Ball Valve Sealing Assembly Using Pressure-Activated Sleeve
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Solution Overview
Problem
Existing ball valve assemblies face challenges in maintaining a high-quality seal, especially at high fluid pressures, due to the inability of traditional spring-based seals to effectively prevent fluid leakage around the valve member.
Innovation Solution
A sealing arrangement utilizing a deformable, incompressible medium contained around a sleeve in the valve assembly, which redirects fluid pressure to apply a force to a sealing member, ensuring a high-quality seal even at high pressures, and optionally supplemented by a resilient member for low-pressure scenarios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring-based seal is used to seal against the ball, then the seal works at low pressures, but the fluid pressure overcomes the biasing force at high pressures and forces the seal away from the ball causing leakage
Solution Approach 1:
The invention converts the harmful high fluid pressure into a beneficial force by routing it through a hydraulic passage to a piston, where it generates the sealing force needed to press the seal against the ball. The same pressure that tends to overcome the seal is now used to enhance sealing effectiveness.
Solution Approach 2:
The invention uses a hydraulic system where fluid pressure acts on a piston to generate mechanical force. The hydraulic passage directs pressurized fluid to the piston, which then translates this pressure into a sealing force applied to the seal member, ensuring effective sealing at high pressures.
2Reliability
If a spring-based seal is used, then the seal maintains contact with the ball, but the friction force increases making valve operation difficult
Solution Approach 1:
The invention transitions from a static spring-based sealing force to a dynamic hydraulic sealing force that automatically adjusts with fluid pressure. The sealing force increases with pressure, maintaining reliable sealing without requiring excessive friction, and the system adapts to different operating conditions dynamically.
Solution Approach 2:
The sealing system uses the fluid pressure from the system itself to generate the sealing force, rather than relying on an external spring mechanism. The hydraulic system self-regulates the sealing force based on the actual fluid pressure, providing adaptive sealing without additional operational complexity.
3Reliability
If tight tolerances are specified for the sealing surfaces, then sealing quality improves, but manufacturing cost and complexity increase
Solution Approach 1:
The invention changes the sealing mechanism from relying on surface geometry and tight tolerances to relying on hydraulic pressure generation. By using fluid pressure to force the seal against the ball, the system achieves high sealing quality without requiring extremely tight manufacturing tolerances on the sealing surfaces.
Solution Approach 2:
The invention introduces a hydraulic intermediary system (piston and hydraulic passage) that mediates between the fluid pressure and the sealing requirement. This intermediary converts pressure into a controlled sealing force, reducing the need for precision in the direct sealing contact surfaces.
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 solution provides a reliable seal at both high and low fluid pressures, reducing the need for tolerances in valve assembly design and minimizing friction, allowing for easier operation and preventing fluid leakage around the valve member.
Implementation Method 1
a deformable, incompressible, medium contained around the sleeve and arranged such that, in use, a fluid within the sleeve exerts an outward pressure on the sleeve causing the sleeve to deform and act on the medium which applies a force to push the sealing member against the valve member
Implementation Method 2
a fluid within the sleeve exerts an outward pressure on the sleeve causing the sleeve to deform
Data Source
AI summary
The disclosure relates to valve assemblies having a valve body including a first port, a second port and a fluid passageway extending therebetween. A valve member, having a through port, is arranged in the fluid passageway and is moveable between an open and closed positions. A sealing arrangement is arranged between the first port and the valve member and includes a sealing member arranged to seal against the valve member such that fluid cannot flow around an outer surface of the valve member. The sealing arrangement includes a sleeve arranged in the fluid passageway between the first port and the valve member. A deformable, incompressible, medium is contained around the sleeve and arranged such that, in use, a fluid within the sleeve exerts an outward pressure on the sleeve causing the sleeve to deform and act on the medium to push the sealing member against the valve member.