Fireproof Hose Composition for Zero-Flow Flame Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aerospace fluid conveyance products, such as hoses, face challenges in meeting stringent fireproofing requirements, particularly under zero flow conditions, as they tend to degrade during exposure to fire, failing to consistently meet AS1055 and TSO fire performance standards, and often require external fire sleeves that increase weight and complexity.
Innovation Solution
A fireproof hose design featuring multiple layers, including an inner PTFE tube, metallic reinforcement, and an outer thermal insulation layer composed of silicone rubber, expanded graphite, and zinc borate, which provides enhanced fire resistance and meets AS1055 and TSO requirements without the need for external sleeves, offering improved weight reduction and ease of clamping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external fire sleeves are used to meet fireproofing requirements, then fire resistance is improved, but weight and device complexity increase
Solution Approach 1:
The fire-resistant properties are merged directly into the hose construction by incorporating expandable graphite and zinc borate into the thermal insulation layer, eliminating the need for separate external fire sleeves while maintaining fire resistance
Solution Approach 2:
A composite thermal insulation layer is used comprising silicone rubber as the base material combined with expandable graphite and zinc borate additives, creating a material that provides both insulation and fire resistance in a single integrated component
2Reliability
If external fire sleeves are used to meet fireproofing requirements, then fire resistance is improved, but device complexity increases
Solution Approach 1:
The fire-resistant properties are merged directly into the hose construction by incorporating expandable graphite and zinc borate into the thermal insulation layer, eliminating the need for separate external fire sleeves while maintaining fire resistance
Solution Approach 2:
The thermal insulation layer performs multiple functions simultaneously: thermal insulation, fire resistance, and structural integrity, eliminating the need for separate fire protection components
3Object-affected harmful factors
If traditional fireproof covers are used, then fire protection is provided, but they may not consistently meet zero flow requirements under stringent test conditions
Solution Approach 1:
The fire resistance parameters are enhanced by incorporating specific concentrations of expandable graphite (0.1-15 wt%) and zinc borate (3-20 wt%) into the thermal insulation layer, achieving consistent compliance with zero flow requirements under stringent test conditions
Solution Approach 2:
A composite thermal insulation layer is used comprising silicone rubber as the base material combined with expandable graphite and zinc borate additives, creating a material that provides both insulation and fire resistance in a single integrated component
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 hose effectively withstands direct flames for 5 to 15 minutes under zero flow conditions, achieving high flame resistance and char formation, while reducing weight and envelope size, thus meeting stringent aerospace fireproofing standards and ensuring reliable fluid conveyance in extreme temperatures.
Implementation Method 1
achieve a balance between green strength, flame resistance, and char formation
Implementation Method 2
outer thermal insulation layer prepared from a composition comprising a silicone rubber, an expanded graphite, and a zinc borate
Data Source
Figure 1~3
Figure 4
Figure 5
AI summary
A hose is provided capable of meeting fireproof requirements per AS 1055 under no flow condition. The hose has multiple layers of fire protection comprising a silicone rubber layer impregnated with additives including zinc borate and expandable graphite.