API 688 establishes the minimum requirements for controlling pulsations and vibrations in systems powered by positive displacement (PD) machinery. Because PD machines—like reciprocating compressors—move fluid in discrete "pulses" rather than a steady flow, they naturally generate pressure waves that can cause structural fatigue and catastrophic failure if not properly managed.
Acoustic pulsation forces act on piping elbows and changes in area, generating mechanical vibration. API 688 requires a coupled analysis—meaning the mechanical natural frequencies of the piping system must be evaluated against the forcing frequencies from pulsation. api 688 pdf
API 688 addresses systems prone to fatigue and structural damage caused by pulsations and vibrations. It specifically covers: Southwest Research Institute API Std 688 - Accuris Standards Store API 688 establishes the minimum requirements for controlling
⭐⭐⭐⭐ (4/5) – Essential for reliability engineers, but dense for beginners. API 688 requires a coupled analysis—meaning the mechanical