Protecting Fluid Reservoirs from Contamination

Air Sentry® BreathersAir Sentry® breathers should be an integral part of any proactive maintenance and reliability program. The breathers are designed to replace the breather cap or air filter on gear boxes, hydraulic fluid reservoirs, bulk storage tanks, oil drums, oil-filled transformers, and other fluid reservoirs.  Most older style air venting methods provide minimal, if any, contamination control.  Air Sentry® breathers provide the first line of defense in contamination control methodology, utilizing patented designs and featuring color indication silica gel and self-cleaning 2-micron filtration.

Why is Contamination Control Important?

There are two important threats to productivity that an Air Sentry breather can protect you from:

One research group found that greater than 75% of all machine wear related failures were due to particulate contaminants. Frequently the greatest cost of equipment failure is not the component replacement cost, but the labor production downtime. Most particles start off as dirt that becomes airborne, finds its way into lubricant and fuel reservoirs, and is later transported to bearings, bushings, seals, valves, and other machine components. There they become key ingredients in abrasion, erosion, and fatigue failures. The contaminants also cause lubricant degradation, shortening the life of the lubricant and decreasing its ability to lubricate.

With machine clearances measured in thousandths of an inch, it doesn’t take much contamination to affect bearings and other sensitive components. Even particles of 10 micron or smaller can disrupt the lubricant film and cause a great amount of wear.

Moisture is a continuous threat. Its presence in lubricants and hydraulic fluids creates a host of problems including rust, lubricant additive depletion, viscosity changes, oxidation and sludge formation.

Air Sentry® neutralizes contamination while protecting operational efficiencies which is reason enough to go for the gold. Air Sentry® Breathers stop moisture from entering your equipment while still allowing clean air to pass through.

How Does it Work

Air Sentry® Breathers - How It WorksOutside Air Coming In
The patented design allows outside air to enter through the 360° opening in the breather’s top cap. The top cap design overhangs the body of the breather helping protect the breather from rain, sleet, snow, as well as most equipment wash-down procedures.

When contaminated air enters the top of the breather, it passes through a self cleaning solid particle filter. This filter traps solid particles greater than 2 micron and keeps them from entering the breather and ultimately to wear surfaces on your equipment. The filtered air then passes through a bed of silica gel that adsorbs moisture in the air. During this step up to 95% of the water vapor in the air is filtered out.

Finally, the filtered air passes through an additional 2 micron filter in the bottom of the breather to ensure that no harmful particles will enter the tank or reservoir. This three stage filtration design ensures your equipment gets CLEAN, DRY AIR!

As the color indicating silica gel adsorbs moisture it changes from gold to dark green. When the silica gel is adsorbed to its capacity (approximately 40% of its original weight), the breather has fully turned dark green. This color change is easily seen and serves as the visual indication that it is time to remove and replace the disposable breather.

Air Venting Out
Air Sentry® Breathers - How It WorksThe image to the right shows air being expelled back through the desiccant breather from the equipment the breather is mounted on. As contaminated air travels this reverse path, expelled water vapors are adsorbed by the silica gel.

During this reverse air flow process, the silica gel indicates the presence of excessive moisture inside the reservoir as the gold silica gel turns to dark green from the bottom of the breather rather than from the top of the breather.

An additional feature located in the bottom of most Air Sentry® models is a layer of carbon impregnated foam. This carbon pad absorbs small amounts of oil vapor exhaled from the tank and protects the silica gel from minor oil mist contamination. Excessive oil mist control may be required. Adapters are available for applications with excessive oil mist problems.

As the exhausted air passes back through the self cleaning 2-micron filter, located in the top cap of the breather; any particles that were trapped as air entered the system are now back flushed from the filter.

Gallagher Fluid Seals is a trusted distributor of Air Sentry® products. If you want to know more about implementing Air Sentry® breathers into your process, contact us today.