Expansion Joints
On outdoor installations, expansion joints must be installed on straight duct runs greater than seventy feet. ATS recommends expansion joints made of EPDM. EPDM will not only provide ultraviolet protection but corrosion resistance to alkalis and acids as well. EPDM flexible connectors are recommended for connecting the duct to the scrubber and fan to minimize the vibration transfer from the equipment through the duct.
Coefficient of Thermal Expansion of ATS FXP™ duct: 2.0 X in/in X 10-5 X Δ°F of Duct (not ambient temp.) Example: 100’ at 100 Δ°F = 2.0 X 1200” X .00001 X 100 = 2.4”
Important Note: Δ°F refers to change in duct temperature, not ambient temperature.
A rule of thumb to use in figuring expansion of ATS StaticSafe Duct™ is three inches per hundred feet per one hundred degrees in Fahrenheit temperature fluctuation. This is equivalent to 75 mm per 37.75 degrees Celsius temperature fluctuation.
| EXPANSION JOINTS | |||||
|---|---|---|---|---|---|
| Comparative Properties of Typical Elastomers | |||||
| COMMON NAME | NEOPRENE | HYPALON† | VITON†/FLUOREL** | EPDM | TEFLON* ETFE/FEP/PTFE |
| CHEMICAL GROUP | chloroprene | chloro-sulfonyl-polyethelene | fluorocarbon elastomer | ethylene-propylene-diene-terpolymer | fluro-ethylene-polymers |
| Material Designation | |||||
| ANSI/ASTM D1418-77 | CR | CSM | FKM | EPR | AFMU |
| ASTM D-2000 D1418-77 | BC BE | CE | HK | BA CA DA | |
| Abrasion | Very Good | Good | Very Good | Very Good | Good |
| Acid, Concentrated | Good | Good | Excellent | Good | Outstanding |
| Acid, Dilute | Excellent | Excellent | Very Good | Excellent | Outstanding |
| Aliphatic Hydrocarbons | Fair to Good | Fair to Good | Excellent | Poor | Outstanding |
| Alkali, Concentrated | Poor | Good | Poor | Excellent | Outstanding |
| Alkali, Dilute | Good | Good | Good | Excellent | Outstanding |
| Aromatic Hydrocarbons | Fair | Fair | Excellent | Poor | Outstanding |
| Chemical | Fair to Good | Excellent | Excellent | Excellent | Outstanding |
| Cold | Good | Good | Very Good | Very Good | Very Good |
| Compression Set | Fair | Fair | Excellent | Good | X |
| Dielectric Strength | Very Good | Very Good | Very Good | Outstanding | X |
| Dynamic | Fair | Fair | Very Good | Very Good | X |
| Electrical Insulation | Fair to Good | Fair to Good | Fair to Good | Excellent | X |
| Flame | Good | Good | Excellent | Poor | X |
| Heat | Good | Very Good | Excellent | Excellent | Excellent |
| Impermeability | Good | Good | Very Good | Good | X |
| Oxidation | Very Good | Excellent | Excellent | Excellent | Excellent |
| Oxygenated H | Poor to Fair | Poor to Fair | Poor | Excellent | Outstanding |
| Ozone | Very Good | Outstanding | Outstanding | Outstanding | Excellent |
| Rebound- Cold | Good | Fair | Fair | Excellent | X |
| Rebound- Hot | Very Good | Good | Good | Excellent | X |
| Sunlight (Ultraviolet Rays) | Very Good | Outstanding | Outstanding | Outstanding | Excellent |
| Tear | Good | Fair to Good | Fair | Good | X |
| Tensile Strength | Good | Fair | Very Good | Very Good | X |
| Water | Good | Very Good | Very Good | Very Good | Outstanding |
| Water Absorption | Good | Good | Very Good | Excellent | Outstanding |
| Weather | Excellent | Excellent | Excellent | Excellent | Excellent |
x – Consult Manufacturer
*Teflon is a registered trademark of DuPont
**Fluorel is a registered trademark of 3M Companies
†Hypalon and Viton are registered trademarks of DuPont Dow Elastomers
NOTE: The properties or applications shown above are given for general information.
The suitability of a material for your application should be evaluated by a qualified engineer.
The above information has been compiled from several expansion joint manufactures’ data,we assume no responsibility for errors.