TASK-BASED TRAINING INSPECTING A DESICCANT BREATHER

Contamination Control

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WHAT IS A DESICCANT BREATHER?

Desiccant breathers are used to dehumidify incoming air and the headspace of equipment, while also restricting the ingression of small particulates.

WHY USE A DESICCANT BREATHER?

Many machine failure modes are associated with contaminants that breathers help to control. Most equipment comes equipped with a breather that is not sufficient. These OEM breathers will do little to nothing to reduce the ingress of particles and moisture, and they need to be replaced with something better.

WHY INSPECT A DESICCANT BREATHER?

These breathers eventually go bad - they aren't intended to last forever. They become saturated with moisture and lose their effectiveness; they can become clogged, restricting air flow and preventing the machine from breathing. If we're doing inspections well, we can have early warning signs of impending machine problems.

WHAT ARE SOME OF THE STYLES OF BREATHERS?

The OEM breather will likely look something like Figure 1: These do very little in terms of contaminant restriction - they do nothing for moisture and only prevent the ingression of very large particles; we are more concerned with fine particles.

Next, we have passive-style breathers (See Figure 2). In this sense, passive means the breather is open and breathing at all times: it will allow air in and out, and it is cleaning and dehumidifying the entire time. Next are check valve breathers (See Figure 3).

Unlike the passive, open-all-the-time breathers, these breathers feature check valves that keep the breather sealed until it needs to breathe. This style of breather also comes equipped with a pressure gauge that indi-