CSM RE2521-BLN

Summary

Product identification

This is a low-pressure grade Reverse Osmosis (RO) element designed for brackish water applications.

• Product Name: RE 2521-B LN / RE2521-BLN
• Membrane type: Thin-Film Composite
• Membrane material: Polyamide (PA)
• Element configuration: Spiral-Wound, FRP Wrapping
• Effective membrane area: 12 ft² (1.1 m²)

Operating limits

• Max. Pressure Drop / Element: 15 psi (0.1 MPa)
• Max. Pressure Drop / 240” Vessel: 60 psi (0.41 Mpa)
• Max. Operating Pressure: 600 psi (4.14 MPa)
• Max. Feed Flow Rate: 6 gpm (1.36 m³/hr)
• Min. Concentrate Flow Rate: 1 gpm (0.23 m³/hr)
• Max. Operating Temperature: 113 °F (45 °C)
• Operating pH Range: 2.0–11.0
• CIP pH Range: 1.0–13.0
• Max. Turbidity: 1.0 NTU
• Max. SDI (15 min): 5.0
• Max. Chlorine Concentration: < 0.1 mg/L

Feed water

Design Guidelines for Various Water Sources (flux in gfd)

• Wastewater Conventional (SDI < 5): 8–12 gfd
• Wastewater Pretreated by UF/MF (SDI < 3): 10–14 gfd
• Seawater, Open Intake (SDI < 5): 7–10 gfd
• Seawater, Beach Well (SDI < 3): 8–12 gfd
• Surface Water (SDI < 5): 12–16 gfd
• Surface Water (SDI < 3): 13–17 gfd
• Well water (SDI < 3): 13–17 gfd
• RO permeate (SDI < 1): 21–30 gfd

Saturation Limits (Using Antiscalants)

• Langlier Saturation Index (LSI): <+1.5
• Stiff and Davis Saturation Index (SDSI): <+0.5
• CaSO₄: 230% saturation
• SrSO₄: 800% saturation
• BaSO₄: 6,000% saturation
• SiO₂: 100% saturation

Product water

• Permeate flow rate: 300 GPD (1.1 m³/day)
• Stabilized salt rejection: 99.2%
• Minimum salt rejection: 99.0%

The stated product performance is based on data taken after 30 minutes of operation at the following test conditions:

• 1,500 mg/L NaCl solution at 150 psig (1.0 MPa) applied pressure
• 15% recovery
• 77 °F (25 °C)
• pH 6.5–7.0 Permeate flow rate for each element may vary but will be no more than 15%.

Mechanical / hydraulic

• Dimensions (RE 2521-BLN):
  • A: 21.0 inch (534 mm)
  • B: 2.5 inch (64 mm)
  • C: 0.75 inch (19.1 mm)
  • D: 1.1 inch (28 mm)
  • E: 1.1 inch (28 mm)
• All RE2521 elements fit nominal 2.5 inch (64 mm) I.D. pressure vessels.
• Each membrane element is supplied with one brine seal, one interconnector (coupler), and four o-rings.
• Part Numbers:
  • RE 2521-BLN: 40000305
  • Inter-connector: 40000223
  • Brine Seal: 40000223

General Handling Procedures

• Elements must be kept dry at room temperature (7–32°C; 40–95°F) and should not be stored in direct sunlight.
• If the polyethylene bag is damaged, a new preservative solution (sodium bisulfite) must be added and air-tight sealed to prevent drying and biological growth.
• Permeate from the first hour of operation should be discarded to flush out the preservative solution.
• Elements should be immersed in a preservative solution during storage, shipping, and system shutdowns to prevent biological growth and freezing. The standard storage solution contains 1% by weight sodium bisulfite or sodium metabisulfite (food grade).
• For short term storage (i.e., one week or less), 1% by weight sodium metabisulfite solution is adequate for preventing biological growth.
• Keep elements moist at all times after initial wetting.
• Avoid excessive pressure and flow spikes.
• Only use chemicals compatible with the membrane elements and components. Use of such chemicals may void the element limited warranty.
• Permeate pressure must always be equal to or less than the feed/concentrate pressure. Damage caused by permeate back pressure voids the element limited warranty.

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Disclaimer: This summary is based on extracted text and may not include all figures, footnotes, or the latest revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

PDF datasheet