Pressure Vessel End Fitting Retention With Pressure-Relief Venting
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Solution Overview
Problem
Existing pressure vessels face issues with end fittings disengaging due to high pressures, leading to potential leaks and loss of compressed gas, as current retention methods like barbed stems and crimped shells are insufficient for high-pressure systems.
Innovation Solution
Implementing retention techniques such as drilling holes in the stem for pressure relief, using anchor assemblies with pressure-piercing arms, adhesive plugs for secure fixation, and bulkhead assemblies with collars and tethers to enhance the retention of end fittings in pressure vessels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If barbed stems and crimped shells are used to retain end fittings, then the structure is simple and easy to manufacture, but the retention force is insufficient under high pressure conditions
Solution Approach 1:
The retention system is divided into multiple independent components: barbed stem for initial anchoring, crimped shell for structural support, and spring-loaded cap with sealing element for final securing. Each component performs a specific retention function, and the combination provides cumulative retention force sufficient for high-pressure applications while maintaining relative manufacturing simplicity
Solution Approach 2:
The end fitting assembly combines multiple materials with different properties: the barbed stem provides mechanical interlocking, the crimped shell provides structural reinforcement, and the spring-loaded cap with sealing element provides both retention and pressure sealing. This composite approach achieves high retention force through material and structural diversity
2Reliability
If higher retention force is achieved through design modifications, then end fitting security improves, but the manufacturing process becomes more complex
Solution Approach 1:
The barbed stem is pre-formed with barbs during manufacturing, allowing it to be inserted and anchored in a single preliminary action. The spring-loaded cap is pre-assembled with the sealing element, so that during installation, the end fitting is secured in one definitive action when the cap is engaged, ensuring reliability without requiring multiple complex manufacturing steps
Solution Approach 2:
The spring-loaded cap automatically engages and secures the end fitting when installed, using the spring force to maintain constant retention pressure. The sealing element self-adjusts to seal the interface between the end fitting and pressure vessel, providing reliable security without requiring additional manual adjustment or complex assembly procedures
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
These methods increase the retention capacity of end fittings, changing the failure mode from disengagement to controlled leakage or slow leak, ensuring the end fittings remain secure under high pressures, thereby preventing complete disconnection and extending the life expectancy of the pressure vessels.
Implementation Method 1
The stem may further include holes extending through a surface of the stem, venting the compressed gas as the stem moves out of the cavity, and reducing pressure on the end fitting
Implementation Method 2
The adhesive plug and the stem may be directly couple at a fixed position within the cavity of the pressure element and to prevent end fitting disengagement below the predetermined pressure threshold
Data Source
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AI summary
A pressure vessel assembly includes a pressure element storing compressed gas and a shell enclosing the pressure element and capture the compressed gas that permeates from the pressure element. The pressure vessel assembly includes an end fitting extending into a cavity of the pressure element and from the pressure element through the shell. The end fitting includes a stem that extends out from the shell in one direction and into the cavity of the pressure element in an opposite direction and a cap that surrounds the pressure element and the stem at a location external to the pressure element. The pressure vessel assembly includes a retention component sustaining engagement of the end fitting with at least one of the pressure element or the shell below a predetermined pressure threshold.