The single greatest cause of oil not performing as it should is fluid contamination

Contamination is a real world problem that—if not prevented or controlled it can cause the system to work much less efficiently or even cause catastrophic failure.

My Hydraulic Power Unit is sealed so how does the oil inside become contaminated?

Contamination can be generated within a hydraulic circuit due to ingress of airborne moisture, dust particles, failing hydraulic components and poorly cleaned hoses.

I've poured new oil into my hydraulic power unit therefore it must be perfectly clean right?

Just because the oil is new, does not mean it is clean. Contaminants including moisture and dust can enter the oil if storage barrels are not sealed or stored properly.

Introduction to Hydraulic Oil Contamination

In hydraulic fluid power systems, power is transmitted and controlled through hydraulic oil under pressure within an enclosed circuit. The Hydraulic oil is both a lubricant and a power-transmitting medium.

The presence of solid contaminant particles in the oil interferes with the ability of the hydraulic fluid to lubricate and causes wear to the components. The extent of contamination in the fluid has a direct bearing on the performance and reliability of the system and it is necessary to control solid contaminant particles to levels that are considered appropriate for the system concerned.

A quantitative determination of particulate contamination requires precision in obtaining the sample and in determining the extent of contamination.

Liquid Automatic Particle Counters (APC) work on the light-extinction principle, this has become an accepted means of determining the extent of contamination.
The accuracy of particle count data can be affected by the techniques used to obtain such data.

Analysing Oil Particulate Contamination

The NAS 1638 reporting format was developed for use where the principle means of counting particles was the optical microscope, with particles sized by the longest dimension per ARP598. When APC’s came in to use this provided a method of analysing a sample much faster than the ARP598 method.

The ICM automatically measures and displays particulate contamination, moisture and temperature levels in various hydraulic fluids. It is designed specifically to be mounted directly to systems, where ongoing measurement or analysis is required, and where space and costs are limited

Off-Line Hydraulic Oil Filtration

The use of “off-line” hydraulic filtration systems has multiple benefits, allowing your hydraulic circuit to be cleaned whilst completing its daily tasks.
Working in a similar method as a dialysis machine, contamination is removed from the hydraulic fluid with the use of a built in filtration
system whilst the system is continually monitored for reductions in contamination.

Our range of portable filtration systems can be adapted to suit your requirements. Flow rate, pressure range and cleanliness levels can all be tailored to your particular application.

Download Our Oil Contamination Guide