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Dow Filmtec NF270-4040 Nanofiltration Membrane

2,500 GPD replacement nanofiltration membrane element

The Filmtec NF270-4040 membrane elements are ideal for removing a high percentage of TOC and THM precursors with medium to high salt passage and medium hardness passage. The Filmtec NF270 membrane is an ideal choice for surface water and ground water where good organic removal is desired with partial softening. NF270-4040 has a fiberglass outer wrap.

Membrane Type:Polyamide Thin-Film Composite (TFC)
Maximum Operating Temperature:113F (45C)
Maximum Operating Pressure:600 psi (41 bar)
Maximum Feed Flow Rate:16.0 gpm (3.6 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:2,500 GPD (9.5 m3/day)*
Stabilized Salt Rejection:>97.0%

*Permeate flow and salt rejection based on the following test conditions: 2,000 ppm MgSO4, 77F (25C) and 15% recovery at the pressure specified above. NF270-4040 individual elements may vary -15% / +50%.

**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).

Filmtec NF270-4040 Nanofiltration Membrane


   A: 40.0" (1,016mm)
   B: 1.05" (27mm)
   C: 0.75" (19mm)
   D: 3.9" (99mm)
Filmtec NF270-4040 Size Chart
Model Diameter Inches Length Inches Active Surface
Area ft2 (m2)
Test Pressure Permeate Flow
GPD (m3/day)
(w/ Free Shipping)
Filmtec NF270-4040
Our Stock #703149987
Dow Part #149987
4 40 70 (4.8) 82 (7.6) 2,500 (9.5)
MSRP: US$870.25
Price: US$487.00
You save: $383.25

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Notice: The use of this product in and of itself does not necessarily guarantee the removal of cysts and pathogens from water. Effective cyst and pathogen reduction is dependent on the complete system design and on the operation and maintenance of the system.

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