The sophistication of modern machines (such as earth moving, construction, trucks, cranes, utility vehicles, cars and some house hold items used in the performance of some kind of work) has given rise to higher system pressures and/ or tighter internal clearances to meet demands for increased productivity and efficiency. Tighter internal clearance makes system less tolerant to contaminants. Some industry publications1 quote experts as saying that 75% to 90% of hydraulic systems component (e.g. pumps, motors, cylinders and Valves) failures are caused by system contamination, other fluid system have similar trends. Also a recent Canadian study found out that ‘particle contaminated hydraulic oil’ account for 82% of all wear. Setting cleanliness standards and forming contamination control teams is ‘key’ to achieving success.
Contamination can cause machine productivity and efficiency to drop to as much as 20 percent to 30 percent before an operator even detects a loss in performance. Contaminants can be introduced into a system or be aggravated through wrong operation/ application of machine, repair and operating environment, maintenance and repair works or the way parts, components and fluids are store.
A good understanding of the effect of contaminants in today’s machines, its implementation and control initiatives can go a long way in improving machine performance, reliability, extending component life and lowering your operating and maintenance costs.
The number one enemy of any fluid system is contaminant. Most modern machines/ equipment have closed systems, which may employ one or more form of fluid system for their operation. The only effective way to combat it is to ensure cleanliness at all levels of operations.
According to Caterpillar Equipment manufacturer “a half-teaspoon of dirt in a drum (208 liters or 55 US gallons) of hydraulic oil exceeds the contamination allowed in new machines rolling off its assembly lines”.
Treating contaminated system
When your sample test result interpretation confirms a contaminated system, prompt action is required to restore the system cleanliness. The longer a contaminated system is operated, the faster components wear, system efficiency erodes and oil properties break down.
Identify and correct the cause of elevated contamination levels. The system clean up high may require the use of high efficiency filters, “kidney loop” filtration, oil changes or complete system flushing may be appropriate, depending on contamination levels.
Highly contaminated systems can be serviced by draining the fluid, flushing the system, and replacing all packing, filters, gaskets, etc. where applicable in the affected components or system before refilling with a clean and right type of fluid. Carry out fluid sample analysis to ascertain the status of the system.
Note: Follow guidelines as outlined in the technical manuals for such procedures.
Reference
- 1 Hydraulics & Pneumatics – April 01, 2007, Equipment today- August, 1997, Technical Service Bulletin 96-3R1- Filter Manufacturers’ Council, Machine Design Publication 13-SEP-01
- Operation and maintenance manuals for Caterpillar, Komastu and Ingersoll rand.
- Caterpillar’s “improving fuel system durability” – media number SENR9620
- Contact any oil sampling lab world wide for their technical brochure
- Caterpillar’s “Oil and your engine”- media number SEBD0640
- Caterpillar’s“Optimizing Oil Change Intervals” PEDP7035
- ISO 4406:1999 Hydraulic fluid power – Method for coding the level of contamination by solid particles