Vented Boss Fitting for Pressure Vessel Liner Gas Release
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Solution Overview
Problem
Pressure vessels experience gas diffusion into the liner under pressurization, leading to gas accumulation between the liner and shell, causing separation and potential leaks upon depressurization, which can trigger false leak detectors.
Innovation Solution
A vented fitting with a gas-permeable feature, such as channels, is positioned between the boss and shell to allow trapped gas to vent to the atmosphere, preventing separation and unwanted leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the pressure vessel is pressurized, then the vessel can contain and transport fluids under pressure, but gas diffuses into the liner and accumulates between the liner and shell causing separation and potential leaks
Solution Approach 1:
The vented fitting is pre-installed on the boss before the liner is formed, with gas permeable features already in place. This preliminary positioning ensures that when gas accumulates during pressurization, it can immediately escape through the pre-configured venting path, preventing liner-shell separation and false leak detections
Solution Approach 2:
The vented fitting acts as an intermediary component between the boss and the shell, providing a controlled interface for gas escape. The gas permeable features in the fitting's inner surface create a dedicated pathway that mediates the gas accumulation problem, allowing controlled venting while maintaining the structural integrity of the pressure vessel
2Stress or pressure
If gas accumulates between the liner and shell, then gas pressure increases, but this causes separation of the liner from the shell and potential leaks
Solution Approach 1:
The vented fitting extracts the harmful gas accumulation from the system by providing a dedicated escape pathway. The gas permeable features allow gas to be removed from the interface between liner and shell, preventing the buildup of pressure that would cause separation and maintain the bond integrity between these components
3Reliability
If gas escapes through the shell, then leak detectors are triggered, but this causes false leak detections when no actual leak exists
Solution Approach 1:
The vented fitting provides a controlled intermediary pathway for gas escape that is distinct from actual leak paths. By routing gas through the designated gas permeable features of the fitting rather than allowing uncontrolled escape through the shell, the system maintains reliable leak detection while eliminating false alarms
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 vented fitting effectively reduces damage to the liner and prevents false leak detection by allowing gas to escape, maintaining the integrity of the pressure vessel under pressure changes.
Implementation Method 1
Pressure vessels experience gas diffusion into the liner under pressurization, leading to gas accumulation between the liner and shell
Data Source
AI summary
An apparatus is configured to be positioned between a boss and a shell of a pressure vessel. The boss includes a bore therethrough, and the bore has a longitudinal axis. The apparatus includes an annular body and a gas permeable feature. The annular body includes an inner surface configured to abut the boss and an outer surface configured to abut the shell. The annular body has opposite first and second ends relative to the longitudinal axis. The gas permeable feature is provided on the inner surface and extends at least from the first end to the second end. The disclosure also describes a pressure vessel including a shell, and boss, and an apparatus positioned between the boss and the shell. A method for forming a pressure vessel includes mounting a boss on a mandrel, positioning an annular fitting about a neck of the boss, forming a liner, and forming an outer shell.