Dynamic performance of high temperature ceramic check valves.

摘要

Ten check valves were redesigned to accommodate ceramic springs and seats. Standard check valves typically have components in them, which are unsuitable for high temperature and corrosive environments. The usage of ceramic components in check valves will be shown to be an effective solution for high temperature applications. The ceramic springs and seats were machined using a SD 300 Prazi lathe, specially modified for computer automation. The material used for machining the springs was Yttria (Y ₂O₃) stabilized zirconia. The springs were of 10, 12, 14 and 16 Turns Per Inch (TPI) respectively. Deflection measurements were carried out at ambient temperatures for all the ten ceramic springs with one spring from each set subjected to high temperature deflection measurements. The cracking pressure measurements both at ambient temperatures and to temperatures of 625°C were carried out using a high temperature sandbath. Cracking pressures for the ceramic valves were relatively constant as a function of temperature and ranged from 8.44 ± 0.182 to 26.455 ± 0.186 psi for the 16 to 10 TPI respectively. The experimental data for cracking pressure from the deflection measurement of the springs was correlated to a metal spring design equation after some modifications. A variable pitch ceramic spring was also successfully designed and machined.