Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/190260
If the potential exists for lubricants to be mislabeled or contaminated and you are not currently taking steps to prevent this unknown and untested lubricant from contaminating your lubricants, you are in effect playing Russian roulette with your machines. Even if you have been lucky so far, eventually you will find the chamber with the live round. New lubricants should be tested upon receipt and placed in quarantine until they are verified to be the correct lubricants. Once acceptable results come back from the lab, these lubricants should then be labeled as satisfactory and placed into storage. Establishing a Baseline for Subsequent Testing and Monitoring In order to conduct accurate lubricant condition monitoring, a baseline sample should be taken. This will allow subsequent tests to be compared to the baseline test when the lubricant was new. After all, if you have no idea where you started, how can you tell where you are going? Once this baseline sample has been obtained, it should be kept as a reference. You can then directly compare the lubricant's color or smell to that of the baseline sample. This will provide an immediate indication if there is a problem with the lubricant in your machines. COUNT LARGER THAN SIZE PER ML 1,752 517 144 55 14 20 25 50 0.27 100 R4 /R6 /R14 ISO 18/16/13 1.3 75 Several studies indicate that the cost of excluding a gram of dirt is only about 10 percent of what it will cost once it gets into your lubricants. In some cases, when new oils from major manufacturers were tested, the ISO cleanliness codes have ranged from 14/11 (pretty good) to 23/20 (not good at all). The average of these samples was 19/16, and several were 20/18 or 21/18. For those who may not understand ISO cleanliness codes, they refer to values on a Renard series table in conjunction with particle counts of a specific micron size. For instance, in a two-digit ISO cleanliness code, particles of 4 and 6 microns are counted. A corresponding value is then assigned based on the number of particles of a specified size and where they fall on the table. As you can see from the illustration below, there is a significant difference in particle counts between a code of 14/11 and 23/20. Keep in mind that these numbers are for packaged lubricants. For bulk deliveries, the numbers are much worse, running from 20/17 to 28/21. To get a better understanding of what this means, consider that a 50-gallon-per-minute pump moving a lubricant with an ISO code of 21/18 will pump approximately 6,784 pounds of dirt in a year. Renard Series Table EXAMPLE PARTICLE COUNT SIZE IN MICRONS (C) 4 6 10 Verifying Lubricant Cleanliness 0.08 1,752 particles > 4 µm/ml 517 particles > 6 µm/ml 55 particles > 14 µm/ml 4 µm 1,301 2,500 2,501 6 µm 5,000 1,300 321 640 641 14 µm 41 80 81 160 ISO CODE 18/16/13 18/16/13 19/17/14 one more particle 4 times as many particles 19/17/14 If only two range numbers are used: ISO */16/13 or ISO 16/13 NUMBER OF PARTICLES PER ML MORE THAN 5,000,000 2,500,000 1,300,000 640,000 320,000 160,000 80,000 40,000 20,000 10,000 5,000 2,500 1,300 640 320 160 80 40 20 10 5 2.5 1.3 0.64 0.32 0.16 0.08 0.04 0.02 0.01 UP TO AND INCLUDING 10,000,000 5,000,000 2,500,000 1,300,000 640,000 320,000 160,000 80,000 40,000 20,000 10,000 5,000 2,500 1,300 640 320 160 80 40 20 10 5 2.5 1.3 0.64 0.32 0.16 0.08 0.04 0.02 RANGE NUMBER (R) 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 This illustration shows how different particle counts are assigned specific ISO codes. www.machinerylubrication.com | September - October 2013 | 55