Design and thermal performance of ceramic valves

Two commercially available valves, a ball and a check valve, which were not suitable for high temperature applications were redesigned and retrofitted with ceramic components and high temperature seals. Both valves had a maximum temperature rating of 204°C. The use of advanced ceramic materials for critical components of valves is shown to be an effective solution.;Ceramic seats and springs for the valves were machined from zirconia tubing on a bench lathe that was automated with a PC-based motion control system. The ball of the ball valve was designed from 99.5% alumina. Detailed accounts are presented on valve redesign procedures. Testing apparatuses and methods are described.;The deflection of ceramic spring was successfully modeled using Hooke's law. The performances of various valve seats developed are also documented. Results from cracking pressure measurements of the check valve for temperatures up to 600°C showed deviation from linearity at temperatures greater than 500°C due to physical property changes in the stainless steel components. The test on ball valve was partially successful.