High Temperature Valves

For a fuel cell technology developer, we invented a family of compact high-temperature valve and actuator designs for switching / metering the flow of hot jet fuel vapor within a system. As COTS valves have lower operating temperature limits due to their materials of construction, an innovative approach that utilized higher-temperature materials was needed.

The function of these devices were demonstrated on developmental systems.

Challenge

As JP-8 and Jet-A1 jet fuel have boiling points above 350 °C, switching valves handling this fluid while in a vapor state must be capable of continuously withstanding 450°C – 650°C fluid temperatures. Since conventional valve seat materials such as PEEK have temperature limits of 350°C and because chromium-steel alloys (stainless steels, etc.) have a tendency to coke at temperatures above 430°C when exposed to hydrocarbons, an innovative approach was required.

Solution

•  researched valve seat materials and technology, fluid properties of heavy-fraction fuels
•  developed 3-D CAD models of the valve body and actuators using SolidWorks® software
•  machined prototypes, evaluated performance and refined the design and the CAD models

Services/Skills

•  DFM (Design for Manufacture) principles
•  Materials Science
•  Mechanical Engineering
•  Mechanical Design
•  3-D CAD modeling
•  CNC machining, prototype fabrication, assembly, testing

Results

Compact valve bodies designed and built, with performance that exceeded specifications. Pneumatic and electric actuators were also developed which provided automatic operation within various systems.
•  custom valves were leak-tight to less than 1 cc/min or .01% of flow (vapor)
•  life cycle testing demonstrated leak-free performance for over 25,000 switching cycles
•  valves enabled systems to operate at higher efficiencies by not condensing and re-heating working fluids
•  cost-effective, easy to produce, rugged and robust, clean operation