Drill Saddle Heating Element Geometry for Leak-Free Pipe Welding

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Solution Overview

Problem

Existing tapping saddle designs for connecting plastic pipes suffer from a cold zone at the inner diameter transition, leading to weak points and potential detachment under pressure, and previous solutions either cause wire discharge or melt issues or fail to optimize welding, resulting in leaks.

Innovation Solution

A heating element geometry with meandering loops protruding into the inner diameter of the socket, arranged concentrically to the central axis, ensures the welding area extends to the drill hole, eliminating the cold zone and preventing wire or melt escape, using a carrier material like polyethylene with a twisted wire winding that is sewn or pressed onto the saddle piece.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional heating element geometries are used, then manufacturing is simple, but the welding area does not extend to the drill hole resulting in leaks

Engineering Contradiction:
Improveheating element fabricationVSAvoidweld quality
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The heating element is formed into meandering loops with concentric circular geometry that extend into the inner diameter region. This curved, loop-based configuration allows the welding area to naturally extend to the drill hole area, ensuring complete coverage and leak-free welding, while the loop structure can be manufactured using standard winding techniques.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 configuration ensures a strong, leak-free connection by eliminating the cold zone and preventing the saddle piece from detaching from the main pipe, while allowing the wire to expand during heating, thus maintaining a secure bond without wire displacement.

Implementation Method 1

a heating element geometry preferably made of wire being arranged on the inner diameter of the saddle piece, which serves to weld the tapping saddle to the main pipe

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3392025B1Heating element geometry for use in a drill saddle
Publication Date: 2022.06.22 GEORG FISCHER WAVIN AG
  • EP3392025B1 patent drawingFigure 1
  • EP3392025B1 patent drawingFigure 2
  • EP3392025B1 patent drawingFigure 3

AI summary

Heating element geometry (6) for use in a tapping saddle (1), method for tapping and tapping saddle (1) for a medium-carrying main pipe (7) made of plastic comprising a nozzle (2), wherein the nozzle (2) has a central axis (11), a saddle piece (4), wherein a heating element geometry (6) is arranged on the inner diameter (5) of the saddle piece (4), which serves to weld the tapping saddle (1) to the outer circumference of the main pipe, wherein the heating element geometry (6) has a winding (8) preferably made of wire, wherein the winding (8) has an outer winding area (10) and an inner winding area (9), wherein the winding of the inner winding area (9) runs in meandering loops (12) along a circle concentric to the central axis (11) of the nozzle (2).