High-Pressure Switching Valve Sealing with Deformable Body
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure liquid chromatography (HPLC) check valves face challenges in maintaining leaktightness due to tensile stresses in materials like ruby and ceramic, which are strong in compression but prone to fracture under fluid pressure, leading to potential leaks and reduced reliability at pressures above 1000 bar.
Innovation Solution
A switching valve design incorporating an elastically or plastically deformable sealing body within a fully enclosed space, subjected to a predetermined pressure, which provides a radially inward preload on the valve seat and guide elements, using materials like PEEK for the sealing body and stainless steel or titanium alloys for the housing, ensuring the valve remains leaktight even at high pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If hard materials like ruby, sapphire, or ceramic are used for valve seat and guide element, then compression strength is improved, but tensile strength remains low leading to fracture risk under fluid pressure
Solution Approach 1:
A metal sleeve acts as an intermediary component between the hard ceramic valve seat/guide element and the housing. The metal sleeve absorbs the tensile stresses generated by fluid pressure, while the ceramic components primarily experience compressive stresses, preventing fracture and maintaining reliability.
Solution Approach 2:
The valve assembly uses a composite structure combining ceramic materials (for compression resistance) with a metal sleeve (for tensile strength). This composite approach allows each material to be used in the stress condition it handles best, resolving the contradiction between compression strength and tensile fracture resistance.
2Reliability
If sealing components are used to prevent leaks, then leaktightness is improved, but plastic deformation occurs in continuous use at high pressures
Solution Approach 1:
The metal sleeve serves as a mediator that distributes and absorbs the high contact pressures between sealing components. This prevents excessive localized stress that would cause plastic deformation, thereby maintaining leaktightness throughout the service life even under continuous high-pressure operation.
Solution Approach 2:
The invention changes the pressure distribution parameters by introducing the metal sleeve, which modifies how pressure is transmitted through the sealing components. This pressure redistribution prevents the threshold for plastic deformation from being exceeded, extending the duration of reliable sealing.
3Reliability
If dual valve units are arranged in series to increase reliability, then fail safety is improved, but device complexity increases
Solution Approach 1:
The metal sleeve merges the support and sealing functions for multiple valve units into a single integrated component. This allows dual or multiple valve units to be arranged in series within a common housing with shared sealing and structural elements, maintaining high reliability while reducing overall device complexity compared to separate valve assemblies.
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 enhances the reliability and longevity of high-pressure check valves by maintaining leaktightness and reducing the risk of material failure, allowing operation at extremely high pressures with a simpler design and fewer components, ensuring consistent performance.
Implementation Method 1
an elastically and/or plastically deformable sealing body (27)... which seals off said through flow channel and subjects the valve seat element and the guide element to an inward-directed preload pressure
Implementation Method 2
an elastically and/or plastically deformable sealing body (27)... which seals off said through flow channel and subjects the valve seat element and the guide element to an inward-directed preload pressure
Implementation Method 3
This sealing must withstand alternating loads up to the maximum pressure of the pump on a sustained basis
Data Source
AI summary
A switching valve, in particular for controlling a fluid subject to high pressure is described. The switching valve has at least one valve unit, which includes a valve seat element and a switching element guided movably in a guide element, wherein the valve seat element and the switching element interact to provide a switching valve function. The valve seat element and the guide element are provided in a housing. The valve seat element, the guide element and the housing form a through flow channel for the fluid to be controlled. An elastically and/or plastically deformable sealing body is provided in a fully enclosed space between the inner wall of the housing and the outer walls of the valve seat element and of the guide element. The sealing body can be subject to a predetermined pressure to seal off the through flow channel from the housing and subject the valve seat element and the guide element to an inward-directed preload.