Flow Control Valve Elastomeric Seal for Pressure-Driven Sealing

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Solution Overview

Problem

Conventional flow control valves face issues with high costs, premature failure, and increased operating torque due to the use of metal springs and clamps, as well as reliability problems with o-rings relying on interference fits, which lead to leakage and maintenance challenges.

Innovation Solution

A flow control valve utilizing elastomeric seals with convolutions that expand or contract based on pressure differentials to maintain a seal between the valve's housing and rotatable shaft, eliminating the need for metal components and interference fits, thereby reducing leakage and operating torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal springs and clamps are used to maintain seal contact, then sealing reliability is improved, but cost increases and operating torque increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes metal springs and clamps from the sealing system, extracting the problematic components that caused high cost and high operating torque. The sealing function is maintained through the elastomeric material's inherent properties rather than mechanical biasing devices.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical spring-clamp system with an elastomeric seal that uses material elasticity and pressure differential to maintain sealing contact. This substitution eliminates the need for complex mechanical biasing devices while maintaining sealing reliability.

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

2Reliability

If metal springs and clamps are used to maintain seal contact, then sealing reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent employs an elastomeric seal that can be manufactured at lower cost compared to metal springs and clamps. The elastomeric material allows for simpler, more economical manufacturing processes while maintaining adequate sealing performance throughout the valve's service life.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the material parameter from metal to elastomer, fundamentally altering the sealing mechanism from mechanical biasing to elastic deformation and pressure-driven contact. This parameter change enables lower manufacturing cost while maintaining sealing reliability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If o-rings rely on interference fit to prevent leakage, then sealing is achieved, but high compressive loads make the seal more prone to failure

Engineering Contradiction:
Improvesealing effectivenessVSAvoidseal strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent creates a dynamic sealing system where the elastomeric seal responds to pressure differentials by expanding or contracting to maintain optimal sealing contact. This dynamic adjustment allows the seal to adapt to varying operating conditions without requiring high static compressive loads, thereby preventing seal failure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastomeric seal serves itself by using the process fluid's pressure differential to generate the sealing force. The higher pressure fluid automatically pushes the seal against the lower pressure side, eliminating the need for external biasing mechanisms or high compressive pre-loads that would weaken the seal.

Inventive Principle:
Principle #25Self-service

4Reliability

If springs and clamps are used to bias seal ends, then leakage is prevented, but additional assembly steps are required

Engineering Contradiction:
Improveleakage preventionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the sealing function and the biasing function into a single elastomeric component. The seal body itself provides both the sealing contact surface and the elastic response to pressure differentials, eliminating the need for separate springs and clamps. This integration simplifies assembly to a single step while maintaining leakage prevention.

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

The elastomeric seal provides leak-proof sealing, low operating torque, and reduced costs compared to traditional solutions, while minimizing wear and ensuring reliable valve operation.

Implementation Method 1

the convolution (42) expands or contracts due to a pressure differential across the seal wall (56)

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

The elastomeric seal provides leak-proof sealing... utilizing one or more convolutions (42) that expand or contract due to a pressure differential

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2909514B1Valve system and method
Publication Date: 2018.02.21 ROBERTSHAW CONTROLS CO
  • EP2909514B1 patent drawingFigure 1~2
  • EP2909514B1 patent drawingFigure 3
  • EP2909514B1 patent drawingFigure 4~5

AI summary

A flow control valve includes a housing forming internal passages in fluid communication with a port of the valve, and an internal cavity. A flow direction block is disposed in the internal cavity and forms at least one flow passage extending through a portion thereof. The flow direction block is moveable within the internal cavity such that the free ends of the least one flow passage can be selectively aligned with a respective internal passage along an interface as the flow direction block is moved from a first, closed position to a second, open position. A seal is disposed around each interface and includes an internal face, which presses against an outer surface of the flow direction block, and an external face, which presses against the housing. Sealing function is improved, at least in part, by a differential fluid pressure that acts on the seal.