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The 2521 reverse osmosis (RO) membrane is a small-scale, industrial-grade RO membrane element. Membranes of this specification are commonly used in small- to medium-sized water treatment systems that handle water volumes falling between those of residential and large-scale industrial applications.
What Does 2521 Mean?
- “25”: Indicates that the nominal outer diameter of the membrane element is 2.5 inches (approximately 63.5 mm).
- “14”: Indicates that the total length of the membrane element is 14 inches (approximately 356 mm).
Description
- Compact Design
Compared to mainstream 4040 (40-inch) or 8040 membranes, the 2521 model is significantly smaller in size. It is ideal for space-constrained, skid-mounted, or portable water treatment equipment.
- Cost-Effective for Small-to-Medium Flow Rates
For businesses requiring 1 to 2 tons of purified water daily, the 2521 membrane offers a superior solution: it avoids the short service life associated with residential-grade membranes (such as 3012 or 400G models) under high-demand operation, while also saving space and reducing initial investment costs compared to 4040 industrial systems.
Performance Parameters
| Model | 2521 |
| Effective membrane area, ft² (m²) | 13 (1.2) |
| Average yield, GPD (m³/d) | 300 (1.1) |
| Salt rejection (%) | 99 |
| Max. inflow temperature (℃) | 15 |
| Max. water flow, GPM (m³/h) | 6 (1.4) |
| Working pressure, psi (MPa) | 150 (1.03) |
| Max. working pressure, psi (MPa) | 600 (4.2) |
| Max. water temperature (℃) | 45 |
| Max. inflow SDI15 | 5 |
| Free chlorine concentration (mg/L) | <0.1 |
| Continuous running water pH range | 3–10 |
| Chemical cleaning water pH range | 2–11 |
| Max. single membrane element pressure drop, psi (MPa) | 15 (0.1) |
Application Scenarios
01. Ultra-low Pressure / Low-pressure Membranes
- Primary Water Sources: Tap water, low-salinity groundwater.
- Applications: Commercial water purification systems (office buildings, schools, hospitals), pre-treatment for laboratory ultrapure water systems, food and beverage processing water, etc.
02. High-rejection / Brackish Water Membranes
- Primary Water Sources: Groundwater with higher salinity, electroplating wastewater, industrial circulating water.
- Applications: Small-scale industrial boiler feed water, car wash water recycling, reclaimed water reuse systems.