The ULP21-4040 is a 4-inch × 40-inch ultra-low pressure (ULP) spiral wound reverse osmosis (RO) membrane. It is designed for energy-efficient desalination of low to medium salinity water sources (TDS < 2000 ppm).
Technical Specifications：
Model: ULP21-4040
Active Membrane Area: 100 sq. ft.
Permeate Flow: 2600 GPD
Max Working Pressure: 600 psi
Max Feedwater Temperature: 45°C
Max Feedwater SDI: 5
Key Advantages：
1. Ultra-Low Pressure Operation
Operates at ~150 psi (1.03 MPa), which is ~2/3 the pressure of standard low-pressure membranes
Reduces energy consumption by ~30% and lowers capital costs for pumps, piping, and vessels.
2. High Rejection & Stable Performance
Delivers ~99% salt rejection, comparable to standard membranes, but at much lower pressure.
Maintains high flux even at low temperatures (e.g., ~85% of nominal flux at 5°C).
3. Wide Feedwater Compatibility
Ideal for surface water, groundwater, tap water, and municipal water with TDS < 2000 ppm.
Suitable for commercial, light industrial, and large residential RO systems.
4. Fouling Resistance
34 mm wide feed channel design slows scaling and fouling, extending cleaning cycles.
Typical Applications：
Bottled/packaged water production
Drinking water purification (commercial & light industrial)
Boiler feedwater pretreatment
Food & beverage processing
Pharmaceutical water preparation
Small-scale desalination
Why Choose ULP21-4040?
Cost-effective: Lower energy and equipment costs.
High performance: Near-99% rejection at ultra-low pressure.
Reliable: polyamide thin-film composite (TFC) technology.
Standard size: Fits standard 4-inch RO pressure vessels.
Maintenance & Operation Tips：
Pre-treatment is critical: Ensure SDI ≤ 5, no free chlorine, and proper pH control.
Regular flushing: Periodic
