Ball Valve Sealing Insert to Prevent Gasket Unseating
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Solution Overview
Problem
Existing ball valves face issues with sealing gaskets becoming unseated due to fluid turbulence at high pressures, especially when the ball closes, leading to inefficiencies and increased costs with the use of primers which lose effectiveness at high temperatures and are not certified for potable water applications.
Innovation Solution
The ball valve employs sealing means with a cylindrical base body made of polymeric or silicone material co-molded around an annular stiffening body, eliminating the need for a primer and ensuring reliable sealing through deformable external sealing surfaces and annular protrusions, which maintain constant elasticity and prevent unseating under varying pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If sealing gaskets made of elastomer are used to ensure high operation capabilities, then the elasticity and operation capability of the ball-type element are improved, but the gasket becomes unseated from the seat due to fluid turbulence at medium and high pressures
Solution Approach 1:
The sealing gasket is constructed as a composite structure with a polymeric or elastomeric base body co-molded with a metallic insert. The base body provides elasticity for operation capability, while the metallic insert provides stiffness to resist unseating forces from fluid turbulence, thus resolving the contradiction between ease of operation and sealing reliability
Solution Approach 2:
The metallic insert is strategically positioned within the elastomeric base body to provide localized stiffness exactly where needed to prevent unseating, while the rest of the gasket maintains its elastic properties for sealing contact, thus achieving both operation capability and sealing reliability
2Strength
If a metallic insert with primer is used to make the gasket stiffer, then the unseating problem is partially addressed, but the primer loses effectiveness at high temperatures and is not certified for potable water applications
Solution Approach 1:
The adhesive layer is designed as a thin, replaceable intermediate layer between the metallic insert and base body. While the adhesive may degrade at high temperatures, the modular design allows for maintenance and replacement of the sealing gasket assembly, maintaining system reliability without requiring permanent high-temperature adhesive bonds
Solution Approach 2:
An adhesive layer is introduced as an intermediary between the metallic insert and the polymeric base body. This adhesive mediator provides sufficient bonding for structural integrity while allowing for maintenance replacement, and its use is certified for potable water applications, thus resolving the temperature and certification reliability issues
3Strength
If primer is used to improve adhesion between the main body and metallic insert, then the bonding is improved, but the main body becomes more rigid and production costs increase
Solution Approach 1:
The adhesive layer thickness is optimized to provide sufficient bonding strength while maintaining the elasticity of the base body. By controlling the adhesive parameter (thin layer), the gasket remains flexible enough for operation while achieving adequate adhesion, thus avoiding excessive rigidity and simplifying production
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 reliable, cost-effective, and maintainable ball valve with high operational capability, maintaining constant elasticity and preventing unseating issues, even at medium to high pressures, while ensuring effective sealing without the need for primers and reducing actuation torque.
Implementation Method 1
a substantially cylindrical base body (51) made of polymeric material or silicone material
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A ball valve (1) for controlling the flow of fluids in ducts, comprising a hollow valve body (11) which forms in an upper region an access inlet (11a) and is provided with at least one open tubular intake portion (12) and at least one open tubular delivery portion (13) for connection to a respective duct portion, a hollow ball-type flow control element (2) accommodated in the hollow valve body (11), the ball-type element (2) being provided with at least one flow passage (2a) and being able to move rotationally between at least one flow intake position and a flow control position, a stem (3) which is integral or adapted to be rendered integral with the ball-type element (2) and can be actuated to allow its rotation through a preset angle from the intake position to the flow control position and vice versa, sealing means (50) being provided which are arranged between each one of the two open tubular portions (12, 13) and the ball-type element (2). The sealing means (50) respectively comprise a substantially cylindrical base body (51) made of plastic material which is co-molded around at least one annular stiffening body (53) which forms at least one angular positioning segment (53a), the base body (51) having an internal annular surface (52) designed to face a portion of the outer surface of the ball-type element (2) and a sealing surface (54), which is arranged opposite with respect to the internal annular surface (52) and is designed to face a respective annular shoulder (121a, 131a) of a respective gasket seat (121, 131), the gasket seat (121, 131) being provided with a longitudinal seat portion (122a, 132a) which is arranged substantially at right angles to the angular shoulder (121a, 131a) and is designed to face the outer surface (55) of the sealing means (50), between the outer surface (55) of the sealing means (50) and the respective longitudinal seat portion (122a, 132a) there being provided at least one restrained flow passage for the fluid which is adapted to allow, with the ball-type element in the flow control position, the passage of fluid from the open tubular intake portion (12) toward the hollow valve body (11).