Elesa’s new high-filtration breather caps

In hydraulic systems, fluid cleanliness is essential. While attention is often focused on the filters within the circuit, one crucial aspect is sometimes overlooked: the need to filter the air entering the reservoir during operation. If the incoming air is contaminated, the oil becomes contaminated too, causing premature wear of components and increased maintenance costs.

To address this issue at its source, Elesa has developed a new range of high-filtration breather caps: the SFP-AF, SFV-AF and SFW-AF models. This new range has been designed to meet the growing demand for higher levels of hydraulic fluid cleanliness and protection, preventing external contaminants from entering the reservoir and helping to maintain machinery performance.

The key technological innovation is the integration of a new polyester air filter with a filtration rate of 3 μm and a filtration efficiency of over 98%. Compared with Elesa’s usual breather caps, these new solutions provide a significantly more effective barrier against airborne contaminants. By reducing the ingress of abrasive particles into the reservoir, they help extend the service life of hydraulic components and minimise machine downtime caused by wear.

DESIGN FEATURES

In addition to their high filtration performance, the new series incorporates design features intended to ensure ease of installation, reliable sealing and durability in demanding operating conditions:

Secure fastening: the threaded fitting features a hexagonal profile, allowing a higher tightening torque to be applied using a spanner and ensuring effective compression of the NBR synthetic rubber flat washer.
Reliable sealing: the special internal geometry of the breather cap is designed to prevent fluid leakage to the outside, helping to keep the external environment clean and safe.
High-performance materials: the cover and threaded fitting are made of black (RAL 9005) polyamide-based (PA) technopolymer. The cover also features laser-engraved graphic symbols for clear and durable visual identification.

THREE CONFIGURATIONS FOR DIFFERENT APPLICATION REQUIREMENTS

The range comprises three variants, each designed to meet different reservoir pressure requirements:

Standard breather cap, SFP-AF: the basic version of the range, equipped with an internal splash guard. It is available with or without a dipstick for visual fluid level checks.

Breather cap with overpressure valve, SFV-AF: incorporates an overpressure relief valve made of technopolymer and fitted with an NBR synthetic rubber O-ring. The valve opens when the pressure exceeds a predefined threshold. Two settings are available: 0.350 bar (model SFV-AF-350MB) and 0.700 bar (model SFV-AF-700MB). This configuration helps limit air exchange and the ingress of moist external air

Breather cap with double valves, SFW-AF (overpressure and suction): ideal for systems with variable reservoir volumes, this version features an overpressure valve set at approximately 0.350 bar and a suction valve made of NBR synthetic rubber, with a stainless steel spring, set at approximately 0.030 bar. This double-valve system helps maintain controlled pressure conditions inside the reservoir, reducing the risk of structural deformation and limiting the uncontrolled ingress of contaminants

APPLICATIONS

Elesa’s high-filtration breather caps are suitable for a wide range of applications, including, but not limited to, agricultural machinery, earthmoving equipment and professional gardening equipment, where operating conditions are often dusty and demanding.
Other typical applications include remote-controlled tool carriers and professional brush cutters, where hydraulic system reliability is essential for safe and productive operation.