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MI-FLEX Adaptor - Ø 300 (20-300-MAE)

Discover the superior MI-FLEX Adaptor Ø 300 by National Flues. Our premium 316L stainless steel adaptor seamlessly connects ridged flue systems to MI-FLEX flexible liners, ensuring a secure and compliant chimney installation. Read more...
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At a Glance

  • Constructed from high-quality 316L stainless steel (0.6mm thick)
  • Seamlessly connects ridged single wall flue systems to MI-FLEX flue liners
  • Provides a gas-tight seal when installed correctly
  • Withstands temperatures up to 600°C (T600 designation)
  • Suitable for wood (with <20% moisture), oil, gas, and smokeless coal
  • Compliant with BSEN 1856-2 standards and Building Regulations Document J

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Price Match Guarantee: If you find the same product cheaper within 48 hours, we’ll match it and refund the difference.

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Have Questions?
Phone: 01670 206999
Email: sales@nationalflues.com

The MI-FLEX Adaptor - Ø 300 is a high-quality, 0.6mm 316 stainless steel fitting designed to seamlessly connect a ridged single wall flue system to a MI-FLEX flexible flue liner of the same diameter. Essential for creating a complete and efficient chimney system, this adaptor ensures a gas-tight seal when correctly installed inside an existing masonry chimney. It's suitable for use on a variety of fuel sources including wood (with less than 20% moisture), smokeless coal, gas, and oil, and can withstand temperatures up to 600°C (T600 designation).

To comply with Building Regulations Document J, it’s vital that the flexible flue liner is fully enclosed within a masonry chimney, never boxed in with timber or plasterboard. This adaptor, part of the MF20 MI-FLEX accessories range, makes it easy to transition between your flue system and liner, enhancing both safety and efficiency.

SKU: 20-300-MAE

Delivery Information* +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Monday, November 17th. This is based on current lead times. Bear in mind that it is a busy time of year. If you need a product delivered by a specific time in the next 7 days, then please give us a call on 01670 206 999. Visit our Shipping Information page for more information.

About National Flues Ltd +

We began over 30 years ago as a fireplace shop in the North East. We now supply hundreds of trade professionals and thousands of retail customers, all across the UK, every month. We are still a family owned business, lead by the MD Neil, and always try our best to deliver the best possible experience. We also price match, so give us a call if you find this cheaper and want to buy from us. Visit our about us page to read a bit more.

Technical Specifications
SKU20-300-MAE
Material316L Stainless Steel, 0.6mm
SizeØ 300 mm
Temperature RatingUp to 600°C (T600 designation)
ApprovalsHETAS / CE
FuelsWood (<20% moisture), Smokeless Coal, Gas, Oil
DesignationBSEN 1856-2 T600 N1 W V2 L50012 G
SystemMI-FLEX Accessories MF20
Installation must be performed within a masonry chimney in accordance with Building Regulations Document J. Ensure the flexible flue liner is fully enclosed within the chimney and never boxed in with timber or plasterboard. When installing, utilise approved sealing methods such as fire cement, ceramic rope, tape, or other high-temperature sealants to create a reliable, gas-tight joint. Carefully follow the manufacturer’s instructions, and consider engaging a professional if you are unsure about any part of the installation process.

The MI-FLEX Adaptor - Ø 300 is constructed from high-quality 0.6mm 316 stainless steel.

Yes, the adaptor is suitable for use with wood (less than 20% moisture), smokeless coal, gas, and oil.

No, the MI-FLEX Adaptor must be used within a masonry chimney as per Building Regulations Document J.

The MI-FLEX Adaptor can withstand temperatures up to 600°C (T600 designation).

Sweep your chimney at least once a year, but if using solid fuels, twice a year is recommended: at the end of the heating season and the start of the next.

Fire cement, ceramic rope, tape, or high-temperature sealant should be used to secure the adaptor and ensure a gas-tight seal.

For solid fuel applications, you can find a HETAS registered chimney sweep at www.hetas.co.uk.

 

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