Giant Air Breathers and Desiccant Breathers

Desiccant air breathers of type SDB from STAUFF are a combination of tank breathers and tank breather dryers. Variants of the type SDB-CV are additionally equipped with several spring-loaded check valves in opposite directions with an opening pressure of 0.01 bar. This contributes to extending the service life of the dryer material, but can possibly also result in 0.01 bar underpressure/overpressure within the hydraulic system. If in doubt, please consult the supplier of the critical system component beforehand. 

When tanks or gears are fitted with a breathing element, moisture can penetrate into the system. Temperature fluctuations allow the moisture to condense. This can accelerate the ageing process of the fluid and cause damage to the components of the system.

With SDB desiccant air breathers on the other hand, the incoming air first passes through the dryer material. The condition of the drying material changes as the absorbed moisture increases and the colour changes gradually from red to orange. Orange drying material should be replaced immediately. The dryer material consists of non-toxic ZR gel granules. STAUFF desiccant air breathers do not contain any harmful substances as per EU Directive 99/45/EC and 2001/60/EC. 

The incoming air then passes through a replaceable air filter element (giant air breather) with a filter grade of 3 micrometres to filter out any dirt particles. An optical capacity indicator is also available for determining the condition of the air filter element. 

SDB-CV desiccant air breathers can also be retrofitted with a layer of active charcoal drying material (1/3) and a layer of regular drying material (2/3) (vapour filtration). 

STAUFF supplies an extensive spare parts range with replaceable air filter elements (giant air breathers) and replacement drying materials. Adapter plates, capacity indicators and droplet separators are also available as accessories. 

Type AP adapter plates simplify the installation of desiccant air breathers and allow a capacity indicator to be connected. With the adapter plates, desiccant air breathers can be connected directly to existing connection points in the tank with a connection pattern as per DIN 24557, Part 2. 

The adapter plates additionally provide a female thread G1/8 BSP (ISO 228) for installing an optical FM capacity indicator.  

Adapter plates are made of polyamide (PA). The delivery also includes a blind plug, an O-ring made of NBR (Buna-N®) and 6 hexagon socket screws (ISO 4762). 

Optical capacity indicators of type FM are connected to the G1/8 BSP female thread (as per ISO 228) of the adapter plate and provide information on the remaining capacity of the air filter element. A red marking shows when the element has to be replaced. The indicator can subsequently be reset by pressing the Reset button and used again. 

Droplet separators of type TBA-OD reduce the emission of oil vapours through desiccant air breathers and other breathers. 

The accessories range for air filter elements is completed with type TBA screw-in adapters. These are available in a variety of different thread combinations and allow direct connection of giant air breathers and common spin-on filters with female thread to the hydraulic tanks for use as separate air filters.