The Industry Standard for Brackish Water Filtration
For industrial operators requiring reliable water demineralization and purification, the BW30-4040 specification remains one of the most trusted standards in the Reverse Osmosis (RO) industry. Designed for brackish water applications, the Dow Filmtec BW30-4040 (and its high-performance industrial equivalents) offers a balance of high rejection rates and robust flow capabilities, making it a cornerstone for light industrial systems.
At Purecowater, we understand that maintaining peak system performance requires membranes that meet rigorous specifications. Whether you are looking for direct replacements or high-efficiency industrial equivalents, understanding the capabilities of the BW30-4040 style membrane is essential for optimizing your filtration process.
What is the BW30-4040 Membrane?
The BW30-4040 is a 4-inch diameter, 40-inch length spiral-wound membrane element. It utilizes a Polyamide Thin-Film Composite (TFC) material, known for its durability and high performance in separating salts from water.
The “BW” stands for Brackish Water, indicating its optimization for feed water with moderate salinity (typically up to 2,000–5,000 ppm TDS), such as tap water, well water, or surface water sources. Its fiberglass outer shell allows it to withstand high pressure drops, making it ideal for multi-element housings used in commercial and industrial skids.
Note on Product Evolution: While the classic BW30-4040 has been an industry staple, many manufacturers (including DuPont/Dow) have transitioned to newer revisions like the BW30 PRO-4040. Industrial equivalents provided by Purecowater are designed to match or exceed the original flow and rejection specifications, ensuring seamless retrofitting into existing equipment.
Key Features and Benefits
- Broad Cleaning pH Range: Capable of withstanding cleaning chemicals within a pH range of 1–13, allowing for aggressive cleaning of fouling agents like scale and organics.
- 34-Mil Feed Spacer: Many industrial equivalent models feature a thicker chemical feed spacer (34 mil) which reduces the impact of fouling and lowers the pressure drop across the vessel.
- High Salt Rejection: Delivers 99.5% stabilized salt rejection, ensuring high-quality permeate for sensitive applications.
- Fiberglass Exterior: The hard shell construction is superior to tape-wrapped elements for industrial applications, providing structural integrity in systems with multiple elements in series.
Technical Specifications
Below are the typical performance standards for a BW30-4040 industrial equivalent membrane. These figures represent the benchmarks for high-quality replacements.
| Specification | Value |
|---|---|
| Permeate Flow Rate | 2,400 GPD (9.1 m³/d) |
| Stabilized Salt Rejection | 99.5% |
| Dimensions | 4.0″ Diameter x 40″ Length |
| Active Surface Area | 78 ft² (Typical) to 85 ft² (Pro Series) |
| Applied Pressure | 225 psi (15.5 bar) |
| Feed Spacer Thickness | 34 mil |
*Note: Performance is typically based on 2,000 ppm NaCl feed solution at 225 psi, 77°F (25°C), and 15% recovery. Individual element flow may vary.
Operating Limits
To ensure the longevity of your membrane elements, operating within the manufacturer’s limits is crucial. Industrial equivalents of the BW30-4040 are designed to handle robust industrial environments.
| Parameter | Limit |
|---|---|
| Max. Operating Pressure | 600 psi (41 bar) |
| Max. Operating Temperature | 113°F (45°C) |
| Max. Feed Flow Rate | 16 gpm (3.6 m³/hr) |
| Max. Silt Density Index (SDI) | SDI 5 |
| Free Chlorine Tolerance | < 0.1 ppm |
Applications
The versatility of the BW30-4040 specification makes it the “workhorse” of the water treatment industry. Common applications include:
- Municipal Drinking Water: Reducing TDS and contaminants to meet safe drinking standards.
- Spot-Free Rinse: utilized in car washes and glass manufacturing for residue-free water.
- Boiler Feed Water: Pre-treatment for boilers to prevent scaling and improve thermal efficiency.
- Food & Beverage: Ensuring consistent water quality for production.
- Water Reuse: Treating wastewater for secondary industrial capacity.
Why Choose Purecowater for your Membrane Needs?
Finding the right replacement membrane can be challenging with the shifting landscape of product names and technical revisions (such as the shift from BW30 to BW30 PRO). Purecowater streamlines this process. As a distributor for major brands like LG Chem, Veolia (Suez), and other Engineered Solutions, we can supply the exact industrial equivalent necessary to keep your RO unit running at peak efficiency.
Whether you need a single 4040 element or a full skid replacement, our team tackles both solid and liquid filtration problems with expertise.
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Contact us today to find the perfect liquid filtration solution for your specific application.