Using Fiber-Optic Pressure Sensors To Detect Cavitation And Flow Instabilities In Centrifugal Pumps

Lecturepg. 133This paper introduces the benefits of applying the fiber-optic Fabry-Perot interferometer (ffpi) pressure sensor as a means of detecting cavitation and flow instabilities in centrifugal pumps. The need for monitoring dynamic pressure pulsations in pumps as a means of preventing catastrophic failures resulting from severe hydraulic fluctuations has always existed in the pumping industry. However, the ability to continuously sense such phenomena has heretofore not been available with conventional pressure sensors. The development of the ffpi pressure sensor has made high temperature monitoring in process pumps possible. Their ability to function reliably at temperatures exceeding 700 degrees F, and in hazardous environments, make them ideal for use in real-world process applications. Actual pump test stand data are presented, demonstrating how harmful hydraulic instabilities, such as cavitation and low flow instabilities, can be readily detected using this new sensor. Data from field tests involving typical process pumps are also presented showing actual cavitation and other flow maladies. For completeness, the authors present a practical analytical method for assessing dynamic pressure data to determine its severity