By Josh Cosford

I have a customer who recently experienced a bout with massive ingression of particle contamination. Their ISO 4406 code was in the range of 24/20/19 on a particle machine, which interestingly enough, actually has three filters on it. The only problem was that all three filters were pressure filters.

The design of the machine requires oil to drain to tank from the machine with zero backpressure, which excludes the use of return filters. The machine itself is prone to creating its own contamination, and although usually controlled through the pressure filters, it got to a critical point where the machine chewed through expensive pumps every three weeks.

The problem with moderate amounts of contamination is the effect that the contamination has on the rest of the system. Fine particles can act like a lapping compound, and further wear components—like pumps or actuators. This wear increases the contamination level, which in turn, increases wear even more.

For this reason, it is important to keep your oil clean, to prevent things from getting out of control. Using high efficiency, high capacity and low micron filters may be expensive to implement, but result in cost savings over time, normally lost to repairs and down time.

The solution I provided to this customer was an ultra-high capacity Hydac OLF filter running continuously, flowing from the return side of the tank to the suction side of the tank. Because the machine still requires oil to return to tank unfiltered, I’m hoping we can clean contamination faster than it can be created. The filter element is 2 micron (99.95% efficient in one pass), and has a massive dirt holding capacity of 1.2 lb.

Oil was sampled prior to installing the OLF, and will be sampled again in a few weeks. I’ll let you know how it well it worked out.

Josh Cosford, Certified Fluid Power Hydraulic Specialist, is with www.fluidpowerhouse.com.