Principal Applications

  • Dealkalization
  • Deionization
  • Softening
  • Softening - Aqueous organic solutions


  • SST shorter diffusion path benefits:
  • Highest regeneration efficiency
  • Very low leakage
  • Highly resistant to iron fouling
  • Lower rinse volumes
  • Lower operating costs
  • Excellent physical/chemical stability


  • Coflow regenerated systems
  • Counterflow regenerated systems
  • Potable water treatment

Regulatory Approvals

  • Certified by the WQA to NSF/ANSI-61 Standard

Typical Packaging

  • 1 ft³ Sack
  • 25 L Sack
  • 5 ft³ Drum (Fiber)
  • 1 m³ Supersack
  • 42 ft³ Supersack

* SST® is a registered trademark of Purolite LLC

Typical Physical & Chemical Characteristics:

Polymer Structure Porous crosslinked polyacrylic acid
Appearance Spherical Beads
Functional Group Carboxylic Acid
Ionic Form H+ form
Dry Weight Capacity (min.) 5.5 eq/kg (H+ form)
Moisture Retention 36 - 44 % (H+ form)
Particle Size Range 300 - 1600 µm
< 300 µm (max.) 1 %
Reversible Swelling, H+ → Ca2+ (max.) 20 %
Reversible Swelling, H+ → Ca2+ (operating) 7 %
Reversible Swelling, H+ → Na+ (max.) 50 %
Specific Gravity 1.17
Shipping Weight (approx.) 710 - 760 g/L (44.4 - 47.5 lb/ft³)
Temperature Limit 120 °C (248.0 °F)

Hydraulic Characteristics

Pressure Drop

The pressure drop across a bed of ion exchange resin depends on the particle size distribution, bed depth, and voids volume of the exchange material, as well as on the flow rate and viscosity of the influent solution. Factors affecting any of these parameters— such as the presence of particulate matter filtered out by the bed, abnormal compressibility of the resin, or the incomplete classification of the bed—will have an adverse effect, and result in an increased head loss. Depending on the quality of the influent water, the application and the design of the plant, service flow rates may vary from 10 to 40 BV/h.

Pressure Drop Across Resin Bed


During up-flow backwash, the resin bed should be expanded in volume between 50 and 70% for at least 10 to 15 minutes. This operation will free particulate matter, clear the bed of bubbles and voids, and reclassify the resin particles ensuring minimum resistance to flow. When first putting into service, approximately 30 minutes of expansion is usually sufficient to properly classify the bed. It is important to note that bed expansion increases with flow rate and decreases with influent fluid temperature. Caution must be taken to avoid loss of resin through the top of the vessel by over expansion of the bed.

Backwash Expansion of Resin Bed