Stepped Diaphragm Valve Structure for Stable Seal Pressure
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Solution Overview
Problem
Conventional diaphragm valves require complex and time-consuming two-stage tightening processes to ensure seal contact pressure, and excessive tightening torque can reduce the seal contact pressure due to cushion rubber extension, complicating the assembly and installation process.
Innovation Solution
A diaphragm valve design featuring a first portion with a curved plate shape and a second portion with a flat plate shape and smaller thickness, forming a step, where the sealing band is located on the second portion, allowing for higher tightening torque without cushion rubber extension, and a bonnet with an inner step to moderate pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If higher tightening torque is applied to the bolts and nuts, then the seal contact pressure between the diaphragm and valve body is improved, but the cushion rubber extends outward causing the reaction force to reduce and seal contact pressure to decrease
Solution Approach 1:
The diaphragm is designed with a step structure that creates different thickness regions: a first thickness in the central portion and a second, smaller thickness in the peripheral portion. This local differentiation allows the peripheral cushion rubber to be constrained by the step, preventing outward extension while maintaining adequate seal contact pressure in the sealing region.
Solution Approach 2:
The diaphragm's peripheral portion is segmented from the central portion by the step structure, creating distinct functional zones. The peripheral portion with reduced thickness acts as a separate element that confines the cushion rubber, while the central portion maintains the necessary thickness for sealing functionality.
2Reliability
If two-stage tightening process is implemented, then consistent seal contact pressure is achieved, but the assembling process becomes complex and installation efficiency is reduced
Solution Approach 1:
The step structure on the diaphragm automatically confines the cushion rubber in its proper position during a single tightening operation. This self-constraining mechanism eliminates the need for complex multi-stage tightening procedures, as the structure itself prevents the problems that would otherwise require staged assembly.
3Reliability
If two-stage tightening process is implemented, then seal contact pressure is maintained, but installation time is increased
Solution Approach 1:
The step structure is pre-formed on the diaphragm during manufacturing, creating a built-in constraint mechanism that prevents cushion rubber displacement from the outset. This preliminary structural preparation eliminates the need for time-consuming sequential tightening operations during installation.
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 consistent and efficient seal contact pressure without the need for two-stage tightening, maintaining seal integrity and reducing assembly complexity while allowing higher tightening torque without cushion rubber extension.
Implementation Method 1
The cushion rubber 20c is made of a material having an elastic modulus smaller than the sealing member 20s and thus causes the diaphragm 20a to closely contact the valve body 10
Implementation Method 2
excessive tightening torque of the bolts 30 and nuts 50 may cause the cushion rubber 20c to extend out, the reaction force F to be reduced
Data Source
AI summary
A diaphragm valve 100 includes a valve body 10, a diaphragm 20, a bonnet 40, and a compressor 60. The diaphragm 20 includes a first portion 21 and a second portion 22 surrounding the first portion 21, the first portion 21 having a first thickness T1 and a curved plate shape, the second portion 22 having a second thickness T2 smaller than the first thickness T1 to form a step and having a flat plate shape. The second portion 22 includes a sealing band SB surrounding the first portion 21. The bonnet 40 has an inner step 43 that contains a part of the first portion 21 and the inner step 43 has a depth G in the Z direction larger than a difference T1−T2 between the first and second thicknesses.