Heating device with plastic connectors

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Solution Overview

Problem

Existing heating appliances face issues with connecting plastic connectors to stationary pipes, as improper torque application during installation can damage the connectors and lead to leaks, especially when brass nipples are replaced with plastic ones.

Innovation Solution

A plastic connector with an external seal and groove for clamping on the hydraulic module side, featuring a molded flange with lugs, is used. A mating piece with corresponding grooves ensures a positive engagement, and the connector rotates when excessive torque is applied, indicating a secure connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If plastic connectors are used to replace brass nipples, then cost and weight are reduced, but the connectors become vulnerable to damage from excessive torque during installation

Engineering Contradiction:
Improvecost reductionVSAvoidconnector damage resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent converts the harmful effect of excessive torque into a beneficial self-limiting mechanism. When torque exceeds the predetermined limit, the weak point in the connector body yields and causes the connector to disengage from the counterpart, automatically preventing further damage. This transforms the vulnerability of plastic material into a protective feature that safeguards against installation errors.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If high torque is applied to ensure reliable connection, then connection security is improved, but plastic connectors may be damaged or destroyed

Engineering Contradiction:
Improveconnection securityVSAvoidconnector integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent incorporates a predetermined weak point designed with lower mechanical strength than other parts of the connector. This weak point acts as a pre-prepared safety mechanism that will fail first under excessive load, protecting the main body and threaded connection from damage. The weak point is intentionally designed to yield at a specific torque threshold, providing beforehand protection against over-tightening.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Ease of operation

If installers use improper torque application, then installation simplicity is maintained, but connection reliability deteriorates due to damage and leakage

Engineering Contradiction:
Improveinstallation simplicityVSAvoidconnection seal integrity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connector performs self-protection without requiring external monitoring or control systems. The predetermined weak point automatically detects when torque exceeds the safe limit through mechanical stress, and self-activates the disengagement mechanism. This eliminates the need for torque wrenches or trained installers, making the system self-regulating and foolproof against improper installation.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4534922B1Heating device with plastic connectors
Publication Date: 2026.04.08 VAILLANT GMBH(DE)
  • EP4534922B1 patent drawingFigure 1~2
  • EP4534922B1 patent drawingFigure 3~4
  • EP4534922B1 patent drawingFigure 5~6

AI summary

Heating device for space heating and/or hot water preparation, equipped with a mounting plate 50 for connecting the heating device to stationary domestic circuits, a hydraulic module comprising a plastic structural body with connecting channels for directing a heat transfer fluid between the hydraulic module and the stationary domestic circuits, each channel being equipped with a connecting connector 10.