Composite Diaphragm Valve for Leak Prevention

Solution Overview

Problem

Diaphragm valves face issues with membrane rupture due to excessive tightening during assembly, leading to leaks and reduced service life, especially in high-pressure applications, and require precise manufacturing to prevent over-tightening.

Innovation Solution

A composite membrane design featuring an inner elastomeric area with a fabric insert and an outer thermoplastic or duroplastic area of higher hardness, which acts as a support to distribute forces and prevent excessive compression, combined with a spring-loaded pin to prevent incorrect assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the diaphragm is clamped tightly between housing parts to ensure sealing, then sealing performance is improved, but the diaphragm material in the rim bead is displaced radially inwards causing stress and potential rupture

Engineering Contradiction:

Improvesealing performanceVSAvoiddiaphragm integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The diaphragm is designed with a two-region structure: an inner region made of elastomeric material for flexibility and sealing, and an outer region made of harder material for structural support and force distribution. This local differentiation allows the outer region to resist radial displacement during clamping while the inner region maintains sealing capability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The diaphragm combines two different materials with complementary properties: elastomeric material (softer, more flexible) for the inner sealing region and harder material for the outer structural region. This composite construction enables the diaphragm to simultaneously achieve good sealability and resistance to clamping-induced stresses.

Inventive Principle:

Principle #40Composite materials

2Force

If the screw connection is tightened beyond the specified torque to ensure proper clamping, then clamping force is improved, but material accumulation occurs at the constriction causing stresses and potential diaphragm rupture

Engineering Contradiction:

Improveclamping forceVSAvoiddiaphragm integrity

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The invention changes the physical parameter of the diaphragm material in the outer region by using harder material with higher resistance to deformation. This allows the diaphragm to withstand higher clamping forces without experiencing the material displacement and stress accumulation that would occur with softer, uniform material throughout.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the diaphragm is made entirely of soft elastomeric material to ensure flexibility and sealing, then sealing capability is improved, but the diaphragm becomes susceptible to deformation and rupture under excessive tightening

Engineering Contradiction:

Improvesealing capabilityVSAvoidassembly tolerance

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The diaphragm is designed with a two-region structure: an inner region made of elastomeric material for flexibility and sealing, and an outer region made of harder material for structural support and force distribution. This local differentiation allows the outer region to resist radial displacement during clamping while the inner region maintains sealing capability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The diaphragm combines two different materials with complementary properties: elastomeric material (softer, more flexible) for the inner sealing region and harder material for the outer structural region. This composite construction enables the diaphragm to simultaneously achieve good sealability and resistance to clamping-induced stresses.

Inventive Principle:

Principle #40Composite materials

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 composite membrane design enhances the valve's reliability, prevents membrane rupture, ensures high tightness, and extends service life while allowing for easy identification and assembly, meeting stringent sterile use requirements.

Implementation Method 1

The spring-loaded pin is designed to exert a force that prevents incorrect assembly

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

A composite membrane design featuring an inner elastomeric area with a fabric insert and an outer thermoplastic or duroplastic area of higher hardness, which acts as a support to distribute forces

Methodology Applied

Scientific EffectStress distribution:

Data Source

PatentEP3324084B1Membrane valve

Publication Date: 2020.11.18 SISTO ARMATUREN

Figure 1
Figure 2
Figure 3

AI summary

Publication with Fig. 3. The invention relates to a diaphragm valve with a diaphragm (5) that seals between chambers. The diaphragm (5) is arranged between at least two housing parts (1, 7). The diaphragm (5) has an inner region (17) to which an outer region (18) adjoins. The outer region (18) has a higher hardness than the inner region (17).