Threaded Pipe Coupling Assembly for Space-Limited Trenchless Installation

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Solution Overview

Problem

The existing pipe strings for trenchless installation require a large installation site due to the need for welding multiple pipes together, which is impractical in urban environments and results in space constraints and nuisance to the surroundings.

Innovation Solution

A pipe string system using a pipe coupling assembly with plastic circumferential walls and screw threads, allowing sequential installation of pipes within a pre-formed underground cavity, reducing the required installation site length and enabling easier assembly and higher tensile strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple pipes are welded together on the installation site to form a long pipe string, then the pipe string can be installed in a trenchless manner, but the installation site requires a large length (700-2000 meters) to accommodate the pipe string during construction

Engineering Contradiction:
Improvetrenchless installation capabilityVSAvoidinstallation site length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The pipe string is divided into modular sections with standardized couplings. Each pipe section can be independently installed and connected, eliminating the need to assemble the entire long pipe string at once. The coupling assembly includes a coupling body with internal threads and external screw threads that mate with pipe end sections, allowing incremental assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Pipe couplings are pre-installed on pipe end sections during manufacturing before the pipes are transported to the installation site. This preliminary action eliminates the need for on-site welding and assembly operations, allowing pipes to be quickly connected by simply screwing them into the pre-installed couplings.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If pipes are welded together on the installation site, then the pipe string can be formed for trenchless installation, but welding beads formed at the inside of the pipes during welding are nearly impossible to remove over distances of 200 meters or more

Engineering Contradiction:
Improvepipe string formationVSAvoidwelding bead removal
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The welding process and weld seams are completely extracted from the pipe string construction process. Instead of welding pipes together on-site, the invention uses mechanical coupling assemblies with screw threads that connect pipe end sections without any welding, thereby eliminating the creation of internal welding beads that would need to be removed.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The thermal welding process is replaced with a mechanical connection system. The coupling assembly uses external screw threads on the coupling body that mate with internal screw threads in the pipe end sections, creating a secure mechanical connection without any heat application or weld bead formation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If a large installation site is used to accommodate the pipe string during construction, then the pipe string can be assembled, but this results in nuisance to the surroundings and lack of space in urban environments

Engineering Contradiction:
Improvepipe string assemblyVSAvoidnuisance to surroundings
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

All complex assembly operations including coupling installation and pipe joining are performed before transportation to the installation site. Pipes arrive with couplings already attached, and connection is achieved by simple screwing operations that require minimal space and generate no nuisance to surrounding areas.

Inventive Principle:
Principle #10Preliminary action

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 allows for efficient trenchless installation with reduced site requirements, minimizing environmental impact and ensuring the pipe string can withstand significant tensile forces during jacking or pulling.

Implementation Method 1

the first pipe coupling comprises a plastic first circumferential wall that is provided with a first external screw tread, and wherein the second pipe coupling comprises a plastic second circumferential wall that is provided with a second external screw thread

Methodology Applied
Scientific EffectScrew thread: Screw

Implementation Method 2

the coupling sleeve comprises a third circumferential wall that is provided with a first internal screw thread that mates with the first external screw thread of the first pipe coupling, and a second internal screw thread that mates with the second external screw thread of the second pipe coupling

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4083485A1Pipe string for trenchless installation
Publication Date: 2022.11.02 DYKA
  • EP4083485A1 patent drawingFigure 1A~1B
  • EP4083485A1 patent drawingFigure 2A
  • EP4083485A1 patent drawingFigure 2B

AI summary

The invention relates to a pipe string for trenchless installation, comprising a first pipe and a second pipe which are coupled to each other by means of a pipe coupling assembly, wherein the first pipe comprises a first pipe end section that is connected with a first pipe coupling of the pipe coupling assembly, and wherein the second pipe comprises a second pipe end section that is connected with a second pipe coupling of the pipe coupling assembly, wherein the first pipe coupling comprises a plastic first circumferential wall that is provided with a first external screw tread, and wherein the second pipe coupling comprises a plastic second circumferential wall that is provided with a second external screw thread, wherein the pipe coupling assembly comprises a coupling sleeve for coupling the first pipe coupling with the second pipe coupling, wherein the coupling sleeve comprises a third circumferential wall that is provided with a first internal screw thread that mates with the first external screw thread of the first pipe coupling, and a second internal screw thread that mates with the second external screw thread of the second pipe coupling, and wherein the first pipe coupling has a first length and the coupling sleeve has a second length, wherein the first length is equal to or larger than the second length.