Issuing body
API
Latest edition
5th Edition (2014, R2021)
Region
USA, Global
Equipment items
6
Scope
Vibration, axial-position, bearing temperature monitoring for rotating machinery.
Key requirements (7)
- Machinery protection systems for rotating equipment.
- Standard sensors: 8 mm proximity probes (eddy current), velocity sensors, accelerometers, KPH probes for speed.
- Signal: 200 mV/mil sensitivity for proximity probes (5 V across 25 mil gap).
- Standard alert/shutdown: 25 µm Alert / 50 µm Trip on shaft displacement (typical, tunable).
- Bearing temperature RTD: 100 Ω Pt; 110 °C Alert / 120 °C Trip typical.
- Casing vibration (accelerometer / velocity): 7.6 mm/s RMS typical alert for centrifugal machines.
- API 670 monitoring system has 2-out-of-3 voting for trips, with bypass keys for maintenance.