Ball Valve Seat Compression Assembly for High-Temperature Sealing
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Solution Overview
Problem
Current systems for compressing ball-valve seats in high-temperature applications, especially with hot and adhesive fluids, face limitations in temperature resistance, compactness, and the risk of clogging, with existing solutions either being ineffective above 500°C or requiring high steam consumption for maintenance.
Innovation Solution
An annular assembly comprising a sleeve, head rings, annular shims, and a stack of helical springs or graphite rings, which provides a compact and adaptable sealing mechanism that maintains contact force between the ball-valve seat and ball, even at elevated temperatures, without the need for steam cleaning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal bellows is used to compress the seat, then the spring function and sealing are provided, but the assembly becomes vulnerable to clogging by adhesive fluids that solidify at lower temperatures
Solution Approach 1:
The patent uses a flexible graphite membrane instead of a metal bellows. This membrane is impermeable to fluids but can be easily cleaned by steam or other fluids, preventing clogging while maintaining the sealing function. The membrane flexes to provide the necessary spring action without being vulnerable to solidification of adhesive fluids.
2Temperature
If graphite rings are used to provide sealing, then temperature resistance is increased above 500°C, but high axial compression (15-20 MPa) is required which can hinder ball operation
Solution Approach 1:
The patent employs a flexible graphite membrane that provides sealing at high temperatures without requiring high compressive forces. The membrane's flexibility allows it to conform to the ball surface and maintain sealing through its own elastic properties rather than external compression, thus avoiding interference with ball operation.
Solution Approach 2:
The invention changes the material properties by using a flexible graphite membrane with specific thermal and mechanical characteristics. This membrane maintains its sealing capability at temperatures above 500°C while having lower stiffness than solid graphite rings, reducing the compressive force transmitted to the ball.
3Reliability
If steam injection is used to prevent bellows clogging, then the bellows remains functional, but steam consumption increases and is discharged into the main pipe
Solution Approach 1:
The flexible graphite membrane is designed to be easily cleaned by steam or other fluids, allowing it to maintain its own functionality without requiring continuous steam injection. The membrane can be cleaned periodically or even during operation with minimal steam consumption, and the cleaning fluid does not need to be discharged into the main pipe.
4Reliability
If elastomeric or polymeric materials are used for sealing, then the sealing function is effective, but the temperature range is limited to a maximum of 300°C
Solution Approach 1:
The patent uses a flexible graphite membrane, which is a carbon-based material with exceptional temperature resistance. Graphite remains stable and maintains its mechanical properties at temperatures above 500°C, unlike elastomeric or polymeric materials that degrade at lower temperatures. This allows the sealing function to be maintained in high-temperature environments.
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 enables a compact, high-temperature-resistant sealing assembly that prevents fluid blockage and maintains contact force, ensuring effective operation without steam consumption, thus addressing the limitations of prior systems.
Implementation Method 1
a stack of means of compression, in this case made up of helical springs
Implementation Method 2
a stack of means of compression, in this case made up of helical springs
Implementation Method 3
an upstream stack of base rings, in this case made of graphite
Data Source
AI summary
An annular assembly for compressing a seat of a ball-valve, including: a valve body or insert, including an annular internal counter-bore that defines an inner counter-bore diameter; a sleeve inserted into the annular internal counter-bore, defining at least one outer diameter of the sleeve; the body or the insert defining with the sleeve an annular housing in which the assembly includes, in succession: a downstream stack of head rings, an annular head shim, a stack of mechanisms of compression, an annular base shim, and an upstream stack of base rings.