Composite Pressure Test Door for Aircraft Fuel Tanks
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Solution Overview
Problem
Current pressure test doors are ergonomically challenging due to their weight and require multiple latching mechanisms, leading to increased installation time, maintenance, and safety concerns, while also lacking a reliable seal and pressurization indication.
Innovation Solution
A lightweight pressure test door made from composite materials, such as fiber-based composites, with a dome-shaped body, rim, and flange, featuring a compression seal and visible pressure indicator, allowing single-handed installation and removal without latching mechanisms, and providing improved structural strength and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a traditional metal pressure test door is used, then structural strength is maintained, but weight increases to about fifteen pounds and ergonomic safety deteriorates
Solution Approach 1:
The patent applies composite materials (fiber-based composites) to construct the pressure test door body, replacing traditional metal materials. This substitution maintains the required structural strength while significantly reducing the door weight from fifteen pounds to approximately two and a half pounds, thereby resolving the contradiction between strength and weight.
2Reliability
If four latching mechanisms are used to seal the chamber, then sealing reliability is improved, but device complexity increases and installation time increases
Solution Approach 1:
The patent removes the four latching mechanisms from the pressure test door design entirely. Instead, it employs a simple flange and seal configuration where the seal engages with the chamber opening through compression forces applied during installation, eliminating complex latching mechanisms while maintaining sealing reliability.
Solution Approach 2:
The sealing function is segmented into distinct components: the flange provides the engagement surface, the seal provides the sealing action, and the door body provides structural support. This segmentation allows each component to perform its function independently, simplifying the overall design while maintaining reliability.
3Strength
If a heavy pressure test door is used, then structural strength is maintained, but ease of operation deteriorates during overhead installation
Solution Approach 1:
By using fiber-based composite materials, the door weight is reduced from fifteen pounds to approximately two and a half pounds. This weight reduction dramatically improves ease of operation during overhead installation, allowing users to install and remove the door without excessive physical strain while maintaining sufficient structural strength for the application.
4Reliability
If multiple latching mechanisms are used, then sealing reliability is improved, but installation time increases
Solution Approach 1:
The patent eliminates the four latching mechanisms that required manual engagement, replacing them with a simple flange and seal system. This extraction of complex mechanisms reduces installation time significantly while the seal design maintains reliability through proper compression and engagement with the chamber opening.
Solution Approach 2:
The seal is pre-positioned on the flange during manufacturing, and the flange is designed to automatically engage with the chamber opening when the door is installed. This preliminary preparation eliminates the need for manual latching operations during installation, reducing installation time while maintaining sealing reliability.
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 solution reduces installation time, enhances ergonomic safety, and provides a reliable seal with direct pressurization indication, while being easier to store and maintain, with reduced weight and cost compared to traditional metal-based doors.
Implementation Method 1
a compression seal disposed on the contour lip operable for providing a compression seal of the opening port upon pressurization of the vessel
Data Source
AI summary
An apparatus operable to seal an opening in an aircraft fuel tank during a pressure test of the fuel tank is described. The apparatus includes a substantially dome shaped body having a perimeter. The body further includes a rim extending in an orthogonal direction about the perimeter and a flange extending in a normal direction from the rim and about the perimeter. The flange is sized to engage the fuel tank about the opening. The apparatus further includes a sealing gasket proximate an intersection of the rim and the flange, extending completely around the perimeter. The seal is oriented to provide a sealing function between the fuel tank and the body as pressure is increased within the fuel tank.