Thermally Expandable Fire-Stop Seal for Pipe Conduits
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Solution Overview
Problem
Current pipe transit systems face challenges in maintaining watertightness and preventing fire spread, especially in conduits with smaller cross-sectional dimensions, where thermal expansion is constrained, leading to early sealant layer breakdown and compromised sealing integrity after exposure to fire.
Innovation Solution
A thermally expandable fire-stop system is designed with a device that expands radially to seal off conduits, featuring a thermally expandable material with non-linear expansion characteristics, and a retainer to optimize performance, allowing for early heat absorption and sticking to the pipe and conduit surfaces, while inhibiting axial expansion to enhance sealing efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thermally expandable device is used to seal conduits, then fire spread is prevented and watertightness is maintained, but in conduits with smaller cross-sectional dimensions, thermal expansion is constrained leading to early sealant layer breakdown
Solution Approach 1:
The patent applies parameter changes by modifying the expansion characteristics of the thermally expandable device. It uses materials with non-linear expansion characteristics that expand more slowly initially and accelerate later, and controls the expansion temperature range to match the softening temperature of the pipe material. This resolves the contradiction by preventing premature sealant layer failure while ensuring reliable sealing against fire spread.
Solution Approach 2:
The patent applies local quality by creating different functional zones within the conduit system. The thermally expandable device is positioned to expand preferentially in the radial direction rather than axially, creating localized expansion zones that seal the conduit without overwhelming the sealant layer. This localized control of expansion resolves the contradiction between achieving reliable sealing and maintaining sealant layer strength.
2Speed
If the thermally expandable device expands rapidly, then fire spread is blocked quickly, but the sealant layer breaks down early due to constrained expansion in smaller conduits
Solution Approach 1:
The patent changes the expansion speed parameter by selecting thermally expandable materials with non-linear expansion characteristics. These materials exhibit slower initial expansion that accelerates at higher temperatures, matching the thermal response of the pipe material. This resolves the contradiction by delaying rapid expansion until the pipe softens, protecting the sealant layer while ensuring quick fire blocking when needed.
Solution Approach 2:
The patent applies preliminary action by positioning the thermally expandable device and sealant layer in advance, and by designing the system so that the pipe softening occurs before rapid device expansion. This sequence of events - pipe softening first, then device expansion - protects the sealant layer while ensuring fire spread is blocked quickly once expansion begins.
3Speed
If axial expansion is allowed, then the device can respond to heat quickly, but sealing efficacy is reduced due to expansion in the wrong direction
Solution Approach 1:
The patent applies asymmetry by designing the thermally expandable device and conduit configuration to create unequal expansion resistance in different directions. The device is constrained to expand preferentially in the radial direction rather than axially, ensuring that expansion occurs in the direction that provides effective sealing. This asymmetric constraint resolves the contradiction by directing expansion energy toward sealing efficacy while maintaining heat response capability.
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 system effectively seals conduits by crushing thermally weakenable pipes and blocking oxygen supply, maintaining watertightness before and after a fire, even under high water pressure, and remains effective even after cooling, ensuring prolonged sealing integrity.
Implementation Method 1
a thermally expandable device which includes at least one component having a non-linear thermal expansion characteristic
Implementation Method 2
The surfaces then form a sticky material. The device can then firmly fix itself within the conduit
Implementation Method 3
the pipe will weaken and the thermally expandable device will then crush that pipe and further seal off the conduit
Data Source
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AI summary
A pipe transit system comprising: a conduit having an axial direction; at least one sealing device; and at least one rubberlike thermally expandable device, the conduit being suitable for receiving at least one pipe, the at least one sealing device comprising vulcanized fire-resistant rubber and being suitable for sealing in an assembled condition of the system between an inner wall of the conduit and the at least one pipe, the thermally expandable device being suitable for surrounding in the assembled condition the at least one pipe at a position which is in axial direction, relative to at least one of the at least one sealing device, at or toward the end of the conduit.