Valve with Segmented Lip and Solid Seals for Backflow Prevention

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Solution Overview

Problem

Existing valves with non-return functions face challenges in achieving high sensitivity and effective backflow prevention, especially under small pressure differences, with response sensitivity often being inadequate and backflow prevention insufficient.

Innovation Solution

The valve design incorporates a solid seal and a lip seal with a stop mechanism, where the solid seal provides full sealing and the lip seal ensures high sensitivity with a small pressure difference requirement, and the stop protects both seals from excessive deformation under high pressure, allowing for optimal force distribution and preventing damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a compression spring is used to press the valve disk into the valve seat for backflow prevention, then backflow prevention is achieved, but the response sensitivity is reduced and the valve requires excessive pressure to open

Engineering Contradiction:
Improvebackflow preventionVSAvoidresponse sensitivity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The sealing function is segmented into two distinct sealing elements: a lip seal for backflow prevention and a solid seal for full sealing. This segmentation allows each seal to be optimized for its specific function, with the lip seal providing sensitive backflow prevention and the solid seal ensuring complete sealing without requiring excessive spring force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sealing mechanisms are applied to different regions of the valve disk. The lip seal is positioned to contact the valve seat at a specific location for backflow prevention, while the solid seal provides additional sealing contact. This local differentiation of sealing quality enables the valve to achieve both high sensitivity and reliable backflow prevention.

Inventive Principle:
Principle #3Local quality

2Reliability

If the spring force is increased to improve backflow prevention, then sealing reliability is improved, but the valve disk and seal are subjected to excessive stress and potential damage

Engineering Contradiction:
Improvesealing reliabilityVSAvoidseal durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A stop mechanism is introduced that limits the maximum closing force applied to the valve disk. This stop prevents the compression spring from exerting excessive force on the seals, thereby cushioning the seals against damage while still maintaining sufficient sealing pressure for reliable backflow prevention.

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

3Device complexity

If a single seal is used for both backflow prevention and full sealing, then the device complexity is reduced, but the seal is subjected to excessive stress and cannot achieve both high sensitivity and complete sealing

Engineering Contradiction:
Improveseal structureVSAvoidsealing performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sealing system is divided into two separate seals: a lip seal for backflow prevention and a solid seal for full sealing. This segmentation allows each seal to be optimized for its specific function without compromising the other, achieving both high sensitivity and complete sealing reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sealing mechanisms are applied to different regions of the valve disk. The lip seal is positioned to contact the valve seat at a specific location for backflow prevention, while the solid seal provides additional sealing contact. This local differentiation of sealing quality enables the valve to achieve both high sensitivity and reliable backflow prevention.

Inventive Principle:
Principle #3Local quality

4Ease of operation

If the valve disk is made freely movable in the guide bushing for sensitivity, then response sensitivity is improved, but the valve cannot generate sufficient closing force under high back pressure

Engineering Contradiction:
Improveresponse sensitivityVSAvoidclosing force
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The valve combines two sealing mechanisms (lip seal and solid seal) that work together to provide both sensitivity and closing force. The lip seal provides sensitive response to back pressure, while the solid seal ensures complete sealing and generates sufficient closing force under high back pressure conditions.

Inventive Principle:
Principle #5Merging (Combining)

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 design enables reliable flow even with small pressure differences, effective backflow prevention, and high sensitivity, while protecting the seals from damage, ensuring a durable and efficient valve operation.

Implementation Method 1

the valve disk or the spindle is not permanently connected to an adjusting wheel, but can be moved freely from the adjusting wheel in a guide bushing, the guide bushing in turn being firmly connected to the adjusting wheel. When the valve is closed, the adjusting wheel presses the valve disk into the valve seat via the guide bush and the spindle. In the open valve position, the valve disk is pressed into the valve seat by an elastic element, usually a compression spring.

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

However, if the spring pressure is overcome by the pressure of a fluid, the valve is opened and the fluid can flow through the valve in a desired direction.

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 3

A flow of the fluid in the opposite direction is made impossible by the fact that the valve disk is pressed into the valve seat by the compression spring (and additionally by the fluid pressure) in the event of counter-pressure.

Methodology Applied
Scientific EffectCompression force: Compression

Data Source

PatentEP2369207B1Valve
Publication Date: 2014.08.27 R NUSSBAUM & CO
  • EP2369207B1 patent drawingFigure 1a
  • EP2369207B1 patent drawingFigure 1b
  • EP2369207B1 patent drawingFigure 2a~2d

AI summary

The valve has a valve plate (4) with a solid gasket (12) for full sealing and a lip seal (11) for preventing a reverse flow. A stop (4a) is formed for the valve plate for load removal of the solid gasket. The solid gasket and the lip seal are formed at an annular seal (10). The annular seal is tapered between the lip seal and the solid gasket. The solid gasket or the lip seal is made of a rubber material, particular ethyl-probylen-diene rubber or hydrogenated acrylonitrile-butadiene rubber. The valve plate is made of copper alloy which contains silicon and zinc as alloying components.