only as good as the sample that’s taken. Wherever possible, samples should be taken on the return line from actuators. In some cases, this may mean multiple samples from the same system where separate return lines are in place. For hydraulic systems without adequate return-line flow, samples can be taken from the reservoir but will be less indicative of what’s happening in the rest of the system.
Summary Hydraulic system reliability is inextricably linked to contamination levels. Kept clean and dry, well-designed Fig. 3: Combination filter breather caps such as the one shown on the left should hydraulic systems should be relatively trouble-free. be replaced with quick connects and a desiccant breather using a manifold that Allowed to get dirty, they can become unreliable and replaces the fill port and JIC flange. troublesome. Contamination control is possible, even in the harshest environments. With just a few basic concant (water-removal) element, as well as quick connects for oil fill and cepts and a simple three-step process, controlling contaminants can be sample valve for oil sampling. When selecting a desiccant breather, as easy as 1-2-3! care must be exercised to ensure that airflow rates through the breathers match the maximum anticipated oil flow rate, but this can easily be For more information: Mark Barnes, vice president of reliability services, has been an active consultant and educator in the maintenance achieved for even the largest systems. and reliability field for over 17 years and has worked with clients around the world to design and implement lubrication improvement plans. Measuring contamination levels The final step in the process requires the use of oil analysis to Contact him at mark.barnes@descase.com. validate that our contamination control measures are having the desired effect. For hydraulics, measuring the degree of contamina- REFERENCES tion in the oil should be commonplace. For particle contamination, 1How Important is the ISO Cleanliness Code in Oil Analysis? Matt particle counting using the ISO 4406:99 standard outlined above should Spurlock, Machinery Lubrication Magazine May-June 2012 be used, while for water content, % or ppm of water should be reported 2Proactive Maintenance for Mechanical Systems, E. C. Fitch, FES Inc., using the Karl Fischer water test (ASTM D6304). However, oil analysis is 10:30 AMETEKAPT10017-R_eBrick-7.625x4.875_FPJ_APT10017 09/11/12 AM 1992 Page 1
The new 955 eBrik linear displacement transducer.
Price and performance so well balanced, it just might displace potentiometers. At last, there’s a purely electronic solution to position sensors. Our new 955 eBrik uses magnetostrictive technology so there’s no contact, no moving parts, nothing to wear out. No erratic position signals. Available in 1" to 72" stroke lengths, it’s economical and versatile enough for many applications, field-programmable, and the perfect replacement for old-style potentiometers. Learn more at our website or send e-mail to gemco@ametek.com.
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