Welded Check Valve Assembly for Low-Particle High-Purity Sealing
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Solution Overview
Problem
Check valves with threaded connections face high manufacturing costs and potential media leakage due to temperature variations, which can lead to particle generation and compromised fluid flow control, especially in high-purity applications like semiconductor manufacturing.
Innovation Solution
Welding polymeric components together to create check valves, using thermal welding techniques while incorporating retaining features that keep components away from the weld site to prevent damage and ensure a higher quality seal, reducing particle generation and improving fluid flow control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If threaded connections are used to assemble check valve components, then the manufacturing process is traditional and easy to implement, but the manufacturing cost increases and temperature variations cause media leakage
Solution Approach 1:
The patent merges the sealing function and connection function into a single welded joint, eliminating the separate threaded connection components. The weld directly joins the valve body and cover, providing both structural connection and sealing in one operation, which improves seal quality while reducing manufacturing complexity and cost.
Solution Approach 2:
The patent replaces the mechanical threaded connection system with a thermal welding process. Instead of using screws and threads to join components, the invention uses heat to fuse the polymeric components together, eliminating the need for machining and assembly of threaded parts while providing superior sealing.
2Productivity
If threaded connections are used to assemble check valve components, then the assembly process is simple, but particle generation occurs during assembly and fluid flow control is compromised
Solution Approach 1:
The patent replaces mechanical assembly operations (screwing, threading) with a thermal welding process that joins components without mechanical contact. This eliminates particle generation from machining and assembly operations while maintaining productivity through a streamlined single-step joining process.
3Reliability
If thermal welding is used to join polymeric components, then a higher quality seal is produced and manufacturing is simplified, but the welding process may damage or improperly bond melt processable components at the weld site
Solution Approach 1:
The patent extracts the heat-sensitive components (poppet assembly, spring, disc) from the welding zone by positioning them inside the valve body away from the weld interface. The welding is performed on the external surfaces of the valve body and cover, separating the thermal process from the sensitive internal components to prevent heat damage.
Solution Approach 2:
The patent performs preliminary assembly of the internal components (poppet, spring, disc) into the valve body before performing the welding operation. This ensures components are in place and protected before heat is applied, preventing improper bonding or damage during the welding process.
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
Simplifies the manufacturing process, enhances the quality of the seal, and improves performance in high-purity applications by eliminating threaded connections and minimizing particle generation, thereby ensuring reliable fluid flow control in check valves.
Implementation Method 1
Check valves may be welded using thermal welding techniques
Implementation Method 2
retaining features that allow polymeric check valve components to be held away from the site of the weld
Data Source
AI summary
Welded check valves include a poppet assembly, a spring, and a disc that contacts the spring. The disc may be held at a position away from a weld when forming the welded check valve. Embodiments may include retention features configured to allow one or more of the poppet assembly and disc to pass the retention features in an assembly orientation, and to retain those elements when they are in an operational orientation. Methods include inserting the poppet assembly, contacting the poppet assembly with a spring, inserting a disc, retaining the disc away from a weld side, and welding the check valve together. The poppet assembly and/or disc may pass one or more retaining features when inserted, and be retained by the retaining features when the check valve is operated. The weld may be a thermal weld.