VentilFlex 25 RKV

VentilFlex25 RKV

VentilFlex 25 RWVFlexible composite liner with high heat-resistance for kitchen extraction ducts

DIN EN 12237, TG 1216
Pressure class: D
Fire class: A2-s1, d0
Fire resistance class: Class EI 60

What is VentilFlex25  RKV?


VentilFlex25 RKV is based on a glass fibre reinforced thermosetting resin, which is as strong as steel, when set, but has much better corrosion resistance than other materials. It is extremely thin (4.5mm), has no joints and is installed by Kompozit’allUK’s trained and certified engineers. VentilFlex25 RKV is used in ventilation ducts and exhaust systems for temperatures up to 450°C, most commonly used in Kitchen Extractors and commercial Kitchen Extractors. The duct has a CCTV survey carried out to confirm dimensions and condition of the duct. Access is required at both ends of the duct; if no access is available the fan or canopy will be removed. The VentilFlex25 RKV is inserted into the duct, inflated with air and cured with steam. Once the curing process is complete, access doors can be cut into the VentilFlex25 RKV, the canopy/fan can be refitted and the duct is ready for use. The duct is now gas tight and because a smooth inner surface is left with no joints the duct can be easily cleaned and give a fire rated lining in the duct.

Most installations are carried out in one day or can be installed out of hours to minimise disruption and downtime.

All duct shapes can be obtained, rectangular, triangular, circular and many more.

Why composite material?

VentilFlex25 RKV is made of thermosetting resin material with fibre glass reinforcement (composite) that has physical (steel strength) and chemical (acid-resistant, alkali-resistant) properties that are perfectly suited for lining ducts. Its special resin composition guarantees high thermal resistance.

Kitchen Extraction

FAQWhy Choose VentilFlex25 RKV Over the Alternatives?

  • The most flexible lining system available, from 80mm to over 1000mm diameter
  • Will mould to the shape of the duct and can increase and decrease in dimensions through the duct run
  • Maximises lining diameter for efficient operation
  • One of the highest fire resistance liners (tested and proven)
  • High insulation for better fire containment
  • Best corrosion resistance – protecting occupant’s health
  • Quick & clean to install – minimises disruption
  • Long working life – best value for money
  • Guaranteed for 25 years

Why Choose an Accredited Kompozit’allUK Installer?


VentilFlex25 RKV is fast and easy to install by engineers with the relevant training, skill and product knowledge. Kompozit’allUK engineers are factory trained and experienced to ensure your installation is completed within budget and timeframe, and subsequent maintenance issues are avoided.

Some independent, unlicensed installers may claim to offer VentilFlex25 RKV solutions. However, we strongly recommend only working with a Kompozit’allUK registered installation partner.

Our partners have the equipment and training to provide accurate CCTV surveys and efficient installations. This is essential for you to get the right specification and size of lining. Each engineer and surveyor is required to renew their certification on an annual basis; keeping their skills and knowledge up-to-date.

Request a Quote

For a fast, no obligation quote, or for any queries about installation, please call 01622 717374 today, or send an email to