Characterization of centrifugal compressors´ thermo-elements used in journal and thrust bearing temperature monitoring

Recently the availability of operating machines has become a key driving factor in item selection among both supplier and customer. Actually production loss targets should be below one stop every two years; unfortunately because of auxiliary components complexity, sensors and transmitters in particular, failures occur often and affect the whole machine availability. In order to avoid unscheduled stops we performed a reliability study on a particular class of thermo-resistances used in crude oil extraction. The main factors affecting this kind of devices are oil troubling forces acting on sensor textures which lie on the thrust bearing. This problem arises as a consequence of the machine rotating speed, the vibrations which affect the head configuration and stability, and the assembling phases. In this paper we supply a description of the solution implemented in order to obtain a stronger and more reliable device and the accelerated test plan followed in order to prove it. Finally we performed a Failure Tree Analysis (FTA) in order to take into account maintenance as well as assembling operations.