Hydrogen Pipe Coupling with Spring-Loaded Inner Sealing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing hydrogen piping systems face challenges in achieving a reliable and leak-tight coupling, especially in cryogenic applications where the temperature and pressure conditions are extreme.

Innovation Solution

The hydrogen pipe coupling arrangement incorporates a multiple-wall pipe design with a sealing arrangement and a pressing device, along with a spring-energized flange concept to increase the seal seating load, ensuring a secure and leak-tight connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a pressing device is used to press the coupling portions together, then the connection strength is improved, but the sealing reliability deteriorates under extreme cryogenic temperature and pressure conditions

Engineering Contradiction:
Improveconnection strengthVSAvoidsealing reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The sealing arrangement is segmented into multiple independent sealing elements (first sealing element on the first inner pipe, second sealing element on the second inner pipe) that work together to provide redundant sealing. This segmentation ensures that if one sealing element fails, the other can maintain the seal, thereby improving sealing reliability under extreme conditions while maintaining connection strength through the pressing device.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates a compensating mechanism that applies pre-compression force to the sealing elements before the extreme cryogenic conditions are fully established. This pre-cushioning compensates for the thermal contraction that occurs when liquid hydrogen is introduced, ensuring that the sealing elements maintain adequate contact pressure and sealing reliability throughout the temperature transition, preventing leaks that would otherwise occur due to the worsening of sealing conditions.

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

2Loss of energy

If multiple-wall pipe design is used with inner and outer pipes, then the thermal insulation performance is improved, but the device complexity increases

Engineering Contradiction:
Improvethermal insulation performanceVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent employs a nested doll configuration where the first inner pipe is nested within the first outer pipe, and the second inner pipe is nested within the second outer pipe. The coupling portions are designed to connect these nested structures, with the inner pipe coupling portions positioned inside the outer pipe coupling portions. This nesting arrangement provides effective thermal insulation by creating vacuum or insulating material spaces between the inner and outer pipes, while the integrated coupling design minimizes the added complexity by using a unified coupling structure that handles both inner and outer pipe connections simultaneously.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 solution enhances the seal performance and leak-tightness of hydrogen pipe couplings, meeting the stringent safety and operational requirements for hydrogen distribution systems, particularly in cryogenic applications.

Implementation Method 1

at least one spring element configured to apply a pre-pressing force onto the inner seal in addition to the pressing force of the pressing device

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4299960B1Hydrogen pipe coupling arrangement with enhanced inner sealing
Publication Date: 2025.04.16 AIRBUS OPERATIONS GMBH
  • EP4299960B1 patent drawingFigure 1
  • EP4299960B1 patent drawingFigure 2
  • EP4299960B1 patent drawingFigure 3~9

AI summary

In order to enhance the sealing of a coupling for a hydrogen pipe, a coupling for coupling multi-wall pipe sections (22.1, 22.2) has been proposed which is equipped with an inner seal (38) and an outer seal (40) and a pressing device (27, 27.1, 27.2) that presses the pipe sections together. The hydrogen pipe coupling arrangement (10) comprises at least one spring element (50, 50.1, 50.2) configured to apply a pre-pressing force onto the inner seal (38) in addition to a pressing force of the pressing device (27, 27.1, 27.2).