International RO Membrane Size Standards
A four-digit sizing convention, such as 1812, 4040, and 8040, where the first two digits represent outer diameter in inches and the last two digits represent total length in inches.
| Application Segment | Size Code | Diameter × Length | Physical Dimensions | Standard Capacity Range |
|---|---|---|---|---|
| Residential / Domestic | 1812 | 1.8" × 12" | 4.6 × 30.5 cm | 50-100 GPD |
| Light Commercial | 2012 | 2.0" × 12" | 5.0 × 30.5 cm | 120-200 GPD |
| Commercial | 3012 | 3.0" × 12" | 7.6 × 30.5 cm | 300-400 GPD |
| Small Industrial | 2521 | 2.5" × 21" | 6.4 × 53.3 cm | 250-350 GPD |
| Medium Industrial | 2540 | 2.5" × 40" | 6.4 × 101.6 cm | 500-1,000 GPD |
| Industrial / Commercial | 4021 | 4.0" × 21" | 10.2 × 53.3 cm | 800-1,200 GPD |
| Standard Industrial | 4040 | 4.0" × 40" | 10.2 × 101.6 cm | 1,900-2,600 GPD (~7,200 L/day) |
| Large-Scale / Municipal | 8040 | 8.0" × 40" | 20.3 × 101.6 cm | 6,000-12,000 GPD (~29,800 L/day) |
Key Technical Criteria & Guidelines
- Standard Length for Industrial Plants: 40 inches.
- The Sizing Trade-Off: Larger sizes can reduce pipeline complexity and operational cost per liter.
- Cross-Compatibility: A standard 4040 membrane can fit a universal 4040 pressure-vessel housing.
- International Certifications: Top-tier residential and commercial membranes are tested against international testing standards such as NSF/ANSI Standard 58 for material safety and structural performance constraints.