R-AB-4 Desiccant Air Breathers

Air Breather Specification


Normal Capacity: 35 SCFM
Air Flow / psi Drop: 0.70 psi at 35 SCFM
Dimensions: A – 10 (254), B – 3.00 (76), C – 1.50 (38)

Replacement Element: Yes - R-AB-ELE


The R-AB-4 features inlet and outlet check valves located in the reusable cap (head), which control both the airflow into the reservoir and the airflow out of the reservoir and prolongs the life of the desiccant by allowing the air to flow through the breather only when needed to protect the integrity of the reservoir by establishing the thresholds of vacuum (air in) and pressure (air out).

Check valve settings are 0.3 psi in and 2.1 psi out.

The R-AB-4 also includes a reusable top cap which allows for the economic replacement of the desiccant cartridge.


  • Bi-directional Air Flow
  • As moist air flows through the breather’s filtration system, it is cleaned of impurities and dried. Expelled air partially regenerates the silica gel and "backflushes" the particulate to prolong the life of the breather.
  • Durable Construction
  • The desiccant air breathers are manufactured from rugged ABS plastic and impact-modified Plexiglas.
  • Water Vapor Absorbent
  • Silica gel is chemically inert, non-toxic, non-deliquescent, non-corrosive and environmentally disposable. Its internal structure of interconnected microscopic pores absorbs up to 40% of its weight. The operating temperature range is -20°F to 200°F (-29°C to 93°C).
  • Color Indicator
  • As the gold silica gel absorbs water, it turns green to indicate that it has reached its functional capacity and that replacement of the breather is required.
  • Dual Anti-static Filter System
  • The solid contaminant filters are designed to reduce the potential for explosion in dusty environments.
  • Safety Sealed
  • To ensure a long shelf life and premium operating performance, each desiccant breather is individually sealed and vacuum packed to protect it from moisture before it is placed in service. All seals are easily removable without the use of tools or sharp instruments.


  • Anti-static features to protect against fire ignition
  • High water absorption capacity (up to 18.5 oz)
  • Long operating life and low maintenance costs
  • Environmentally safe disposable silica gel
  • Compatibility with a variety of applications
  • Prevents rust and oxidation
  • Minimizes component wear and maintenance
  • Curtails freezing and additive depletion
  • Diminishes fluid degradation and orifice blockage
  • Extends oil filter and hydraulic system life



  • New and Retrofit Applications
  • Gear Boxes
  • Hydraulic Reservoirs
  • Storage Tanks


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