Dow Filmtec NF270-400 40 inch × 8 inch Nanofiltration Membrane
The Filmtec NF270-400 nanofiltration element is a high area, high productivity element designed to remove a high percentage of TOC and THM precursors while having a medium to high salt passage; medium hardness passage. The Filmtec NF270-400 element is an ideal element for surface and ground water applications where good organic removal is desired with partial softening in order to maintain a minimum level of hardness for organoleptic properties and preservation of distribution networks. The high active area membrane combined with low net driving pressure of the membrane allows the removal of these compounds at low operating pressure.
- Membrane Type: Polyamide Thin-Film Composite (TFC)
- Maximum Operating Temperature: 113F (45C)
- Maximum Operating Pressure: 600 psi (41 bar)
- Maximum Pressure Drop: 15 psi (1.0 bar)
- Maximum Feed Flow Rate: 70.0 gpm (15.9 m3/hr)
- pH Range, Continuous Operation: 2-11***
- pH Range, Short-Term Cleaning: 1-12* (30min)
- Maximum Feed Silt Density Index: 5 SDI
- Free Chlorine Tolerance: <0.1 ppm**
- Permeate Flow Rate*: MgSO4: 12,500GPD (47.3 m3/day), CaCl2: 14,700 GPD (55.6 m3/day)
- Stabilized Salt Passage: MgSO4: <3%, CaCl2: 40-60%
*Permeate flow and salt passage based on the following test conditions: 500 mg/l CaCl2, 70 psi (0.48 MPa), 77ºF (25ºC) and 15% recovery. 2,000 mg/l MgSO4, 70 psi (0.48 MPa), 77ºF (25ºC) and 15% recovery. Flow rates for individual elements may vary +/-15%.
**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 recommends removing residual free chlorine by pretreatment prior to membrane exposure. Most RO systems have carbon pre-filters for this purpose.
***Maximum temperature for continuous operation above pH 10 is 95F (35C).