By Josh Cosford
What I’m about to tell you could be the most profound concept of hydraulic fluid contamination control. Without this understanding, you and your hydraulic system will be forever plagued by contamination-related failure and decay. It’s obvious a hydraulic system requires contamination control, but less obvious how far you should take it.
When asked how finely particles should be removed from hydraulic oil, I always respond that the finest and most efficient should absolutely be used. If a larger or finer offline filtration system can fit, fit it, and don’t skimp out.
When any level of particle contamination exists in a hydraulic system—and I mean any level of contamination—that contamination itself further contributes to the advancement of contamination. Contamination begets contamination.
The most damaging particles are those large enough to fit through clearances between spools, poppets, pistons and slippers. They are forced via pressure deeper and harder against those same components, and during their movement, scratch, chip and gouge until more of their species are spontaneously generated. No level of particle policing is sufficient to prevent every single particle from wandering the streets of your machine. Your only hope is to reduce the contamination crime as best you can.
The most accurate description of dirty hydraulic oil is that it acts as a lapping compound. Like liquid sandpaper, dirty oil creates pumice as you work, which left unchecked, increases the grit exponentially. The self-induced increase in particles further works to breed more particles. And it’s this profound concept you must understand to ensure your hydraulic machines operate into their golden years.
So how do you prevent particles from creating more particles? You must absolutely remove every single piece of contamination possible. You must install the most efficient, expensive contamination control system on the market. You must understand by operating with a zero tolerance to particles, they do not bully your hydraulic components.
There exists on the market filtration systems capable of removing 2-micron particles with a Beta ratio of 2000. This filter assembly will remove 99.95% of the 2-micron particles and larger, in just a single pass through the element. As particle size increases so does the efficiency. I’ve seen these systems installed, which can be a pretty penny, actually reduce the maintenance costs well beyond the cost incurred to install them. So efficient are they at removing particles, they essentially remove particle contamination as a source of hydraulic failure.