If 80% of all hydraulic failures on machinery can be traced back to contaminated oil, why do maintenance engineers place their faith in component monitoring? Chris Gray, Filtration Product Manager at Bosch Rexroth explains why oil sampling is the key to greater machine uptime.
Preventive maintenance and component monitoring are two of the big buzzwords being used more and more across British manufacturing.
This continues to puzzle organisations, particularly in relation to hydraulics, because figures suggest that only 20% of unplanned downtime can be identified through component monitoring. In fact, 80% of all hydraulic failures on machinery can be traced back to contaminated oil.
Surely then, oil analysis is a more reliable option as part of a modern day programme. The truth of the matter is that oil analysis has the capability to prevent expensive repairs, minimise downtime, detect early damage to components, optimise filtration systems and even provide environmental relief through the minimisation of wasted oil.
There are three types of contamination which can be identified by oil analysis. The first is solid particles, such as dirt and dust particles which can cause jamming; influence control behavior, prematurely wear components leading to failure and a reduction in machine availability.
The second type of contamination is liquid contamination which are in the main water and fluid mixtures. This type of contamination can cause corrosion and wear, along with impairment of viscosity and even cause a chemical reaction with the fluid which can impact lubricating properties.
Finally, gaseous contamination, such as air, can have a number of serious consequences. Foaming in the oil sequences; inaccurate response of valves; energy loss; damage to pumps; chemical reactions with the fluid and oxidation, can all result in a reduction in machine availability.
These failures are directly attributable to oil contamination, via components such as cylinder rods. What’s more, once in place, there is often a chain reaction of particles. One particle rubbing against another breaks off and splits into two. Two particles split to become four, and four become eight. Often, the solution is simple, such as the installation of offline filter units.
The problem for many maintenance teams is time and resource. While oil analysis can be incredibly effective as part of a preventive maintenance programme, it does take valuable time which takes engineers away from more critical, problems which they encounter every day. All-too-often, no oil analysis is undertaken or the schedule falls by the wayside as more critical issues take priority.
Oil analysis, such as the Bosch Rexroth oil analysis service, can identify how much particulate is potentially affecting the smooth running of a machine. What’s more a recognised industry standard is now in place, ISO 4406, which measures 100 millilitres of oil and gives a particulate reading.
Only regular oil analysis can prevent build-up of particulates and ensure the machine stays available 100 per cent of the time. Cleanliness of the oil is crucial and is a far superior method of identifying potential problems than component monitoring and offers the opportunity to identify appropriate levels of filtration and, if necessary, upgrade.
Monitoring oil cleanliness is therefore the most important factor to prevent failures and should become a must in any modern maintenance and servicing regime.
To find out more about Bosch Rexroth visit www.boschrexroth.co.uk .