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3.0" Diameter Models
  • Improved OSMOTIK® seawater reverse osmosis elements offer the highest productivity while maintaining excellent salt rejection.
  • OSMOTIK® SW30 membranes elements have the highest flow rates available to meet the water demands of both sea-based and land-based desalinators.
  • Improved OSMOTIK® seawater membrane combined with automated, precision element fabrication result in the most consistent product performance available.
  • Product Specifications
    ProductApplied Pressure psig (bar)Permeate Flow Rate gpd (m3/d)Stabilized Salt Rejection (%)
    SW30-3021-700800 (55)700 (2.6)99.5
    SW30-3031-900800 (55)900 (3.4)99.5
    SW30-3040-1500800 (55)1500 (5.7)99.5
  • Permeate flow and salt rejection based on the following test conditions: 32,000 ppm NaCI, pressure specified above, 77°F (25°C) and the following recovery rates: SW30-3021-5%, SW30-3031-6% & SW30-3040-8%
  • Permeate flows for individual elements may vary +/-20%.
  • For the purpose of improvement, specifications may be updated periodically.
  • Figure 1
    Seawater Spirals Figure 1
    ProductMaximum Feed Flow Rate gpm (m3/m)
    Dimensions - Inches (mm)
    SW30-3021-70014 (0.05)21.0 (533)2.9 (73.66)0.75 (19)
    SW30-3031-90014 (0.05)31.0 (787)2.9 (73.66)0.75 (19)
    SW30-3040-150014 (0.05)40.0 (1,016)2.9 (73.66)0.75 (19)
  • SW30-3021, SW30-3031 & SW30-3040 elements fit nominal 3.0 inch I.D. pressure vessel.
  • Pressure rating must be verified from the vessel manufacturer.
  • FRP outer wrap.
  • Operating Limits
    Membrane TypeHigh Rejection Polyamide Thin-Film Composite
    Maximum Operating Temperature113°F (45°C)
    Maximum Operating Pressure1,000 psig (1.0 bar)
    Maximum Pressure Drop14.4 psig (1.0 bar)
    pH Range, Continuous Operation3-11
    pH Range, Short-Term Cleansing1-13
    Maximum Feed Silt Density IndexSDI 5
    Free Chlorine Tolerance<0 ppm
  • Maximum temperature for continuous operation above pH 10 is 95°F (35°C).
  • Refer to Cleaning Guidelines.
  • Under certain conditions, the presence of free chlorine and other oxidizing agents will cause premature membrane failure. Since oxidation damage is not covered under warranty, Osmotik recommends removing residual free chlorine by pretreatment prior to membrane exposure.
  • Proper start-up of reverse osmosis water treatment systems is essential to prepare the membranes for operating service and to prevent membrane damage due to overfeeding or hydraulic shock. Following the proper start-up sequence also helps ensure that system operating parameters conform to design specifications so that system water quality and productivity goals can be achieved. Before initiating system start-up procedures, membrane pretreatment, loading of the membrane elements, instrument calibration and other system checks should be completed. Please follow instructions provided by reverse osmosis system manufacturer.

    Avoid any abrupt pressure or cross-flow variations on the spiral elements during start-up, shutdown, cleaning or other sequences to prevent possible membrane damage. During start-up, a gradual change from a standstill to operating state is recommended as follows:

  • Feed pressure should be increased gradually over a 30-60 second time frame.
  • Cross-flow velocity at set operating point should be achieved gradually over 15-20 seconds.
  • Permeate obtained from first two hours of operation should be discarded.
  • General Information
    • Keep elements moist at all times after initial wetting.
    • If operating limits and guidelines given in this bulletin are not strictly followed, the limited warranty will be null and void.
    • To prevent biological growth during prolonged system shutdowns, it is recommended that membrane elements be immersed in a preservative solution and kept cool above 33°F
    • The customer is fully responsible for the effects of incompatible chemicals and lubricants on elements.
    • Maximum pressure drop across an entire pressure vessel (housing) is 50 psi (3.4 bar).
    • Avoid static permeate-side backpressure at all times.

    Notice: The use of this product in and of itself does not necessarily guarantee the removal of cysts and pathogens from water. Effective cyst and pathogen reduction is dependent on the complete system design and on the operation and maintenance of the system.

    Notice: No freedom from any patent owned by Osmotik or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for customer’s use and for ensuring that customer’s workplace and disposal practices are in compliance with applicable laws and other government enactments. Osmotik assumes no obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED.