Adjustable Shroud Gas Regulator for Droop Compensation
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Solution Overview
Problem
Conventional gas regulators experience 'droop' where the outlet pressure decreases below the set control pressure due to the inherent force and area changes of the control spring and diaphragm, leading to inadequate pressure regulation and inefficient gas flow.
Innovation Solution
An adjustable regulator design featuring a valve disc with a shroud that can be axially displaced to direct gas flow effectively, compensating for 'droop' by adjusting the position of the shroud relative to the valve disc, thereby enhancing the control pressure and flow characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional control spring and diaphragm are used in the actuator, then the regulator can maintain a set control pressure, but the outlet pressure decreases below the set control pressure due to force and area changes (droop)
Solution Approach 1:
The patent changes the physical parameters of the control element by introducing a shroud that extends beyond the sealing surface of the valve disc. This shroud creates a restricted flow path that artificially induces lower pressure registration at the diaphragm, compensating for the droop effect and maintaining accurate outlet pressure control throughout the valve travel range.
Solution Approach 2:
The shroud acts as an intermediary element between the valve disc and the diaphragm. It modifies the pressure distribution by creating a restricted flow path that directs gas flow in a specific manner, thereby influencing the pressure registration at the diaphragm to compensate for control spring force changes.
2Productivity
If the control spring expands to open the valve port, then gas flow increases to meet demand, but the control spring force decreases leading to inadequate pressure regulation
Solution Approach 1:
The shroud modifies the flow parameters by creating a restricted path that maintains more uniform pressure registration at the diaphragm throughout valve opening. This allows the control spring to expand fully for high flow capacity while the shroud's flow restriction compensates for the decreasing spring force, maintaining pressure regulation accuracy.
Solution Approach 2:
The shroud preliminarily counteracts the droop effect by creating an artificial pressure differential before it becomes problematic. The restricted flow path pre-compensates for the upcoming decrease in control spring force, ensuring stable pressure regulation even as the valve opens and flow capacity increases.
3Reliability
If the shroud extends beyond the valve disc sealing surface, then gas flow is directed effectively and droop is prevented, but the device complexity increases
Solution Approach 1:
The shroud is merged with the valve disc assembly, forming an integrated control element. This combination achieves the dual function of sealing (via the valve disc) and flow direction/pressure control (via the shroud) without requiring separate components, thereby minimizing the increase in device complexity while maintaining pressure control accuracy.
Solution Approach 2:
The shroud performs multiple functions: it directs gas flow away from the actuator, creates artificial pressure registration at the diaphragm, and compensates for droop. This multi-functionality reduces the need for additional components, offsetting the complexity increase with functional consolidation.
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 adjustable shroud configuration prevents 'droop' by artificially inducing a lower pressure registration at the diaphragm, increasing gas flow and maintaining the set control pressure, allowing for tuning of the regulator for specific applications while maintaining pressure relief functionality.
Implementation Method 1
The diaphragm 24 senses the outlet pressure of the regulator valve 14... the diaphragm 24 senses this decreased outlet pressure. This allows the control spring 30 to expand and move the piston 32 and the right-side of the control arm 26 downward
Implementation Method 2
The control assembly 22 further includes a control spring 30 in engagement with a top-side of the diaphragm 24 to offset the sensed outlet pressure
Implementation Method 3
the shroud directs the flow of fluid through the valve port toward the outlet of the valve body when the valve disc is in an open position
Data Source
Figure 1
Figure 1A
Figure 2
AI summary
A gas regulator comprises an actuator and a valve body, wherein the actuator includes a valve disc with a cylindrical shroud that extends beyond the valve disc to direct the flow of fluid through the regulator toward the outlet of the valve and away from the actuator. This configuration advantageously reduces the amount of pressure drop experienced by the actuator during normal operation, thereby minimizing a phenomenon known as "droop." At least in one embodiment, the shroud can be adjustable and/or removable to allow the regulator to be tuned for specific applications.