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Tel: 01709 821002



Neilson Hydraulics can offer a solution to the hidden problems that exist in your hydraulic system.


Contaminated oil is the main reason for operational problems and breakdowns in hydraulic systems. To prevent the interruption of operations, continuous oil maintenance is essential. Many companies still use early 20th century technology in an attempt to keep their oil clean. At the best the oil will become almost clean, but not entirely.

Using electrostatic oil cleaners (ELC’s) by Kleentek you can match modern demands of productivity, product quality and environmental control.

This ensures higher operational security as well as maintain maximum profit.

What is contamination?

Contamination within oil based systems can be split into 3 groups, these are:

Hard Contaminants
> Wear metals, dust and fibres

Soft Contaminants
> Oxidation peoducts and depleted additives

> Free or emulsified


What effect does contamination have?

The quality of your oil has a direct effect on:
> Hard Contaminants
> Machine Availability
> Profits
> Scrap Rate
> Energy Consumption
> Oil Life
> Environmental Issues


What are the problems caused by oxidation?

> Oxidation products adhere to metallic surfaces leading to the "sandpaper effect" and stick slip operation of control valves
> Acidic by-products increase TAN of oil
> Oil additives are depleted
> Oxidation products encourage further breakdown of the oil.



How do I know the level of contamination?

Easy, contact us and we will arrange for an oil test to be performed on site to show you instantly to what level and what type of contaminants are present in your oil. The oil checker kit used is also available for sale should you wish to perform this test within your own maintenance schedule.


Contaminant Checker

> Checks dirt by a membrane filter
> Checks water by electric heat
> Compare dirt and cleanliness with colour photo sample

Example of differing oil cleanliness standards:

By looking at the ISO and NAS grades for each sample you would believe that both are clean. If this is the case, then why does a servo valve fail in one of the systems.

The answer is not in the ISO or NAS grade, but in the gravimetric test, which shows sample 1 to be heavily contaminated with high levels of oxidation, also evident by the build up of deposits on the valve itself.

Oil in sample 2 is very clean and has been achieved by the use of an ELC unit.

How do ELC's compare with traditional filters?

Look at the chart below and it is clear to see that the ELC units remove more of the unwanted particles from the oil than traditional filters do. This is because traditional filters rely on physically trapping the contaminants with the ratio of areas in the membrane fibres which is normally restricted to >1µ, whereas the ELCs' trap the contaminants by electrostatic attraction, where size is irrelevant.

How does the ELC work?

Within used oil about 75% of the contaminants are oxidation products. These products naturally hold a polarity, which means that they are attracted to any metallic components within the system. Over time these products form layers on the components and therefore reduce the working clearances, causing premature failure. Oxidation and the resultant acid formation attacks the seals and gaskets in the system leading to leaks.The ELC unit uses the unique properties of these particles and by passing the oil through its' electrostatic field collector, the ELC attracts the contaminants to either of the opposite fields. This method means that no matter what the size of the contaminant is (even <1µ), its' polarity "draws" it to one of the collector elements, therefore removing it from the oil. 

Oxidation products are eliminated, thus acidic build up is removed and over time the surfaces of the components are cleaned.

Please note: ELC's cannot remove the additives from oils as they are soluble and ELCs' only remove insoluble products.

What is the capacity of the ELC?

The ELC's can be used on a varoety of oil:

> Hydrulic Oil
> Turbine Oil
> Circulating Oli
> Gear Oil
> Compressor Oil
> Transformer Oil
> Heat Transfer Oil
> Vegatable Oil
> Ester based oils

With special units for:

> Phosphate ester
> Polyglycols
> All units are available in 240V, 415V 3ph and 110V


To enquire about Kleentek’s Electrostatic Liquid Cleaner (ELC) available to hire or buy from Neilson Hydraulics, please contact us on T: 01709 821 002 / E: or visit: