| dc.description.abstract | Active magnetic bearings (AMBs) are being used for an increasing number of compressors in the oil and gas industry. The applications include cryogenic compressor-expanders, subsea processing, pipeline and other process compressors. The use of AMBs allows totally sealed machines, reduced maintenance, elimination of the lube oil system, enhanced monitoring and diagnostic capability, and provides extremely high levels of reliability. Over the past several decades, these bearings have gone from unique, one-of-a-kind demonstrations to being the bearing of choice in an increasing number of applications. To address the more widespread use of AMB supported rotors, the eighth edition of API 617 includes a new annex which, for the first time, presents an extensive set of specifications that AMB supported compressors and compressor/expanders must meet for API service. The requirements of this annex cover basic design issues, rotordynamics, testing, and auxiliary bearings. This tutorial presents an overview of the new requirements and their rationale, resulting from a joint effort and balance of AMB manufacturers, turbo machinery OEMs and end user experience. Special considerations related to the unique requirements and issues related to rotordynamics are presented. Several examples will be discussed. | en |
