Plug Valve Sealing Structure Using an Intermediate Element
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Solution Overview
Problem
Plug valves face challenges in maintaining fluid tightness due to the difficulty in achieving a perfect match between the cylindrical plug and the orifices, leading to wear and deformation of gaskets, which compromises the seal over time.
Innovation Solution
A plug valve design incorporating an intermediate element with through-orifices and a gasket positioned between the intermediate element and the valve body, utilizing a friction joint between the intermediate element and the plug, and an elastic joint formed by the gasket, which eliminates direct contact between the gasket and the plug, ensuring a continuous contact surface for sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gasket is positioned in compression between the plug surface and the orifice peripheral surface to achieve fluid tightness, then sealing effectiveness is improved, but the gasket is subject to friction and wear from the curved plug surface, causing deformation and loss of sealing quality over time
Solution Approach 1:
The patent introduces an intermediate element (seating element) positioned between the plug and the gasket. This intermediate element has a curved outer surface that matches the curved peripheral surface of the plug, creating a friction joint that prevents direct contact between the gasket and the moving plug. The gasket only contacts the stationary intermediate element, eliminating wear and deformation while maintaining sealing effectiveness.
2Device complexity
If the cylindrical plug surface directly contacts the orifice surface to maintain fluid tightness, then the design is simple, but it is difficult to achieve a perfect match between surfaces due to play between internal parts, compromising sealing quality
Solution Approach 1:
The intermediate element serves as a mediator between the plug and the orifice. Its curved outer surface is designed to match the plug's peripheral surface, while its flat inner surface provides a precise seating surface for the gasket. This intermediate structure compensates for surface matching errors and play between parts, ensuring consistent sealing without requiring extremely tight manufacturing tolerances on the plug and orifice themselves.
3Device complexity
If the gasket is positioned in direct contact with the plug to create a seal, then the number of components is reduced, but the friction causes the gasket to wear or deform at the joining surface, losing fluid tightness over time
Solution Approach 1:
The intermediate element is positioned between the plug and gasket to eliminate direct contact. The friction joint is formed between the curved outer surface of the intermediate element and the curved peripheral surface of the plug, preventing the gasket from experiencing friction and wear. This additional component significantly improves long-term sealing performance while maintaining a relatively simple overall structure.
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 and long-lasting fluid-tight seal by leveraging the elastic properties of the gasket and the friction joint between the intermediate element and the plug, preventing deformation and maintaining efficient sealing over time.
Implementation Method 1
a gasket (4) positioned in compression on an orifice between the intermediate element (3) and the valve body (1), an elastic joint formed by the gasket
Implementation Method 2
a friction joint between the intermediate element and the plug
Data Source
AI summary
A plug valve includes a valve body with an inner volume and two communication orifices, a cylindrical plug having a circuit passing through between two orifices which are arranged to be positioned opposite orifices in the valve body, and an intermediate element having at least two through-orifices opposite respective communication orifices in the valve body. The inner surface of the intermediate element bearing at least one relief of which the top surrounds a through-orifice and forms a continuous contact surface bearing against the surface of the plug. A seal is positioned in compression at an orifice between the intermediate element and the valve body.