Interference-Fit Diaphragm Seal for Leak-Resistant Process Isolation
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Solution Overview
Problem
Existing diaphragm seal technologies, such as welding and thermal bonding, are prone to corrosion and leakage issues, particularly due to vibration and temperature changes, and are costly to implement.
Innovation Solution
A process diaphragm seal is formed using an interference fit between a ring member and a seal body, where a temperature difference is created to establish a secure clamp between the diaphragm and the flange, forming a reliable seal without the need for expensive equipment or processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is used to attach the diaphragm to the seal body, then hermetic joining is achieved, but corrosion susceptibility increases due to welds and heat-affected zones
Solution Approach 1:
The patent replaces the welding process (thermal/chemical joining) with a mechanical interference fit system. A ring member is inserted into a tapered bore of the seal body, creating a mechanical clamp that secures the diaphragm without heat-affected zones or corrosive welds. This mechanical substitution eliminates the harmful chemical bonds while maintaining seal integrity through physical clamping forces.
Solution Approach 2:
The ring member serves as an intermediary component between the diaphragm and the seal body. Rather than directly welding the diaphragm to the seal body, the ring member mediates the connection through interference fit, providing a corrosion-resistant intermediate layer that maintains the hermetic seal while protecting both components from direct corrosive exposure at the joint.
2Ease of manufacture
If mechanical bolting is used to attach the polymer diaphragm, then assembly is simplified, but leakage risk increases due to bolt loosening from vibration and temperature changes
Solution Approach 1:
The patent replaces the bolted mechanical connection with a interference fit mechanism. The ring member's tapered geometry creates a self-tightening effect where the clamping force is distributed continuously around the diaphragm perimeter rather than at discrete bolt points. This eliminates the loosening issue inherent in bolted connections while maintaining assembly simplicity through a single-piece ring component.
Solution Approach 2:
The interference fit system provides dynamic adaptability to temperature and vibration changes. As temperature fluctuates, the thermal expansion and contraction of the ring member and seal body maintain the interference pressure. The continuous contact surface allows the seal to dynamically adjust to vibrational forces without the discrete stress concentration points that cause bolt loosening.
3Strength
If thermal bonding with laser or chemical treatment is used to attach the polymer diaphragm, then bond strength is improved, but manufacturing cost increases due to expensive equipment and processes
Solution Approach 1:
The patent replaces expensive thermal bonding processes (laser treatment, chemical etching) with a purely mechanical interference fit system. The ring member's tapered geometry and elastic deformation provide sufficient bond strength through physical interlocking and friction forces, eliminating the need for costly laser equipment or chemical treatment facilities while achieving equivalent or superior attachment strength.
Solution Approach 2:
The patent changes the attachment mechanism from thermal/chemical parameters to mechanical parameters. Instead of controlling laser power, treatment time, or chemical concentration, the system controls mechanical interference fit parameters such as ring member tolerance, bore taper angle, and material elastic modulus. This parameter transformation enables standard manufacturing processes to achieve the same bond strength at lower cost.
4Ease of operation
If bolts are used to clamp the diaphragm, then assembly is straightforward, but device complexity increases and leakage risk increases due to unscrewing from vibration
Solution Approach 1:
The patent extracts the fastening function from the clamp assembly by integrating the clamping mechanism into a single ring member component. Rather than using multiple bolts, washers, and nuts that require assembly and disassembly, the interference fit ring provides inherent clamping through its tapered geometry, eliminating the need for separate fastening hardware and reducing overall assembly complexity.
Solution Approach 2:
The patent merges the clamping function and the sealing function into a single integrated ring member. The same interference fit mechanism that provides clamping force also creates the seal between the diaphragm and seal body, eliminating the need for separate sealing elements and reducing the number of assembly steps while maintaining ease of operation.
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 solution provides a secure, leak-resistant, and cost-effective attachment method for both metal and polymer diaphragms, eliminating corrosion and assembly complexity issues while ensuring reliable fluid isolation in industrial process control systems.
Implementation Method 1
a temperature difference is created between a flange of a seal body and a ring member. A dimensional gap is created between an interior diameter of an inner wall of the ring member and an exterior diameter of an outer wall of the flange in response to the creation of the temperature difference.
Implementation Method 2
The peripheral portion of the diaphragm is clamped between the inner wall of the ring member and the outer wall of the flange in response to the equalization of the temperatures.
Data Source
Figure 1
Figure 2~3
Figure 4~5A
AI summary
A process diaphragm seal (102) includes a seal body (110), a diaphragm (108) and a ring member (130). The seal body (110) includes a flange (132) that surrounds a cavity (134). The diaphragm (108) includes an active portion (136) that extends over the cavity (134) and a peripheral portion (138) that surrounds the active portion (136). The ring member (130) clamps the peripheral portion (138) of the diaphragm (108) to an outer wall (143) of the flange (132) through an interference fit (128) between an inner wall (142) of the ring member (130) and the outer wall (143) of the flange (132). A seal is formed between the peripheral portion (138) of the diaphragm (108) and the outer wall (143) of the flange (132).