Polymer Bellows Spring Sealing in Check Valves

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Solution Overview

Problem

Conventional polymer springs in check valves used in chemical delivery processes, such as semiconductor fabrication, suffer from leakage, improper sealing, misalignment, and low flow coefficients due to inconsistencies and design flaws.

Innovation Solution

A polymeric bellows spring formed from high-purity fluoropolymers like PTFE, with a single-piece construction and integrated sealing lip and guide, which enhances repeatability, reduces leakage, and stabilizes the spring within the check valve, ensuring proper sealing and efficient fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional polymer springs are used in check valves, then the check valve can be constructed without metal components, but the springs exhibit leakage, failure to properly seal, misalignment, and low flow coefficient

Engineering Contradiction:
Improvecompatibility with corrosive chemicalsVSAvoidsealing performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The spring is constructed from high-purity fluoropolymer materials (PTFE, FEP, PFA, ETFE) which combine chemical inertness with enhanced mechanical properties. This composite polymeric structure provides both corrosion resistance and reliable sealing performance, eliminating the need for metal components while maintaining sealing integrity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the material parameters by using high-purity fluoropolymers with specific molecular structures that provide both chemical resistance and controlled elasticity. The material purity and molecular weight distribution are optimized to achieve consistent spring behavior and reliable sealing without metal components.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If conventional polymer springs are used, then the check valve can operate in chemical delivery processes, but the springs show inconsistencies leading to leakage and improper sealing

Engineering Contradiction:
Improvechemical process compatibilityVSAvoidspring consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

High-purity fluoropolymer materials are used to create springs with consistent molecular structure and properties. The uniformity of these engineered polymeric materials ensures repeatable spring behavior across production batches, eliminating the inconsistencies that plague conventional polymer springs.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention optimizes material parameters including purity levels, molecular weight, and crystallinity of the fluoropolymer to achieve consistent spring characteristics. These controlled material parameters ensure uniform performance across all springs produced for chemical delivery applications.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If a polymeric spring is used instead of metal, then corrosion resistance is improved, but the spring exhibits misalignment and low flow coefficient

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidflow coefficient
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The spring geometry parameters are optimized to maximize flow coefficient while maintaining structural integrity. The bellows configuration with specific dimensions, wall thickness, and expansion characteristics is engineered to minimize flow restriction. Material properties such as elasticity and density are selected to achieve the optimal balance between corrosion resistance and fluid flow performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The bellows spring is designed with dynamic expansion and contraction capabilities that optimize flow characteristics during operation. The spring adapts its geometry in response to pressure changes, maintaining high flow coefficient while providing the necessary sealing force, thus resolving the conflict between corrosion resistance and productivity.

Inventive Principle:
Principle #15Dynamics

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 polymeric bellows spring improves sealing performance, decreases leakage, and increases the check valve's operational life to about 250,000 cycles with a higher flow coefficient, maintaining integrity under corrosive conditions and varying pressures.

Implementation Method 1

The spring includes a bellows between the proximal and distal ends. The bellows are capable of deforming in response to a change in an environmental condition.

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP2867565B1Polymer bellows spring
Publication Date: 2019.05.08 SAINT GOBAIN PERFORMANCE PLASTICS CORP
  • EP2867565B1 patent drawingFigure 1
  • EP2867565B1 patent drawingFigure 2A~2B

AI summary

A spring for use in a check valve is formed from a single piece of a polymeric material and includes a proximal end, a distal end, and a body positioned between the proximal end and the distal end. The body includes a wall, a proximal opening on the wall and a distal opening on the wall, and a bellows between the proximal opening and the distal opening. Further included is a process of forming the spring.