Thousands of litres of hydraulic oil can be saved each year by employing submicrometre continuous in-operation filtration, states wear control specialist Filter Focus South Africa COO Craig FitzGerald.

The company offers two products to the hydraulics industry to decrease the amount of hydraulic oil that is disposed of each year as a result of contamination.

The Filter Focus filtration system comprises a range of off-line filters that remove dirt and contaminants from oil, extending the life of the oil for up to 20 years.

The filters are connected to the oil tank and the filtration system pumps the oil through the filter and sends the clean oil back into the tank to be reused.

“The common practice of many companies is to drain dirty oil and discard it. Many also often tend to replace components on hydraulic systems. If these companies concentrate on keeping the oil clean, there will be no breakdowns of machines, no unreliable equipment and they will not have to drain the oil frequently. This could save companies in the magnitude of billions of rands every year,” says FitzGerald.

He says machines become more efficient and production is increased when cleaner oils are used.

“Hydraulic pumps have an average life span of only about two years, owing to the effects of contaminated oil. Filtered oil guarantees a life extension of ten times the average life of hydraulic components,” states FitzGerald.

He adds that, by using Filter Focus’s filtration system, companies are able to save thousands of litres of oil and protect their machinery.

The environmental benefits of using cleaner and recycled oil are great but companies need to know how to keep hydraulic oil in pristine condition, he notes.

Filter Focus recently conducted an analysis involving two South African oil refineries and measured the extent of contamination in oils. The 4 µm of measured contaminants showed that 1 ℓ of brand-new oil contained 17-million contaminants, as well as wear particles, such as silica dust.

The oil was taken to an independent lab and tested using spectrograph analysis, which identified the wear particles in the oil.

Further, a LaserNet Fines tool was used to conduct a physical count of the contaminants.

Problems associated with hydraulic oils are usually storage or dust related and the oil is highly contaminated by the time it is put into equipment to be used, says FitzGerald.

The contaminated oil then begins to chemically degrade and every contaminant creates up to four wear particles, a cycle which grows exponentially.

“Through our studies, we have taken lubrication, filtration and tribology and combined them to ensure that our products give the best results. We have also combined the three mechanics of filtration – area, depth and radial filtration – to develop the cotton multistage filter element,” reveals FitzGerald.

The hollow cotton fibre absorbs water, moisture and contaminants, which hold onto the inside and outside of the filter element. Because the filter is off-line, the elements can be changed while the system is running.

FitzGerald recommends that oil be prefiltered before being used in hydraulic systems and machinery, as this reduces the risk of introducing external contamination into the machinery.

The filters are available in various ranges, from small on-board and on-vehicle applications to units that are 1.2 m high. The filters are able to work under high-flow and high- contamination conditions.

Seal Saver
The second product offering from Filter Focus to reduce oil contamination and waste is the US-manufactured Seal Saver hydraulic cylinder cover.

“Generally, most hydraulic seals leak oil. This is where dust and other contaminants get into the equipment. These seals become brittle as a result of being exposed to harsh elements and eventually burst, which can result in equipment downtime and unexpected maintenance costs.

“The Seal Saver covers the entire hydraulic cylinder and prevents the seals and cylinder rod from exposure to dirt and harsh elements,” explains FitzGerald.

He adds that seals can be further protected by using a special lubrication that keeps them moist.

Once installed, the Seal Saver opens and closes like an accordion as the cylinder works. The velcro closure and wrap-around design makes installation quick and easy. The product is available in ballistic nylon, Kevlar or silicon, which can handle temperatures of up to 1 000 ºC.

FitzGerald suggests that the simultaneous use of its filtration system and the Seal Saver system will result in the best protection of hydraulic systems, as well as a significant decrease in oil contamination and disposal.

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