The VV-RV series

Sustainable & long maintenance interval

GIEBEL Adsorbers® of the VV-RV series are aeration dryers with a reusable cartridge and a valve section. They are suitable for indoor and outdoor use on hydraulic power packs, gearboxes, storage tanks and mobile machinery.
The plastic housing is filled with 0.15kg (VV-RV 1L) to 4.1kg (VV-RV 5XL) of GIEBEL Xdry®. This desiccant mixture ensures effective drying of the supply air and absorbs up to 1435ml of water (VV-RV 5XL) until the color change is complete. A 3μm filter additionally cleans the sucked-in air. When air is forced out of the system, a layer of activated carbon adsorbs escaping oil mist, protecting the desiccant and environment from contamination. When the adsorber is saturated, both desiccant and, if necessary, all other components of the internal system can be replaced at low cost. The sturdy valve section protects the adsorber from unnecessary loading, enables it to be used in extreme, dusty ambient conditions, and ensures minimal pressure build-up even at high air flows.

Move the mouse pointer over the blue highlighted adsorber components of the VV-RV and learn which task they perform in the adsorber.

Mode of operation

Adsorption – Drying of the supply air

  • The level in the system decreases
  • Humid air is sucked in
  • Valves open at approx. 6 mbar
  • Uniform flow through the adsorber
  • Air is dried to 2%rH
  • Silica gel changes color
  • Air is filtered to 3μm

Dry and clean supply air

Desorption – Separation of oil particles

  • The level in the system increases
  • Dry, oily air is squeezed out
  • Activated carbon absorbs oil mist
  • Dry, oil-free air regenerates the silica gel
  • Silica gel partially recolors

Self-regeneration and oil-free exhaust air

Technical Data


The sucked-in air opens the valves in the lower part of the adsorber already at approx. 6 mbar. After flowing into the adsorber, the air is evenly distributed over the cross-section. The pre-filter disc frees the air from coarse dirt particles.

When flowing through the desiccant, the water molecules are reliably removed from the air. The gap volume of the granulate is optimally selected with 2 to 5 mm grain size and guarantees a minimum pressure build-up with very good drying efficiency at the same time. Thus, a residual air humidity of max. 2% rH and a dew point of -40 °C are achieved at the beginning of the drying process. A 3µm filter ensures that all dirt particles are separated from the ambient air and the silica gel and that the connected equipment is not contaminated.

When air is discharged, a two-stage slosh protection and a layer of activated carbon prevent oil droplets, oil particles and oil mist from entering the desiccant, thus enabling the adsorber to self-regenerate.

With increasing saturation, the orange silica gel grains of the GIEBEL Xdry® fill turn green. If the silica gel grains have turned completely green, the bed must be replaced. After 4-5 replacement cycles at the latest, we also recommend replacing seals, particle filters and activated carbon discs.

Pressure ratio

Spare part kits

Sustainability starts with using product components for as long as their life cycle allows and replacing only those components that show signs of wear. With our spare parts kits for the refillable adsorber series, we ensure that you can replace each individual component of an adsorber as needed.

For example, the desiccant in our adsorbers becomes loaded during use, increasingly loses its ability to adsorb moisture and needs to be replaced, but the adsorber housing is particularly durable. Our refillable adsorbers can therefore be easily opened and the desiccant replaced. Seals, particle filters & activated carbon discs, on the other hand, can withstand a few replacement cycles, depending on the load. However, we recommend replacing them after 4-5 replacement cycles at the latest to ensure smooth operation of the adsorbers.

Our spare parts kits include seals, particle filters, activated carbon discs and other components that match the respective adsorber series. The matching desiccants for the adsorbers are available separately and in different size classes.

Adsorber Spare part kit