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Top Insert Sleeve - Ø 125 (20-125-PS)
At National Flues, our Top Insert Sleeve - Ø 125 is meticulously engineered to provide secure and lasting chimney support. As part of the distinguished MI-FLEX Accessories MF20 range, this product excels in ensuring chimney system integrity and safety. Boasting a natural stainless steel finish, the sleeve is not only aesthetically pleasing but also designed to maintain compliance with UK building regulations. Other synonymous accessories and components in our range are designed to complement this product, ensuring your chimney installation delivers optimal performance every time.
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In Stock
£11.49
Give us a call if you find it cheaper and we'll try to price match.
At a Glance
Made from robust 316L stainless steel
Natural / Stainless Steel finish for longevity
Withstands temperatures up to 600°C (T600)
Certified to HETAS and CE standards
Compatible with wood (under 20% moisture), oil, gas, and smokeless coal
Designed for use with MI-FLEX Accessories MF20 systems
Essential for supporting the weight of flexible flue liners
Works in tandem with Top Plate and Top Clamp
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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.
The Top Insert Sleeve - Ø 125 is an essential component for anyone installing or maintaining a chimney system using MI-FLEX 316 and 904 flexible flue liners. This expertly designed accessory slides seamlessly into the flexible chimney liner at the top of your installation. Used in conjunction with a Top Plate and Top Clamp, it ensures that the flue liner's weight is securely supported without compromising its integrity.
This robust sleeve is suitable for a range of fuel types including wood with less than 20% moisture, smokeless coal, gas, and oil, and can withstand temperatures up to 600°C (T600). According to Building Regulations Document J, a flexible flue liner must be entirely enclosed within a masonry chimney, making the Top Insert Sleeve an indispensable part of your setup. Proper maintenance is crucial; sweeping and inspection should be conducted at least annually by a qualified professional to ensure longevity and performance.
SKU: 20-125-PS
Technical Specifications
Material
316L Stainless Steel
Colour Finish
Natural / Stainless Steel
Temperature Rating
Up to 600u00b0C (T600)
Approvals
HETAS / CE
Compatible Fuels
Wood (<20% moisture), Oil, Gas, Smokeless Coal
System
MI-FLEX Accessories MF20
Dimensions
u00d8 125mm
Designation
BSEN 1856-2 T600 N1 W V2 L50012 G
The Top Insert Sleeve - Ø 125 is designed for easy integration into your chimney system. Begin by ensuring that the flexible flue liner is correctly prepared and positioned within your masonry chimney. Slide the insert sleeve into place at the top of the liner, then secure it using the appropriate Top Plate and Top Clamp. It is essential that the chimney liner remains completely enclosed in a masonry structure in line with Building Regulations Document J. Regular annual sweeping and inspections by qualified professionals are recommended to maintain performance and extend the life of both the flue liner and the sleeve. Avoid using chemical cleaners or mild steel tools during maintenance to prevent damage to the stainless steel surfaces.
The Top Insert Sleeve - Ø 125 is used to support the weight of a flexible flue liner at the top of a chimney stack, ensuring the integrity of the installation.
Yes, this insert sleeve is suitable for wood with less than 20% moisture, smokeless coal, gas, and oil.
The Top Insert Sleeve can withstand temperatures up to 600°C, meeting the T600 designation.
Yes, Building Regulations Document J requires that the flue liner be completely enclosed inside a masonry chimney. A non-masonry enclosure like timber or plasterboard is not acceptable.
The chimney system should be inspected and swept at least once a year. For chimneys serving solid fuel appliances, it's recommended to sweep twice a year – at the end of the heating season and at the start of the next one.
No, chemical cleaners and mild steel tools should never be used to sweep stainless steel chimneys. Always consult a professional chimney sweep.
The Top Insert Sleeve should be used alongside a Top Plate and Top Clamp to ensure the flue liner is securely supported.
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.
Read our review in our Top Insert Sleeve - Ø 125 buyers guide
Comprehensive Buyers Guide for the Top Insert Sleeve - Ø 125
The Top Insert Sleeve - Ø 125 is an indispensable accessory for anyone involved in the installation or maintenance of a chimney system. This guide will take you through everything you need to know about this product to assist you during your purchase decision.
Overview and Key Benefits
The sleeve is manufactured from high-quality 316L stainless steel, a material renowned for its resistance to heat and corrosion. With a natural, polished finish, it not only performs exceptionally but also adds a refined touch to your chimney installation. Designed to support the flexible flue liner at the top of a masonry chimney, this product addresses a critical aspect of chimney safety by ensuring that the weight of the liner is properly managed. The Top Insert Sleeve - Ø 125 is an integral component when used in conjunction with a Top Plate and Top Clamp, thereby providing a complete and secure support system.
Safety and Compliance
One of the most compelling reasons to invest in the Top Insert Sleeve - Ø 125 is its compliance with the strict HETAS and CE standards, ensuring it meets all current safety regulations. Building Regulations Document J mandates that the flue liner be entirely enclosed within a masonry chimney—a specification that this product fully satisfies. This commitment to safety and regulation compliance means that you can have complete confidence in the performance and reliability of the product, whether you are a trade professional or a retail customer.
Technical and Performance Specifications
- Material & Finish: Crafted from 316L stainless steel, offering excellent durability and resistance to corrosive elements.
- Temperature Resistance: Withstands extreme temperatures up to 600°C, ensuring performance even under the harsh conditions of a working chimney.
- Fuel Compatibility: Versatile in its application, making it suitable for wood (with less than 20% moisture), oil, gas, and smokeless coal burning appliances.
- Certification: HETAS and CE approved, meeting rigorous UK standards.
Installation Tips and Warnings
Installing the Top Insert Sleeve is straightforward provided the correct steps are followed. Always ensure that the flexible flue liner is inserted securely into the masonry chimney before fitting the sleeve. It should be used in combination with a Top Plate and Top Clamp to achieve optimal stability. Key Warning: Non-masonry enclosures such as timber or plasterboard are not acceptable under current building regulations. Regular maintenance is critical—annual inspections and sweeping by a qualified professional are advised to preserve the system's integrity. Additionally, avoid any chemical cleaners or inappropriate tools that could damage the stainless steel finish.
Addressing Common Objections
Some potential buyers may have concerns regarding the compatibility of the Top Insert Sleeve with different types of fuels. The product’s design ensures that it is fully functional with a variety of fuels including wood (with moisture content below 20%), oil, gas, and smokeless coal. Another common objection is the complexity of installation; however, the product is designed for ease of integration with minimal additional support components. With clear guidance available and professional installation recommended, any initial concerns should be easily resolved.
Maintenance and Long-Term Performance
Longevity and safety are paramount when it comes to chimney components. Regular maintenance not only extends the lifespan of the Top Insert Sleeve but also ensures that your entire chimney system continues to operate safely and efficiently. We recommend that you schedule a thorough inspection by a professional at least once a year, particularly during the periods before and after the heating season. These precautions help in identifying potential issues before they escalate into significant problems and allow you to replace or upgrade components as needed.
Integrating with Complementary Accessories
For full system optimisation, consider pairing your Top Insert Sleeve - Ø 125 with complementary accessories. Our range includes the Top Plate and Top Clamp, both of which work harmoniously with the sleeve to deliver a secure, complete solution for stabilising your chimney liner. The synergy between these components provides an extra layer of security, ensuring that the chimney system remains robust and compliant with all safety standards.
Final Considerations and Purchase Decision
Selecting the right component for your chimney setup can be challenging, but the Top Insert Sleeve - Ø 125 by National Flues stands out as a reliable, industry-approved solution. It is designed to meet the exacting demands of modern heating systems while ensuring that your installation is safe and compliant with UK regulations. With its blend of durability, performance, and ease-of-installation, this product represents an investment in the long-term safety and efficiency of your home.
If you have any queries or need further advice on how the Top Insert Sleeve - Ø 125 fits within your specific installation requirements, our knowledgeable team is always here to assist. Take the next step towards a secure, efficient chimney system by opting for National Flues’ top-quality accessories.
Buy now or call 01670 206 999.
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