TW 30-4021 Tapwater – Reverse osmosys membranes 900GPD 4″ x 21″

Permeate flow (m3/day): 900GPD

Size (Inch): 4″ x 21″

SKU: TW 30-4021 Category:


DOW Filmtec TW30-4021 RO Membrane 900 GPD, a 4″ x 21″ Reverse Osmosis Membrane that can provide RO quality water up to 900 gallons per day at a 8% recovery rate. It can operate at feed pressures ranging from 225 psi to 600 psi with 99.5% salt rejection. This element offers the highest quality water for small commercial systems purifying less than 10 gallon per minute(2300 L/h) of RO water and is the industry standard for reliable operation and production of the highest quality water in commercial applications.

Filmtec RO elements separate salts from water and are produced with an automated fabrication process for precision, consistency, and reliability offering high rejection of dissolved solids and organics and operate very efficiently at lower pressures. The TW30-DOW Filmtec Tap Water Thin Film-Commercial RO membranes are tape-wrapped—-built with the same high quality membranes and materials of construction as industrial elements, except for the hard outer shell, and are more economical for commercial systems with one or two elements per housing. In addition to the highest quality water and the lowest energy costs, DOW membranes also deliver savings through its increased resistance to fouling by providing the industry’s longest lasting and most reliable performance.

This membrane is a part of the “Small Commercial Elements” line of products by DOW FILMTEC and are applied in commercial water treatment systems, food service, hospitality industry, medical and research institutions. Its advanced technological design is manufactured for excellent structural stability and more productivity than other elements.


TW30-4021 Key Features and Benefits:

  • 900 Gallons per day.
  • 600 psi maximum operating pressure.
  • Removes chemical contaminants.
  • Reduce wastewater volumes by increasing water reuse.
  • High flux results in high yields.
  • Low energy costs with high rejection providing good water quality.
  • Durable with Good Cleanability for Long Element Life.
  • DOW FilmTec high quality, long lasting and reliable performance.


Model/SKU: DWC06
Manufacturer ID(Part#): TW30-4021 (Part #80608)
Dimensions(Diameter x Length): 4″ x 21″ (actual 3.9 x 21)
Stabilized Salt Rejection: 99.5%
Permeate Flow Rate(Gallons per Day, gpd): 900 Gal/Day (3406 L/Day or 3.41 m3/day) *
Maximum Feed Flow Rate (Gallons per Minute, gpm): 14.0 gpm (3.2 m3/hr)
Applied Pressure(psi): 225 psi (15.5 bar)
Maximum Operating Pressure(psi): 600 psi (41 bar)
Maximum Pressure Drop(psi): 13 psi (0.9 bar)
Maximum Operating Temperature(°F): 113°F (45°C)
pH Range, Continuous Operation: 2 – 11 **
pH Range, Short-Term Cleaning: 1 – 13
Maximum Feed Silt Density Index(SDI): SDI 5
Free Chlorine Tolerance(ppm): < 0.1 ppm ***
Membrane Style: Drop-in Element
Membrane Material: Polyamide Thin-Film Composite
Active Area: 36 sq. ft.
Outer Wrap: Tape-wrapped fiberglass outer shell
Housing/Pressure Vessel Size(inch): 4 inch