Valve Seal Compression via Welded Holding Ring
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Solution Overview
Problem
Conventional valves for high-purity and ultra-high-purity gas applications suffer from seal abrasion, dead spots, and potential leakage due to the presence of teeth or screwing mechanisms, which compromise gas-tightness and reliability.
Innovation Solution
A valve design featuring a polymeric annular seal with an outer annular shoulder and a holding ring with a radial lip and annular bead, fixed by a circumferential gas-tight weld, ensuring controlled compression and eliminating dead spaces, along with a secondary metallic seal for added reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If teeth are used in the holding ring to retain the seal, then the seal is retained securely, but the seal undergoes abrasion generating particles and dead spots
Solution Approach 1:
The invention removes the harmful teeth structure from the holding ring, extracting the source of seal abrasion. Instead of using teeth to retain the seal, the patent uses a smooth holding ring with an annular groove that contains the seal through geometric confinement and compression, eliminating particle generation while maintaining secure seal retention.
Solution Approach 2:
The patent employs a flexible polymeric seal that can be compressed and deformed to fit tightly within the annular groove defined by the holding ring and lower stem. This flexible seal design allows for secure retention through compression rather than mechanical interlocking with teeth, avoiding abrasion while maintaining reliability.
2Reliability
If the holding ring is fastened by screwing to the lower stem, then the assembly is secured, but gas-tightness cannot be guaranteed at the threads and particles are generated
Solution Approach 1:
The invention removes the threaded connection between the holding ring and lower stem, extracting the source of potential leakage and particle generation. Instead of screwing, the patent uses a press-fit or interference fit arrangement where the holding ring is retained by the annular groove geometry and compression of the seal, ensuring gas-tightness without threaded interfaces.
Solution Approach 2:
The patent replaces the threaded mechanical connection with a compression-based retention system. The holding ring is secured through the compression of the polymeric seal within the annular groove, substituting the threaded fastening mechanism with a seal-compression mechanism that ensures gas-tightness without creating leakage paths or generating particles.
3Reliability
If the holding ring is screwed onto the lower stem, then the assembly is secured, but torsional forces deform the seal
Solution Approach 1:
The invention removes the screwing operation that applies torsional forces to the seal. The holding ring is installed and secured without rotational tightening, using instead a press-fit or compression-based retention method that applies only axial force, preventing seal deformation while maintaining assembly security.
Solution Approach 2:
The patent changes the installation parameters from rotational (screwing) to axial (pressing). The holding ring is installed by applying axial compression force rather than rotational torque, fundamentally changing the force application mode to prevent torsional deformation of the seal while achieving secure assembly retention.
4Reliability
If crimping is used to assemble the holding ring, then the assembly is secured, but gas-tightness and precise seal tenure cannot be guaranteed
Solution Approach 1:
The patent replaces the crimping mechanical system with a compression-based retention system. The holding ring secures the seal through uniform axial compression within the annular groove, providing precise control over seal tenure and ensuring gas-tightness without the variability and potential damage associated with crimping operations.
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 design provides enhanced gas-tightness, prevents leakage, and ensures reliable operation even in the event of seal damage, making it suitable for high-purity gas applications.
Implementation Method 1
The holding ring is fixed to the obturating member by an outer, circumferential gas-tight weld, such that the annular bead penetrates axially into the outer annular shoulder of the annular seal to compress it.
Implementation Method 2
the annular seal is pressed against the first seat such that it ensures the main gas-tightness (sealing) of the valve
Data Source
AI summary
A valve for pressurized or liquefied gas comprises a valve body (12) with a gas flow channel (16) and in this channel a sealing seat (30) for an open/close element (32) having a free end (60) where a shoulder (62) is provided. An annular seal (64) is mounted on the free end (60) of the open/close element (32), the annular seal (64) having a front end face (66) facing the sealing seat (30) and a rear end face (68) resting on the shoulder (62) of the open/close body. A holding ring (70) surrounds the annular seal (64) circumferentially and comprises a radial lip (72) that bears on the outer edge of the front end face (66) of said annular seal (64). The annular seal (64) includes an outer annular shoulder (74) on the edge of its front end face and the radial lip (72) with the holding ring (70) has an annular bead (76) facing this outer annular shoulder (74) of the annular seal (64). The holding ring (70) is fixed to the open/close element (32) by a leaktight outer circumferential weld (77), so that the annular bead (76) passes axially into the outer annular shoulder (74) of the annular seal (64) to compress it.