Conduit Coupling Shell Geometry to Prevent Gasket Extrusion

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Solution Overview

Problem

Existing pipe coupling technologies face challenges in providing a reliable and adaptable sealing solution for fluid conduits of varying diameters, often resulting in gasket material extrusion and compromised sealing efficiency.

Innovation Solution

The improved conduit coupling assembly features a unique design with first and second arcuate sleeve members, a connecting assembly, and an arcuate gasket with a radial-split configuration. The inwardly-facing arcuate surfaces of the sleeve members have a non-uniform radius, allowing for a radial gap between the gasket and the sleeve, which accommodates different pipe diameters without gasket material extrusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional pipe coupling with uniform radius sleeve is used, then the structure is simple and easy to manufacture, but gasket material extrusion occurs and sealing efficiency is compromised when accommodating pipes of varying diameters

Engineering Contradiction:
Improvesealing efficiencyVSAvoidsleeve structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sleeve transitions from a uniform radius structure to a non-uniform radius structure with varying curvature along its length. This allows different sections of the sleeve to accommodate different pipe diameters, preventing gasket extrusion while maintaining reliable sealing across varying pipe sizes.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sleeve's geometric parameter (radius) is changed from constant to variable along its longitudinal axis. This parameter modification enables the coupling assembly to adapt to pipes of different diameters, solving the extrusion problem while preserving sealing effectiveness.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a fixed-radius sleeve design is used, then manufacturing is straightforward, but adaptability to different pipe diameters is limited

Engineering Contradiction:
Improveaccommodation of varying pipe diametersVSAvoidsleeve fabrication complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The sleeve is designed with locally varying radius characteristics, where specific sections have different curvature radii to match different pipe diameters. This localized differentiation provides adaptability while maintaining a relatively simple overall structure that can be manufactured using conventional techniques.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sleeve incorporates a dynamic geometric profile that transitions smoothly between different radius sections. This dynamic design allows the coupling to adapt to various pipe sizes without requiring multiple different sleeve components, balancing versatility with manufacturing simplicity.

Inventive Principle:
Principle #15Dynamics

3Reliability

If the sleeve tightly contacts the gasket to ensure sealing, then sealing pressure is adequate, but gasket material extrusion occurs under compression

Engineering Contradiction:
Improvesealing pressureVSAvoidgasket material extrusion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The non-uniform radius design creates varying contact pressure distributions along the sleeve-gasket interface. Sections with larger radius provide lower compression to prevent extrusion, while sections with smaller radius provide higher compression to ensure sealing, thereby eliminating both extrusion and inadequate sealing simultaneously.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sleeve's non-uniform geometry pre-combats the extrusion problem by providing controlled compression zones before the gasket is fully compressed. The varying radius profile acts as a built-in cushioning mechanism that distributes compression forces to prevent material extrusion while maintaining adequate sealing pressure.

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

Data Source

PatentEP3880998B1Extended range encapsulation shell
Publication Date: 2025.04.23 DRESSER WATER LLC
  • EP3880998B1 patent drawingFigure 1
  • EP3880998B1 patent drawingFigure 2
  • EP3880998B1 patent drawingFigure 3

AI summary

A conduit coupling assembly having first and second sleeve members configured to be tightened to a fluid conduit, an arcuate radial split gasket configured to be positioned between the first and second sleeve members and the fluid conduit, the first sleeve member having an inwardly-facing arcuate radial surface with first and second arcuate portions and a third arcuate portion between the first and second arcuate portions that has a radius from the longitudinal axis of the pipe that is less than the radius of the first and second arcuate portions, and the second sleeve member having an inwardly-facing arcuate radial surface with first and second arcuate portions and a third arcuate portion between the first and second arcuate portions that has a radius from the longitudinal axis of the pipe that is less than the radius of the first and second arcuate portions.