Monosphere 550A UPW

Summary

Product identification

DOWEX™ MONOSPHERE™ 550A UPW (OH) is a uniform particle size, strong base anion exchange resin designed for single or mixed bed demineralization in ultrapure water (UPW) applications.

Description

This high purity, Type 1 strong base anion resin is suitable for roughing, intermediate, and polishing ion exchange loops, either in a two-bed system followed by a mixed bed, or in a mixed bed following reverse osmosis. It is characterized by its light color, exceptional crush strength, and high (>95%) conversion of exchange sites to the hydroxide (OH⁻) form. Low total organic carbon (TOC) levels are achieved through deliberate functionalization and rinsing.

Typical Physical and Chemical Properties

• Physical form: White to amber translucent spherical beads
• Matrix: Styrene-DVB, gel
• Functional group: Quaternary ammonium
• Ionic form as shipped: OH⁻ form
• Total volume capacity, min: 1.0 eq/L (21.9 kgr/ft³ as CaCO₃)
• Moisture retention capacity: 55–65 %
• Harmonic mean diameter: 590 ± 50 µm
• Uniformity coefficient, max: 1.1
• Whole uncracked beads, min: 95 %
• Friability (average, min): > 200 g/bead (95 % > 200 g/bead)
• Particle density, approx: 1.08 g/mL
• Shipping density, approx: 657 g/L (41 lbs/ft³)

Suggested Operating Conditions

• Maximum operating temperature:
  • Single bed (OH⁻ form): 60°C / 140°F
  • Mixed bed (OH⁻ form): 60°C / 140°F
• Resin bed depth, min:
  • Single bed: 800 mm (2.6 ft)
  • Mixed bed: 450 mm (1.5 ft)
• Flow rates:
  • Service/fast rinse: 10–60 m/h (4–24 gpm/ft²)
  • Backwash: See Figure 1 in the official PDF.
  • Regeneration/displacement: 4–10 m/h (1.6–4 gpm/ft²)
• Total rinse requirement: 2–5 BV*
• Regenerant:
  • Type: 4–8% NaOH
  • Temperature: Ambient or up to 50°C (122°F) for silica removal

UPW Specific Properties

• Ionic conductivity rinse down, max. (as packaged): 1 µS/cm
• TOC rinse down to: 4 ppb (+) (see Figure 3 in the official PDF)

*1 BV (Bed Volume) = 1 m³ solution per m³ resin or 7.5 gals per ft³ resin.

Hydraulic Characteristics

• Backwash: Figure 1 in the official PDF shows bed expansion as a function of backwash flow rate and water temperature.
• Pressure drop: Figure 2 in the official PDF shows pressure drop data as a function of service flow rate and water temperature. This data is valid at the start of the service run with clear water and a correctly classified bed.
• Rinse performance: Figure 3 in the official PDF illustrates conductivity and TOC rinse-down curves.

Packaging

• 5 cubic foot fiber drum

Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror