Split Control Valve Body With PTFE Seals for Cryogenic Leakage
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Solution Overview
Problem
Control valves used in cold-weather applications, such as hydrogen filling stations, face challenges with standard seals failing in low temperatures, leading to leakage and reduced operational reliability.
Innovation Solution
A split valve body design with coaxial bores and chambers, incorporating spring-energized seals and a piston mechanism to control fluid flow, along with a diaphragm and cap configuration, ensures reliable operation in extreme cold by maintaining seal integrity and reducing leakage points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If standard seals are used in control valves for cold-weather applications, then the valve can operate in low temperatures, but the seals fail and leakage occurs
Solution Approach 1:
The patent changes the material parameters of the seals by using PTFE (polytetrafluoroethylene) instead of standard elastomeric seals. PTFE maintains its sealing properties at extremely low temperatures down to -400°F, whereas standard seals become brittle and fail. This material parameter change resolves the contradiction between operating temperature range and seal reliability.
Solution Approach 2:
The patent employs composite construction in the valve body design, combining PTFE sealing surfaces with metal valve components. This composite approach allows the valve to leverage the temperature resistance of PTFE for sealing while maintaining the structural strength of metal components, thereby achieving both wide temperature operation and reliable sealing.
2Ease of repair
If a split valve body design is used, then assembly and maintenance become easier, but the number of components and potential leakage points increases
Solution Approach 1:
The valve body is segmented into two main sections: a stationary body and a movable plug assembly. This segmentation allows the plug to be easily removed and replaced for maintenance while the stationary body remains fixed. The segmentation provides ease of repair without significantly increasing overall complexity, as the division follows the functional movement boundaries of the valve.
Solution Approach 2:
The sealing surfaces are extracted as separate, replaceable PTFE components rather than being integral to the valve body. This allows the seals to be independently maintained and replaced without replacing entire valve components, reducing maintenance complexity while improving ease of repair.
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 control valves to function reliably in temperatures as low as -400°F, using high-quality seals that maintain performance and extend the lifespan of cold-temperature seals, while reducing the number of components and potential leakage points, thus enhancing operational efficiency and durability.
Implementation Method 1
The control valve also includes a spring. The spring is positioned within the chamber. In response to an input received at the input port, the piston compresses the spring and moves the valve plug between a closed position and an open position.
Implementation Method 2
In response to an input received at the input port, the piston compresses the spring and moves the valve plug between a closed position and an open position.
Data Source
AI summary
An example control valve includes a split valve body. The split valve body includes a first body portion, a second body portion, a flow path, an inlet port, and an outlet port. The flow path passes through the first body portion and the second body portion. The first body portion is coupled to the second body portion. The control valve also includes a valve seat. The valve seat is disposed between the first body portion and the second body portion. The control valve also includes a valve plug. The valve plug is movable relative to the valve seat to control fluid flow through the control valve.