Hydraulic Oil - Without The Dirt

Hydraulic oil straight from the drum has a typical cleanliness level of ISO 4406 21/18. A 110 L/min pump operating continuously in hydraulic oil at this cleanliness level will circulate 20 kilograms of dirt to the hydraulic system's components each year!

To add hydraulic oil, and not the dirt, always filter new oil prior to use in a hydraulic system. This can be accomplished by pumping the oil into the reservoir through the system's return filter. The easiest way to do this is to install a tee in the return line and attach a quick- connector to the branch of this tee. It is important that a non-return valve is installed between the T- and the incoming line from the system to ensure that the oil will be filtered into the reservoir and not into the system.

Attach the other half of the quick-connector to the discharge hose of a drum pump. When hydraulic oil needs to be added to the reservoir, the drum pump is coupled to the return line and the oil is pumped into the reservoir through the return filter. As well as filtering the oil, spills are avoided and the ingress of external contamination is prevented.

The benefits of carrying out this simple modification are well worth the minor cost involved. As an alternative a separate filling filter can be mounted to the reservoir with the described quick coupler arrangement and filler pump to filter the replenishment oil. Strainers are not sufficient anymore for the sophisticated hydraulic systems as used in the modern world and therefore it is so important that the oil entering the reservoir is clean.