Flow Induced Pulsation (FIP)

Fluid flows in piping passing the entry to a closed end sidebranch, can generate vortices which coincide with strong acoustic resonances in the sidebranch and result in pulsations being generated which propagate both upstream and downstream within the main line. These pulsations impart periodic, mainly axial, forces at pipe bends and this can quickly shake the whole pipe system.

PIPAC® Analysis
Spectrum utilizes world-leading software package PIPAC® (PIPework ACoustics) to determine acoustic resonances in complex closed-end sidebranches. With 30 years of use in determining acoustic resonances in complicated branch networks, this package enables accurate and realistic determination of the major acoustic resonance frequencies.

Effect on Pipework
Small bore connected pipework may flex excessively or may have incorrect supports. Either way, high stress concentrations may arise leading to fatigue failure at connection points.

Mitigation
Modification of the supports and bracing of the small bore piping and analysis using FE package ANSYS® can detune responses from the frequency of pulsation.