Pressure Balanced Trim Gas Regulator Droop Reduction
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Solution Overview
Problem
Conventional gas regulators experience 'droop' phenomena, where the outlet pressure decreases below the set control pressure due to the inherent force reduction of the control spring and increased diaphragm area, and are sensitive to upstream pressure variations, affecting their ability to maintain desired downstream pressures.
Innovation Solution
The implementation of a pressure loading device and balanced trim in the gas regulator, which includes a diaphragm subassembly and disc and balancing subassembly, where the pressure loading device applies a consistent force to the diaphragm and the balancing diaphragm compensates for upstream pressure forces, ensuring accurate control of downstream pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional control spring is used to regulate outlet pressure, then the regulator can maintain control pressure through spring force, but the outlet pressure decreases below the set control pressure due to spring force reduction and increased diaphragm area (droop phenomenon)
Solution Approach 1:
The patent changes the force application mechanism from a control spring acting on a lever arm to a pressure loading device that applies force directly to the diaphragm. This parameter change eliminates the mechanical leverage effects and spring force variations that cause droop, providing more stable and accurate outlet pressure control.
Solution Approach 2:
The patent extracts the pressure loading function from the control spring mechanism and implements it as a separate pressure loading device. This separation allows the control spring to be replaced with a simpler spring that only needs to balance the pressure loading device, rather than compensating for both pressure loading and droop effects.
2Device complexity
If a conventional regulator design is used, then the structure is simple, but the regulator is sensitive to upstream pressure variations affecting downstream pressure control
Solution Approach 1:
The patent introduces a pressure loading device as an intermediary between the upstream pressure source and the control diaphragm. This intermediary balances the upstream pressure forces before they reach the control mechanism, making the downstream pressure control independent of upstream pressure variations and improving reliability.
3Productivity
If the control spring force reduces and diaphragm area increases during operation, then the regulator can accommodate flow variations, but the outlet pressure drops below the set control pressure
Solution Approach 1:
The patent uses pneumatic pressure from the pressure loading device to apply force directly to the diaphragm, replacing the mechanical spring force system. This pneumatic approach maintains consistent force application regardless of diaphragm area changes or flow variations, preventing pressure droop while maintaining flow regulation capacity.
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 solution reduces the effects of 'droop' and makes the regulator less sensitive to upstream pressure variations, allowing for more accurate control and higher rated capacities, maintaining the desired downstream pressure with reduced sensitivity to inlet pressure fluctuations.
Implementation Method 1
a pressure loading device to which the control spring is connected and that applies a loading force to the diaphragm
Implementation Method 2
disc and balancing subassembly having a valve disc and a balancing diaphragm, where the balancing diaphragm compensates for upstream pressure forces
Data Source
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AI summary
A gas regulator includes an actuator, a regulator valve, and pressure loading device. The pressure loading device provides a pressure load to a surface of a diaphragm of the actuator to act against a downstream pressure being applied to the opposite surface of the diaphragm and being controlled by the regulator. As the downstream pressure varies and the diaphragm displaces to move a control element to regulate the downstream pressure, the pressure loading device maintains a specified load pressure. The regulator may further include a balanced trim applying a balancing force to offset a force of an upstream pressure on the control element.