Desiccators – FAQs

What is a breather desiccator?

A breather desiccator is a desiccant cartridge that is mounted to a breather valve.

Why are they called breathing desiccators?

Because the air that passes through the breather valve is forced through the desiccant in the cartridge screwed into the back of the breather valve. With a static desiccator, the air is not forced through the desiccant bed.

How much desiccant can the desiccator cartridge hold?

The desiccator cartridge for standard 1″ breather valves can be up to about 18″ long and they will hold about 6 grams of desiccant per inch of length. However, anything over about 6″ should probably be supported inside your package as the porous polyethylene tubing is not strong enough to support the cantilevered desiccant weight beyond that. Desiccant cartridges are not able to be attached to the 2″ or 4″ breather valves.

Does the desiccant cartridge affect the air flow through the valve?

Yes. The desiccant cartridge reduces the flow for a given pressure drop by 67 – 75%.

What desiccant materials are available in breathing desiccators?

The most common are molecular sieve, either Type 4A or Type 13X, or silica gel. However, any desiccant material that does not “pack” will work. When the desiccant material “packs” it can completely block the flow of air through the desiccator, rendering it non-breathable. It will still function to desiccate, but not for breathing.

What is the difference between a desiccator and a desiccant basket?

While both are packages intended to hold desiccant, a desiccant basket holds pre-packaged or bagged desiccant. It is intended to mount through a container wall and provide an easy way to replace desiccant from the outside of the container. AGM desiccant baskets have long lasting, easily removable, stainless steel covers that will accept a security wire to provide evidence of tampering and come in a variety of standard lengths. Custom lengths are available upon request. Desiccators are usually packed with loose, or bulk desiccant, and are located inside the container or item. They are intended to keep a specific sealed space dry. Some of AGM’s customers’ complex pieces of hardware have had as many as six desiccators, each protecting a different area of the item, as well as a desiccant basket in the container to keep the container interior and item exterior dry.

What sizes, shapes and materials are desiccators available in?

AGM has made desiccators in literally hundreds of shapes and sizes ranging from the size of a small grape up to eight foot long tubes and every conceivable size and shape in between. Desiccators have been made from aluminum, stainless steel, bronze and many plastics including polystyrene, ABS, polycarbonate, acrylic, polyester, polyproplene, and combinations of plastics and metals. Manufacturing processes for desiccator components can utilize one or more of the following: milling, turning, stamping, vacuum forming, injection molding and casting.

What size desiccant baskets are available?

There are two standard diameters currently available, the 2″ TA476 series and the 4″ TA486 series. Each is available in several standard lengths with custom lengths available upon request.

Can I put a breather valve in the cover of the desiccant baskets?

Yes. The 2″ diameter is available with either a TA340, TA333, or TA330 series valve as a TA476, or with the TA440 valve as the TA478 series. The 4″ diameter is available with the above choices but is also large enough to accommodate the TA770 series valve for increased breathing capacity.

What size mounting holes are required, and, is mounting hardware provided?

The TA476/TA478 series require a 2.015″ diameter mounting hole while the TA486 series requires a 4.015″ diameter mounting hole. All necessary mounting hardware is provided.

Additional Resources: