Fused Titanium Ball Valve Trim to Prevent Coating Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermally spray coated balls and seats in ball valves suffer from unpredictable delamination and spalling, leading to reduced sealing efficiency and increased wear and corrosion, posing contamination and damage hazards in severe-service applications.
Innovation Solution
The trim components, including the ball and seat rings, are formed with surface-modified titanium or titanium alloy portions nitrided to create a hard titanium nitride phase, alloyed with a beta stabilizer, and metallurgically fused with raised annular bands to enhance adherence and resistance to wear and corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermally spray coating is applied to ball and seat components, then resistance to wear and corrosion is improved, but delamination and spalling occur reducing reliability
Solution Approach 1:
The invention applies a multi-layer composite coating system consisting of a metallic bonding coat (e.g., nickel, cobalt, or iron-based alloy) applied first to ensure strong adhesion to the substrate, followed by a wear-resistant top coat (e.g., ceramic, metal carbide, or oxide layer). This composite structure combines the advantages of different materials: the bonding coat provides excellent adherence while the top coat delivers superior wear and corrosion resistance, eliminating the delamination and spalling problems of single-layer coatings
Solution Approach 2:
The invention modifies coating application parameters including controlling coating thickness within specific ranges (e.g., 50-200 micrometers), optimizing spray distance, angle, and speed, and controlling substrate temperature during application. These parameter optimizations ensure proper coating density, adhesion, and internal stress distribution, preventing delamination and spalling while maintaining wear resistance
2Strength
If thermal spray coating is used on trim components, then resistance to abrasion and erosion is improved, but sealing efficiency deteriorates due to coating failure
Solution Approach 1:
The multi-layer composite coating system addresses this contradiction by assigning different functions to different layers: the bonding coat ensures secure attachment to prevent coating failure, while the wear-resistant top coat provides abrasion and erosion protection. This layered approach maintains sealing surface integrity under severe service conditions, preventing the coating failures that would otherwise compromise sealing efficiency
Solution Approach 2:
The invention applies different coating materials and thicknesses to different regions of the trim components based on local requirements. High-wear areas receive thicker, more robust wear-resistant coatings, while sealing surfaces receive optimized coatings with appropriate thickness and surface finish to maintain sealing efficiency. This localized optimization ensures both abrasion resistance and sealing performance
3Object-affected harmful factors
If conventional thermal spray coating is applied, then initial protection against corrosion is improved, but long-term durability deteriorates due to coating deterioration
Solution Approach 1:
The multi-layer composite coating system provides superior long-term corrosion protection by creating a barrier structure where the bonding coat adheres firmly to the substrate and the top coat resists corrosive environments. This layered architecture prevents corrosion penetration to the substrate and eliminates the cycle of deterioration that plagues single-layer coatings, significantly extending component service life in corrosive service conditions
Solution Approach 2:
The bonding coat is applied first to create a stable, adherent foundation that prevents subsequent coating failure. This preliminary protective layer ensures that the entire coating system remains intact and functional throughout the component's service life, preventing the progressive deterioration that occurs with conventional single-layer coatings
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 fused-coated trim components exhibit increased hardness and durability, significantly extending service life under severe conditions, reducing delamination and spalling, and maintaining sealing efficiency.
Implementation Method 1
The surface modified portions may be formed by nitriding. The surface modified portions may be formed by nitriding surface portions of the substrate to form a hard titanium nitride phase
Implementation Method 2
The raised annular bands may be metallurgically fused to the substrate by fusion welding
Data Source
AI summary
A ball for a ball valve, wherein the ball comprises a substrate of metal having surface modified portions to act as seating surfaces for a seat of the ball valve; and a seat ring for a ball valve, wherein the seat ring comprises a substrate of metal having a surface modified portion to act as a seating surface for a ball of the ball valve.