Bidirectional Valve Seal Arrangement with Axial Support
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure hydraulic valves, especially those for subsea installations, face durability issues due to mechanical loading of bidirectional seals, which leads to deformation when two opposite lip seals cooperate, as the compressive force from hydraulic pressure causes one seal to be subjected to mechanical stress, limiting their effectiveness.
Innovation Solution
A valve-seat arrangement with an intermediate, axially displaceable seal-supporting element that separates the abutment surfaces of the seals, preventing compressive force transmission between the seals, and a balanced secondary sealing barrier design where the outer diameter of one seal is larger than the inner diameter of the contact surface and vice versa, ensuring consistent compressive force application regardless of pressure direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two opposite lip seals are used to form a bidirectional sealing barrier, then sealing effectiveness in both pressure directions is improved, but seal durability deteriorates due to mechanical loading and deformation
Solution Approach 1:
The sealing barrier is segmented into two independent unidirectional seals (first seal and second seal) that can move independently relative to the valve-seat holder. Each seal is supported by separate abutment surfaces on the seal-supporting element, allowing them to respond independently to pressure from different directions without transmitting mechanical loads to each other, thereby maintaining sealing effectiveness while preventing deformation and extending durability
Solution Approach 2:
The seal-supporting element acts as an intermediary between the two seals and the valve-seat holder. It provides separate abutment surfaces for each seal, preventing direct transmission of compressive forces between the seals. This intermediary structure allows each seal to be pushed against its respective abutment surface without subjecting the other seal to mechanical loading, resolving the contradiction between sealing effectiveness and durability
2Force
If hydraulic pressure pushes one seal against its abutment, then sealing force is improved, but the opposite seal is subjected to compressive force causing deformation
Solution Approach 1:
The sealing system is divided into two independent sealing paths with separate abutment surfaces on the seal-supporting element. When hydraulic pressure pushes one seal against its abutment, the seal-supporting element moves axially to accommodate this movement without transmitting the compressive force to the other seal. This segmentation allows each seal to generate sealing force independently while maintaining its shape and preventing deformation
Solution Approach 2:
The seal-supporting element serves as a mechanical intermediary that decouples the two seals from each other. It provides separate abutment surfaces that allow each seal to be pushed against independently. When one seal is subjected to hydraulic pressure, the seal-supporting element absorbs the resulting axial movement and prevents transmission of compressive forces to the opposite seal, thereby maintaining sealing force while preventing deformation
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 enhances the durability and functionality of high-pressure hydraulic valves by preventing seal deformation and maintaining effective sealing performance under varying hydraulic pressures without degrading the seals.
Implementation Method 1
a spring system applying an initial push force to a valve-seat holder, in which the valve seat is arranged, by means of a spring system
Implementation Method 2
Additional push force is provided by a hydraulic pressure against a piston surface arranged in the valve-seat holder
Implementation Method 3
unidirectional seals, that is to say lip seals that resist pressure only from one side
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A valve seat arrangement (4) in a hydraulic valve (1) provided with a bidirectional secondary barrier (5) including a first, upstream seal (51) and a second, downstream seal (52) and an intermediate, axially movable seal-supporting element (53), the seal- supporting element (53) including, at a first end, an annular first seal abutment (531) surrounded by a second supporting abutment surface (534) displaced in the axial direction towards a valve seat (42); and the seal-supporting element (53) including, at a second end, an annular second seal abutment (532) surrounding a first supporting abutment surface (532) displaced in the axial direction away from the valve seat (42).