Flexible Chimney Liners


Stainless Steel Flexible Chimney Liners

Flexible liners are used in most installations, although classed as a temporary installation these liners can last for many years if the correct fuel is used and are swept regularly. The advantage of flexible liners is the relatively quick installation time, therefore reducing installation costs

There are generally two grades of flexible liner used

316 grade flexible liners To EN 1856-2 T600 N1 D Vm L50012-G

904 grade flexible liners To EN 1856-2  T600 N1 D Vm L70012-G

316 grade is  generally used when the appliance installed is primarily burning seasoned wood, small amounts of coal can be used but if coal is used regularly then the life span of the liner will be reduced

904 grade is recommended when burning both wood and coal, this is a higher grade of stainless steel with a higher acid resistance and will  have a longer life span.

To break the information down (T600) is the operational temperature (N1) operating on natural draught (D) Not suitable for condensing appliances (VM) is the corrosion resistance


What is Stainless Steel?

'Stainless' is a term coined early in the development of these steels for cutlery applications. It was adopted as a generic name for these steels and now covers a wide range of steel types and grades for corrosion or oxidation resistant applications.

Stainless steels are iron alloys with a minimum of 10.5% chromium. Other alloying elements are added to enhance their structure and properties such as form-ability, strength and cryogenic toughness. These include metals such as:

  • Nickel
  • Molybdenum
  • Titanium
  • Copper


Non-metal additions are also made, the main ones being:

  • Carbon
  • Nitrogen

The main requirement for stainless steels is that they should be corrosion resistant for a specified application or environment. The selection of a particular "type" and "grade" of stainless steel must initially meet the corrosion resistance requirements. Additional mechanical or physical properties may also need to be considered to achieve the overall service performance requirements.


Compound data 316 grade

Carbon* 0.08% max Chromium 16.00-18.00%
Manganese 2.00% max Nickel 10.00-14.00%
Silicon 1.00% max Molybdenum 2.00-3.00%
Sulphur 0.03% max    
Phosphorous 0.03% max    

(*Carbon content on 316L 0.03% max


Compound data 904 grade

Carbon 0.02% max Chromium 19.00-23.00%
Manganese 2.00% max Nickel 23.00-28.00%
Silicon 1.00% max Molybdenum 4.00-5.00%
Phosphorous 0.045% max Copper 1.00-2.00%
Sulphur 0.035% max