Ball Valve Sealing Structure Without TIG Welding Heat Damage
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Solution Overview
Problem
Conventional ball valves in the air-conditioning and refrigeration sectors face issues with seal damage during assembly due to uncontrolled TIG welding, overheating, and potential leaks, especially when using high-pressure gases like R744, and require complex welding/brazing operations that can lead to valve rejection and coolant gas leakage.
Innovation Solution
A ball valve design that eliminates TIG welding by using O-rings in closed seats for sealing between the valve body and sleeve, allowing for connection via external flanges that can be welded separately, made from materials like brass and stainless steel with differentiated sealing gaskets for compatibility with various refrigerant fluids, and enabling easy replacement without pipe cutting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If TIG welding is used to seal the body and sleeve, then a sealed connection is achieved, but the high temperature can damage the sealing berths and O-ring sealing
Solution Approach 1:
The sealing function is segmented from the welding process. Instead of welding the body and sleeve directly together, the invention introduces separate sealing elements (O-rings in grooves, sealing berths) that perform the sealing function independently of the mechanical connection, allowing the body and sleeve to be joined by screws without thermal damage.
Solution Approach 2:
Sealing intermediaries (O-rings and sealing berths) are introduced between the body and sleeve to perform the sealing function. These intermediaries are positioned in grooves and abutment surfaces, creating sealed chambers without requiring direct thermal contact between the metal components.
2Object-affected harmful factors
If the valve is cooled with cold gas during welding, then thermal damage to sealing elements is reduced, but the welding process becomes more complex and time-consuming
Solution Approach 1:
The harmful welding process is extracted from the sealing function. Instead of using welding to create the seal, the invention removes the welding step entirely for the sealing purpose, using mechanical assembly with screws and separate sealing elements instead, thereby eliminating the need for complex cooling procedures.
3Ease of manufacture
If flared copper pipe connections are used, then welding/brazing can be performed, but the valve body is at risk of overheating and damage
Solution Approach 1:
The connection system is segmented into separate components: external flanges with pockets for pipe insertion, and the valve body with screw connections. This segmentation allows pipes to be connected to the flanges without direct thermal contact with the valve body, eliminating overheating risk while maintaining ease of installation.
4Object-affected harmful factors
If threaded connections are used instead of welding, then overheating damage is avoided, but threadings may lead to leaks of coolant gas
Solution Approach 1:
Different sealing qualities are applied to different locations: O-rings provide sealing for the threaded actuation stem, while sealing berths provide sealing for the ball valve ports. The external flanges use pocket designs that allow thermal isolation. Each location receives the appropriate sealing method for its specific requirements.
Data Source
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AI summary
A ball valve (100) for use in the air-conditioning and refrigeration sectors, which comprises a valve body (1) provided with an accommodation seat (2) for a ball (3), a stem (5) being coupled to the ball (3), through the valve body (1), for actuating the ball (3), a sleeve (7) being coupled at one end of the valve body (1), with the interposition of O-rings (10, 11) arranged in seats (35, 36) that are completely closed when the sleeve (7) is coupled to the valve body (1).