Triple-Offset Valve Layout for Unobstructed High-Cv Flow
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Solution Overview
Problem
Conventional valves with a disc and shaft configuration obstruct the flow path, leading to reduced maximum achievable flow coefficient (Cv), especially in high-pressure systems requiring low torque and frictionless metal-to-metal sealing.
Innovation Solution
A triple-offset valve design with a disc that rotates between open and closed positions without obstructing the flow path, featuring a stem supported by the valve body on opposite sides and a seat ring that is easily replaceable, ensuring unobstructed flow passageways and increased flow coefficient.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a disc and shaft configuration is used to regulate flow, then the valve can control flow rate, but the disc and shaft obstruct the flow path causing pressure drop and reduced flow coefficient
Solution Approach 1:
The shaft is extracted from the flow path by positioning it laterally offset from the centerline, and the disc is extracted from obstructing the flow path by using a triple-offset configuration where the disc sealing surface is offset from both the rotation axis and the seat. This removes the obstructing elements while preserving the flow regulation function.
Solution Approach 2:
The valve transitions from a conventional two-dimensional disc rotation in the flow path to a three-dimensional triple-offset configuration where the disc, seat, and shaft are offset along multiple axes. This dimensional change allows the disc to seal effectively while being positioned outside the main flow path, eliminating obstruction.
2Stress or pressure
If a triple-offset configuration is used for high-pressure systems, then low torque and frictionless sealing are achieved, but the flow path may still be obstructed
Solution Approach 1:
The shaft is extracted from the centerline position and placed in a lateral offset position, removing it from the flow path. The disc is extracted from obstructing the flow by using the triple-offset sealing configuration, allowing the disc to seal against the seat while positioned outside the main flow path.
Solution Approach 2:
The valve body is designed with a localized enlarged side portion that provides space for the disc to rotate in the open position without obstructing the flow path. This local structural modification enables unobstructed flow while maintaining the triple-offset sealing capability elsewhere in the valve.
3Ease of operation
If the disc is positioned in the flow path for quarter-turn rotation, then the valve can open and close efficiently, but the obstruction reduces the maximum achievable flow coefficient
Solution Approach 1:
The valve transitions from a two-dimensional disc rotation in the flow path to a three-dimensional triple-offset configuration where the disc, seat, and shaft are offset along multiple axes. This dimensional change allows the disc to seal effectively while being positioned outside the main flow path, eliminating obstruction.
Solution Approach 2:
The valve body includes a localized enlarged side portion that accommodates the disc in the open position, creating space that prevents obstruction of the flow path while maintaining the quarter-turn operation capability.
Data Source
AI summary
A valve comprising a valve body including a first end and a second end spaced apart along a longitudinal axis, a central portion disposed between the first end and the second end, wherein the first end and the second end define a first flow passageway and a second flow passageway, respectively, and wherein the central portion defines an interior chamber, wherein the first end of the valve body includes a bore, and a removable seat disposed in the bore and defining at least in part the first flow passageway.