Return line filters are designed to filter the oil that is returning to the reservoir under low pressure, therefore, ensuring the oil that enters the reservoir is already cleaned to the required ISO4406 contamination level.
There are three main categories of return line filters - Tank top mounted, spin-on and in-line mounted filters.
Tank top mounted filters are widely used in mobile applications as most of the filter is housed within the reservoir thus saving space on the vehicle. They also provide a wide range of flow capacity up to 3000l/min.
Spin-on filters offer an ease of element change due to the fact the canister is mounted directly onto the filter head. Flow rates up to 300 l/min.
In-line filter are mounted before the reservoir where there is little or no space available to mount directly onto the tank. Because they are externally mounted they can be fitted to take very large flows in industrial applications. Capacity can be up to 15000 l/min.
Typical micron ratings for return filters range from 2 micron to 125 micron depending on the required ISO4406 cleanliness level of the fluid in the system.