X-line Rack is a revolutionary, pre-engineered ultrafiltration (UF) solution. This unique concept creates maximum flexibility in rack design and a minimized footprint. The concept makes use of the ingenious OptiFlow cap with integrated header. The cap is designed to eliminate vortex shedding, resulting in a very limited pressure drop and a smooth downward flow to the membranes.
Due to its dead-end operation with hydraulic cleaning and chemically enhanced backwashes, the versatile X-line Rack is suitable for a wide range of industrial and municipal applications.

The X-line Rack was developed in conjunction with the Aquaflex, Seaflex and HFS60 membranes, further emphasizing the concepts’ flexibility. If you have any questions, please contact us.

Features and specifications

  • Highly flexible and scalable
  • Integrated headers: easy and fast assembly
  • Small footprint
  • Minimized turbulence in the skid
  • Optimized footprint-to-flow ratio
  • Favorable total cost of ownership
  • Suitable for many industrial and municipal applications, including potable water

  • Designed for Aquaflex, Seaflex and HFS60
  • Maximum pressure: 3 bar
  • Temperature range: 0-40°C (non-freezing)
  • Head loss:
    • During filtration: 0.1 – 1.0 bar
    • During backwash: 0.7 – 2.5 bar


Learn more about the X-line rack in our datasheets:

Datasheet X-line
Datasheet X-line connection configurations 

Pentair X-Flow - X-line configurations

An overview of the configuration possibilities and typical layouts for the X-line Rack with manifold. Please note that all rows in a system have to be of equal length.


OptiFlow Cap
The X-line OptiFlow Cap offers an ingenious solution to the major challenges posed by turbulence and vortex shedding. The piping, connections and bends in UF systems create turbulence and uneven flows to the membranes. In most designs this causes vortex shedding, resulting in massive pressure loss across the header connecting the modules. The first module in a skid gets to handle a much larger flow than the last one, with negative effects on performance.

Vortex shedding is typically solved by limiting the number of modules fed from a common header. However, this solution leads to smaller racks and higher costs. OptiFlow Caps create a smooth downward flow to the membranes by limiting the pressure drop over the endcaps and headers by 90 percent.

A steady and well-distributed flow means better and consistent performance during the entire lifecycle, and an optimal footprint-to-flow ratio. The OptiFlow caps and flexible design of the X-line enable scalability and virtually any rack configuration.

X-Flow has developed a range of manifolds which deliver a simple, compact, and low-cost interface between the filtration unit and piping.

The standardized range of manifolds further leverages the X-line Rack’s flexibility and results in almost limitless configuration possibilities, with variations in the number of racks per manifold, rows per rack, and length of the rows. Such flexibility makes for very compact and highly accessible installations.

Pentair X-Flow - The OptiFlow cap is designed to eliminate vortex shedding.