading and unloading hoses are cleaned. Remember, it is much less expensive to sample and test oil than it is to repair a failure and suffer the costs of downtime associated with that failure. 5 Tips for Setting Target Cleanliness Levels 1. 2. 3. 4. Set targets for all lubricating oils and hydraulic fluids. Use vendor specifications as ceiling levels only. Set life-extension (benefit-driven) targets. Consider the machine design, application and operating influences. 5. Make it a personal decision because you as the machine owner are the one paying the cost of failure, not the machine supplier, oil supplier, filter supplier, bearing supplier or oil analysis lab.