Bumblebee Linens

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

DOW™ FILMTEC™ SW30ULE-440i is an element of choice for low to medium salinity and temperature waters, for permeate staged systems for stringent water quality targets, and for high feed salinity brackish water applications. It has the highest sustainable flow rate available in the industry, coupled with high rejection of NaCl and boron. This performance can lead to significant capital and operation cost savings, especially when this element is mixed with other element types in the same pressure vessel, using the “internally staged design” approach. . In addition, the combination of highest active area and thickest feed spacer of the Dow FILMTEC membranes results in higher productivity and lower cleaning frequency enabling sustainable lower lifecycle cost. Benefits of the DOW FILMTEC SW30ULE-440i element include:

• The highest seawater element flow rate in the industry, coupled with high rejection, allowing ultralow energy consumptions. This enables lowest capital and operation cost in a seawater system.
• The highest guaranteed active area of 440 ft2 (41 m2) permits lowest system cost by maximizing productivity and enables accurate and predictable system design and operating flux.
• The combination of highest active area with wide feed spacer (28 mil) allows low cleaning frequency and high cleaning efficiency.
• Utilization of the distinct iLEC™ Interlocking Endcaps that help reduce system operating costs and reduce the risk of O-ring leaks that cause poor water quality (see Form No. 609-00446 for information on the 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.
• Automated, precision fabrication with a greater number of shorter membrane leaves reduces the effect of overall fouling and maximizes element efficiency, lowering cost of operation.

Product Type
Polyamide Thin-Film Composite

40 in x 7.9 in

Product Specifications

Flow Rate
Rejection (%)
Rejection (%)
(psig) (bar) (GPD) (m³/h)
9,000 34.1 86.4 99.6
  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 ± 17%.
  3. Minimum Salt Rejection is 99.50%.
  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.

Operating and Cleaning Limits

Operating Temperature
Operating Pressure
Pressure Drop
pH Range,
Continuous Operation
pH Range,
Short-Term Cleaning (30 min.)
Maximum Feed
Silt Density
Index (SDI)
113°F (45°C) 1,200 psig (83 bar) 13 psig (0.9 bar) 2 – 11 1 – 13 SDI 5 < 0.1 ppm

• Maximum temperature for continuous operation above pH 10 is 95°F (35°C).
• Refer to guidelines in “Cleaning Procedures” for more information.
• 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.