Electrically Isolated Tube Coupling for ESD-Safe Fluid Connections

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Solution Overview

Problem

Existing connections for electrically conductive tubular components fail to effectively isolate against electrostatic charge transfer and electrical current flow, which is crucial in fluid transport systems, particularly in aerospace applications where electrostatic discharge and electromagnetic events can occur.

Innovation Solution

The solution involves a connection apparatus comprising a first electrically conductive tube with a flared end, a second electrically conductive tube with an outer flange, and a nut with internal threads that engage the flared end, featuring a deformable rim to secure the connection and prevent electrical isolation, along with electrical isolators to reduce current flow and electrostatic discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing connection methods are used for electrically conductive tubular components, then the connection structure is simple, but electrical isolation against electrostatic charge transfer and current flow is insufficient

Engineering Contradiction:
Improveelectrical isolation effectivenessVSAvoidconnection structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connection system is divided into multiple functional segments: a first electrically conductive tube, a second electrically conductive tube, and at least one electrical isolator positioned between them. This segmentation allows each component to perform its specific function - the conductive tubes for fluid transport and the isolator for electrical isolation - thereby achieving effective electrical isolation without requiring complete redesign of the entire connection system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An electrical isolator is introduced as an intermediary component between the first and second electrically conductive tubes. This isolator acts as a mediator that blocks electrostatic charge transfer and electrical current flow while still allowing the tubes to be mechanically connected for fluid transport. The isolator can be in the form of a non-conductive sleeve, coating, or integrated feature on one of the tubes.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If electrical isolators are added to prevent electrostatic discharge and current transfer, then electrical isolation effectiveness is improved, but the connection device complexity increases

Engineering Contradiction:
Improveprotection from electrostatic dischargeVSAvoidnumber of connection components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electrical isolation function is merged with the existing connection structure rather than being implemented as a completely separate component. The isolator is integrated into the connection assembly, positioned between the two conductive tubes, and works in conjunction with standard connection elements like flared ends, flanges, and nuts. This merging approach provides electrical protection while minimizing the increase in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The connection system is designed to serve multiple functions simultaneously: mechanical connection for fluid transport and electrical isolation for safety. The electrical isolator component is designed to fulfill both the isolation requirement and fit within the existing connection geometry, allowing the same connection assembly to handle both fluid flow and electrical protection without requiring separate dedicated systems.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This configuration effectively isolates the electrically conductive tubes, preventing electrostatic discharge and electrical current transfer, ensuring safe operation in environments prone to electromagnetic events, such as in aircraft and spacecraft systems.

Implementation Method 1

the nut comprises a deformable rim adjacent to a secondary retention notch of the flared end of the first electrically conductive tube and configured to deform into engagement with the secondary retention notch

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

a first electrical isolator having a central passageway; a first electrically conductive tube having a flared end disposed around the first electrical isolator

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP3663625B1Apparatus and methods for connecting a first electrically conductive tube and a second electrically conductive tube
Publication Date: 2022.08.24 THE BOEING CO
  • EP3663625B1 patent drawingFigure 1
  • EP3663625B1 patent drawingFigure 2A~2D
  • EP3663625B1 patent drawingFigure 3A~3D

AI summary

An apparatus includes first and second electrically conductive tubes, first and second electrical isolators, and a nut. The first electrical isolator has a central passageway. The first electrically conductive tube has a flared end disposed around the first electrical isolator. The flared end includes external threads. The second electrically conductive tube has an outer flange. The second electrical isolator is disposed around the second electrically conductive tube and engages the outer flange. The nut is disposed around the second electrically conductive tube and engages the second electrical isolator. The nut includes internal threads corresponding to the external threads of the flared end of the first electrically conductive tube.