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TWINFLEX MF
THE ULTIMATE FLEXIBLE FLUE LINER

TWINFLEX MF

Some people think that flexible chimney liners are all much the same. Experienced installers know this is not the case, in fact Our Twinflex MF has several unique features which set it apart from 'ordinary' chimney liners.

Triple Lock Construction

Twinflex has inner and outer wall jointed and locked in 3 planes. This gives maximum joint integrity and allows even weight and load distribution throughout the entire length of the installation.

Superior Quality

Twinflex is built with high performance 316 or 904 molybdenum steels. The smooth inner bore allows optimum passage of flue gases and draining of condensates.

High Overlap

The Twinflex is simply superior. The unique large overlap of the joint formed by the inner skin protects against acid penetration. On close inspection you’ll find some liners on the market with minimal or non existent overlaps.
20Year Guarantee

316 Grade


35Year Guarantee

904 Grade



Technical Details

Fuel type Gas, Oil and approved solid fuels
Diameter Range 100mm, 125mm, 150mm, 175mm, 200mm
Inner Liner Material 0.1mm grade 316L stainless steel / 0.1mm grade 904L stainless steel
Outer Casing Material 0.1mm grade 316L stainless steel
0.1mm grade 904L stainless steel
Joint Method Triple lock joint system
Designations BS EN 1856-2 T600 N1 D VmL40022 G
BS EN 1856-2 T600 N1 D VmL40022 G
CE Approved Yes
Maximum Operating Temperature 600°C negative pressure
Warranty 20 years 316 grade
35 Years 904 grade

Gallery

FAQ

How do i register my liner warranty?
All Twinflex MF liners come with a 20 year 316 liner warranty & 35 year warranty for 904 grade liner. Your invoice confirms you purchased the liner from Turner & Wilson. Please complete the liner registration form on our website to apply for your warranty.
What does my warranty cover?
WARRANTY CONDITIONS: H Docherty Ltd obligations under the terms of this warranty are to supply replacement product for failures due to manufacturing defects only. It specifically does not cover labour costs, or any other incidental or consequential losses. The complete installation has been designed and installed in accordance with Approved Document J of the Building Regulations and any Local or National Building Regulations. The liner has been installed in accordance with H Docherty Ltd installation instructions. The installation has been completed by a HETAS or NAPIT registered installer, or alternatively has been approved and signed off by Local Authority Building Control. A Notice Plate must be visible stating the date of installation, the name and address of the installer and the type, size and make of the liner. The liner must not be modified or changed in any way If you change the appliance, it is best practice to also change the liner. The Lifetime Warranty is non-transferable and only applies to the initial purchaser of the product Fuel 8.1. Fireflexmaster is suitable for use on oil, gas and approved solid fuels. 8.2. Use only high quality solid fuels as recommended by HETAS or SFA. 8.3. In the case of wood the moisture content should be no greater than 20%. 8.4. 316L grade stainless steel flue liners are suitable for continuous use with oil, gas & wood. It is also suitable for occasional use of mineral fuels, but this must be limited to 20% of the total fuel burnt to be covered by the LIFETIME conditional warranty. It is not suitable for long term or continuous use with mineral fuels such as smokeless fuels or bituminous coal. 8.5. 904L grade stainless steel flue liners are suitable for continuous use with oil, gas & wood. It is also suitable for occasional use with mineral fuels, but this must be limited to 20% of the total fuel burnt to be covered by the LIFETIME conditional warranty. The appliance Fireflexmaster is serving must not be located where there is risk of chemical contamination Long periods of slumbering will greatly reduce the life expectancy of Fireflexmaster. For this reason slumbering is not recommended. Chimneys located on external walls, or large chimney voids and tall chimney stacks should be insulated to avoid the risk of condensation and corrosion. Evidence of a chimney fire will invalidate this warranty. When burning smokeless fuels the liner must be swept at least once a year by a competent professional chimney sweep (such as APICS, GMCS, or HETAS approved sweep) and certificates must be kept and made available in the event of a warranty claim. When burning wood or bituminous coal, the liner should be swept at least twice a year. The use of proprietary cleaning compounds are not recommended and will invalidate the warranty. A suitable system for sweeping Fireflexmaster liners would be a Viper with 7mm ROD for liners up to 8” and a 9mm ROD for 8” and above. The use of power brush systems is only recommended for straight flues and the flue must only be power swept on the downward direction with the brush being pushed up the flue. With a suitable brush head with lateral whip lines, brush heads that have whips terminating in the centre of the brush with exposed protruding ends are not recommended. To validate the warranty, the installer must register the installation by completing the registration form at www.docherty.co.uk/liner-warranty-registration/. A warranty confirmation will be sent by way of receipt, this should be kept in a safe place as it will be required in the event of making a warranty claim. Making a warranty claim 17.1. The householder/user should make any warranty claim against the installer or the company or individual they purchased the product from. 17.2. H Docherty Ltd will only accept warranty claims from those individuals or companies that purchased the goods directly. 17.3. Claims should be made through the H Docherty Ltd branch network (www.docherty.co.uk) quoting the warranty registration number, date of installation, type and diameter of product, appliance, fuel used and details of the fault or warranty claim. 17.4. In all cases, H Docherty Ltd reserves the right to inspect the product in situ before agreeing to replace any product under the terms of this warranty. 17.5. If the reason for failure is anything other than a manufacturing defect, then H Docherty Ltd reserve the right to charge for any relevant inspection Nothing in this warranty affects the consumer’s statutory rights under the Customer Rights Act 2015.