Collection: CPA Series-High Rejection Brackish Water Hydranautics Membranes
CPA Series – High Rejection Brackish Water Hydranautics Membranes
The CPA (Composite Polyamide) series from Hydranautics, a Nitto Group company, sets the industry standard for high salt rejection in brackish water reverse osmosis. Built on a proven composite polyamide thin-film membrane, CPA elements are widely specified for applications where water purity is critical, including municipal drinking water production, industrial process water, power generation, pharmaceutical manufacturing, and semiconductor fabrication, where even trace levels of dissolved solids can compromise a process.
This collection spans several CPA generations and configurations. The generation number (CPA2, CPA3, CPA5, CPA6, CPA7) reflects the membrane's rejection performance, with CPA7 representing Hydranautics' newest and highest-rejection brackish water chemistry. Within most generations, "LD" (Low Differential Pressure) models use a thicker feed spacer designed to minimize colloidal fouling and reduce pressure drop over the element's service life, while "MAX" models use the same high-rejection membrane chemistry with roughly 10% more active membrane area, allowing system designers to achieve the same output with fewer elements and a smaller equipment footprint. Elements are available in 2.5-inch, 4-inch, and 8-inch diameters to match a range of system sizes, from compact commercial installations up to large municipal and industrial plants.
Choosing the right element: For smaller commercial systems, select a 2.5" or 4" element sized to your housing; for higher-capacity municipal or industrial systems, select an 8" element. If minimizing fouling and pressure drop over time is the priority, choose an "LD" model; if maximizing output per pressure vessel and reducing system footprint is the priority, choose a "MAX" model. For the highest available salt rejection, prioritize CPA7 over earlier generations.
CPA Series Membrane Comparison
|
Model
|
Nominal Size
|
Permeate Flow Rate
|
Test Pressure
|
Salt Rejection
|
Price
|
|
CPA2-2540
|
2.5" x 40"
|
Not published¹
|
225 PSI
|
99.4%
|
$203.45
|
|
CPA2-4040
|
4" x 40"
|
2,250 GPD
|
225 PSI
|
99.5%
|
$287.10
|
|
CPA-4040E
|
4" x 40"
|
2,250 GPD
|
225 PSI
|
99.5% (99.2% Min)
|
$321.75
|
|
CPA5-LD-4040
|
4" x 40"
|
2,100 GPD
|
225 PSI
|
99.7%
|
$270.13
|
|
CPA7-LD-4040
|
4" x 40"
|
2,300 GPD
|
225 PSI
|
99.8%
|
$296.99
|
|
CPA5-LD
|
8" x 40"
|
11,000 GPD
|
225 PSI
|
99.7%
|
$643.49
|
|
CPA5 MAX
|
8" x 40"
|
12,000 GPD
|
225 PSI
|
99.7% (99.6% Min)
|
$650.63
|
|
CPA6-LD
|
8" x 40"
|
8,000 GPD
|
225 PSI
|
99.75% (99.6% Min)
|
$645.38
|
|
CPA6 MAX
|
8" x 40"
|
8,800 GPD
|
225 PSI
|
99.75% (99.6% Min)
|
$866.25
|
|
CPA3-8
|
8" x 40"
|
11,000 GPD
|
225 PSI
|
99.7%
|
$661.11
|
|
CPA7-LD
|
8" x 40"
|
11,500 GPD
|
225 PSI
|
99.8%
|
$810.81
|
|
CPA7 MAX
|
8" x 40"
|
12,600 GPD
|
225 PSI
|
99.8% (99.7% Min)
|
$766.50
|
|
ESNA1-LF-LD-4040²
|
4" x 40"
|
1,900 GPD
|
75 PSI
|
Not published
|
$355.41
|
Always confirm exact specifications against Hydranautics' current official documentation before purchase or system design.
