Butterfly Valve Wear Interface Thrust Load Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Butterfly valves face issues with increased force requirements and wear due to thrust loads, leading to potential unseating of the disc and permanent binding, compromising flow control and valve functionality.
Innovation Solution
A butterfly valve design featuring a thrust load reacting section with a wear interface comprising a tungsten carbide contact surface and a nickel alloy matrix coating, which minimizes wear and friction by distributing contact stresses over larger areas, reducing the need for high control forces and extending the valve's operational life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sealing elements and canted shafts are added to improve sealing ability, then sealing performance is improved, but the force required to control the valve increases
Solution Approach 1:
The thrust load is segmented and distributed to multiple contact surfaces including the thrust bearing, shaft, and wear interface components, rather than concentrating it on a single sealing element, thereby reducing the force required for valve control while maintaining sealing performance
Solution Approach 2:
A thrust bearing and wear interface components are introduced as intermediary elements between the sealing elements and the valve shaft, absorbing and distributing the thrust loads to reduce the control force required while preserving sealing ability
2Reliability
If increased control force is applied to maintain sealing, then sealing performance is maintained, but wear and frictional material loss accelerate
Solution Approach 1:
The material properties at the wear interface are changed by using tungsten carbide and nickel alloy matrix coatings, which have superior wear resistance compared to conventional materials, thereby reducing frictional material loss while maintaining the sealing performance under increased control forces
Solution Approach 2:
Composite materials consisting of tungsten carbide particles in a nickel alloy matrix are used at the wear interface, combining the hardness and wear resistance of tungsten carbide with the toughness and ductility of nickel alloy, thereby reducing material loss while maintaining sealing integrity
3Ease of manufacture
If conventional wear interface materials are used, then manufacturing is simpler, but wear resistance is insufficient leading to disc unseating and binding
Solution Approach 1:
Instead of making the entire valve components from high-wear-resistance materials, the tungsten carbide and nickel alloy coatings are applied locally only at the wear interface surfaces where contact occurs, providing enhanced wear resistance precisely where needed while keeping the rest of the valve manufacturing simple and cost-effective
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 design effectively manages thrust loads and reduces wear, preventing disc binding and extending the valve's lifespan while maintaining precise flow control and sealing capabilities.
Implementation Method 1
minimizes wear and friction by distributing contact stresses over larger areas
Implementation Method 2
minimizes wear and friction by distributing contact stresses over larger areas
Data Source
AI summary
A butterfly valve comprises a housing including a bore, a rotatable shaft passing through the bore, a disc mounted to the shaft for controlling the flow of a fluid through the bore, a thrust load reacting section and a wear interface. The thrust load reacting section includes a thrust plug assembled in a thrust reacting end of the shaft and a thrust plate secured to the housing. The thrust plate has a well for axially retaining the thrust plug and the thrust reacting end of the shaft. The wear interface includes a first contact region on the thrust plug with a first contact surface and a second contact region at the base of the well with a second contact surface. A portion of the first contact surface is spherical and in contact with a portion of the second contact surface.