Relief Valve Poppet Dynamics for Hydraulic Leakage Control
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Solution Overview
Problem
Existing relief valves in hydraulic systems, particularly in blowout preventers, face challenges in maintaining a reliable seal under high pressure conditions and preventing leakage over thousands of cycles, as they often experience significant leakage due to the inability to effectively manage pressure variations.
Innovation Solution
A relief valve assembly with a poppet mechanism that increases its closing force with input pressure, utilizing a biasing chamber and an unloading valve to control fluid flow, allowing the poppet to open and close reliably by reducing pressure on its backside when a prescribed pressure is reached, thereby minimizing leakage and maintaining a seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional relief valve is used to limit pressure in hydraulic systems, then pressure relief function is provided, but significant leakage occurs under high pressure conditions over thousands of cycles
Solution Approach 1:
The relief valve employs a dynamic sealing mechanism where the poppet is progressively closed as a function of input pressure. The closing force increases with pressure, allowing the valve to adapt to varying pressure conditions and maintain reliable sealing over thousands of cycles without significant leakage
Solution Approach 2:
The valve changes the pressure parameter on the backside of the poppet to control opening and closing. By reducing backside pressure below a predetermined proportion of inlet pressure, the poppet opens to allow fluid flow; by increasing backside pressure, the poppet closes to prevent leakage
2Reliability
If the poppet is held closed with high force to prevent leakage, then sealing is improved, but the valve cannot open to relieve pressure when needed
Solution Approach 1:
The biasing chamber acts as an intermediary mechanism that mediates between the closing force requirement and the opening capability. By controlling the pressure in the biasing chamber, the valve can maintain strong sealing when needed while allowing the poppet to open when pressure relief is required
Solution Approach 2:
The valve operates with periodic opening and closing actions based on pressure conditions. The poppet repeatedly opens and closes in response to pressure variations, reliably sealing after thousands of cycles while still allowing pressure relief when the prescribed pressure condition is reached
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 solution enables the relief valve to operate reliably under high pressure conditions, reducing leakage and ensuring consistent sealing performance over numerous cycles without significant fluid loss, even under fluctuating pressure conditions.
Implementation Method 1
a pressure line configured to provide an input pressure to the backside of the poppet, whereby in a first state increasing the input pressure increases a force of the poppet against the valve seat to reduce leakage between the valve seat and the poppet
Implementation Method 2
an unloading valve in the evacuation line for blocking fluid flow from the biasing chamber to the drain port, until pressure in the inlet exceeds a first pressure setting which causes the unloading valve to open to allow fluid flow through the evacuation line
Implementation Method 3
pressure of the fluid on the backside of the poppet is reduced below a predetermined proportion of a pressure at the inlet while the front side of the valve portion is exposed to the inlet pressure to allow the poppet to move away from the valve seat thereby allowing fluid to flow
Data Source
AI summary
Provided is a relief valve with an inlet, and outlet, and a backside of a poppet fluidly connected to an input pressure to increasingly close the poppet as a function of input pressure until a prescribed pressure condition is reached. Upon the prescribed pressure condition being reached, the relief valve decreases pressure on the backside of the poppet to open the poppet and allow fluid flow from the inlet to the outlet. Increasingly closing the poppet allows the relief valve to operate under high pressure conditions and repeatedly open and close to reliable seal without significant leakage after thousands of cycles.