Branch Pipe Connector Sealing for Damaged Mortar-Lined Main Pipes

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Solution Overview

Problem

Existing connection devices fail to provide sufficient sealing when connecting side pipes to main pipes with damaged inner surfaces, particularly in cast iron pipes lined with mortar, due to damage during drilling and the risk of mortar detachment, leading to sealant migration and compromised sealing.

Innovation Solution

A connecting device with a circumferential front sealing lip that divides the receiving space into two sub-spaces, allowing controlled introduction of sealant, combined with a rear sealing lip to ensure uniform distribution and additional sealing levels, reducing the volume of sealant needed and preventing corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a connection hole is drilled into the main pipe to connect a branch pipe, then the branch connection is enabled, but damage to the mortar lining occurs leading to insufficient sealing

Engineering Contradiction:
Improvebranch connection capabilityVSAvoidsealing effect
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The receiving space is divided into two separate sub-spaces by the front sealing lip: a first sub-space that is sealed off from the main pipe lining damage, and a second sub-space that contacts the potentially damaged lining. This segmentation prevents sealant migration paths while maintaining branch connection capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The front sealing lip acts as an intermediary element between the injection channel and the main pipe lining. It creates a controlled interface that prevents direct contact between the sealant and damaged mortar areas, ensuring reliable sealing despite lining damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If the receiving space volume is reduced to minimize sealant usage, then material cost decreases, but sealing coverage may be insufficient

Engineering Contradiction:
Improvesealant consumptionVSAvoidsealing coverage
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

By segmenting the receiving space into two sub-spaces, the patent reduces the total volume of sealant needed compared to filling the entire receiving space, while ensuring adequate sealing coverage in both sub-spaces through controlled sealant introduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first sub-space is designed with specific volume characteristics to contain the sealant introduction process, while the second sub-space is configured to provide the necessary sealing coverage against the main pipe lining, optimizing both material usage and sealing effectiveness locally.

Inventive Principle:
Principle #3Local quality

3Strength

If additional holes are drilled for fasteners in addition to the connection hole, then the connection device can be securely fastened, but the risk of extensive mortar lining damage increases significantly

Engineering Contradiction:
Improvefastening securityVSAvoidmortar lining damage
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The collar serves multiple functions: it provides structural support for the connection device, enables fastening through integrated features, and creates the receiving space for sealant. This multi-functionality reduces the need for additional holes that would further damage the mortar lining.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The front sealing lip and collar structure act as intermediaries that distribute fastening forces away from the mortar lining, allowing secure attachment without requiring additional holes through the damaged lining areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Achieves reliable sealing even with extensive damage, minimizing sealant usage, preventing corrosion, and eliminating the need for resource-intensive corrosion protection treatments.

Implementation Method 1

the sealant is introduced into the first sub-space, specifically through an injection channel according to the proposal

Methodology Applied
Scientific EffectFluid injection and flow:

Implementation Method 2

a front sealing lip provided on the seal of the connection device, which extends essentially radially outward and which advantageously separates the receiving space, or at least reduces the volume of the receiving space

Methodology Applied
Scientific EffectPhysical barrier separation:

Implementation Method 3

a collar 7 which is formed onto a base body 8 of the connecting device 5 and rests against the lining 2 inside the main pipe 1

Methodology Applied
Scientific EffectMechanical contact and support:

Implementation Method 4

The high sealing performance of the proposed connection device makes it possible to generally dispense with such corrosion protection treatment, thus saving resources. The airtight sealant prevents the penetration of corrosive media.

Methodology Applied
Scientific EffectCorrosion protection through sealing:

Data Source

PatentEP4279676B1Connection device with improved sealing effect in the interior of a damaged main pipe
Publication Date: 2025.07.02 FUNKE KUNSTSTOFFE GMBH
  • EP4279676B1 patent drawingFigure 1
  • EP4279676B1 patent drawingFigure 2~3

AI summary

In a connection device (5) for connecting a main tube (1) provided with a connection bore (4) to a side tube (3), comprising a first end (19) that can be inserted into the main tube (1) through the connection bore (4), wherein the connection device (5) has a collar (7) in the region of its first end (19) that can be applied to the inside of the main tube (1) and extends radially outwards, comprising a second end (20) that can be connected to the side tube (3), comprising a base body (8) designed as a tube section, comprising an elastic seal (11) on the collar (7), comprising a spacer ring (10) surrounding the base body (8) outside the main tube (1), which is shaped such that a receiving space (16) that can be filled with a flowable sealant (17) is created between the spacer ring (10) on the one hand and the base body (8) and the main tube (1) on the other hand, and comprising a clamping ring (9), it is proposed that the seal (11) a circumferential,The front sealing lip (15) extends substantially in a radial direction outwards, and the front sealing lip (15) separates a first sub-space (25) from the receiving space (16), which adjoins the spacer ring (10), and the spacer ring (10) has an injection channel which opens into the first sub-space (25).