The Dow Filmtec SW30-4040 is a premier seawater reverse osmosis (RO) membrane element designed to deliver high-quality permeate water from seawater sources. Widely recognized as a standard in the industry, this 4-inch membrane element offers an exceptional balance of productivity and salt rejection, making it ideal for marine and land-based desalination applications.
Overview: High Performance Seawater Desalination
The SW30-4040 element (Part Number 80741) is engineered to produce 1,950 gallons per day (GPD) of fresh water while maintaining a stabilized salt rejection rate of 99.4%. This membrane utilizes Dow’s advanced polyamide thin-film composite technology, ensuring durability and consistent performance over a long operational life.
One of the distinct advantages of the SW30-4040 is its ability to operate effectively at lower feed pressures compared to other seawater elements. This capability allows system designers to reduce pump sizes and lower overall energy consumption, optimizing the cost of water production.
Key Benefits
- High Productivity: Generates up to 1,950 GPD, meeting the rigorous demands of marine desalinators.
- Energy Efficient: High flux design reduces energy usage and pressure requirements.
- Excellent Rejection: ~99.4% salt rejection ensures high-quality potable water suited for drinking and critical applications.
- Durability: Constructed with a hard fiberglass outer shell and robust membrane chemistry that allows for cleaning across a wide pH range (1–13).
Technical Specifications
Below is a detailed breakdown of the performance specifications for the SW30-4040 membrane. These metrics are essential for engineers and operators integrated this element into new or existing RO systems.
| Specification | Value |
|---|---|
| Model / Part Number | SW30-4040 / 80741 |
| Membrane Type | Polyamide Thin-Film Composite |
| Permeate Flow Rate | 1,950 GPD (7.4 m³/day) |
| Stabilized Salt Rejection | 99.4% |
| Applied Pressure (Testing) | 800 psi (55 bar) |
| Active Surface Area | 80 ft² (7.4 m²) |
| Dimensions (Dia. x Length) | 4.0 inches x 40 inches |
| Feed Spacer Thickness | 28 mil |
Operating Limits
Adhering to these operating limits is crucial to maximize the lifespan of the membrane and maintain warranty validity.
| Maximum Operating Pressure | 1,000 psi (69 bar) |
| Maximum Operating Temperature | 113°F (45°C) |
| Maximum Feed Flow Rate | 16 gpm (3.6 m³/hr) |
| Maximum Pressure Drop | 15 psig (1.0 bar) per element |
| pH Range, Continuous Operation | 2 – 11 |
| pH Range, Short-Term Cleaning | 1 – 13 |
| Free Chlorine Tolerance | < 0.1 ppm |
| Maximum Feed Silt Density Index (SDI) | SDI 5 |
Common Applications
The versatility of the SW30-4040 makes it a preferred choice for a variety of sectors requiring reliable desalination:
- Marine & Yachting: Compact desalination units on boats and yachts to produce fresh water from the ocean.
- Small Municipal Systems: Providing potable water for coastal communities and island resorts.
- Commercial & Industrial: Process water treatment requiring high purity.
- Offshore Platforms: Essential water supply for oil and gas rigs.
Looking for Filtration Solutions?
Purecowater specializes in solving complex liquid and solid filtration challenges. Whether you need replacements for Dow Filmtec membranes or assistance with WTS, Veolia, or LG membrane solutions, our team is ready to help you optimize your system.