The Dow Filmtec BW30-4040 is a 4-inch diameter, 40-inch long brackish water reverse osmosis membrane element for light commercial and point-of-entry water treatment systems. Each element produces 2,650 GPD (10 m3/day) of product water at 99.5% stabilized salt rejection — suitable for restaurants, hotels, small clinics, light manufacturing, and commercial food service applications treating municipal or ground water up to 10,000 ppm TDS.
The BW30-4040 uses Dow Filmtec thin-film composite (TFC) polyamide construction, providing consistently high rejection rates and better fouling resistance than cellulose acetate membranes. The 4040 form factor fits standard 4-inch pressure vessels used in commercial point-of-use and light commercial RO systems.
Technical Specifications
| Parameter | Value |
|---|---|
| Element type | Brackish Water RO (BW) |
| Element size | 4 inch x 40 inch |
| Permeate flow rate | 2,650 GPD (10 m3/day) |
| Stabilized salt rejection | 99.5% |
| Test conditions | 2,000 ppm NaCl, 225 PSI, 77F, 15% recovery |
| Pressure vessel size | 4-inch standard |
| Maximum feed TDS | 10,000 ppm |
Installation Notes
- Requires dechlorination before membrane contact — free chlorine above 0.1 ppm degrades TFC polyamide
- Recommended pre-filtration: 5-micron sediment cartridge plus activated carbon block
- Maximum operating temperature: 113F (45C)
- Permeate flow rates for individual elements may vary plus or minus 20%
- Compatible with standard 4-inch pressure vessels; verify end-cap connection type before ordering
Related Resources
- Commercial RO Systems — full range for restaurants, clinics and offices
- All RO Membranes — browse full membrane catalog
- Get Expert Help — compatibility verification and replacement ordering
AMPAC Water Systems designs and manufactures advanced water treatment solutions for commercial, industrial, and municipal applications. From RO systems and PFAS removal to zero liquid discharge and smart water technology — engineered for your needs.
