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Dow Filmtec LP-4040
Reverse Osmosis (RO) Membrane

2,900 GPD low pressure/high capacity light industrial / commercial / whole house replacement reverse osmosis (RO) membrane element

Membrane Type:Polyamide Thin-Film Composite (TFC)
Maximum Operating Temperature:113F (45C)
Maximum Operating Pressure:600 psi (41 bar)
Maximum Pressure Drop:13 psi (0.9 bar)
Feed Spacer Thickness:34 mil
Maximum Feed Flow Rate:6 gpm (1.4 m3/hr)
pH Range, Continuous Operation:2-11***
pH Range, Short-Term Cleaning:1-13* (30min)
Maximum Feed Silt Density Index:5 SDI
Free Chlorine Tolerance:< 0.1 ppm**
Permeate Flow Rate:2,900 GPD (11.0 m3/day)*
Stabilized Salt Rejection:99.2%

*Permeate flow and salt rejection based on the following test conditions: 77F (25C), 15% recovery, applied pressure of 145 psig (10 bar), and a 500 ppm NaCl feed stream. Permeate flow rates for individual elements may vary +/-20%.

**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).

Note: FILMTEC LP-4040 can replace TW30HP-4040 and will produce roughly 30% more permeate and improved salt rejection at TW30HP-4040 test conditions.

Filmtec LP-4040 Reverse Osmosis (RO) Membrane


   A: 40.0" (1,016mm)
   B: 1.05" (26.7mm)
   C: 0.75" (19mm)
   D: 3.9" (99mm)
Filmtec LP-4040 Size Chart
Model Diameter Inches Length Inches Active Surface
Area ft2 (m2)
Test Pressure Permeate Flow
GPD (m3/day)
(w/ Free Shipping)
Filmtec LP-4040
Our Stock #7030404005
Dow Part #212819
4.0 40 78 (7.2) 145 psi 2,900 (11.0) Sorry, this item has been discontinued by the manufacturer. Filmtec recommends the LC LE-4040 as a replacement for this item.

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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