Frequently Asked Questions
Frequently Asked Questions
Relate the modest cost of a Des-Case unit to costs for equipment rebuild/repair, machinery down-time, oil or fluid replacement, contaminated and spoiled products, etc.
Some examples are:
1. Rebuilding a gearbox can cost hundreds and even thousands of dollars in parts and labor, plus the lost time.
2. Equipment failure can shut down a production line.
3. Contaminated food grade oils or pharmaceutical fluids must be disposed of.
4. Water in electrical control cabinets and transformer installations can result in explosions.
Des-Case breathers are simple to install, and their periodic monitoring requires no technical expertise.
How long does it last?
This depends on the environment. Some guidelines are listed but will vary with conditions.
On Water Contamination
The disposable models, DC-2, DC-3 and DC-4, contain blue silica gel, which is visible through the plastic case. When the silica gel changes to a light pink color, the unit has reached 100% saturation and must be replaced.
It is normal for the first few units to change color and require rapid replacement if the unit already has significant water contamination in the reservoir. This means the product is doing its job. Remember that the breather will remove water in the reservoir as it reverts to the vapor phase with increased operating temperature.
If the environment is not unusually moist the unit can be expected to last between 6 and 8 months or longer before color change requires replacement. The final service life will vary dependent upon moisture presence and airflow and cannot be predicted for any given application.
On Abrasives/Dust Contamination
The breather filter assembly has the ability to "back-flush" itself when the system expels air, due to the unique woven loop design of the filter material. Operational experience has shown that, in most applications, the unit will require replacement due to moisture saturation before the particulate filters require replacement. However, it is recommended that for an environment with very heavy airborne contamination, the unit be changed every six months or 3000 operating hours.
Can I replace the desiccant?
No. The cost of the replacement filter pads and hygroscopic agent is approximately 70% of the total unit cost. The only salvageable parts would be the plastic case and cap which are pressed together. If this tight fit were not achieved in the rebuild, abrasive materials and moisture could bypass the filter.
These units, models DC-2, DC-3, and DC-4, may be disposed of as solid waste, and present no environmental impact. Material Safety Data Sheets are available from Des-Case or your local distributor.
How can I prevent saturation in very wet environments?
Mount the unit in the driest location. Use the remote mounting method to get the unit away from direct water spray.You can order a plastic "skirt" to slip on the bottom of the breather to keep water droplets from entering through the openings where air enters into the disposable breather.
Do I have to seal the unit?
For best results, it is recommended that a silicone sealer is used to mount the unit to the field adapter or threaded adapter, and that thread seal tape or silicone is used on the adapter threads.
If the unit is accidentally broken, will the desiccant enter the reservoir?
Due to the standpipe design of the unit it is unlikely this would occur, as the foam pads would contain the material. The materials used in its construction are impact resistant.
What size do I need?
All three models are rated to 20 cfm (150 gpm). The unit should be sized by looking at system height restrictions and the amount of water adsorption desired.
Remember that you should not always fit the smallest unit for economy of purchase price. When comparing the three common sizes DC-2, DC-3 and DC-4, the price variation is approximately 30% from the least expensive to the most expensive. However, the DC-4 unit has twice the drying ability of the DC-2, and the DC-3 unit has one-and-a-half times the drying capacity of the DC-2.
Can I purchase larger units?
Yes. Des-Case manufactures steel hygroscopic breathers. These rugged units are:
1. Designed for high heat, corrosive, or extremely dirty environments.
2. Available in both carbon steel and stainless steel.
3. Three sizes, the largest will retain up to one gallon of water.
4. One (1) micron particulate filtration.
5. Easily replaceable filter element and desiccant bag filter
6. Where are Des-Case breathers used?
7. Generally, any reservoir, tank, cabinet, or piece of equipment that breathes in and expels air, and where water or dirt in that air would be detrimental to the contents or operation.
Suggested applications include:
2. Hydraulic Systems - all types
3. Bearing Circulating Systems
4. Robotic Hydraulic Equipments
5. Transformers with Oil Cooled Design
6. Non-aqueous Chemical Process Storages/Handling Tanks
7. Diesel Fuel Storage Tanks
8. Mobile Earthmoving Equipments
9. Agricultural Equipments
10. Vacuum and Welding Chambers
What about European Community directives N°98/98/EC & 67/548/EEC regarding the use of cobalt chloride?
This administrative directive concerns the classification, packaging and labeling of dangerous substances. In July 2000, European Directive No67/548/EEC 'reclassified' cobalt chloride and added it to a list of thousands of other chemical substances to a Category 2B (possibly carcinogenic to humans). No tests specific to "cobalt chloride" were performed in Europe, rather the testing was done on "cobalt sulphate." This created carcinogenicity by comparison, with a subsequent requirement for specific labeling. Only the Sulfate Cobalt animal test results schown a carcinogenicity effect, but NOT the COBALT CHLORIDE used in the DESCASE BREATHERS.
A trace amount of cobalt chloride (less than 0.5%) is used as the indicator in blue silica gel. When people use products where they can refill, buy and manipulate-or otherwise, directly handle- the blue silica gel, the packaging and the labeling of the products that contain the chemical substance must be in accordance with the European directive. The health risk associated with self-indicating (blue) silica gel therefore only exists when handling the material and/or being exposed to the dust.
Due to the design and intended use of the Des-Case breather, there is no risk of contact with the internal chemical substance and it does not fall subject to this directive. Des-Case went through a long, arduous process to ensure that its breathers were in accordance with these European regulations. As a result, Des-Case Europe breathers have received official approval for industrial use in the European Community. Breathers with DESCASE Europe label have the CE logo conformity and are in conformity with the new european regulation REACH.
In the United States, there are no such regulations. The concentration of chemical indicator falls well below the tolerance levels set by U.S. regulatory agencies.
Is cobalt chloride a health hazard?
Cobalt chloride is like any other industrial chemical, treat it with respect! From a safety standpoint, cobalt chloride is considered harmful when ingested or inhaled at high enough levels.
When analyzing this chemical compound, the cobalt ion is the assumed culprit.
Here are a few facts about cobalt:
. Cobalt is an essential element in humans, as a constituent of vitamin B12.
. The general population may be exposed to cobalt in air, drinking water and food.
. Human tissues and fluids normally contain low levels of cobalt.
. Cobalt has both beneficial and harmful effects on health. At low levels, it is part of Vitamin B12, which is essential for good health. At high levels, it may be toxic.
. Cobalt chloride is a common ingredient in animal feed.
. One of the underlying principles of toxicology is that 'the dose makes the poison.' In other words, something is poisonous when it exceeds a certain threshold concentration.
Cobalt chloride exposure limits for an 8-hour workday, 40-hour workweek are:
. OSHA PEL .05 mg/m3 (PEL: permissible exposure limit as a time weighted average)
. ACGIH TLV .02 mg/m3 (TLV: threshold limit value as a time weighted average)
. To put it in perspective, you would have to break 115 DC-4 breathers per week, pulverize the silica gel dust and circulate it into the air system of an average size automotive plant to get anywhere close to these threshold limits.
Can silica gel in Des-Case breathers be regenerated?
No, the end user cannot regenerate the silica gel in Des-Case breathers. The cap on the disposable models is pressure sealed and should not be removed. For the rebuildable steel units, the desiccant is enclosed in a polyester filter bag. This bag and its contents are disposed off and replaced when it is time to recharge the unit.
In theory, silica gel can be regenerated, but it is not advised without taking proper precautions (i.e. suitable effective dust mask). Activities that generate respirable dust should be minimized or altogether abandoned. Also, for breather applications the temperatures would have to be high enough to burn off any oil mist collected within the silica gel granules and this process would destroy the porous structure of the silica gel.
What about landfill issues?
Breathers should be disposed of in the same manner as used oil filters due to the fact that some oil will likely collect in the breather during its service life. Please consult your local, state and federal regulations. In Europe, the breathers must be disposed as rags and paper impreganted with oil or as plastic grease cartdriges.
What should not get lost in this discussion is the impact that desiccant breathers have on the life of lubricants. Proper use can extend lubricant life up to three times in many cases. This not only reduces oil consumption, but also greatly diminishes the impact of oil disposal on the environment.
Has Des-Case evaluated alternative silica gels?
Des-Case constantly evaluates new and unique desiccants to find the safest products that represent the best value for end users. The following data were considered when exploring 'blue' versus alternates.
The cobalt compound used in Des-Case breathers has not been specifically identified as a possible carcinogen. The bulk of scientific research to date does not support a link between cobalt chloride and cancer. The same is not true of phenolphthalein, the chemical change agent most commonly used in the yellow/orange indicating gel, also known as 3,3-Bis(4-hydroxphenyl)phthalide. This gel is used in various applications, including desiccant breathers currently being marketed by other manufacturers.
A review of the MSDS for phenolphthalein as produced by JT Baker indicates that this substance is a suspected cancer hazard. A recent study conducted by the National Toxicology Program (TR-465) concluded, "There was clear evidences of carcinogenic activity of phenolphthalein." The International Association for the Research of Cancer also classifies phenolphthalein as possibly carcinogenic to humans. Phenolphthalein, like its cobalt chloride counterpart, is also harmful when swallowed or inhaled at high enough levels.
Independent studies show that there is no adsorptive advantage to the gold indicating silica gel. Also, oil mist can render the yellow silica gel inactive yet cause it to retain its yellow hue, which creates confusion as to whether the silica gel requires replacement. The color change in Des-Case breathers is more pronounced even in oil mist situations.
In addition to consulting with specialty chemical supplier Kaltron-Pettibone, Des-Case posed the question to a Fortune 500 chemical company who responded that cobalt chloride would be the preferred chemical indicator especially in an industrial setting.
Other gels use iron sulfate as the color indicator, known to cause cardiac disturbances, kidney and liver damages. Toxicological properties of this material have not been fully investigated. The safety and effectiveness of new indicating gels on the market also have not been proven.
After evaluating all of the data available, Des-Case concluded that 'blue' was still the best choice when considering color change properties, end user safety and environmental friendliness. Des-Case will continue to evaluate progress in new silica gels as well as track new developments of existing silica gels.
Are alternative gels available for purchase?
As a very large importer of desiccants, Des-Case has access to silica gels using any number of color indicators. While 'blue' is the color of choice, Des-Case stocks orange indicating gel (which changes to colorless or white), yellow (which changes to a green), non-indicating silica gel (clear), as well as molecular sieve and activated alumina.
If a customer has a strong preference for a particular color or type of gel, Des-Case is happy to make a substitution in the breathers and will price and label accordingly.
Where can I go for more information?
Answers to these top questions provide a glimpse at the extensive research conducted and time invested to ensure that you receive a 'safe' breather when specifying Des-Case.
Supporting documents and additional information may be found at the following websites:
Mallinckrodt Baker, Inc. (Leading supplier of high purity chemicals, subsidiary of Tyco International, Inc. a Global 500 company)
MSDS Cobalt Chloride» www.jtbaker.com/msds/englishhtml/C4928.htm
MSDS Phenolphthalein » www.jtbaker.com/msds/englishhtml/P2015.htm
National Toxicology Program» ntp.niehs.nih.gov/index.cfm?objectid=72016262-BDB7-CEBA-FA60E922B18C2540
United States Environmental Protection Agency» www.epa.gov/ttnatw01/hlthef/cobalt.html