Desiccant Breather Filters

Desiccant filters protect gearboxes, hydraulic tanks, and oil reservoirs by preventing the ingress of moisture and particles during equipment breathing.

Proper selection depends on thermal behavior, system criticality, and environmental conditions.

Why install a desiccant breather?

When equipment heats up and cools down, air enters and exits the reservoir during the breathing process.
That air contains:

  • Dust 
  • Moisture
  • Environmental contaminants

What does moisture cause in the system?

The presence of moisture can lead to:

  • Oil oxidation
  • Sludge formation
  • Additive degradation
  • Reduced lubricant service life
  • Premature failure of bearings and gears

 Solution

The desiccant breather removes moisture and particles before air enters the system, protecting the lubricant and the internal components of the equipment.

Types of Desiccant Breathers

Desiccant Breather WITHOUT Valve

How does it work?

Allows continuous airflow through the filtration media and desiccant.

Air flows freely in and out, passing through:

  • Particle pre-filter
  • Silica gel chamber
  • Safety post-filter

Recommended when:

  • The equipment breathes continuously
  • There is no significant internal pressure
  • Installed in dry indoor environments
  • Secondary or low-criticality equipment

Advantages:

  • Simple design
  • Lower cost
  • Direct installation

Desiccant Breather WITH Valve

How does it work?

Incorporates a bidirectional valve that opens only when a pressure differential exists.

Example:
The valve opens at 1 PSI, allowing:

  • Air intake when vacuum is generated
  • Air release when overpressure occurs
  • When there is no pressure differential, the valve remains closed.

Recommended when:

  • Equipment experiences significant thermal cycles
  • Installed in humid environments
  • The system is critical

Extended desiccant service life is required

Greater contamination control is desired

Advantages:

  • Longer desiccant life
  • Reduced exposure to ambient air
  • Better moisture control in tropical climates
  • Ideal for mining, palm oil, agro-industry, and outdoor applications