Product Lines

Plate-type Heat Exchangers

V-FLEX® Vortical Flow Heat Exchangers

V-FLEX: The best of both worlds

APEX Group applied its expertise in design and manufacturing high quality, heavy-duty heat exchangers to develop the patented V-FLEX product line, which combines the advantages of both plate-type and tubular heat exchangers. These advantages are strengthened with the incorporation of the VORTI-FLEX® Technology.

The efficiency of a plate-type heat exchanger
As a substitute for round tubes, elongated heat transfer elements are used to construct flat or undulated heat transfer panels. This allows our V-FLEX heat exchanger to gain all the advantages of the plate-type concept: compact size, low operating pressure drop, low fouling tendency and high thermal efficiency, compared to a conventional tubular heat exchanger. This has direct effect on savings in energy consumption and maintenance costs, as well as reduction in CO2 emissions.

The pressure resistance of a tubular heat exchanger
V-FLEX’s elongated heat transfer elements ensure mechanical integrity at higher differential pressures between the two working fluids. They can support pressures from 0.5 barg up to 5 barg – whether the fluids are gaseous, liquid, or multi-phase. In contrast, plate-type heat exchangers have typical differential pressure limits of 0.5 barg.

Key Features


  • Constructed from elongated rectangular elements
  • Offers advantages of both the plate type and the tubular heat exchanger:
    • high thermal efficiency
    • increased differential pressure resistance
  • The working fluid inside the heat transfer element can be gaseous, liquid or multi-phase
  • Higher resistance to cyclic temperature loads
  • Modified geometry of the heat transfer surface to enhance the heat transfer coefficient with VORTI-FLEX® Technology
  • Suitable for working with corrosive (condensing) fluids (with A-CORREX® Technology)

Fluids Handled:

  • Combustion air
  • Flue gas from combustion of: gaseous fuels, liquid fuels, solid fuels, waste, biomass
  • Vapor, condensing or non-condensing
  • Industrial exhaust streams
  • Liquids (i.e. water, steam)

Typical Services:

  • Combustion Air Preheater
  • Gas-Gas Heater
  • Flue Gas Cooler/ Condenser
  • Air/exhaust gas heat exchanger for gas turbines
Typical Technical Specifications:
  • Design Temperature:
    • Up to 900 °C for metallic
    • 200 °C for polymer composite
  • Design Differential Pressure:
    • up to 5 barg for metallic
    • 0.1 barg for polymer composite
  • Duty Range: Unlimited
  • Thermal Effectiveness: ~97%
  • Pressure Drop Rates: 0-0.1 bar
  • Leakage Rates: 0.0 – 0.5%
Applicable Technologies:
  • APEX® Free-flow Technology – to minimize flow separation & fouling and maximize ability to clean.
  • AIR CURTAIN® Technology – to control heat transfer surface temperature to avoid “cold corner” corrosion.
  • APEX® VariaFlow – to ensure uniform flow-field temperature profile at the fluid outlet.
  • APEX® Erosion Technology – to improve resistance of the heat transfer elements against erosion.
  • A-CORREX® Technology – to prevent acid dew point or water dew point corrosion.
  • APEX-delfino® Technology – to optimize the fluid flow distribution and temperature profile.
  • VORTI-FLEX® Technology – to enhance the heat transfer coefficient between two fluids in laminar or transient flow.
Extra Benefits

Easy maintenance with APEX® Free-flow Technology
APEX® Free-flow Technology is incorporated in the V-FLEX heat exchangers, which ensures that the heat transfer surfaces are easily accessible for cleaning. Furthermore, APEX Free-flow Technology prevents the formation of large and undesired flow recirculation zones inside the heat transfer core, minimizing risks of fouling and erosion issues. This delivers the extra benefit of saving costs due to low maintenance requirements.

Opportunity to operate in corrosive environments
By applying A-CORREX® Technology to V-FLEX products, we offer also the possibility to safely operate the V-FLEX heat exchangers in corrosive environments. This opens new possibilities for their use in emerging technologies, such as carbon capture and storage (CCS), that require fluid gas temperatures to fall below the acid dew point.

VORTI-FLEX® Technology
Thanks to their flat shape, the inner and outer surfaces of the V-FLEX’s elements can be easily manipulated to increase turbulence of the fluid flow field for maximum efficiency.

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