Pressure filters play a central role in the safe operation of hydraulic systems. Their task is to protect downstream hydraulic components such as servo valves from potential contamination that may occur in the hydraulic circuit.

Due to their placement in the (high) pressure line - typically directly after the pump - they ensure the oil cleanliness necessary for trouble-free operation.

Without a pressure filter, dirt particles, abrasion and other contaminants in the oil cause components to wear prematurely. This risks operational safety and ultimately reduces the performance of the entire hydraulic system. Therefore, the use of pressure filters is a crucial factor for an efficient and reliable hydraulic system.

Learn in this article how pressure filters from ARGO-HYTOS increase the performance and reliability of hydraulic systems and thus reduce operating costs.

What is the structure of pressure filters and what functions do their components perform?

Pressure filters are critical building blocks in hydraulic systems. They consist of various components that work in harmony to clean the hydraulic fluid and protect the system.

• The filter element is at the heart of the system. It removes the dirt particles from the hydraulic fluid.
• Easy-to-maintain filter housings made of aluminum or steel are designed to permanently withstand the operating pressure.
• A bypass valve is often installed. It opens as the pressure differential in the filter housing increases.
• Clogging indicators are a useful option. They indicate the right time for a filter element change and thus guarantee optimum utilization of the filter service life.

The task of a hydraulic filter is to ensure the desired oil cleanliness. Filters are leak-free and can withstand the operating pressure for many millions of pressure changes. At very low fluid temperatures or when the dirt holding capacity of the filter element is exhausted, the bypass valve opens. The fluid then flows only partially through the filter element. This can lead to less efficient dirt retention and potential system malfunctions. This operating condition can be avoided by timely filter maintenance.

To prevent damage, the filter element is protected from excessive differential pressures by the bypass valve. This keeps the hydraulic system supplied with oil, prevents damage to pumps and minimizes unplanned downtime.

An important extra is the clogging indicator. It can be optical or electrical and indicates when the filter element needs to be changed. This ensures that the system runs efficiently while preventing potential damage.

Regular maintenance and timely replacement of filter elements are crucial for the operational reliability of the entire hydraulic system.

What is the importance of pressure filters in particularly critical hydraulic systems?

In hydraulic systems containing particularly sensitive or safety-relevant components, pressure and high-pressure filters play a crucial role. They are the heart of the hydraulic system, as they ensure optimum operation and longevity of the entire system. In such critical systems, special filter models without bypass valves (so-called safety filters) are used to ensure maximum operational reliability in every conceivable operating situation.

This special pressure or high-pressure safety filters are equipped with extremely robust and highly stable filter elements. Even under extreme differential pressure loads, they retain their function and integrity without suffering any damage. They thus provide indispensable protection for the high-quality and often costly components of such hydraulic systems. An example of such components are valve blocks for safety-related functions.

These safety filters ensure the operational safety of the system and prevent expensive failures and repair costs.

Another essential element of the previously described safety filters without bypass valve is the clogging indicator.

Since regular or timely maintenance of the filters is crucial for the operational reliability of the entire system, clogging indicators on safety filters are usually indispensable.

In some hydraulic systems, short-term changes in the direction of flow may occur due to the system. To ensure that filtration is reliably maintained even in such situations, pressure filters can be equipped with a reversing control. In this design, several check valves in the filter housing ensure that the flow direction for the filter element remains constant.

In this way, pressure filters make a significant contribution to the smooth operation, performance and longevity of hydraulic systems. They not only protect the sensitive components of the systems and extend their service life, but also help to maintain high operating performance.

Pressure filter for different pressure ranges

Pressure filters, despite having the same function and installation location in the hydraulic circuit, are divided into different groups in common usage. As a rule, a distinction is made between low-pressure filters, medium-pressure filters and high-pressure filters. The choice of the appropriate filter is therefore based not only on filter fineness and nominal volume flow, but also on the operating pressure:

1. low-pressure filters are used at comparatively low operating pressures. The ARGO-HYTOS portfolio includes, for example, the FNL 1000 low-pressure filter, which can be used up to 40 bar. It is a reliable choice for applications with low operating pressure due to its robustness and efficiency. It makes it possible to make your hydraulic components more durable and require less maintenance.
2. medium pressure filters are used in systems with operating pressures of around 100 to 250 bar. ARGO-HYTOS also offers solutions for this, such as the medium pressure filter D 072, which impresses with its high operational reliability and efficiency. By integrating this filter into your system, you can increase uptime and minimize potential downtime and associated costs.
3. high-pressure filters are designed for use in systems with an operating pressure of over 250 bar. Here, ARGO-HYTOS provides a wide range of high pressure filters. They are characterized by resistant housings and excellent filtration performance. At such high operating pressures, it is particularly worthwhile to access products from the ARGO-HYTOS portfolio, as they are guaranteed to permanently withstand harsh operation due to extensive testing and field trials.

Pressure filter - the life insurance for hydraulic systems

Pressure filters - an almost too modest name for the often indispensable components in hydraulic systems. These inconspicuous technical elements are true shields that protect hydraulic components from contamination, maintain performance and ensure a safe working environment. Their usefulness extends far beyond the filtration process. It has a profound effect on the efficiency and longevity of the entire hydraulic system.

Whether low, medium or high pressure systems, the wide range of pressure filter variations makes it possible to find the perfect filter for any hydraulic system. ARGO-HYTOS is your reliable partner in the world of hydraulic systems. Our innovative and reliable filter solutions help extend the service life of hydraulic components and prevent expensive downtime.

In safety-critical systems, special pressure filter models without bypass valves underline their indispensability. These models with robust filter elements can withstand even the highest pressure loads and thus guarantee uninterrupted and safe operation.

Special attention is paid to filter maintenance and timely replacement of filter elements. This illustrates the seriousness with which the hydraulics industry treats operational safety. Clogging indicators are an important tool in this regard. They help to determine the optimum time for changing the filter elements. In this way, they ensure the smooth functioning of the plant.

In systems that experience momentary changes in flow direction, pressure filters once again demonstrate their adaptability by being equipped with reversing control. This ensures that filtration is reliably maintained - regardless of ambient conditions.

In summary, pressure filters are an indispensable link in the chain of hydraulic systems. They ensure that the system as a whole functions smoothly and efficiently. In this way, they help to extend the service life of the system. Therefore, they are much more than just "filters." They are the true guardians of hydraulic systems.

Your contact to ARGO-HYTOS

We will be pleased to convince you of the advantages of our filter systems in a personal meeting. Do you need competent support in selecting the right pressure filter, or would you like to discuss a very specific project with our experts? The best thing to do is to contact us today!