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What Are Hydraulic Filters?

A hydraulic filter is a component used by hydraulic systems to continuously remove contaminants in the hydraulic oil. This process will purify the hydraulic fluid and protect the system from damage created by the particle contents. Hydraulic filters are a crucial element of any system using hydraulic power and are designed to filter oil, water or other liquids, within a hydraulic installation application. Hydraulic systems have an increased risk of contamination due to wear of components, ingression from seals or low-quality liquid. Therefore no fluid power system should be complete without the use of a filter. Hydraulic filters help to keep the hydraulic fluid contaminant free.


Why are hydraulic filters used in hydraulic systems?

 Hydraulic filters are used anywhere in a hydraulic system where particle contamination is to be removed. Particle contamination can be ingested through the reservoir, created during the manufacture of system components, or generated internally from the hydraulic components themselves (especially pumps and motors).

 Hydraulic filters are mainly used in a variety of hydraulic systems in the industry. These filters have many advantages that ensure the safe working of a hydraulic system. Some of those advantages of hydraulic oil filters are listed below: 


  • Eliminate the presence of foreign particles in hydraulic fluid.
  • Protect the hydraulic system from the dangers of particle contaminants.
  • Improves the overall efficiency and productivity.
  • Compatible with most of the hydraulic system.
  • Low cost for maintenance.
  • Improves the service life of hydraulic system.


 What are the types of hydraulic filters?

 There are several types of hydraulic filters, and they are often classified by where they are designed to be placed in the hydraulic system. The most common hydraulic filter types are:


In-Line Filters – Placed directly on the fluid line, may be suction side (before the pump) or pressure side (after the pump but before the valves and cylinders), inlet, outlet, and media are aligned


Off-Line – Consists of a separate pump and filter linked directly to the reservoir, often used to supplement main system filters


Tank - May be positioned on or within the fluid reservoir, may have an accessible head on the tank exterior for easy access and media replacement


Spin-On – Consists of an in-line head screwed onto. Threaded canister, easy to install and economical


Return Line – Filter is placed directly on return line, can also be spin-on, in-line, or tank mounted


Duplex – Actually a valve/filter assembly permitting flow to 2 separate filters in order to maintain flow during filter maintenance.


At Neilson Hydraulics and as a hydraulic group with VHS Hydraulic Components, we stock a variety of hydraulic filters from brands including, Bosch Rexroth, Eaton and Ikron. To speak to our technical sales department please call: 01709 821 002 or email: sales@neilson-hydraulics.co.uk.