Flexible Intumescent Fire Collar Insert for Variable Pipe Sealing

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Solution Overview

Problem

Existing fire protection collars are inflexible and unable to effectively seal cables or pipes with varying diameters, leading to gaps that compromise smoke and fire tightness, especially when retrofitting or sealing cable bundles, and fail water jet tests due to gaps between half-bodies.

Innovation Solution

A resiliently deformable, two-part intumescent fire protection insert with structured surfaces on abutting elements, allowing for easy adaptation to varying diameters and providing interlocking seals that withstand high pressure and maintain tightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rigid sheet metal casing with a fixed circumference is used, then the fire protection insert can support expansion pressure effectively, but it cannot adapt to cables or pipes with varying diameters, leaving gaps that compromise sealing

Engineering Contradiction:
Improveadaptability to varying cable/pipe diametersVSAvoidsealing reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The fire protection insert uses a flexible molded body instead of rigid sheet metal, allowing it to deform and conform to different cable or pipe diameters while maintaining sealing integrity. The flexible material enables the insert to adapt to varying geometries without compromising the smoke and fire tightness.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The insert material's physical parameters (flexibility, deformability) are changed to allow dynamic adaptation. The molded body can be compressed during installation and then expands to fill the available space, changing its volume and shape parameters to seal around cables or pipes of different sizes.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If a thin strip fire protection insert is used to fit within a fixed sleeve, then it can be installed in standard collars, but it does not completely fill the space, creating gaps for smoke and fire penetration

Engineering Contradiction:
Improveinstallation compatibility with standard collarsVSAvoidsmoke and fire penetration through gaps
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The insert transitions from a static thin strip to a dynamic molded body that can change shape and volume. During installation, it is compressed to fit within the sleeve, then expands dynamically to completely fill the available space, eliminating gaps while remaining compatible with standard collar dimensions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The insert's volume parameter is increased from a thin strip to a fully volumetric molded body. This parameter change allows it to completely fill the space within standard collars, preventing smoke and fire penetration while maintaining installation compatibility.

Inventive Principle:
Principle #35Parameter changes

3Strength

If a non-compressible fire protection insert is used, then it maintains structural integrity, but it cannot seal gaps between individual cables in a bundle

Engineering Contradiction:
Improvestructural integrityVSAvoidsmoke penetration through cable gaps
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The molded body uses flexible material that can be compressed during installation to fit around cable bundles. This flexibility allows it to deform and seal in the gaps between individual cables, while the material's inherent strength maintains structural integrity and prevents collapse under fire conditions.

Inventive Principle:
Principle #30Flexible shells and thin films

4Object-affected harmful factors

If additional sealing measures like fire protection foam are applied to seal cable bundles, then smoke tightness can be achieved, but the installation process becomes time-consuming and complex

Engineering Contradiction:
Improvesmoke tightnessVSAvoidinstallation time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The fire protection function and sealing function are merged into a single molded body component. The insert simultaneously provides fire protection through its intumescent material and sealing through its ability to deform and fill gaps, eliminating the need for separate sealing operations and reducing installation time.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The molded body performs multiple functions: it provides fire protection, seals gaps between cables, and installs as a single component. This multi-functionality replaces the need for separate sealing materials and operations, streamlining the installation process while achieving smoke tightness.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The flexible, structured fire protection insert ensures smoke and fire tightness for cables and pipes of varying sizes without additional sealing, passing water jet tests, and allows easy installation and retrofitting without compromising integrity.

Implementation Method 1

an intumescent fire protection insert

Methodology Applied
Scientific EffectIntumescent expansion: Intumescent Materials

Implementation Method 2

the intumescent fire protection insert is designed as a resiliently deformable molded body

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the surfaces of the abutting surfaces being structured

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4043080B1Flame retardant sleeve
Publication Date: 2025.08.06 HILTI AG
  • EP4043080B1 patent drawingFigure 1~2
  • EP4043080B1 patent drawingFigure 3
  • EP4043080B1 patent drawingFigure 4

AI summary

A fire protection collar for sealing off pipes passing through walls or ceilings, which can be mounted on a wall or ceiling, comprises an intumescent fire protection insert, a wall part surrounding the fire protection insert, on the inside of which the fire protection insert is arranged, and at least one fastening part projecting radially outwards in the area of ​​at least one end face of the wall part, and is characterized in that the intumescent fire protection insert is designed as a flexibly deformable, two-part molded body formed by two half-cylinders, which completely fills the space enclosed by the housing.