Düker GmbH

Cast iron benefit: Non-combustibility

As yet, national "reaction to fire" are still being used in many European countries. However, in the long run people will have to get used to "Euroclasses", the reaction to fire as per EN 13501-1.

Düker SML has been classified A1 "non-combustible" as per EN 13501-1. This is the best existing classification.

For the classifications A2 up to D, additional values must be stated for "s" (smoke generation) and "d" (flaming droplets). Therefore the classification for   Düker MLK-protec, TML and MLB is A2, s1, d0 - the second best existing classification of a total of 40 classes.

The following table gives the approximate correspondence between the new European classification and some older national classifications:



Reaction to fire
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Cast iron benefit: no flashover

The classifications contained in EN 13501-1 are based on the typical phases of a fire in a room. A small-scale fire will at first spread quite slowly. In the process, the heat radiation will increase continuously. When the heat release surpasses a certain limit, all neighbouring combustible materials will ignite in a sudden burst - the so-called flashover. After the flashover, the odds of survival in the room decline rapidly.

As described in annex A of EN 13501-1, the classifications of reaction to fire indicate if and how fast a construction product provokes a flashover:



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Cast iron benefit: no flaming droplets

Flaming droplets, i. e. the falling down of burning material, does not occur on Düker drainage pipe systems, neither in tests nor in practice.

For plastic pipe systems, flaming droplets need always be taken into account. Even "reaction to fire" classifications with the "d0" parameter are misleading in this respect. It must be considered that during the fire test that is carried out to determine the "d" parameter (SBI test as per EN 13823), flaming droplets are recorded only in a very limited way.

A realistic fire test at the MPA Erwitte institute showed that all brand plastic drainage pipes installed there produced flaming droplets. Those burning material particles fell through the correctly installed fire protection collar into the lower storey, where they ignited other parts of the plastic pipe installation. This resulted effectively in a fire transmittal downwards, in spite of the penetration seal, within just over 20 minutes.

For more information about this fire test, please contact your Düker sales team.




test assembly (excerpt)
flaming droplets after approx. 10 minutes
ignition of the bend after just over 20 minutes!

Cast Iron Benefit: little smoke generation

If installed with couplings whose rubber gaskets are completely covered by stainless steel collars (e.g. Dükorapid®), the pipe system remains closed in case of a fire. Any smoke generated by heat effects on the inner coating remains within the pipeline and ist then evacuated through the ventilation openings over the roof.




SML Specifier's Manual (pdf, 5.185 KB)

with detailed information on reaction to fire of Düker SML.

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