Balanced Valve Port for Fluid Regulator Droop
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Solution Overview
Problem
Conventional gas regulators with balanced valve ports experience instability and reduced flow capacity at high inlet pressures due to varying inlet pressure effects, leading to undesirable 'droop' phenomena.
Innovation Solution
The design incorporates a pressure sensing labyrinth and sealed second pressure sensing passages within the valve plug and port housing, ensuring equal and opposite forces are applied to the sealing surface and diaphragm, maintaining consistent performance across varying inlet pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If passages are disposed within the control element to allow fluid flow through the balancing cavity, then high flow capacity at low inlet pressures is achieved, but inlet pressure variations cause sensing pressure reduction and droop instability at high inlet pressures
Solution Approach 1:
The pressure sensing function is segmented into two separate pathways: a first pressure sensing passage through the valve plug for accurate outlet pressure sensing, and a second pressure sensing passage through the port housing for inlet pressure balancing. This segmentation allows each passage to be optimized for its specific function, preventing the droop phenomenon while maintaining high flow capacity.
Solution Approach 2:
A balancing piston is introduced as an intermediary element between the inlet pressure source and the diaphragm. The piston receives inlet pressure through the second pressure sensing passage and transmits it to the diaphragm, isolating the outlet pressure sensing pathway from inlet pressure variations and eliminating the droop instability.
2Productivity
If the valve opens to increase flow capacity, then more fluid can pass through, but the sensing pressure on the balancing diaphragm reduces causing droop phenomenon
Solution Approach 1:
The balancing piston serves as an intermediary that decouples the inlet pressure source from the diaphragm's sensing surface. It receives varying inlet pressure through the second passage and transmits a compensated pressure to the diaphragm, maintaining stable sensing pressure regardless of valve position or inlet pressure changes.
Solution Approach 2:
The system changes the pressure parameter transmitted to the diaphragm by using the balancing piston to compensate for inlet pressure variations. The piston creates a balanced pressure condition where the diaphragm experiences stable sensing pressure independent of inlet pressure fluctuations, preventing droop while allowing full flow 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 configuration maintains continuous increase in rated flow capacity even at high inlet pressures, preventing the drop-off seen in conventional designs, ensuring optimal operational performance.
Implementation Method 1
a fluid pressure resident on the sealing surface of the valve plug is also resident in the balancing cavity to apply equal and opposite first and second forces to the sealing surface of the valve plug and the first surface of the balancing diaphragm
Data Source
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AI summary
A balanced port control assembly includes a control element with a valve plug coupled to a valve stem and a pressure sensing labyrinth defined at least partly by the valve plug. The pressure sensing labyrinth provides for fluid communication between a sealing surface of the valve plug and a balancing diaphragm carried internally of the control element. The pressure sensing labyrinth includes at least one pressure sensing passage extending from the sealing surface and into the valve plug along a central longitudinal axis of the control element. So configured, fluid pressure resident on the sealing surface of the valve plug is also resident on the balancing diaphragm such that equal and opposite forces are applied to the control element.