What are pump breathers? | Lubripedia

A pump breather is a device that allows air to enter and exit a pump or reservoir while preventing the entry of contaminants such as dust, dirt, and moisture.
Breathers are essential for maintaining clean and dry operating conditions inside pumps, hydraulic tanks, and lubrication systems.
They protect both the lubricant and equipment from contamination and pressure build-up.

Function of pump breathers:

During normal operation, the oil level in a pump or reservoir can rise and fall as the fluid expands, contracts, or circulates.
This movement causes the internal pressure to change, and air must be exchanged with the atmosphere.

A pump breather:

• Allows clean air to flow in and out of the system.
• Prevents the entry of dust, moisture, and other airborne particles.
• Helps maintain pressure balance and prevent seal damage.
• Reduces oxidation and degradation of the oil caused by moisture or debris.

Types of pump breathers:

There are several types of breathers used in lubrication and pump systems:

• Standard vented breathers – simple openings with basic filtration, allowing air exchange while blocking large contaminants.
• Desiccant breathers – contain drying material (such as silica gel) to remove moisture from incoming air.
• Filtered breathers – use fine filters to remove dust and particles.
• Combination breathers – combine filtration and moisture control for maximum protection.

Desiccant breathers are the most effective in contamination-sensitive systems, such as turbines, gearboxes, and hydraulic reservoirs.

Applications:

• Lubrication systems and oil reservoirs.
• Hydraulic systems and tanks.
• Gearboxes and bearing housings.
• Pumps and filtration units.
• Industrial machinery and mobile equipment.

In each case, pump breathers help maintain clean oil and reliable system performance.

Maintenance and best practices:

• Inspect breathers regularly and replace desiccant units when saturated (colour change is a common indicator).
• Ensure the breather is properly sealed and fitted to the reservoir.
• Avoid using open vents or uncovered fill ports.
• Store and handle breathers carefully to prevent premature contamination.
• Record breather replacement intervals as part of your preventive maintenance plan.

A clean and dry breather helps extend the life of both the oil and the equipment.