High Rejection, Seawater Reverse Osmosis Element
Description Dow Water & Process Solutions offers various premium seawater reverse osmosis (RO)
elements designed to reduce capital and operation cost of seawater RO systems.
DOW FILMTEC™ Elements combine premium membrane performance with automated
precision fabrication which takes system performance to exceptional levels.
DOW FILMTEC™ SW30HRLE–400 Elements offer a combination of high rejection and low
energy requirements to allow lower total costs with medium- and high-salinity feedwater.
Benefits of the DOW FILMTEC SW30HRLE–400 element include:
 Helps systems to be designed and operated to optimize operating cost through lower
energy consumption or to optimize capital cost through higher productivity at lower
operating fluxes.
 High NaCl and boron rejection to help meet World Health Organization (WHO) and
other drinking water standards.
 Effective use in permeate staged seawater desalination systems without impairing the
performance of the downstream stage.
 High performance over the operating lifetime without the use of oxidative posttreatments. This is one reason DOW FILMTEC elements are more durable and may
be cleaned more effectively over a wider pH range (1 – 13) than other RO elements.
 Automated, precision fabrication with a greater number of shorter membrane leaves
reducing the effect of overall fouling and maximizing element efficiency, helping to
lower your cost of operation.
Product Type Spiral-wound element with polyamide thin-film composite membrane.
Product Specifications
Active Area Feed Spacer
Thickness (mil)
Permeate Flow Rate Stabilized Boron
Rejection (%)
Stabilized Salt
(ft Rejection (%) 2
) (m2
) (GPD) (m3
SW30HRLE–400 400 37 28 7,500 28 92 99.8
1. The above values are normalized to the following conditions: 32,000 ppm NaCl, 5 ppm boron, 800 psi (5.5 MPa),
77°F (25°C), pH 8, 8% recovery.
2. Permeate flows for individual elements may vary ± 15%.
3. Minimum Salt Rejection is 99.65%.
4. Stabilized salt rejection is generally achieved within 24 – 48 hours of continuous use; depending upon feedwater
characteristics and operating conditions.
5. Product specifications may vary slightly as improvements are implemented.
6. Active area guaranteed ± 5%. Active area as stated by Dow Water & Process Solutions is not comparable to the
nominal membrane area figure often stated by some element suppliers. Measurement method described in
Form No. 609-00434.
Page 2 of 3 ®™ Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow Form No. 609-00425, Rev. 1
December 2016
DOW FILMTEC™ Element (in.) (mm) (in.) (mm) (in.) (mm)
SW30HRLE–400 40.0 1,016 1.125 ID 29 ID 7.9 201
1. Refer to Dow Water & Process Solutions Design Guidelines for multiple-element applications. 1 inch = 25.4 mm
2. Element to fit nominal 8-inch (203-mm) I.D. pressure vessel.
Operating and
Cleaning Limits
Maximum Operating Temperature a b 113°F (45°C)
Maximum Operating Pressure b 1,200 psig (83 bar)
Maximum Element Pressure Drop 15 psig (1.0 bar)
pH Range, Continuous Operation a 2 – 11
pH Range, Short-Term Cleaning (30 min.) c 1 – 13
Maximum Feed Silt Density Index (SDI) SDI 5
Free Chlorine Tolerance d < 0.1 ppm
a Maximum temperature for continuous operation above pH 10 is 95°F (35C).
bOperation at pressures up to 1,200 psig (83 bar) is allowable under certain conditions. Consult your Dow representative for advice on
applications above 1,000 psig (69 bar) and/or above 95°F (35C).
c Refer to guidelines in “Cleaning Procedures” for more information.
d 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, Dow Water & Process Solutions recommends removing residual free chlorine by pretreatment prior to
membrane exposure. Please refer to technical bulletin “Dechlorinating Feedwater” for more information.
Before use or storage, review these additional resources for important information:
 Usage Guidelines for DOW FILMTEC™ 8” Elements
 System Operation: Initial Start-Up
 Handling, Preservation and Storage
* Permeate obtained from first hour of operation should be discarded
Regulatory Note These membranes may be subject to drinking water application restrictions in some
countries; please check the application status before use and sale.
Dow has a fundamental concern for all who make, distribute, and use its products, and for
the environment in which we live. This concern is the basis for our product stewardship
philosophy by which we assess the safety, health, and environmental information on our
products and then take appropriate steps to protect employee and public health and our
environment. The success of our product stewardship program rests with each and every
individual involved with Dow products—from the initial concept and research, to
manufacture, use, sale, disposal, and recycle of each product.
Page 3 of 3 ®™ Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow Form No. 609-00425, Rev. 1
December 2016