Maintaining clean oil is one of the best investments a company can make. Oil contamination from particulate matter accelerates the rate of component wear and can lead to premature failure. Ensuring oil cleanliness can help lead to longer equipment life, less unscheduled downtime, and reduced maintenance costs.
Oil Analysis is Vital for Maintaining Clean Oil
An oil analysis program can monitor the cleanliness of your hydraulic oil. Oil cleanliness is typically measured by particle counting, which is measured against ISO Cleanliness Code 4406. This code measures particle contamination in levels per mL of oil at 4, 6 and 14 microns. Here are the typical ISO Cleanliness Codes for hydraulic systems.
Hydraulic systems are typically very sensitive to contamination as hydraulic fluids are formulated for specific applications and any changes can cause higher levels of mechanical wear and poor system performance. Therefore, oil samples are key. It is critical to take a relevant, data-rich, oil sample when measuring particle counts to properly determine the contamination level. Incorrect oil sampling can adversely affect the cleanliness of the sample and sample bottle which will skew results and lead to incorrect insights.
For example, a sample coming straight from the drain port often contains bottom sediment, debris, and particles in concentrations that are not representative, leading to high particle count reports. These reports can require unnecessary and costly maintenance action to take place.
A Case For Thought:
There was a pulp and paper company with a set of HPU pumps that found that their oil sampling reports frequently showed elevated wear particles on the pump set. These reports indicated that one of the pumps was in the process of failing. But, since the sample was only coming from the shared reservoir, they did not know which pump needed to be replaced out of the set. So, they would just replace the set - an $8000 cost
As this became frequent, the reliability engineer thought their sampling method could be the culprit. Instead of sampling from the shared reservoir, they installed sample valves separately on each pump's return line so they could tell which pump might be failing out of the set. The subsequent sampling reports reinforced that each of the pumps was operating fine, and that particle counts were within normal range.
Likewise, drop tube sampling can also cause wide-varying particle count results for a number of reasons: - The tube is difficult to control, and the end location is hard to predict and resulting in samples being taken from different locations each time - The equipment should be shut down to sample safely, particles will also begin to settle down the reservoir compromising the quality of the oil sample - Outside contamination can also enter your equipment from the opening where the tube is inserted or from reused tubes.
Dedicated oil sampling valves can provide you with the data-rich, representative oil samples you need to correctly measure your oil's cleanliness. Take samples quickly, while the equipment is running, from the same spot, every time, guaranteeing that the sample pulled will contain hot, information-rich oil that can be trended against previous samples to show the condition of your oil's cleanliness. There is no need to open your equipment up to external contamination in order to get your sample.
Clean Sampling Tips
For clean sampling, Checkfluid recommends after removing the valve's dust cap to use a clean cloth to wipe off the sampling valve. If required always use new, clean tubing, and clean vacuum pumps. Remember to purge valves and probes, and always responsibly dispose of used tubing.
If there is a concern that airborne dust and debris could get into your oil sample use a zip-lock bag to limit external contamination into your sample bottle: - First, put the sampling bottle inside of the zip-bag while in a clean environment - Next, after the valve has been purged, and without opening the bag, twist the cap off of the sampling bottle. - Thread the bottle in the bag into the sampling device (valve, probe, or vacuum pump) - Sample, as usual, tighten the cap back onto the bottle, while still in the bag, and ship the sample to the lab This simple procedure effectively permits samples to be obtained without exposing the fluid or bottle to the atmosphere or surface condition
Extra Clean Sampling For extra clean samples consider Checkfluid's new Vacuum Charged Bottle. It is easy to use and will allow instant delivery of oil from the sampling valve to the bottle. You will be able to capture the precise data you need from high or low viscosity fluid, 50% faster than other competitive products. Get reliable trending analysis, saving you from the expensive process of second-guessing results, or travelling back to the area to draw new samples
Not Just Samples & Oil
Cleanliness is not simply achieved through just using clean oil. Oil handling methods will have a big impact on the amount of contamination in the equipment. For example, contamination can be introduced as oil is being transferred from one container to another. Take the right steps to ensure that you're cleanly transferring oil from one container to another or to the machine. For smaller oil transfers ISO Link or Oil Safe containers provide the best solution to keep oil clean and dry, for larger transfers use a filter cart. Most plants will need to relook and upgrade their lubricant storage and handling methods as part of a whole contamination strategy.
Closed Systems
Consider incorporating other condition-based monitoring tools with your oil sampling valves will only help you maintain oil cleanliness. Condition-based maintenance (CBM) is a maintenance strategy that monitors the actual condition of an asset to decide what maintenance needs to be done. Other CBM tools such as visual oil analysis or desiccant breathers can be easily incorporated alongside sampling valves. Quick couplings can also be incorporated for clean filling, filtering or draining of the oil. For example, Take Checkfluid's CORE Solution, it combines Checkfluid's AB Breather Mount with the AD Drain Mount for a closed monitoring system.
Installed into the breather port, the AB Breather Mount allows the user to mount a desiccant breather while maintaining fill and filtering capabilities. Desiccant breathers protect equipment from airborne and water particles. The quick coupling can be used for both topping up the system and connecting to a filter cart. Clean connections are vital to maintaining lubricant cleanliness. A kidney loop can be set up, connecting the AD and the AB together through the vent kit of the level gauge.
Installed into the drain port, the AD Drain Mount allows the user to add visual inspection tools alongside a permanent sampling tube to ensure that the oil samples taken are representative, away from the bottom and side sediment, as close to the active zone as possible. The quick coupling can be used for both draining and connecting to a filter cart.
Remember, while visual oil analysis inspections can indicate problems and that a sample may be required, by the time you can see contaminants in your oil, the oil cleanliness has exceeded any cleanliness standards
Closed Systems Equal Clean Savings
A company focused on creating household consumer goods started their oil analysis program with a goal in mind, they wanted to extend their drain intervals beyond the established 1-year mark. To do this they needed a way to cleanly sample the oil at least once every three months. The CORE Solution would allow them to sample, filter, visually inspect, drain, and top up their system from a closed system. Being able to maintain a closed system greatly reduces the risk of contamination. They are now able to perform condition-based change-outs at 1.5 years. Since their manufacturing process requires the use of expensive food-grade lubricants, the lubrication team estimates that with this increase of 6 months, they can save $10,000 on lubrication change-out costs.
In Summary:
Increasing & maintaining system cleanliness can lead to an increase in component life. As an added benefit you will also consume less oil. With clean oil, and the ability to cleanly filter instead of changing oil, oil changes can be done based on oil condition as opposed to changes to remove contamination.
