DOW FILMTEC SW30XLE-440i Membrane

Product Description

DOW FILMTEC SW30XLE-440i offers a good combination of productivity and rejection resulting in a low energy seawater element and low operating cost. It is ideal for two-pass seawater designs and high TDS brackish water applications. DOW FILMTEC SW30XLE-440i comes with iLEC™ Interlocking Endcaps that reduce system operating costs and reduce the risk of o-ring leaks that cause poor water quality.


  • High flux reduces energy use or pressure required
  • Good rejection results in good quality water;
  • High boron rejection
  • Filmtec performance and quality

Important Information

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 refer to the application information literature entitled “Start-Up Sequence” (Form No. 609-02077) for more information.

Operation Guidelines

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 hour 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.
  • 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.
Product Part number Active area Maximum operating pressure Permeate flow rate Typical boron rejection % Minimum salt rejection % Stabilized saltrejection %
ft2 (m2) psig (bar) GPD (m3/d)
SW30XLE-440i 219219 400 (37) 1,200 (83) 9,000 (34) 91.5 99.6 99.8

Dow Water & Process Solutions offers various premium seawater reverse osmosis (RO) elements to reduce capital and operation cost of seawater RO systems. DOW FILMTEC™ products combine premium membrane performance with automated precision fabrication and maximize system output to unprecedented performance.

DOW FILMTEC™ SW30XLE-440i offers  medium salinity and medium temperature feed waters an advanced combination of high productivity and high rejection through extra-low energy consumption and single-pass design. It is also an ideal choice for two-pass seawater designs or high salinity brackish water applications. The combination of highest active area and thickest feed spacer of the Dow FILMTEC membranes results in higher productivity and lower cleaning frequency which enable sustainable lower lifecycle cost. Benefits of SW30XLE-440i include:

  • Active area of 440 sq. ft., enables systems to be designed to deliver the lowest total cost of water by optimizing energy consumption, system productivity and operating flux.
  • The highest guaranteed active area of 440 ft2 (41 m2) permits lowest system capital cost by maximizing productivity and enables accurate and predictable system design and operating flux.
  • The combination of highest active area with thickest feed spacer (28 mil) allows low cleaning frequency and high cleaning efficiency.
  • Utilization of the distinct iLEC™ interlocking endcaps help reduce system operating costs and reduce the risk of O-ring leaks that can cause poor water quality (See Form No. 609-00446 for information on cost-saving benefits).
  • Sustainable high performance over the operating lifetime, because oxidative treatments are not used in membrane production. This is one reason DOW FILMTEC elements are more durable and may be cleaned more effectively over a wider pH range (1-13) than most other RO elements, which use oxidative treatments.
  • Can effectively be used in permeate staged seawater desalination systems without impairing the performance of the downstream stage.
Operating Limits
  • Membrane Type Polyamide Thin-Film Composite
  • Maximum Operating Temperaturea 113°F (45°C)
  • Maximum Element Pressure Drop 15 psig (1.0 bar)
  • pH Range, Continuous Operation 2 - 11
  • pH Range, Short-Term Cleaning (30 min.) 1 - 13
  • Free Chlorine Tolerance <0.1 ppm
  • Seawater desalination
  • Municipal drinking water
  • Industrial desalination
[custom-documents] [/custom-documents]
(2 reviews) Write a Review
  • 5
    Always in stock!

    Posted by Wilmin P. on Jan 22nd 2020

    I have been a faithful user of dow filmtec membranes for many years due to long-term consistency. Terrific products

  • 5
    Top seller

    Posted by Osvaldo B. on May 19th 2019

    I love these membranes for my factory.

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