Localized Vacuum Sealing for On-Site Thick-Wall Laser Welding

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Solution Overview

Problem

Large vacuum chambers required for electron beam and laser beam welding in high vacuum are cumbersome, costly, and impractical for welding large, thick-walled components like pressure pipelines and pressure vessels on-site due to size, weight, and limited space, making it difficult to create and maintain a high vacuum for deep welds.

Innovation Solution

A device using sealing plates and retaining elements to create a localized vacuum chamber within the components, allowing for precise sealing and efficient generation of high vacuum for laser welding, with the laser beam directed radially to form deep welds without requiring a large, transportable vacuum chamber.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large vacuum chamber is used to contain the component for electron beam or laser beam welding, then high vacuum can be achieved for deep penetration welding, but the vacuum chamber becomes cumbersome, costly, and difficult to transport

Engineering Contradiction:
Improvevacuum qualityVSAvoidtransportability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The vacuum chamber is segmented into a portable external chamber and an internal vacuum seal arrangement within the pipe. The sealing plate divides the pipe interior into a vacuum zone and non-vacuum zone, allowing the vacuum to be contained in a small, transportable chamber rather than requiring a large chamber to encompass the entire pipe.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The vacuum chamber is nested within the pipe structure itself. The sealing plate is inserted into the pipe, and the vacuum chamber is positioned within the pipe interior, creating a nested configuration where the vacuum environment is contained within the workpiece structure rather than requiring a separate large external chamber.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Manufacturing precision

If a large vacuum chamber is used to provide high vacuum for welding thick-walled components, then deep penetration welds can be achieved, but the equipment becomes extremely costly

Engineering Contradiction:
Improveweld depthVSAvoidvacuum chamber size
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The vacuum environment is applied locally only to the immediate welding zone rather than to the entire pipe or large component. The sealing plate creates a localized vacuum chamber around the weld area, providing high vacuum conditions precisely where needed for deep penetration welding while avoiding the cost and complexity of a large overall vacuum system.

Inventive Principle:
Principle #3Local quality

3Reliability

If a large vacuum chamber is used for welding on-site, then high quality welds can be achieved, but the evacuation time increases significantly

Engineering Contradiction:
Improveweld qualityVSAvoidevacuation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The vacuum system is segmented into a small isolated chamber rather than a large volume. By dividing the pipe interior into a small vacuum zone using the sealing plate, the evacuation time is dramatically reduced because only a small volume needs to be pumped down to high vacuum, while the rest of the pipe remains at atmospheric pressure.

Inventive Principle:
Principle #1Segmentation

4Adaptability or versatility

If the welding fixture is moved along the weld seam for on-site welding, then welding of large components can be performed, but space is limited and vacuum chamber construction is not possible

Engineering Contradiction:
Improveon-site welding capabilityVSAvoidvacuum chamber construction
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The vacuum system is segmented into a small portable chamber that can be positioned at different locations along the pipe. The sealing plate creates an isolated vacuum zone that can be moved to different welding positions, enabling on-site welding without requiring a large fixed vacuum chamber to encompass the entire component.

Inventive Principle:
Principle #1Segmentation

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

Enables high-quality, efficient, and cost-effective on-site welding of thick-walled components with deep welds, reducing heat input and ensuring occupational safety, while minimizing the need for large, cumbersome vacuum equipment.

Implementation Method 1

high-power lasers in a high vacuum... Due to the high power density and high power, the metallic component begins to melt locally and form a vapor capillary

Methodology Applied
Scientific EffectLaser beam: Laser

Implementation Method 2

the metallic component begins to melt locally and form a vapor capillary. This so-called deep penetration welding effect

Methodology Applied
Scientific EffectVapor capillary formation: Evaporation

Implementation Method 3

a sealing plate (11) is inserted into the pipe (1) to seal the joining zone (3) against the environment

Methodology Applied
Scientific EffectVacuum sealing: Vacuum

Implementation Method 4

The retaining elements (13) on both sides of the joining zone (3) are essentially identical in design... a frictional connection is created between the retaining elements (13) and the tubes (1)

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4190476B1Device and method for laser beam welding of thick-walled pipes and pressure vessels
Publication Date: 2026.02.18 UNIVERSITAT STUTTGART
  • EP4190476B1 patent drawingFigure 1
  • EP4190476B1 patent drawingFigure 2
  • EP4190476B1 patent drawingFigure 3

AI summary

A device and method for electron beam welding of thick-walled pipes or container segments are proposed. The device enables the rapid, safe, and high-quality joining of thick-walled pipes or container segments on-site, for example, at a power plant construction site, using an electron beam or a laser beam.