DOW FILMTEC BW30-400 Membrane

Product Description

DOW FILMTEC BW30-400 Membrane elements are the product of choice when high quality permeates are required. BW30-400 is a DOW FILMTEC™ Brackish Water Reverse Osmosis (BWRO) 8” Element, which can separate salts from water. Previously known as BW30 8040, the BW30 400 is produced with an automated fabrication process that ensure precision, consistency, and reliability.

BW30 400 has a very robust membrane chemistry, it has the widest pH range for cleaning (pH 1 – 13) than the other RO elements, so as you know one pH change means its 10 times the concentration of the chemical change, so you know if a membrane says pH range of 1 to 13, just think about how tough the durable membrane has to be in order to clean the wider pH ranges and when you are able to clean at wider pH ranges, your membrane is going to clean better which means you’re going to need to clean less often too, therefore your membrane life is going to be longer and the cleaning cost is going to be less too because if you clean membrane one time less per year, you are saving the cleaning cost per element.

BW30-400 is perfect for municipal and industrial water treatment systems that produce more than 10 GPM of permeate. It has higher rejection using less energy and resisting foulants in challenging waters. It is the best choice if you are dealing with controlled pre-treatment waters and seeking consistent, high performance, long element life and increased productivity.


  • Decades of proven performance
  • Delivers high quality permeate water while minimizing CAPEX
  • Offers the most effective cleaning performance, robustness and durability due to its widest cleaning pH range (1 – 13) tolerance and the support of Dow technical representatives high rejection gives good water quality;
  • Filmtec performance and quality

 Cleaning Conditions (pH Ranges)

Topic FILMTEC™ Comments
Calcium carbonate scaling pH 1-2 @ 35°C Best cleaning done at pH 1-2 and warm water
Biological or Organic fouling pH 12 @35°CpH 13 @25°C Best cleaning done at pH 12 and warm water
All FILMTEC™ RO membranes pH 1-12 @ 35°CpH 1-13 @ 25°C Sign of robust & durable membrane
Extended soaking Same as cleaning pH ranges Sign of robust & durable membrane

Important Information

Proper start-up of 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 DOW™ FILMTEC™ Reverse Osmosis and Nanofiltration Three-Year Prorated Limited Warranty (Form No. 609-02077) 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 membrane pressure vessel (housing) is 50 psi (3.4 bar).
  • Avoid static permeate-side backpressure at all times.
Product Part number Active area ft2 (m2) Feed spacer thickness (mil) Permeate flow rate gpd (m3/d) Stabilized salt rejection (%) Minimum salt rejection (%)
BW30-400 98650 400 (37) 28 10,500 (40) 99.50% 99.00%
  1. Permeate flow and salt (NaCl) rejection based on the following standard test conditions: 2,000 ppm NaCl, 225 psi (15.5 bar), 77°F (25°C), pH 8, 15% recovery.
  2. Flow rates for individual elements may vary but will be no more than 15% below the value shown.
  3. Stabilized salt rejection is generally achieved within 24-48 hours of continuous use; depending upon feedwater characteristics and operating conditions.
  4. Sales specifications may vary as design revisions take place.
  5. Active area guaranteed ± 3%. Active area as stated by Dow Water & Process Solutions is not comparable to nominal membrane area often stated by some manufacturers. Measurement method described in (Form No. 609-02077).

DOW™ FILMTEC™ BW30-400 is the product of choice when the highest quality permeate is required. It was the first 400 square foot membrane element on the market and continues to be widely used in new equipment and retrofits where system capital and productivity are factors.

  • Dow’s superior automated manufacturing technology results in the most consistent performance element-to-element and year-after-year.
  • BW30-400 elements deliver high flow and high rejection without being chlorinated during the manufacturing process. This is one reason why DOW FILMTEC elements are more durable and may be cleaned over a wider pH range (pH 1-13) than other RO elements.
  • With more than a decade of proven performance, BW30-400 is the product you can rely on for years of trouble-free operation.
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
[custom-usage] [/custom-usage]
(135 reviews) Write a Review
  • 5
    Very energy efficient membranes!

    Posted by Shane Z. on May 10th 2020

    They were able to handle a big quantity for us more than once. Excellent

  • 5
    Good supplier

    Posted by Soufine B. on Feb 18th 2020

    They were able to handle a big quantity for us more than once. Excellent

  • 5
    always in stock

    Posted by Dascarildo D. on Jan 11th 2020

    always in stock

  • 5
    Price is great.

    Posted by Jose M. on Nov 12th 2019

    Competitive price

  • 5
    Great after sales service.

    Posted by Hilsa S. on Oct 5th 2019

    Best supplier

  • 5
    High quality water...

    Posted by Nestor F. on Aug 28th 2019

    Best price

  • 5
    Better priced...

    Posted by Henrique W. on Jun 14th 2019

    Great price

  • 5
    High flow rate

    Posted by Minha M. on May 6th 2019

    fast shipping

  • 5
    Knowledgeable people from the sales to engineering

    Posted by Kelson D. on Apr 2nd 2019

    Will buy these membranes again!

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