Diaphragm Seal Interference-Fit Assembly for Leak Prevention
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Solution Overview
Problem
Existing diaphragm seal technologies in the process industry face issues with leakage due to corrosion in welded metal diaphragms and susceptibility to leaks from mechanical bolting of polymer diaphragms, particularly under vibration and temperature changes, and are costly due to thermal bonding processes.
Innovation Solution
A process diaphragm seal is formed using an interference fit between a ring member and a seal body, where a temperature difference creates a dimensional gap allowing the diaphragm to be clamped securely, forming a seal between the diaphragm and the seal body, eliminating the need for costly welding or thermal bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is used to attach metal diaphragm to seal body, then hermetic sealing is achieved, but corrosion susceptibility increases causing leakage
Solution Approach 1:
The patent removes the welding process entirely from the attachment method. Instead of welding the diaphragm to the seal body, a retaining ring mechanically retains the diaphragm within the seal body cavity, extracting the harmful welding operation while maintaining sealing integrity through the retaining ring structure.
Solution Approach 2:
The retaining ring acts as an intermediary component between the diaphragm and the seal body. Rather than directly joining the diaphragm to the seal body through welding, the retaining ring mediates the connection, providing mechanical retention without creating corrosion-susceptible weld joints.
2Ease of manufacture
If mechanical bolting is used to attach polymer diaphragm to seal body, then attachment is achieved, but leakage occurs due to bolt loosening from vibration and temperature changes
Solution Approach 1:
The patent removes bolts and O-rings from the assembly. The retaining ring provides attachment without requiring fasteners that can loosen, eliminating the source of vibration-induced leakage while maintaining ease of manufacture through simplified component selection.
Solution Approach 2:
The retaining ring design accommodates dynamic conditions (vibration and temperature changes) by providing a flexible yet secure retention mechanism that maintains sealing pressure without the rigid, fixed-position bolts that prone to loosening under dynamic stress.
3Reliability
If thermal bonding with laser or chemical treatment is used to attach polymer diaphragm, then secure bonding is achieved, but manufacturing cost increases
Solution Approach 1:
The patent removes the expensive laser or chemical treatment processes entirely. The retaining ring provides secure attachment through simple mechanical retention, eliminating the need for costly surface treatments while maintaining bonding strength equivalent to or exceeding thermal bonding methods.
Solution Approach 2:
The retaining ring is a simple, inexpensive mechanical component that replaces expensive thermal bonding processes. While the retaining ring itself is a permanent component, it substitutes for expensive one-time thermal bonding operations, reducing overall manufacturing cost.
4Reliability
If welding is used to join diaphragm to seal body, then hermetic seal is formed, but complexity of assembly increases
Solution Approach 1:
The patent removes the complex welding operation from the assembly process. The retaining ring provides hermetic sealing through simple mechanical insertion and retention, eliminating the need for skilled welding operations, equipment, and post-weld inspection while maintaining seal integrity.
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 interference fit provides a secure and cost-effective sealing solution that prevents leakage and corrosion, simplifying assembly while maintaining the integrity of both metal and polymer diaphragms, enhancing the reliability of 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 ring member clamps the peripheral portion of the diaphragm to an outer wall of the flange through an interference fit between an inner wall of the ring member and the outer wall of the flange.
Data Source
AI summary
A process diaphragm seal includes a seal body, a diaphragm, and a ring member. The seal body includes a flange that surrounds a cavity. The diaphragm includes an active portion that extends over the cavity and a peripheral portion that surrounds the active portion. The ring member clamps the peripheral portion of the diaphragm to an outer wall of the flange through an interference fit between an inner wall of the ring member and the outer wall of the flange. A seal is formed between the peripheral portion of the diaphragm and the outer wall of the flange.