DOWEX Ion Exchange Resins WATER CONDITIONING MANUAL

Ion Exchange Resin Operational Information
9.6 Resin Stability and Factors
Ion exchange resins are manufactured for extended use. There are, however, a number of factors that
can impact resin life. Major factors are described in the following sections.
9.6.1 Temperature
All ion exchange resins have a recommended maximum operating temperature as indicated in their
product datasheets. Operation of ion exchange resins at elevated temperatures can cause degradation of
the functional sites and loss of ion exchange capacity. For DOWEX resins, the following guidelines have
been established to minimize the chances of premature degradation (Table 16 through Table 18).
Table 16. Guidelines for strong acid cation resins.
Resin Type Na Form Maximum H Form Maximum
8% gel 250°F (120°C) 250°F (120°C)
10% gel 265°F (130°C) 265°F (130°C)
Macroporous 300°F (150°C) 300°F (150°C)
Table 17. Guidelines for strong base anion resins.
Resin Type Cl Form Maximum OH Form Maximum
Type 1 212°F (100°C) 140°F (60°C)
Type 2 160°F (70°C) 95°F (35°C)
Acrylics 120°F (50°C) 95°F (35°C)
Table 18. Guidelines for weak functionality resins.
Resin Type Maximum
Weak base anion 212°F (100°C)
Weak acid cation 250°F (120°C)
These temperature maxima are intended only as guides. Thus, a temperature limitation does not mean
that the resin will be unstable above and stable below this temperature. It should also be recognized that
thermal degradation is proportional to the product of time and temperature. Thus, an occasional excursion
for a brief time to a temperature above the maximum may result in little or no loss in performance. When
exposed to higher than the recommended temperature, however, the resin will often lose its functional
groups, which will result in loss of capacity and reduced resin life (Figure 23).
DOWEX Ion Exchange Resins 52 Water Conditioning Manual