Patent ID: 7692553

Claim:
A leak detecting system for a rotary union, the rotary union comprising a shaft rotatably supported within a housing, the shaft having therein a first passage for conducting a fluid axially through the shaft, wherein the shaft terminates within the housing at a terminal end exposing the first passage, wherein the rotary union further comprises a first annular seal element affixed to the terminal end, wherein the first seal element coaxially abuts a second annular seal element that is affixed about a second passage that is stationary with respect to the housing, the first and second seal elements normally sealing against each other such that the fluid passes between the second and first passages, the leak detecting system comprising: a sensor element located within the housing and surrounding the shaft, the sensor element being configured to detect the fluid, if present, at any position surrounding the shaft; and at least one electrical conduit connected to the sensor element for carrying a signal indicating that the sensor element has detected the fluid at any position around the shaft.