This Practice provides guidance for the application of instrumentation to monitor rotating equipment for machinery protection, enhanced performance, and predictive maintenance.

This Practice describes the following:
a. Typical applications for continuous on-line monitoring of rotating equipment
b. Types of monitoring that could be provided and where they are typically applied
c. Installation considerations specific to type of monitoring equipment
d. General calibration and functional checkout considerations
e. Documentation recommendations

Types of rotating equipment covered in this Practice include centrifugal compressors, centrifugal pumps, gears, steam turbines, gas turbines, electric motors and generators, and other shaft driven equipment.

This Practice does not cover the design of anti-surge controllers, performance controllers, seal gas systems, and other equipment auxiliary systems. For information on surge detection and anti-surge control, refer to API 670.