Overview - Chemical Concentration Influences Seal Performance
Ethylene oxide (EO) is one of the most aggressive chemical streams that elastomer seals encounter in
transportation and/or in chemical processing operations. Results from recent DuPont testing indicate that
end users should take care when selecting seal materials for EO or other oxirane services. As a result of
laboratory testing complemented by field analysis, DuPont has determined that the concentration of the
EO can influence the seal’s performance.
Typically 100% concentrations of EO are encountered in chemical transportation, but in chemical
processing plants, EO may be diluted with water therefore reducing the concentration of EO. In
transportation of 100% EO and other oxiranes, DuPont™ Kalrez® Spectrum 6375 perfluoroelastomer
parts are the suggested Kalrez® product for use. However, in lower concentrations of EO seen in
chemical processing facilities, DuPont™ Kalrez® 2035 is suggested.
Because EO is the most aggressive in the chemical category of oxiranes, other oxiranes encountered in
transportation or chemical processing, like propylene oxide (PO) and butenol oxide (BO), should have a
similar but less damaging effect on elastomer seals. It is suggested that customers perform their own
evaluation trials on elastomer seals, since laboratory immersion tests cannot precisely simulate customer
process conditions.