Hydraulic Pressure Line Filter Explained

One of the prerequisites for a hydraulic system to run without interruption is filtering both the fluid and the air that comes into contact with the tank. The contaminants removed by filters are ambient dust entering the hydraulic system through fill plugs and cover gaskets. Most malfunctions occurring in hydraulic systems are caused by contaminated fluids.

Hydraulic Pressure Filter

The hydraulic pressure filter is used to ensure the safe operation of components downstream of the pump. For this reason, these filters should be connected as close as possible to the components that need to be protected.

Functions of the Hydraulic Pressure Filter

Working filters

Providing protection against wear on components
Ensuring the continuity of the desired fluid cleanliness class

Safety filters

Preserving the functionality of components
Safety filters can only be used together with working filters,
Pressure line filters should always be used together with contamination indicators.

The filter housing must be rated to withstand the maximum system pressure.

When Is a Pressure Line Filter Used?

The following points should be considered when deciding whether to use a pressure line filter in a system:

– Does the system contain components that are especially sensitive to contamination (e.g. servo valves and control valves), or that are important to the system’s operation?

– Does the system contain especially expensive components (e.g. large cylinders, servo valves, hydraulic motors) that are quite important for the system’s safety?
– Is the system’s downtime cost quite high?

– Pressure line filters can be used as a safety filter and/or a working filter.

Characteristics of the Pressure Line Filter

Operating pressure: up to 420 bar
Flow rate: up to 330 l/min
Filter fineness: 3-5 µm
Permissible pressure differential ∆p: up to 200 bar, depending on the filter’s construction

Advantages and Disadvantages of Pressure Line Filters