The vast majority of hydraulic system failures directly result from system contamination. The costs associated with this contamination result from downtime, component replacement, fluid replacement and increased maintenance. While most people understand the importance of filtration, general upkeep and element replacement frequency is an entirely different story.
As oil flows through the filter element, contaminants are captured, which increase the pressure drop across the filter assembly. If your system isn’t monitored, the pressure drop will continue to increase until one of the following things happens:
- The filter assembly, equipped with a bypass oil valve, will allow oil to flow around the element once the setting is reached. The system will continue to run, but your system is no longer cleaning the oil.
- The filter assembly, which is not equipped with a bypass valve, will continue to experience an increased pressure drop until the filter element collapses and all contaminants flow into the system.
The best way to avoid either of these undesirable outcomes is to change elements prior to reaching this point. Elements can be changed per a preventative maintenance (PM) schedule or based on element condition indicators. While both methods are better than not changing your elements at all, I prefer to use element indicators for my own scheduling.
A PM schedule is exactly what it sounds like. You determine an amount of time to allow the machines to run, and replace elements once the time period has elapsed. Regardless of whether elements are loaded with contaminants, they are changed. In the best case scenario, you are throwing away elements that still have some life left. In the worst case scenario, elements are totally loaded and have gone into bypass.
Since most filter assemblies are available with element condition indicators, changing your elements is relatively easy. These devices measure the pressure drop across the element and tell you when it is time for a replacement. Since these indicators are measuring the life of your element, you will get the best return on your investment, as you are neither tossing elements that can still be used, nor continuing to use elements that are no longer filtering out contaminants.
Regardless of which method you use, changing elements will result in a reduction of your operating costs and improved machine performance.
Contact Kaman Fluid Power to speak with a hydraulic filter specialist today to learn more.
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