Restrained Plastic Pipe Joint With Metal Locking Segments

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Solution Overview

Problem

Rieber gaskets in plastic pipes offer little resistance to axial separation under fluid pressurization, necessitating the use of costly restraint harnesses to prevent pipe joint separation.

Innovation Solution

Replacing Rieber gaskets with gaskets containing metal locking segments that deform and wedge into the spigot end upon pressurization, forming a seal and preventing separation without damaging the pipes, and configuring the segments to prevent over-translation and radial forces on the bell end.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If Rieber gaskets are used in plastic pipes, then the gasket can be locked into place within the annular groove during belling, but the gasket offers very little resistance to axial separation under fluid pressurization

Engineering Contradiction:

Improvegasket installation during bellingVSAvoidresistance to axial separation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The gasket is segmented into a modular structure consisting of a continuous steel band with embedded elastomeric segments. Each elastomeric segment contains metal reinforcement and provides sealing functionality, while the steel band provides structural integrity and axial resistance. This segmentation allows the gasket to perform multiple functions simultaneously.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The gasket employs composite construction by bonding elastomeric material to a steel band, creating a hybrid structure that combines the sealing properties of elastomers with the strength and axial resistance of metal. This composite approach resolves the contradiction between ease of installation and resistance to axial separation.

Inventive Principle:

Principle #40Composite materials

2Reliability

If restraint harnesses are used to prevent axial separation of pipe joints, then separation is prevented, but the cost and installation time increase significantly

Engineering Contradiction:

Improveprevention of axial separationVSAvoidadditional restraint components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sealing function and axial restraint function are merged into a single integrated gasket component. The elastomeric segments provide sealing while the steel band with embedded reinforcement provides axial resistance, eliminating the need for separate restraint harnesses and reducing overall system complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The gasket is designed as a multi-functional component that simultaneously performs sealing, axial restraint, and structural support functions. This universal design replaces multiple specialized components (sealing gasket plus restraint harness) with a single integrated solution.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 effectively prevents axial separation of plastic pipes under pressurization without the need for additional restraint harnesses, maintaining pipe integrity and reducing installation costs by using metal locking segments that form a secure seal within the annular groove.

Implementation Method 1

metal locking segments that deform and wedge into the spigot end upon pressurization

Methodology Applied

Scientific EffectWedge: Wedge

Implementation Method 2

metal locking segments that deform and wedge into the spigot end

Methodology Applied

Scientific EffectDeformation: Deformation

Implementation Method 3

elastomeric sealing ring

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 4

causing the metal ring to deform and become dislodged from the annular groove

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentUS10436359B2Restrained plastic pipe joint and method of making same

Publication Date: 2019.10.08 HULTEC ACQUISITION LLC

AI summary

A gasket for preventing the separation of a pipe joint formed between plastic pipes such as pipes manufactured from PVC. The invention provides a restrained pipe joint including a first pipe including a bell with a spigot entryway and a substantially V-shaped annular groove. The annular groove includes a front radial wall and a rear radial wall and a gasket seated in the annular groove. The gasket includes an inner radial face, an opening defined by the inner radial face and an outer radial face with a front radial section located adjacent to the front radial wall of the annular groove and a rear radial section located adjacent to the rear radial wall of the annular groove. A plurality of restraining segments is at least partially embedded in the gasket, each restraining segment including a toothed inner face and a smooth, sliding front radial face arranged to slide against the front radial wall of the annular groove and facilitate wedging of the segment between the plastic pipes.