Thales Cryogenics has an extensive background in delivering linear and rotary coolers for military, civil and space programs. During the last years several technical improvements have increased the lifetime of all Thales coolers resulting in significantly higher Mean Time To Failure (MTTF) figures. In this paper not only updated MTTF values for most of the products in our portfolio will be presented but also the methodology used to come to these reliability figures will be explained. The differences between rotary and linear coolers will be highlighted including the different failure modes influencing the lifetime under operational conditions. These updated reliability figures are based on extensive test results for both rotary and linear coolers as well as Weibull analysis, failure mode identifications, various types of lifetime testing and field results of operational coolers. The impact of the cooler selection for typical applications will be outlined.
This updated reliability approach will enable an improved tradeoff for cooler selection in applications where MTTF and a correct reliability assessment is key. Improving on cooler selection and an increased insight in cooler reliability will result in a higher uptime and operability of equipment, less risk on unexpected failures and lower costs of ownership.
Original publication: Proc. SPIE 8353
W. van de Groep , H. van der Weijden, R. van Leeuwen, T. Benschop, Thales Cryogenics BV. Eindhoven, The Netherlands. J.M. Cauquil, R. Griot, Thales Cryogenie SAS, Blagnac France.