Cryogenic Bellows Conduit Assembly With Hermetic Welded Collars
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Solution Overview
Problem
Flexible conduits in cryogenic propulsion systems are susceptible to manufacturing variances and incidental damage, which can lead to potential failure of pressurized-propellant feed lines, posing a risk to the main propulsion system if not timely identified.
Innovation Solution
A conduit design featuring a bellows structure with corrugated plies and hermetic welds, along with a sensor system to monitor conditions within the interstitial space, allowing for detection of leaks and ensuring a strong, reliable connection, while enabling efficient assembly and fault tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flexible conduit is used to accommodate displacements in cryogenic propulsion systems, then adaptability is improved, but reliability deteriorates due to susceptibility to manufacturing variances and incidental damage
Solution Approach 1:
The conduit is divided into multiple segments including a bellows section with corrugated plies, rigid collars, and interstitial spaces. This segmentation allows each component to perform specific functions - the bellows accommodates displacements while the rigid collars provide stable connection points, and the segmentation enables independent monitoring of each section for leaks or damage
Solution Approach 2:
Sensors are introduced as intermediary elements that monitor the interstitial spaces between the bellows plies. These sensors detect leaks or anomalies without being part of the fluid flow path, providing early warning of potential failures while the conduit maintains its flexible, displacement-accommodating structure
2Reliability
If hermetic welds are used to ensure sealed connections, then reliability is improved, but manufacturing complexity increases
Solution Approach 1:
The hermetic sealing function is segmented into multiple locations - welds at the collar-bellows interfaces and potential seals within the interstitial spaces. This distributes the sealing requirement across multiple manageable joints rather than requiring a single complex seal, making manufacturing more feasible while maintaining overall hermetic integrity
Solution Approach 2:
The patent replaces complex mechanical sealing mechanisms with hermetic welds that create metal-to-metal seals. This substitution eliminates the need for separate gaskets, O-rings, or mechanical seal assemblies, simplifying the manufacturing process while achieving superior hermetic sealing reliability
3Reliability
If sensors are added to detect leaks in the interstitial space, then reliability is improved through early leak detection, but device complexity increases
Solution Approach 1:
The leak detection function is extracted from the main fluid transport path and placed in the interstitial space between the bellows plies. Sensors monitor this separate space for leaks without interfering with the primary fluid flow, enabling independent detection of bellows integrity issues while maintaining simple fluid transport
Solution Approach 2:
The sensors serve multiple functions: detecting leaks in the bellows structure, monitoring the integrity of hermetic welds, and potentially detecting structural anomalies in the conduit. This multi-functionality justifies the added complexity by providing comprehensive monitoring with a single sensor system
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 conduit provides a compliant structure for cryogenic fluids, accommodating displacements and ensuring reliable fluid transport by detecting leaks and maintaining a sealed connection, thus preventing damage to the propulsion system.
Implementation Method 1
a first weld hermetically coupling the corrugated inboard ply and the first outer collar portion
Implementation Method 2
a second weld hermetically coupling the corrugated outboard ply and the first inner collar portion
Implementation Method 3
a third weld hermetically coupling the corrugated inboard ply and the second outer collar portion
Implementation Method 4
a fourth weld hermetically coupling the corrugated outboard ply and the second inner collar portion
Data Source
AI summary
A method of fabricating a conduit comprises steps of attaching a first tubular-outboard-ply-end of a tubular outboard ply to a first inner collar portion of a first collar with a second weld and attaching a second tubular-outboard-ply end of the tubular outboard ply to a second inner collar portion of a second collar with a fourth weld. The method also comprises steps of inserting a tubular inboard ply into the tubular outboard ply, threadably interconnecting the first inner collar portion and a first outer collar portion of the first collar, and threadably interconnecting the second inner collar portion and a second outer collar portion of the second collar. The method further comprises steps of attaching a corrugated inboard ply to the first outer collar portion with a first weld and attaching a corrugated inboard ply to the second outer collar portion with a third weld.