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KrosFlo® FS TFF Systems

Fully automate flat sheet tangential flow filtration (TFF) processes such as CFC/D/C up to 500 L with configurable hardware components that deliver an unparalleled combination of automation, configurability, simplicity and compliance.

leverage Integrated diaphragm pump for flat sheet processes

The KrosFlo® FS Systems achieve an unparalleled combination of configurability and automation and compliance for flat sheet TFF processes.  All components, either directly or indirectly, connect to the main KrosFlo® FS diaphragm pump, which then communicates with the KF Comm 2 software for control and monitoring.

  • Configure a minimal number of components for simple applications such as concentration (C) or diafiltration (D)​
  • Plug-and-play additional components for fractionation (F) and multi-step processes (i.e. CDC/D/C)​

Automate and modernize 140 ml - 500 l Flat sheet tff process

KrosFlo® FS-15 System for 140 mL - 15 L Volumes

KrosFlo® FS-15 compiles all the key features required for true walk-away automation and modernization of flat sheet processes from 140 mL up to 15 L, supporting membrane surface area from 0.1 - 0.3 m2.  KrosFlo® FS-15 utilizes a Quattroflow™ 150 SU diaphragm pump delivering flow rates up to 3.0 liters per minute (LPM) and allowing for high pressure applications up to 4 bar.

  • 140 mL - 15 L volume
  • 0.1 - 0.3 m2 filtration area

KrosFlo® FS-500 System for 1.25 L - 500 L Volumes

KrosFlo® FS-500 enables true walk-away automation and modernization of flat sheet processes from 1.25 L up to 500 L, supporting membrane surface area from 0.5 -1.5 m2. KrosFlo® FS-500 centers around a Quattroflow™ QF1200 SU diaphragm pump which delivers flow rates up to 18 LPM and allows for high pressure applications up to 4 bar. The KrosFlo® FS-500 design also utilizes a base plate for optimum flow path length and component geometry, as well as a permeate side flow meter.

  • 1.25 L - 500 L volume
  • 0.5 - 1.5 m2 filtration area


KrosFlo® FS Systems integrate up to 11 components with specifications to process volumes between 140 mL and 500 L. Each system integrates up to three pumps, one main diaphragm pump and two auxiliary peristaltic pumps. Sensors and analytics include up to two scales, flow meter and the Konduit which measures conductivity.

  1.  KF Comm 2 Software
  2.  4-piston diaphragm pump
  3.  KR1 auxiliary pump
  4.  Automatic Back Pressure Control Valve (ABV)
  5.  Scale
  6.  Konduit monitor
  7.  TangenX® Flat Sheet Cassettes
  8.  ProConnex® Flow Path
  9.  Permeate flow sensor
  10.  Stir plate
  11.  KrosFlo® FS-500 base plate
AUTOMATed Multi-step Processes

Walk-away multi-step automation with automated TMP based on 13 built-in process modes 

Plug-and-play modules

Repligen-exclusive advanced microprocessor-based controller enables integrated plug-and-play modularity of all system components

Complete modern Functionality

Complete and up-to-date 21CFR Part 11 compliance and centralized control and monitoring through a single interface


Automatic Back Pressure Control Valve

A Repligen-exclusive technology, the Automatic Back Pressure Control Valve adds transmembrane pressure (TMP) control to every TFF process, reducing operator hands-on-time and improving process reproducibility. 

  • Automatically adjust tubing pinch distance according to user-defined set-points
  • Maintain uniform TMP throughout process run, decreasing membrane fouling
  • Control permeate pressure and flow during microfiltration applications
  • Use with compatible tubing sizes 13, 14, 16, 25, HP15, 17, HP24, 18, HP35, 36, and HP36
  • Activate automatically using inlet, retentate, permeate or transmembrane pressures 

Transfer bi-directional data through
proprietary board

An advanced microprocessor-based controller is integrated into the main KrosFlo® FS System pumps, enabling plug-and-play hardware component behavior. Bi-directional communication is established between the KF Comm 2 software and hardware components, such as the Automatic Back Pressure Control Valve, scales, auxiliary pumps and the Konduit device.

Menu-driven software for optimized TFF

KF Comm 2 Software provides a modern, graphically driven interface for process monitoring and control. Create new experiments based on 13 programmed modes, customize batch reports and plug-and-play hardware components. Add an optional 21 CFR Part 11 feature package for regulated environments.

  • Start a run in only 4 clicks
  • Select from 13 pre-programmed modes 
  • Operate securely on Microsoft SQL® database for stability

KF Comm 2 Software

Scale effortlessly from lab to pilot manufacturing

Transition seamlessly from small scale to larger scale processes. The KrosFlo® FS-15 handles volumes as small as 140 mL to 15 L. The KrosFlo® FS-500 is capable of larger volumes from 1.25 L to 500 L. These two KrosFlo® FS TFF Systems share common hardware architecture, software and pump technology.

  • Scale-up and scale-down with a single platform​
  • Configure across applications (C, D and CFC/D/C)​
  • Operate 21 CFR Part 11 compliant software built on secure Microsoft® SQL Server ​



Innovative TangenX® single-cast technology produces a selective and uniform pore distribution that can enable selection of a higher molecular weight cut off (MWCO). For example, a 50 kD MWCO TangenX® membrane can often replace a conventional 30 kD MWCO membrane for monoclonal antibodies. A macroporous sub-structure below the selective layer can further increase flux.  

Head-to-head comparisons demonstrate a flux increase of up to 30% compared to conventional TFF membranes. Leverage the TangenX® Membrane technology in either TangenX® PRO Reusable Cassettes, SIUS® Single-Use Cassettes and SIUS® Gamma Devices.

TangenX® Flat Sheet Cassettes 


Take a flow path idea to an engineering drawing in minutes with an on-line digital configurator and expert consultation. ProConnex® Flow Paths are configurable from over 250 components, are assembled ISO 7 clean rooms and arrive gamma-irradiated. 

Build a ProConnex® Flow Path around:

ProConnex® Flow Paths

KONDUiT add-on Monitor

The standard KrosFlo® KR2i, KMPi, FS-15 and FS-500 can use time and weight/flow rate as process control set points. Add the Konduit and expand automated process control to include conductivity, UV and temperature for automated process controls. The Konduit integrates with the main pump and KF Comm 2 software with plug-and-play ease.

Konduit adds:

  • End point conductivity control for UF /DF
  • End point UV control for diafiltering free drug from drug delivery particles
  • End point UV control for concentration of certain molecules
  • UV alarm for membrane breakthrough
  • A260 and A280 light sources available

*UV components sold separately



Conductivity Range 0.1 to 100 mS/cm
Temperature Range 0-70°
Pressure Range up to 75 psi (5 bar)
Dimensions (L x W x H): 7¾" x 4¾" x 4½" 
Weight 1.6 kg 


Expand All

KrosFlo® FS-15

KrosFlo® FS-500

Typical process volumes Up to 15 L+ Up to 500 L+
Maximum filter area Up to 0.3 m2 Up to 1.5 m2
Maximum Pressure Up to 60 psi/4 bar
Flow rate Up to 3 LPM Up to 18 LPM
Cassette holder TangenX® SIUS® PD Clamp TangenX® SIUS® Clamp
Reservoirs 1 L PP, Ported Flat Bottom 20 L PP, Ported Flat bottom
Mixing Stir plate mounted on scale
TMP Control Non-invasive/No-product contact
Auxiliary pump KrosFlo® KRJr KR1
Flow Path ProConnex® Flow Path - Single-use high pressure flow path with pump head

KF Comm 2 with optional 21CFR part 11 package