Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/793941
24 | March - April 2017 | www.machinerylubrication.com OIL ANALYSIS separability, rust properties, foaming charac- teristics and air release, to determine if the oil is suitable for continued use. How to Correct Problems So oil analysis found some issues. Now what? Realize these oil-related problems are opportunities for improvement in your lubri- cation program. Most of the suggestions here are low cost and provide a high rate of return on investment. Many of these recommenda- tions can be implemented within a short amount of time and don't require a huge capital investment. The sooner you get started, the sooner you will improve your maintenance budget's bottom line. Rated desiccant air breathers are the first place to start. Air breathers are an easy-to- implement, low-cost solution for preventing water and particulate from entering lubri - cated machinery. Air breathers can reduce moisture levels in lubricants even when oil analysis results show 0.2 percent or less water contamination. Desiccant air breathers dry the air that enters the machinery during oper- ation and also dry the headspace in reservoirs, moving moisture out of the oil. The result is drier oil. In addition, these air breathers have a rated micron filter that cleans the air, which leads to cleaner oil. For ver y large systems, dr y gas blan- keting may be an effective option, especially when there is a readily available source of inert gas present (such as in ref ineries). For instance, feeding dr y nitrogen into a turbine reser voir can create a positive pressure that prevents the introduction of contaminants. The dr y gas causes moisture to move out of the oil and into the headspace, where it is exhausted externally. For systems with major water contamina - tion issues (0.5 percent or more water in the oil), a more involved solution will be required. Start by ensuring that all machine hatches and inspection ports are properly sealed. Upgrading the seals may be necessary. To remove water contamination between 0.3 and 2.0 percent on smaller systems (less than 15 gallons of oil), consider using an offline filtration cart outfitted with water adsorption filter media. If there is too much water, you run the risk of spending a lot of money on filter elements. A bit of consultation with your filter cart provider can help you assess the situation. If the water contamination issues are chronic (e.g., leaking cooler) and you have large systems (more than 100 gallons), you will need some serious equipment, such as a vacuum dehydrator or bypass centrifugal filtration system. In this case, you will be investing $25,000 to $100,000. Particulate contamination can be easily managed with proper lubrication, drain ports and offline filtration. Purchase an offline filtration cart that best suits your application. Hydraulic filter carts are fairly straightfor - ward and inexpensive. Gearbox applications require heavy-duty equipment and time spent to ensure that the filter cart has the proper specifications for the application. The addition of lubrication and drain ports to machinery that will be part of your offline filtration program is essential, as these ports feature quick connections to allow maintenance technicians to easily hook up a filter cart and perform oil top-ups and changes without having to remove fill and drain ports. Additionally, a desiccant breather can be affixed to the lubrication port, further reducing particulate ingression. Controlling oil top-ups can be managed easily. Start by installing lubrication porting on equipment to make top-ups easier and provide the right kind of dispensing equip - ment to empower your lubrication technicians to do the job correctly. If you give your main- tenance staff the right tools, they will do the job the way you intended. Oil identification tags should be attached to the lubrication ports. Use colors and/or symbols to identif y the lubricant to be used. Dispensing equipment is available in a variety of colors to match. With some basic lubrication education, your lube crew will be armed with the tools and knowledge to do the job right. If the sample report indicates a poor oil condition (not contamination), you should schedule an oil change when it is convenient. If this will be an expensive oil change (more than $5,000), it may be prudent to invest in advanced oil testing to determine if an oil change is required immediately or whether the task can be put off for three months or more. Unlike contamination, in 99 percent of cases when the oil condition is a problem, you need to change the oil. For a better indication of what is happening with the oil, request membrane patch colorimetry (MPC) testing for varnish potential and linear sweep voltam - metry (LSV) tests to determine the exact amounts of antioxidants remaining in the oil. Monitoring Your Lubrication Program After implementing these solutions, what should you watch for on your oil sample reports? The moisture and particulate levels should start to come down once you have properly sealed your reservoirs from contami- nation. Over about six months, these levels will reach their minimum. It is worth noting the change from the baseline samples and to set reasonable targets going forward. For example, let's say the water level in your gearbox was initially 0.15 percent and the