Choke Transfer Valve Trim Erosion Mitigation
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Solution Overview
Problem
Existing valve plugs experience rapid erosion due to high velocity and pressure drops, leading to premature failure of the plug head and seat inlet, especially in severe duty service valves, particularly in erosive and corrosive process streams.
Innovation Solution
The implementation of a choke transfer trim that relocates the minimum flow area away from the plug head and seat inlet interface to a downstream location, reducing exposure to erosive forces and increasing the longevity of the valve plug and seat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the minimum flow area is located at the plug head and seat inlet interface for fluid throttling and shut-off, then the valve can effectively control fluid flow, but the plug head and seat inlet experience rapid erosion due to high velocity and pressure drops
Solution Approach 1:
The invention extracts the minimum flow area from the plug head and seat inlet interface location and relocates it downstream to a choke transfer seat. This separation allows the plug head and seat inlet to be removed from the high-velocity erosive environment while maintaining the valve's flow control capability at the new location.
Solution Approach 2:
The invention changes the spatial dimension of the minimum flow area location along the flow path. By positioning the choke transfer seat downstream at a location where the seat inlet is not exposed to high velocity flow, the design moves the flow control function to a different position in the valve assembly, protecting critical components from erosion.
2Device complexity
If the minimum flow area is positioned at the plug head and seat inlet interface, then the valve structure is simple, but erosion causes premature failure of the plug head and seat inlet
Solution Approach 1:
The minimum flow area is extracted from the traditional plug head and seat inlet interface location and placed at a downstream choke transfer seat. This extraction protects the plug head and seat inlet from erosion while maintaining relatively simple valve structure through the use of a additional seat component.
Solution Approach 2:
The valve seat is segmented into multiple functional zones: the plug head and seat inlet interface area is separated from the minimum flow area location. The choke transfer seat is positioned downstream to handle flow control, while the upstream seat inlet remains in a protected, low-velocity environment.
3Productivity
If high velocity flow is used for effective fluid regulation, then flow control capability is improved, but erosion of the plug head and seat inlet increases
Solution Approach 1:
The harmful high-velocity flow conditions are extracted from the plug head and seat inlet interface region by relocating the minimum flow area downstream to the choke transfer seat. This allows effective flow regulation to be maintained at the new location while the original interface remains in a benign, low-velocity environment free from erosive effects.
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
This design effectively decreases the rate of erosion and extends the service life of severe duty service valves by shifting the erosive environment away from the critical interface, ensuring reliable operation even in harsh fluid flow conditions.
Implementation Method 1
Choked flow can cause erosion of the plug head and/or seat and can cause the plug head and/or seat inlet to fail
Data Source
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AI summary
The present invention relates to valve plugs for reducing erosion of the valve plug head and/or seat. More specifically, this invention comprises a valve plug (200) incorporating a choke transfer trim (206) that reduces the time of exposure of the plug head (201) and/or seat (205) to high velocity and high pressure drop at the interface of the plug head and seat when the valve is in the closed position. The choke transfer trim (206) transfers the flow control area (207) of the valve away from the plug head / seat interface to a location downstream, thereby reducing erosion at the interface between the valve plug head and/or seat that is typically used for fluid throttling and shut off.