DESICCANT
BREATHERS

Desiccant Breathers, or contamination control breathers, protect chemical products from moisture contamination. AGM’s desiccant breathers are reusable and protect items in storage drums, storage tanks, hydraulic reservoirs and other areas.

Desiccant Breather Theory and Characteristics

DRUM DESICCANT BREATHER

Many fluids, semi-solids and powders stored in 55-gallon drums will adsorb water vapor when exposed to normal atmospheric humidity. This water vapor will condense, causing these substances to become contaminated and permanently damaged from the resulting chemical changes.

Drum Desiccant Breathers, also known as Drum Vent Dryers, prevent this contamination, which occurs during storage and use. Changes in temperature, barometric pressure, and fluid pumping will result in air entering the drum. This air passes through a column of blue indicating silica gel, which removes and retains the water vapor. The silica gel changes from blue to pink when the desiccant is saturated and requires replacement. The units can also be filled with orange silica gel, which is acceptable for use in the European Union. The Drum Desiccant Breather is reusable — saturated desiccant can easily be replaced by removing the access port plug.

The Drum Desiccant Breather begins to work from the moment it is installed. Field testing has demonstrated that when a Drum Desiccant Breather is fitted to a new drum of uncontaminated fluid, the air space above the fluid is made safe from condensation within a few hours.

 

Contaminated Substances Can Result In:

  • Alteration of Active Properties;
  • Increased Corrositivity;
  • Loss in Dialectric Properties;
  • Viscosity Variation;
  • Chemical Instability; and
  • Coagulation and Sedimentation.
Tank Desiccant Breather

The reusable Tank Desiccant Breather offers an innovative solution to the desiccant breather industry. Instead of wasting yet another traditional breather, now all you have to do is attach a Tank Desiccant Breather to your industrial storage tanks (up to 132,000 gallons) and simply change the desiccant when needed.

Each Tank Desiccant Breather can be filled with a variety of desiccant products, including blue or orange indicating silica gel, molecular sieve, activated alumina and activated carbon. The standard desiccant fill is blue silica gel.

AGM also has the technical expertise to help you select the right Tank Desiccant Breather product, located in our Tank Vent Dryer selection guide.

 

Typical materials which can be readily protected:

  • acetic acid;
  • arklone;
  • brake fluid;
  • ethanolamine;
  • glycerol;
  • monomethylemethacrylate;
  • perklone;
  • polyalcohols;
  • polyethers;
  • sulphuric acid;
  • transformer oils;
  • trichloroethylene; and
  • triklone

 

In addition to water vapor, other contaminants may be removed, including:

  • acetone;
  • acid;
  • ammonia;
  • carbon dioxide;
  • carbon monoxide;
  • ethylene;
  • formaldehyde;
  • freon;
  • hydrogen;
  • oil vapors;
  • oxides of nitrogen;
  • sulphide;
  • sulphur dioxide; and
  • toluene
Transformer Desiccant Breather

The failure or malfunction of many transformers or similar equipment can be directly attributed to the lack of proper control of the level of water vapor entering the equipment. It is essential, therefore, that a very low level of humidity is maintained in the airspace of the conservator tank to avoid deterioration in the insulating properties of the cooling medium.

Transformer Desiccant Breathers provide an economic and efficient means of controlling the level of moisture entering equipment during the change in volume of the cooling medium and/or airspace caused by temperature gradients.

All Transformer Desiccant Breathers (except Re-Actrans) are filled with self-indicating silica gel. This desiccant is blue when active and turns pink when saturated.This allows a visible assessment of the condition of the desiccant. Various sizes and types of packs of this desiccant are available for recharging the desiccant containers.

Transformer Desiccant Breathers provide clear visibility of the desiccant charge through a clear, shatter-proof, UV stabilized polycarbonate cylinder or window, depending upon the size of the unit. Two-way, low pressure valves are fitted in the base of the breather to ensure that atmospheric air enters the desiccant charge when a negative pressure differential occurs within the equipment being protected.

DESICCANT BREATHER F.A.Q.
Drum Desiccant BreatherS

This depends on several factors, such as: how often the drum is emptied, the rate at which the contents of the drum are emptied, the environmental conditions (temperature, relative humidity, and pressure) and changes in those conditions, exposure to sunlight, and the contents of the drum.

The most commonly used desiccant in drum desiccant breathers is blue silica gel, which allows for an easy visual indication as to when the desiccant needs to be replaced. The units can also be filled with orange silica gel, molecular sieve, activated alumina, or activated carbon.

AGM also sells the aforementioned desiccant in bulk form, including prepackaged replacement amounts of the blue silica gel.

A heavy duty industrial model that holds twice the amount of silica gel is available for larger drums or use in harsh environmental conditions (e.g. tropical).

The units will work in temperatures from -4°F to 131°F.

Tank Desiccant BreatherS

The primary factor is the maximum emptying rate. Of secondary importance is the fluid capacity (volume) of the tank. Use our Selection Guide and be sure to select a size with a flow rate greater than the maximum emptying rate of the tank.

This depends on several factors, such as: how often the drum is emptied, the rate at which the contents of the drum are emptied, the environmental conditions (temperature, relative humidity, and pressure) and changes in those conditions, exposure to sunlight, and the contents of the tank. The breathers can easily be refilled without any special tools.

The most commonly used desiccant in tank desiccant breathers is blue silica gel, which allows for an easy visual indication as to when the desiccant needs to be replaced. The units can also be filled with orange silica gel, molecular sieve, activated alumina, or activated carbon.

We recommend a drum desiccant breather.

Transformer Desiccant BreatherS

Transformer desiccant breathers are designed to protect transformer reservoirs and rectifiers from the effects of moisture. Transformer reservoirs have little oil movement, whereas vent dryers are designed for drums and tanks which are being emptied and filled continuously, requiring higher flow rate capacity.

AGM transformer desiccant breathers are constructed of very durable materials. The small units are made from a tough UV stabilized glass loaded polycarbonate. The larger units are constructed from aluminum. All units are fitted with a two-way relief valve mechanism that eliminates all maintenance except for replacing the desiccant once it is saturated. All the breathers have a viewing window (there is 180 degree visibility on the small units) to easily determine when the desiccant needs to be replaced.

This can be established by looking at the maximum oil contents of the transformer or the MVA rating.

This will depend on the size of desiccant breather you fit to the transformer, as determined by our Selection Guide. To increase the time between desiccant change outs, you can always select a unit that is larger than that which is called for in the selection guide.

No. All AGM desiccant breathers are refillable. We provide refill packages of the blue, or orange, silica gel 2-5 mm beads starting at the smallest individual breather size of 1.32 lbs., and other repackaged amounts up to the standard packaging for both the blue silica gel and orange silica gel 2-5 mm beads (25 kg containers). The breathers can easily be refilled without any special tools.