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Long Tail Increasing MI-FLEX Adaptor - Ø 125-Ø 150 (20-125-MRLT)

National Flues presents the Long Tail Increasing MI-FLEX Adaptor (Ø 125-Ø 150), a premium solution crafted in 0.6mm 316 stainless steel for a secure and efficient transition between rigid single wall flue systems and MI-FLEX liners. Read more...
Now only £38.99
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At a Glance

  • Robust 0.6mm 316 Stainless Steel Construction
  • Seamless connection from rigid single wall flue to MI-FLEX liners
  • 25mm increase ensures a secure, gas-tight seal
  • Complies fully with Building Regulations Document J
  • Suitable for multiple fuels including wood, oil, gas and smokeless coal

We Won't Be Beaten On Price

At National Flues, we continuously monitor competitor prices. This ensures that we consistently offer you the best deals on all our products. Here’s how we keep your costs low:

  • Daily Price Matching: Our team adjusts prices to ensure we stay competitive.
  • Bulk Purchasing Power: We sell a lot, so we can negotiate better rates with suppliers, passing the savings directly to you.
  • Operational Efficiency: We have streamlined processes to reduce overhead.

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

Free Delivery Over £100: Orders over £100 are free delivery (call us if delivery is required outside the mainland UK).

“I saved 20% on my purchase compared to other retailers. Exceptional service!” – Jane D.

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

The Long Tail Increasing MI-FLEX Adaptor Ø 125-Ø 150 is meticulously designed to serve as a transitional joint, effortlessly connecting a rigid single wall flue system to MI-FLEX. With a robust construction of 0.6mm thick 316 stainless steel, this adaptor increases by 25mm from the single wall to the flexible flue liner. Ideal for use with MI-FLEX 316 and 904 flexible flue liners, it ensures a secure and stable connection for appliances operating at temperatures up to 600°C (T600 designation).

Perfect for wood with moisture below 20%, smokeless coal, gas, and oil, this adaptor complies with the Building Regulations Document J which mandates that flexible flue liners be entirely enclosed within a masonry chimney. To guarantee optimal performance and safety, ensure that the bottom fixings are secured with fire cement, ceramic rope, or high-temperature sealant, creating a gas-tight seal. Regular maintenance and sweeping, especially for solid fuel applications, are essential to preserve the integrity and functionality of your chimney system.

SKU: 20-125-MRLT

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.

Technical Specifications
Product ID529
SKU20-125-MRLT
Material316 Stainless Steel
Thickness0.6mm
Operating TemperatureUp to 600°C (T600)
SizeØ 125 – Ø 150
SystemMI-FLEX Accessories MF20
FuelsWood (moisture <20%), Oil, Gas, Smokeless Coal
ApprovalsHETAS / CE
FinishNatural / Stainless Steel
When installing the Long Tail Increasing MI-FLEX Adaptor, first ensure that the flue system and MI-FLEX liner are clean and free from obstructions. Secure the adaptor using appropriate bottom fixings such as fire cement, ceramic rope, or high-temperature sealant to achieve a gas-tight seal. The adaptor is designed for use within a masonry chimney, so it is important to follow Building Regulations Document J. Always double-check that the installation is compliant with local building codes. Regular maintenance, including sweeping and inspections, is recommended—especially for systems used with solid fuels—to ensure the longevity and efficiency of your chimney system. Avoid using chemical cleaners or abrasive tools on the stainless steel to preserve its finish.

The Long Tail Increasing MI-FLEX Adaptor is made from 0.6mm thick 316 stainless steel, ensuring durability and resistance to high temperatures.

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

Absolutely. It complies with Building Regulations Document J, which requires flexible flue liners to be enclosed within a masonry chimney.

You can secure the adaptor using fire cement, ceramic rope, or high-temperature sealant for a perfect gas-tight seal.

The adaptor is designed to handle temperatures up to 600°C (T600 designation).

Chimneys should be swept at least once a year, ideally twice for solid fuel appliances, at the end and start of the heating season, to ensure the system is free from blockages and deposits.

No, it is not recommended to use chemical cleaners or mild steel tools for cleaning stainless steel chimneys. Always use appropriate methods as specified by HETAS.

 

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