Hydranautics CPA5 LD 4040

The Hydranautics CPA5-LD-4040 is a premium 4x40 low fouling reverse osmosis membrane element engineered by Nitto Hydranautics for exceptional performance in brackish water treatment systems. As part of the renowned CPA series, this fourth-generation composite polyamide RO membrane delivers outstanding salt rejection of 99.7% (minimum 99.5%) while producing up to 2,100 gallons per day (7.95 m³/day) of high-purity permeate at just 225 psi (1.55 MPa) applied pressure under standard test conditions (1500 ppm NaCl, 77°F/25°C, 15% recovery).

Featuring Low Fouling (LD) technology with a 34 mil (0.864 mm) feed spacer treated for enhanced resistance to colloidal and biofouling, the CPA5-LD-4040 offers an active membrane area of 80 ft² (7.43 m²) in a low-differential-pressure design. This translates to longer operating cycles, reduced cleaning frequency, lower energy consumption, and superior system efficiency compared to standard elements—ideal for applications where feedwater quality varies or pretreatment is conventional.

Key performance highlights include:

• High rejection of salts, silica, TOC, hardness, and nitrates for ultrapure water production
• Maximum applied pressure: 600 psig (4.14 MPa)
• Operating temperature up to 113°F (45°C)
• pH range: 2-11 continuous (1-13 cleaning)
• Maximum feedwater turbidity: 1 NTU
• Chlorine tolerance: <0.1 ppm

Built with a durable fiberglass outer wrap, this 4-inch x 40-inch spiral-wound brackish water RO element excels in municipal drinking water desalination, well water treatment, boiler feedwater makeup, industrial process water, semiconductor ultrapure systems, and TDS reduction prior to ion exchange or other polishing steps.

Upgrade your reverse osmosis system with the Hydranautics CPA5-LD-4040 — the trusted choice for high-rejection, low-energy, low-fouling performance in demanding brackish RO applications. Search terms like CPA5-LD-4040 RO membrane, Hydranautics 4x40 low fouling membrane, 2100 GPD brackish water RO element, or 99.7% rejection Nitto RO membrane lead straight to this powerhouse of reliability and value. Contact us for compatibility verification, system integration advice, or bulk pricing on this industry-leading element.