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MI-FLEX Adaptor 1mm - Ø 125 (20-125-MAE1)

National Flues proudly presents the MI-FLEX Adaptor 1mm - Ø 125, a quintessential component for transforming traditional rigid flue systems into modern MI-FLEX flexible flue liners. This essential adaptor, crafted in durable 316L stainless steel, is the ideal solution for those seeking reliability, safety, and performance in high-temperature applications. Read more...
MI-FLEX Adaptor 1mm - Ø 125
IN STOCK
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Now only £30.99
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At a Glance

  • Premium 316L stainless steel construction |
  • T600 temperature rating for high-heat applications |
  • Compliant with Building Regulations Document J |
  • Secure gas-tight seal when used with approved sealants |
  • Suitable for wood, oil, gas, and smokeless coal appliances

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Phone: 01670 206999
Email: sales@nationalflues.com

The MI-FLEX Adaptor 1mm - Ø125 is a vital component in chimney installations, specifically designed to transition from a single-wall flue system to a MI-FLEX 316 or 904 flexible flue liner. Compliant with Building Regulations Document J, this adaptor ensures your flue liner is securely enclosed within a masonry chimney, capable of withstanding temperatures up to 600°C (T600 designation). Ideal for use with wood (less than 20% moisture), smokeless coal, gas, and oil appliances, this adaptor forms a gas-tight seal when installed with fire cement, ceramic rope, or high-temperature sealant.

SKU: 20-125-MAE1

Delivery Information* +

We work relentlessly to ensure you get your order fast. Estimated delivery for this product is Friday, November 14th. 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.

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Technical Specifications
SKU20-125-MAE1
Material316L Stainless Steel
Nominal Diameter125mm (5 inch)
Temperature Rating600°C (T600)
Fuel CompatibilityWood (under 20% moisture), Oil, Gas, Smokeless Coal
ComplianceBuilding Regulations Document J, HETAS / CE
SystemMI-FLEX Accessories MF20
• Ensure the adaptor is installed within a masonry enclosure as per Building Regulations Document J. • Use high-temperature sealants such as fire cement, ceramic rope, or appropriate tape to secure a gas-tight seal. • Always confirm that the flue liner and adaptor diameters match accurately. • Follow manufacturer guidelines for proper clearance and positioning. • Keep the installation area clear of combustible materials and maintain annual or bi-annual chimney sweeps.

The main purpose is to connect a rigid single-wall flue system to a MI-FLEX flexible flue liner, ensuring a secure and compliant installation.

Yes, it is suitable for wood with less than 20% moisture, smokeless coal, gas, and oil appliances.

The adaptor can withstand temperatures up to 600°C (T600 designation).

You should use fire cement, ceramic rope, tape, or high-temperature sealant to make a gas-tight seal.

No, per Building Regulations Document J, it must be enclosed inside a masonry chimney.

Chimneys should be swept at least once a year, preferably twice if they serve solid fuel appliances—once at the end of the heating season and once before the new season.

No, chemical cleaners or mild steel tools should not be used. Always use appropriate stainless steel cleaning tools.

 

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