Hydraulic Oil Filters for Improved Function & Lifespan

The hydraulic oil filter is an important component in larger hydraulic systems for improving function and extending lifespan. The market offers filters in various grades, allowing the right hydraulic oil filter to be precisely selected for each system.

Contamination in Hydraulic Systems

Even meticulously maintained hydraulic systems are not free from contamination. Dirt particles originate within the system and are introduced from external sources. Common causes for the internal formation of dirt particles include:

• Abrasion
• Hardening
• Cavitation Damage

Abrasion – Hydraulic Oil Filters Protect

Abrasion occurs on all moving parts. In a hydraulic system, these are primarily the pumps and actuators. Even valves with little movement can generate small amounts of abrasion, which then float freely in the volume flow. There, they can cause secondary damage to seals and branches.

Hardening – Captured by the Hydraulic Oil Filter

Hardening in hydraulic oil occurs due to overheating. When subjected to excessive thermal stress, hydraulic oils form microscopic solid particles. These settle as sticky deposits in areas with lower volume flow. Overheated hydraulic oil can also dissolve seals. Their particles then also float in the volume flow and can cause secondary damage.

Cavitation Damage – Prevented by Hydraulic Filters

Cavitation damage occurs due to unfavorable volume flows along valves, branches, constrictions, or at the tip of pump rotors. Cavity means “hollow space”. In the volume flow, this describes small vacuum bubbles that collapse immediately after their formation. The resulting shock wave has an abrasive effect on adjacent metal objects or sealing rubber.

Most foreign particles enter the volume flow from outside. Unprofessional valve changes, lack of care during machining operations, or contaminated fresh oil are the most common causes.

Hydraulic Filters Stop Contamination

Due to the variety of possible causes for hydraulic oil contamination, the use of filters is mandatory in larger systems. Especially with motor-driven pumps, heat generation is always accompanied by a certain risk of overheating. Errors in the cooling system or a slowdown in the volume flow can lead to heat accumulation. This has the described effects (see hardening). A filter captures the free-floating particles and reliably retains them.

Proper Handling of a Hydraulic Oil Filter

If a hydraulic system is equipped with a filter, the manufacturer’s specified change intervals must be observed! By using multiple filters with graded particle retention, their change interval can be synchronized with the hydraulic oil replacement time. If the hydraulic system is then thoroughly cleaned and inspected before the filter and oil change, it will achieve a practically unlimited lifespan.

In critical and hard-to-reach areas, such as branches behind valves, an endoscopic inspection can replace extensive disassembly. This not only detects damaged areas early but also prevents new dirt from entering.