Welded Fluid Line Connection for Hydrogen Leak and Debris Isolation

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Solution Overview

Problem

Welding and cutting processes in fluid line connections, particularly for cryogenic or liquid hydrogen applications, result in debris and hydrogen leakage due to the inability to effectively prevent contamination and escape of hydrogen and debris into the piping system.

Innovation Solution

A method involving a continuous weld connection with a sealing element between two fasteners, such as flanges, that completely surrounds the inner piping, along with a mounting tool to facilitate the connection and ensure a leak-tight seal, and a method to disconnect the connection without contaminating the inner piping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a weld connection is used to prevent hydrogen leakage, then sealing performance is improved, but the welding process generates debris that pollutes the inner piping

Engineering Contradiction:
Improvesealing performanceVSAvoidpiping pollution
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The connection system is divided into separate functional zones: a sealing zone with the sealing element that prevents hydrogen leakage, and a welding zone that is isolated from the inner piping. This segmentation allows welding to occur without contaminating the fluid-carrying passages, resolving the contradiction between achieving reliable seals and preventing debris contamination.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing element acts as an intermediary component between the two fasteners, creating a protective barrier that separates the welding process from the inner piping. This intermediary structure enables the welding operation to proceed while the sealing element prevents welding debris from entering and polluting the fluid lines, thus resolving the contradiction between welding necessity and contamination prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If bolts are used to connect fluid lines, then assembly is simplified, but hydrogen diffuses through the seals

Engineering Contradiction:
Improveassembly simplicityVSAvoidhydrogen containment
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

Different regions of the connection system have different sealing mechanisms: the sealing element provides primary sealing against hydrogen diffusion, while the continuous weld connection provides secondary sealing. This local differentiation of sealing qualities allows the connection to maintain both assembly simplicity (through the sealing element design) and hydrogen containment reliability (through the weld seal).

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sealing element is installed beforehand to provide initial sealing protection against hydrogen diffusion, and the subsequent welding process creates an additional redundant seal. This beforehand cushioning approach ensures that even if one sealing mechanism fails, the other provides backup protection, resolving the contradiction between assembly simplicity and hydrogen containment reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If welding is performed without protection, then the process is faster, but debris penetrates into the piping

Engineering Contradiction:
Improvewelding speedVSAvoiddebris penetration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The sealing element is positioned in advance to enclose the inner piping before the welding process begins. This preliminary protective action creates a barrier that prevents welding debris from penetrating into the piping during the welding operation, allowing the welding to proceed at normal speed without requiring additional protective measures that would slow down the process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sealing element serves as an intermediary protective structure between the welding process and the inner piping. It allows the welding operation to proceed quickly and efficiently while simultaneously preventing debris penetration, thus resolving the contradiction between welding productivity and contamination prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides a leak-tight, clean, and contamination-free weld connection for fluid lines, preventing hydrogen escape and debris entry, with a redundant sealing mechanism to ensure double protection against leakage and pollution during both connection and disconnection processes.

Implementation Method 1

pressing the first and the second fastener against each other so that the sealing element is pressed between the fasteners and seals the enclosed inner piping

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

welding the first fastener to the second fastener, whereby a continuous weld connection is created which completely surrounds the sealing element and the enclosed inner piping

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 3

at least one of the fasteners is surrounded by the mounting tool which presses the fasteners against each other

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4438933A1Method of making a weld connection for a fluid line, method of disconnecting it, welded fluid line connection, and mounting tool
Publication Date: 2024.10.02 AIRBUS OPERATIONS GMBH
  • EP4438933A1 patent drawingFigure 1
  • EP4438933A1 patent drawingFigure 2
  • EP4438933A1 patent drawing

AI summary

A method of making a weld connection for a fluid line, in particular for the transport of liquid hydrogen, comprises the steps: (a) providing a first fastener (11) connected to a first fluid line (12) and a second fastener (13) connected to a second fluid line (14); (b) positioning the fasteners (11, 13) so that they face each other; (c) providing a sealing element (16) between the first fastener (11) and the first fastener (13) so that it encloses an inner piping (17) provided within the fasteners (11, 13) when they are connected; (d) pressing the first fastener (11) and the second fastener (13) against each other so that the sealing element (16) is pressed between the fasteners (11, 13) and seals the enclosed inner piping (17); and (e) welding the first fastener (11) to the second fastener (13), whereby a continuous weld connection (10) is created which completely surrounds the sealing element (16) and the enclosed inner piping (17).