The Aquaflex membrane modules from X-Flow triangle-overlay



Pentair X-Flow XF55 Membrane Elements are based on hydrophilic hollow-fiber ultrafiltration membranes composed of a PES/PVP blend. They have high mechanical and chemical strength, making them suitable for a wide range of applications. The pressurized membrane elements are the industry’s choice for the removal of bacteria, viruses, suspended solids, and colloids.


Hollow fiber ultrafiltration


  • Removal of microorganisms
    • Membrane filtration provides 99.9999% reduction of bacteria and 99.99% reduction of viruses by mechanical means
  • High membrane packing density: One of the industry’s smallest free volume in a membrane elements
  • 100% integrity testing on individual fibers
  • Individual fiber repair
  • Very good antifouling behavior
  • Typical permeate quality:
    • SDI < 3
    • Turbidity < 0.1NTU
  • Excellent chemical resistance:
    • Wide pH range: 2 – 12
    • High chlorine stability:maximum free chlorine 250 mg/l
  • Typical high permeability: low energy consumption

Functional description

The core of the XF55 Membrane Element is the single-fiber, inside-out filtration process that delivers a robust solution. The Membrane Elements can be operated vertical and horizontal and  can be utilized in three of Pentair X-Flow's unique Solutions: 
  • Xiga
  • Aquaflex
  • X-Line

Fields of application

Potable water production
The X-Flow XF55 Membrane Elements provide superior separation performance and effective rejection of viruses and chlorine-resistant organisms such as Cryptosporidium and Giardia

Process water production
The Membrane Elements offer an effective barrier to suspended solids and silt. The permeate can be used directly or, if salinity and dissolved solids are not within the required limits, the permeate can be fed to a downstream RO system.

Effluent polishing

The X-Flow XF55 are a reliable solution to meeting the highest standards for turbidity and microbiology. The polished effluent is ready for high- grade and unrestricted reuse applications.

Pretreatment for Seawater Reverse Osmosis systems

X-Flow's XF55 offer an effective barrier to suspended solids and silt. The almost total removal of suspended solids protects the SWRO from fouling.



Membrane surface area
55 m²
Module dimensions (dxl)
8.7” x 1537.5 mm
Housing material
Membrane material
Hydraulic membrane diameter
0.8 mm
Nominal pore size
20 nm

The Pentair X-Flow XF55 Membrane Element is formally known as Aquaflex 55, Xiga 55, Seaflex 55 and Seaguard 55.

Featured cases

CocaCola slider image

wakefield, united kingdom

potable water production

Witbank slider image

Emalalheni (Witbank) South Africa

Acid mine drainage

WTE-Moscow slider image

South-West Moscow

Surface water