The objective of pulsation analysis is to study (as per API 674) pressure variation in suction pipelines due to pressure waves when anyone pump out of two is running at rated speed.
An efficient transfer matrix approach is used with assumption of a steady pulsating flow condition that will not die-out over time. Also, one dimensional plane wave theory is assumed. The plane wave theory assumption holds for frequencies where the wavelength is larger than twice the pipe diameter. This assumption holds well for most gas systems below 200 Hz. For liquid systems and systems with small pipe diameters, the plane wave theory can be applied for frequencies of 500 Hz or more. A pulsation analysis has been done for Suction & Discharge lines without dampener and with dampener.
Results obtained from pulsation analysis of suction lines with dampeners, show pulsation peaks are under allowable limits as per API 674 3rd edition because pulsation waves generated by the pump are absorbed in pulsation dampeners and pipelines will not face any high peaks with these dampeners.