HS-D series adsorbers protect gearboxes from water droplet ingress while allowing them to breathe. Using an ePTFE filter in the core of the rugged polyamide housing, gear oil is protected from water contamination, even when the gear is used outdoors or cleaned with water.
The 0.3 micrometer pores of the membrane filter retain water or oil, but allow air to flow through. The pressure build-up remains low.
The HS-D membrane filters are an excellent alternative to adsorbers when liquid water is a challenge for a gearbox, but humidity does not cause problems.