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National Flues presents the Increasing MI-FLEX Adaptor, a high-quality, 316L stainless steel solution designed to ensure a secure and flawless connection between rigid single wall flue systems and MI-FLEX flexible liners. Engineered for seamless transitions from Ø 150 mm to Ø 200 mm, this adaptor is an indispensable component for modern, multi-fuel flue installations. The product meets rigorous UK Building Regulations and offers compliance with HETAS and CE standards, making it a trusted accessory for both trade and retail customers in the flue and chimney industry.
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£70.99
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At a Glance
Made from premium 316L stainless steel (0.6mm) for enduring performance
Increases flue size from Ø 150 mm to Ø 200 mm for a seamless transition
Suitable for multi-fuel systems including wood (with less than 20% moisture), gas, oil and smokeless coal
Withstands temperatures up to 600°C (T600 rating) ensuring high heat tolerance
Fully compliant with UK Building Regulations and certified approvals (HETAS / CE, BSEN 1856-2)
Designed for integration with rigid single wall flue systems and MI-FLEX flexible liners
Installation optimised for use within masonry chimneys to secure safe operation
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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:
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“I saved 20% on my purchase compared to other retailers. Exceptional service!” – Jane D.
The Increasing MI-FLEX Adaptor Ø 150-Ø 200 is an essential accessory for your flue installation needs. Crafted from durable 0.6mm 316 stainless steel, this adaptor ensures a seamless connection between your rigid single wall flue system and MI-FLEX 316 or 904 flexible flue liners. This specific adaptor increases the flue size by 50mm, transitioning from Ø 150mm to Ø 200mm smoothly.Designed for multi-fuel flexibility, the MI-FLEX Adaptor can withstand temperatures up to 600°C (T600 designation) and is suitable for use with wood (<20% moisture), smokeless coal, gas, and oil appliances.
Adhering to UK Building Regulations Document J, it is vital that these adaptors are installed completely within a masonry chimney to ensure safety and efficiency.Bottom fixings must be used to secure the connection, with provisions for a gas-tight seal via fire cement, ceramic rope, or high-temperature sealant. This will ensure no flexible liner is exposed externally. Maintenance is straightforward but essential; chimneys must be swept by a competent person, preferably a HETAS registered sweep, at least annually or more frequently for solid fuel appliances.
Proper maintenance keeps your system performing efficiently and safely year-round.
SKU: 20-150-MRD
Technical Specifications
Material
316L Stainless Steel (0.6mm thickness)
Dimensions
Increases flue diameter from u00d8 150 mm to u00d8 200 mm
Temperature Rating
600u00b0C (T600)
Compatible Fuels
Wood (<20% moisture), Oil, Gas, Smokeless Coal
Certifications
HETAS, CE, BSEN 1856-2
System Compatibility
Rigid Single Wall & MI-FLEX Flexible Flue Liners
Installation Requirement
Fully enclosed in a masonry chimney with bottom fixings and gas-tight sealing using high-temperature sealant options
For optimal performance and adherence to UK Building Regulations, the Increasing MI-FLEX Adaptor must be installed entirely within a masonry chimney. Begin by ensuring that the adaptor is correctly positioned to facilitate a smooth transition between the rigid single wall flue system and the flexible MI-FLEX liner. Bottom fixings are essential to secure the connection. Use a gas-tight sealing method – options include fire cement, ceramic rope, or high-temperature sealant – to ensure no part of the flexible liner is exposed externally. It is strongly recommended that installation is carried out by a qualified professional familiar with masonry chimney systems and the specific requirements of flue installations. Regular maintenance, including annual inspections and cleaning by a HETAS registered professional, is crucial in maintaining the system’s safety and efficiency.
The Increasing MI-FLEX Adaptor is suitable for use with wood (with less than 20% moisture), smokeless coal, gas, and oil.
It can withstand temperatures up to 600°C (T600 designation), making it suitable for a variety of fuel types.
The adaptor should be installed entirely within a masonry chimney, with provisions for a gas-tight seal using fire cement, ceramic rope, or high-temperature sealant.
Regular chimney sweeping by a competent person, such as a HETAS registered sweep, at least annually. Twice a year is recommended for solid fuel appliances.
No, UK Building Regulations require that the flexible flue liner and its components be enclosed within a masonry chimney.
Installation should be performed by a professional to ensure it meets all safety and regulatory standards.
You can find a list of HETAS registered sweeps for solid fuel applications at www.hetas.co.uk.
Delivery Information +
We work relentlessly to ensure you get your order fast.
Estimated delivery for this product is Wednesday, April 30th.
If you need faster stove or fireplace delivery please give us a call.
We can often reduce longer lead times if we pay the carrier £25 for express delivery.
Visit our Shipping Information page for more information.
Warranty & Returns +
All our products come with warranties. Mi-Flex offers a lifetime guarantee.
Returns for damaged items are covered by insurance; non-damaged returns incur return delivery costs.
Price Match Guarantee +
We will match any price like for like on a retail basis. Give us a call if you find it cheaper and want to buy from us.
The Increasing MI-FLEX Adaptor is an essential component for anyone looking to upgrade or install a new flue system. Manufactured by National Flues, this adaptor is constructed from premium 316L stainless steel, ensuring unmatched durability and longevity. This guide explains all you need to know about the product, its installation, associated benefits, and why it is a smart addition to your heating or chimney system.
Why Choose the Increasing MI-FLEX Adaptor?
When it comes to flue installations, safety, efficiency, and compliance with building regulations are paramount. This adaptor is specifically designed to provide a smooth transition from a rigid single wall flue system to a flexible MI-FLEX liner, increasing the flue size by 50 mm (from Ø 150 mm to Ø 200 mm). Its robust construction and high temperature resistance (up to 600°C) make it suitable for different fuels such as wood (with less than 20% moisture), gas, oil, and smokeless coal. This is an investment in both future-proofing your home’s heating system and ensuring regulatory compliance.
Key Features and Material Excellence
Utilising 316L stainless steel, this adaptor offers excellent resistance against corrosion and elevated temperatures. Its verified performance under extreme conditions is backed by certifications including HETAS, CE, and BSEN 1856-2. The design not only meets but exceeds UK Building Regulations, giving you the confidence that your flue system is safe from potential hazards. The ease of connecting rigid and flexible liners without compromising on the structural integrity exemplifies the engineering excellence behind this product.
Installation Guidelines and Safety Considerations
For the adaptor to perform at its best, careful and correct installation is essential. The following points summarise the installation requirements:
- Install the adaptor entirely within a masonry chimney as per UK Building Regulations.
- Secure the adaptor using appropriate bottom fixings to establish a robust connection.
- Ensure a gas-tight seal by using fire cement, ceramic rope, or a high-temperature sealant.
- Avoid exposing the flexible liner to the exterior to maintain system integrity.
It is advisable that a qualified professional carries out the installation to avoid any potential installation errors. A secure and properly installed adaptor will not only ensure a longer lifespan but will also maintain the efficiency and safety of your entire flue system.
Maintenance and Performance Optimization
Long-term performance relies on regular maintenance. You should schedule annual inspections by a HETAS registered professional, particularly if you operate a solid fuel appliance. Periodic cleaning and maintenance help in early detection of wear or misalignment, thereby preventing costly repairs down the line. Maintaining a clean flue also ensures optimal combustion efficiency and reduced emission of harmful gases.
Understanding UK Building Regulations
Compliance with UK Building Regulations is non-negotiable when it comes to flue systems. The adaptor is explicitly designed to meet these standards, ensuring that all aspects of the installation from material integrity to safety measures are in line with regulatory requirements. This means that whether you are upgrading an existing chimney or installing a new system, the Increasing MI-FLEX Adaptor provides a safe and compliant solution.
Troubleshooting and Professional Advice
While the adaptor is designed for ease of installation and long-lasting performance, any issues encountered during installation should be addressed immediately. Common issues such as improper sealing or incorrect placement in the chimney can compromise the system's safety. Consulting with a professional installer guarantees that the adaptor performs to its full potential and adheres to safety guidelines. Remember, the initial investment in professional installation saves you from future complications and ensures peace of mind.
Customer Assurance and Final Thoughts
National Flues stands behind the quality of the Increasing MI-FLEX Adaptor. With extensive testing and quality checks, this product is engineered to meet and exceed industry standards. By choosing this adaptor, you are investing in a product that combines innovative design with reliable performance, ensuring that your chimney system functions safely for years to come. The benefits of improved system efficiency, compliance with stringent regulations, and long-term durability make it an essential accessory for any flue installation.
Throughout this guide, we have highlighted all critical aspects of the Increasing MI-FLEX Adaptor—from its engineering and material quality to installation guidelines and maintenance requirements. Whether you are a seasoned professional or a DIY enthusiast, understanding these elements will help you achieve a safe, compliant, and efficient flue system. The detailed specifications and comprehensive installation advice ensure that you have all the necessary information to make an informed decision about your flue system upgrade.
In conclusion, the Increasing MI-FLEX Adaptor is a top-tier product that delivers on safety, performance, and compliance. It is a necessary upgrade for those looking to connect a rigid single wall flue system with a flexible MI-FLEX liner seamlessly. Make the smart choice for your home or business by investing in quality, durability, and safety with this adaptor.
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