DOW FILMTEC BW30HR-440i Membrane

Product Description

The DOW FILMTEC BW30HR-440i element is a high-performing, high productivity element combining the highest active membrane area available in the industry today with the maximum rejection brackish water reverse osmosis (RO) membrane. It incorporates Dow's innovative BW30HR membrane sheet technology, designed to deliver the highest quality RO permeate. This is combined with the cleanability of a 28 mil feed spacer, to minimize capital expenses in high-purity industrial water applications, without increasing operating flux.


  • High rejection results in excellent water quality
  • Reduced downstream polishing required
  • Durable with good cleanability for long element life
  • 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 Active area ft2 (m2) Feed spacer thickness (mil) Permeate flow rate gpd (m3/d) Stabilized salt rejection (%) Minimum salt rejection (%)
BW30HR-440i 440 (41) 28 12,650 (48) 99.7 99.4
Solute NH4+ NO3- SiO2 Boron
Typical rejection (%) 99 98.5 99.9 83
  • Produces 20 percent more water compared to the BW30-400 element, and 10 percent more water compared to the BW30-440i element, at the same operating pressure and with higher rejection, enabling lower capital expense for new systems, or increased water production in an existing system.
  • The BW30HR membrane sheet sustains maximum rejection over the useful life of the RO element of critical solutes, including silica, boron, ammonium and nitrate.
  • Includes iLEC™ (interlocking endcaps) technology, which reduce system operating costs and the risk of o-ring leaks that can cause decreased permeate water quality.
  • Designed using an industry standard 1.125 inch ID permeate tube for interchangeability with other brackish water elements.
Operating Limits
  • Membrane Type Polyamide Thin-Film Composite
  • Maximum Operating Temperature 113°F (45°C)
  • Maximum Operating Pressure 600 psig (41 bar)
  • Maximum Pressure Drop 15 psig (1.0 bar)
  • pH Range, Continuous Operation 2 - 11
  • pH Range, Short-Term Cleaning (30 min.) 1 - 13
  • Maximum Feed Flow 85 gpm (19 m3/hr)
  • Maximum Feed Silt Density Index SDI 5
  • Free Chlorine Tolerance <0.1 ppm
  • Industrial water demineralization
  • Production of municipal drinking water
  • Water reuse
[custom-documents] [/custom-documents]
(3 reviews) Write a Review
  • 5
    You guys are very professional

    Posted by Nilza L. on Apr 14th 2020

    Nothing bad to say about these membranes whatsoever

  • 5
    shipped same delivery, thanks

    Posted by Torres V. on Nov 7th 2019

    After months of using these membrane, I can say they are cutting-edge products!

  • 5

    Posted by Ariclene S. on Nov 21st 2018

    Will buy these membranes again!

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