The DOW FILMTEC NF90 membrane elements provide high productivity performance while removing a high percentage of salts, nitrate, iron and organic compounds such as pesticides, herbicides and THM precursors. The low net driving pressure of the NF90 membrane allows the removal of these compounds at low operating pressures.
Uses for NF90-4040 Membrane Elements
- High flux results in high yields, good rejection results in excellent water quality;
- Low energy usage reduces power consumption and costs;
- durable with good cleanability for long element life;
- Filmtec Performance and quality
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.
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.
- Keep elements moist at all times after initial wetting.
- If operating limits and guidelines given in this bulletin are not strictly followed, the limited warranty 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 pressure vessel (housing) is 30 psi (2.1 bar).
- Avoid static permeate-side backpressure at all times.
|Product||Part Number||Applied Pressure psig (bar)||Permeate Flow Rate gpd (m3/d)||Stabilized Salt Rejection (%)|
|NF90-4040||149983||70 (4.8)||2,000 (7.6)||97.0|
The DOW FILMTEC™ NF90 membrane elements provide high productivity performance while removing a high percentage of salts, nitrate, iron and organic compounds such as pesticides, herbicides and THM precursors. The low net driving pressure of the NF90 membrane allows the removal of these compounds at low operating pressures.
- Membrane Type Polyamide Thin-Film Composite
- Maximum Operating Temperature 113°F (45°C)
- Maximum Operating Pressure 600 psi (41 bar)
- Maximum Feed Flow Rate:
- 4040 elements 16 gpm (3.6 m3/hr)
- 2540 elements 6 gpm (1.4 m3/hr)
- Maximum Pressure Drop:pH Range, Continuous Operation 2 – 11
- tape wrapped 13 psig (0.9 bar)
- fiberglassed 15 psig (1.0 bar)
- pH Range, Short-Term Cleaning (30 min.) 1 – 12
- Maximum Feed Silt Density Index SDI 5
- Free Chlorine Tolerance 0.1 ppm
Ideal Applications Include:
- Commercial water demineralization
- Production of drinking water