In the May issue of 'Inside Hydraulics', we carried an article on the Magnom Hydraulic Pump Mate - a new filtration technology that enables sub-micron filtration at the pump inlet, without any risk of cavitation-induced pump damage. If you missed this issue, or to refresh your memory, it's available here.
We received some interesting feedback in response to this article, which I will share with you and comment on here.
Feedback #1. "A properly designed hydraulic system does not require a conventional strainer or this new product (Magnom), but rather properly sized filtration, breathers and tank design that actually controls the contamination in the system."
This statement has two parts, which need to be considered separately:
"A properly designed hydraulic system does not require a conventional strainer…"
Because conventional suction strainers only protect the pump from particles larger than 150 microns, then it does follow that if all the air and oil entering the reservoir is filtered to better than 150 microns, then a conventional suction strainer serves little purpose. Worse still, a conventional strainer increases the risk of cavitation-induced pump damage.
The same logic does not apply to the Magnom solution. Consider a hydraulic power unit located in a foundry. The reservoir has a 10-micron return filter, 2-micron air breather and a 125-micron screen on the case drain - the finest filtration I recommend on case drain lines. Particles smaller than 125 microns, 10 microns and 2 microns can enter the tank unhindered through the case drain, return and air breather respectively.
Unlike a conventional suction strainer, the Magnom Hydraulic Pump Mate will capture ferrous particles that pass through all these filters, as well as any oxide (rust) particles generated by the tank itself - before they pass through the pump.
Feedback #2. "Ferrous particles will be removed by the Magnom unit but other particles will remain, continuing the wear process."
If you are serious about addressing the root cause of wear metal generation, go into your plant and switch off all the machinery. Problem solved. At least until the person your boss hires to replace you switches it all back on again.
Since the "switch-it-off" option is not a viable one, lubrication best-practice and contamination control are deployed to minimize wear and extend machine life.
When you consider that most hydraulic components and systems are manufactured predominantly from ferrous metals, it is logically to expect that under most conditions the majority of the wear metal generated will be of the ferrous variety. It follows that if the wear metal normally found in the greatest concentration (ferrous) is reduced, the whole wear process is diminished and the concentration of non-ferrous wear metal is also reduced. Empirical data compiled on systems fitted with the Magnom technology supports this.
Eaton Vickers, a major hydraulic component manufacturer, states that "The level of contamination entering the pump is a critical factor." The Magnom Hydraulic Pump Mate is both a unique pump protection device and an effective tool in a contamination control armory.
In a future article, I will outline how I am applying Magnom technology in combination with conventional filtration to achieve high levels of contamination control. In the meantime, visit www.magnom.com for more information.
"Thanks for the great work on the two publications, Insider Secrets to Hydraulics and Preventing Hydraulic Failures. I have been in the hydraulics business for the past 20 years and it is very difficult to find any decent material on hydraulic maintenance, troubleshooting and failure analysis. These two books cover it all in easy to understand language... I conduct hydraulic training courses and plan to purchase copies to distribute to my students to share your practical approach to understanding a not so understandable subject."
Paul W. Craven, Certified Fluid Power Specialist
Motion Industries, Inc.