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Top Clamp - Ø 250 (20-250-C)

The Top Clamp - Ø 250 from National Flues is a high-quality chimney accessory designed to support MI-FLEX flexible flue liners. Perfect for enhancing the safety and efficiency of your chimney system, this clamp is a must-have for any installation requiring robust, stainless steel solutions. Read more...
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At a Glance

  • Made from high-grade 316L stainless steel for durability
  • Natural finish complements any chimney aesthetic
  • Withstands high temperatures up to 600°C (T600 rating)
  • Suitable for wood (with under 20% moisture), smokeless coal, gas, and oil applications
  • Integral part of the MF20 MI-FLEX accessory range for enhanced chimney support

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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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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 Top Clamp - Ø 250 is a crucial installation accessory from the MF20 MI-FLEX range, engineered explicitly for use with MI-FLEX 316 and 904 flexible flue liners. This top clamp is instrumental in creating a fully functional chimney system. It effectively supports the vertical weight of the flue liner when used in conjunction with the Top Plate and Top Insert Sleeve at the stack's top.

Suitable for multiple fuel types including wood with less than 20% moisture, smokeless coal, gas, and oil, this clamp withstands temperatures up to 600°C (T600 designation). As per Building Regulations Document J, it is mandatory to install flexible flue liners completely enclosed within masonry chimneys, excluding any non-masonry enclosures such as timber or plasterboard boxing. The chimney structure must be sound and properly weatherproofed before installation.

Regular sweeping and maintenance, conducted by competent persons such as HETAS registered sweeps, ensure optimal performance and longevity of the chimney system. This should be done at least once a year or twice for solid fuel appliances.

SKU: 20-250-C

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
SKU20-250-C
Material316L Stainless Steel
FinishNatural / Stainless Steel
Fuel CompatibilityWood (under 20% moisture), Smokeless Coal, Gas, Oil
Temperature RatingUp to 600°C
CertificationHETAS / CE
Product RangeMI-FLEX Accessories MF20
Installation is straightforward yet vital for optimal chimney performance. The Top Clamp - Ø 250 must be used in conjunction with the Top Plate and Top Insert Sleeve to effectively support the weight of the MI-FLEX flexible flue liners. Ensure that your chimney system is fully contained within a masonry structure as stipulated by Building Regulations Document J. It is imperative that you inspect the chimney's condition – the masonry must be sound, stable, and fully weatherproofed prior to installation. After fitting, regular maintenance is recommended: a sweep by a HETAS registered professional at least once a year for gas or oil systems, and twice a year if you use solid fuels like wood or smokeless coal. Do not attempt installation on non-masonry enclosures such as timber or plasterboard boxing, as this can compromise the integrity of the chimney system and pose safety risks.

The Top Clamp - Ø 250 is used to support the vertical weight of MI-FLEX flexible flue liners in chimney systems.

Yes, it is suitable for multiple fuel types including wood (less than 20% moisture), smokeless coal, gas, and oil.

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

The chimney must be sound, weatherproofed, and the clamp must be used in conjunction with the Top Plate and Top Insert Sleeve.

Chimney systems should be cleaned and inspected at least once a year, and twice yearly for solid fuel appliances.

No, Building Regulations Document J mandates that flexible flue liners must be enclosed within masonry chimneys only.

For solid fuel applications, a list of HETAS registered sweeps can be found at www.hetas.co.uk.

 

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