Düker GmbH

Penetrations of cast iron pipes through fire-rated ceilings? Child's play!

Düker BSV 90

In general, cast iron pipe installations do not require a lot in the way of fire protection seals when passing through fire-rated walls or ceilings.

The standard EN 1366-3 "Fire resistance tests for service installations - Part 3: Penetration seals" stipulates how pipe seals need to be tested to receive a fire rating such as EI 90. EI 90 means that fire and excessive heat are not transmitted through the ceiling or wall during at least 90 minutes.

On installations composed of cast iron pipes, it is sufficient to install mineral wool mattresses such as Rockwool products around the pipe. If certain minimum distances to combustible pipes can be observed, the mineral wool will only be placed within the ceiling. If a so-called zero-distance is required, the mineral wool must be prolonged somewhat according e.g. to the approved solutions by Rockwool.

However, things are different in case of mixed installations. When only the vertical pipe is in cast iron and all horizontal connections are in plastic material, the plastic pipes require an additional protection.

This is where the Düker fire protection coupling BSV 90 comes into play. According to up-to-date German regulations, penetration seals for mixed installations need to be tested on pipelines open above and below. This assembly and the relatively high test pressure in the fire zone create a chimney effect in non-combustible pipes, which will lead to an immense transmission of fire, heat and smoke.

The Düker BSV 90 is the first penetration seal that was approved particularly for mixed installations in Germany.



This is how it works

Düker BSV 90 Aufbau

click to enlarge

Inside the fire protection coupling, the cast iron pipeline is interrupted by a plastic collar. The intumescent material around it multiplies its volume in case of a fire. The heat of a fire makes the plastic collar melt away and the intumescent material expand. The result: the pipe is obstructed completely.


The expanded material ensures a thermal insulation. It prevents excessive heat transmission as well as the chimney effect described above. Therefore the plastic pipe connected to the cast iron pipe is no longer at risk and can no longer ignite itself through heat effects.

An additional strip of intumescent material on the outside of the steel casing is positioned in the ceiling penetration and thus guarantees the complete closure of the penetration in case of a fire.



Downloads regarding the BSV 90


- Brochure BSV (719 KB)

- Installation instructions (389 KB)




The Fire Protection Coupling in a film

Watch the installation of the BSV 90 on YouTube!

Professional installation even in a narrow ceiling perforation!



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