With the Helix flux enhancement technology, X-Flow addresses a bottleneck in high-solids ultrafiltration (UF) by preventing the buildup of foulants. Helix technology enhances flux, increases flow, and saves energy. By introducing turbulence right at the membrane wall, Helix technology provides continuous mixing and efficient removal of the cake layer that would otherwise reduce the membrane’s hydraulic permeability. The resulting higher permeate flow means higher productivity and lower costs. Due to the effective membrane cleaning at low crossflow velocities, Helix technology significantly reduces the energy footprint compared to standard tubular membrane solutions.
Pentair X-Flow Tubular UF and Helix UF

UF and cake formation

When a stream containing particulate matter is filtered, solids are retained by the membrane. Only soluble compounds and water pass the typical 30nm sized pores. The rejected solids accumulate at the membrane wall, forming a cake layer
which restricts water flux and reduces productivity. To limit the cake formation, typical tubular UF membranes are operated at relatively high crossflow velocities (up to 4m/s), resulting in higher energy consumption.


Helix technology sustains and boosts the productivity of membrane systems with helically winding ridges that provide turbulence and enhanced feed water mixing. The prevention of cake formation allows for higher permeate flows at lower crossflow velocities.

case study - performance comparison

Pentair initially installed two units with six X-Flow Compact 27 membrane elements for leachate treatment. In 2015, 6 standard elements in one unit were replaced with Compact 27 Helix membrane elements. Flux increased from 135 lmh for standard Compact 27 to an impressive 180 lmh with the Compact 27 Helix membrane module. This results in energy savings of around 33 percent.

  • Technology: Crossflow MBR
  • Crossflow velocity: 3.5 m/s
  • UF feed water: 10 – 15 g/l MLSS
  • Energy saved:        33,3%

Helix results

Ghent University in Belgium

Superior Helix performance

why turbulence enhancement?

In any UF process that treats wastewater with high organic content, the limitations of conventional tubular membranes will show up sooner or later:

  • Buildup of foulants at membrane wall
  • Formation of cake layer
  • Drop in flux
  • Drop in productivity
  • Increase in crossflow velocity leads to:
    - rise in energy consumption
    - uneven TMP/ flux profile

  • The membranes equipped with Helix technology deliver up to 100 percent better performance, depending on feed water quality and process characteristics.

Helix technology

A tubular UF membrane is essentially a tube with a selectively permeable wall. In a regular smooth tube, the extent of turbulence depends only on the speed of the water being forced through. Expressed by the Reynolds number, this turbulence will increase with larger tube diameters and volumetric flow rates, and decrease with higher feed water viscosity. The higher the Reynolds number, the stronger the turbulence.

Pentair delivers the new Helix flux enhancement technology for both the 8 mm and 5.2 mm internal diameter tubular membranes. The right choice depends on your filtration process characteristics. In order to enhance your performance, installations currently operating with X-Flow tubular membranes can be retrofitted with  X-Flow Helix tubular membranes of the respective internal diameter.

features and specifications

• Turbulence at the membrane wall
• Prevention of foulant buildup
• Lower crossflow velocities
• Higher productivity
• Lower energy consumption
• Reduced operational expenditure 

join our webinar to learn all about helix

Reading about high-tech innovations such as the flux enhancement Helix technology can make things look more complicated than they really are. To serve our many customers around the world who could greatly benefit from this new technology, Pentair is offering a webinar explaining all the ins and outs in a simple fashion, including a demonstration of the new flux enhancement Helix technology; dramatically improving the productivity and efficiency of you wastewater treatment system has never been easier.

Find out more about this amazing technology by watching our webinar. If you would like to see the on demand webinar, you can watch the recorded version here. This replay will be available for a limited time only. Please make sure you do not miss out on an easy way to learn about game-changing technology in ultrafiltration. Should you have any questions about Helix applications, or if you want to know exactly how Helix can contribute to your operations, projects and the bottom line, do not hesitate to contact us.

“It is well-known that membranes are susceptible to quick caking. The dirt typically sticks to the membrane wall, resulting in a rapid productivity drop. Until now, this problem was usually solved by increasing the crossflow velocity. Put simply, the pressure is increased. However, this requires a lot of energy. The Helix technology addresses this issue by creating an eddy current inside the membrane, thereby causing the particles to not stick at all.”

- Jens Potreck (Global Technology Manager Pentair)