Shrink-Fit Pipe Connection With Sealing Ring for Fast Low-Temp Sealing

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Solution Overview

Problem

Existing pipe connections made from shape memory materials like cross-linked polyethylene take an extended time to seal, especially in low temperatures, often resulting in incomplete sealing or failure, leading to inefficiencies and potential leaks.

Innovation Solution

A pipe connection design featuring a connecting piece with a radially projecting flange and circumferential groove, combined with a sealing ring having an annular profile with multiple annular ridges, allows for a tight seal before the pipe end fully retracts, utilizing back-shrinkage to achieve a leak-proof connection quickly, even at low temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional back-shrinkage connection method is used without sealing ring, then the connection structure is simple, but the sealing time is extended and incomplete sealing occurs frequently in low temperatures

Engineering Contradiction:
Improvesealing reliabilityVSAvoidsealing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The sealing ring is pre-installed in the circumferential groove of the connecting piece before the pipe end is expanded. This preliminary placement of the sealing element ensures that sealing contact is established immediately when the expanded pipe end is inserted, eliminating the waiting period required for shape memory material to naturally shrink and seal in traditional connections.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sealing ring acts as an intermediary element between the pipe end and the connecting piece. It provides a dedicated sealing interface that facilitates rapid and reliable sealing by concentrating the sealing function in a specific component, rather than relying solely on the friction and shrinkage of the shape memory pipe material itself.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If traditional back-shrinkage connection is used, then no additional sealing components are needed, but incomplete sealing and leakage occur frequently especially in low temperatures

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

Solution Approach 1:

The connection system is segmented into distinct functional components: the connecting piece with integrated sealing ring, and the pipe end. The sealing function is separated from the structural connection function, allowing each to be optimized independently. The sealing ring specifically handles the sealing task while the back-shrinkage mechanism provides the mechanical connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing ring serves as an intermediary component that mediates the interface between the pipe end and connecting piece. This dedicated sealing element ensures complete sealing by providing a controlled sealing surface, reducing reliance on the variability of shape memory material shrinkage alone.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple annular ridges are added to the sealing ring, then sealing performance is improved, but the manufacturing complexity of the sealing ring increases

Engineering Contradiction:
Improvesealing performanceVSAvoidsealing ring manufacturing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing ring incorporates multiple annular ridges with varying parameters (different diameters, positions, and cross-sectional shapes) to optimize sealing performance. These parameter variations create multiple sealing contact points that adapt to different surface conditions and ensure reliable sealing even when dimensional tolerances vary during manufacturing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The multiple annular ridges provide dynamic sealing capability where different ridges can engage at different stages of the connection process. As the pipe end shrinks and settles, different ridges make contact sequentially or simultaneously, providing progressive sealing that compensates for manufacturing variations and assembly tolerances.

Inventive Principle:
Principle #15Dynamics

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

Significantly reduces the time required for pipe connections and minimizes the occurrence of incomplete seals, ensuring a reliable and efficient fluid-tight connection across various environmental temperatures.

Implementation Method 1

Commonly used plastic material of the pipes have so-called shape memory, which may be easily deformed and will try to return to their original shape after the deformation

Methodology Applied
Scientific EffectShape memory: Shape Memory Polymer

Implementation Method 2

A sealing ring (3) is provided in the circumferential groove (13a, 13b,...) which sealing ring has an annular profile having an inner surface, being engageable with a connecting piece, and an outer surface, being engageable with the pipe

Methodology Applied
Scientific EffectMechanical sealing: Mechanical Fastener

Data Source

PatentEP4060212A1Pipe connection and method of producing pipe connection
Publication Date: 2022.09.21 UPONOR INNOVATION AB
  • EP4060212A1 patent drawingFigure 1~3
  • EP4060212A1 patent drawingFigure 4~6d
  • EP4060212A1 patent drawingFigure 7~10

AI summary

A pipe connection in the form of a shrinkage connection formed from a connecting piece (1) having a surface structure (11), and a pipe (2) having an inner diameter which is smaller than the outer diameter of the connecting piece (1), wherein the surface structure (11) of the connecting piece (1) comprises at least one radially projecting flange (12) and at least one circumferential groove (13a), the pipe (2) comprises a pipe end (21) which has been expanded in environmental temperature and connected to the connecting piece (1) by back-shrinkage. A sealing ring (3) is provided in the circumferential groove (13a), which sealing ring (3) has an annular profile having an inner surface, being engageable with a connecting piece (1) , and an outer surface, being engageable with the pipe (2), and the outer surface (32) comprises more than one annular ridge adjacent to each other in axial direction.