DOW FILMTEC HRLE-440i Membrane

Featuring breakthrough membrane chemistry, the DOW FILMTEC HRLE-440i element delivers the same 99.5% nominal NaCl rejection as traditional brackish water elements but at 33% lower pressures.

Advantages

• High rejection results in excellent water quality
• Reduced downstream polishing required
• High flux reduces energy use
• Durable with good cleanability for long element life
• Filmtec Performance and quality

General 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.

Important 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. 609-35010) 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 drops are 15 psi (1.0 bar) per element or 50 psi (3.4 bar) per multi-element pressure vessel (housing) whichever value is more limiting.
• Avoid static permeate-side backpressure at all times.