James D. Tison and Kenneth E. Atkins are senior staff engineers at Engineering Dynamics Incorporated in San Antonio, Texas. They have over 20 years of experience each in pulsation and vibration control of reciprocating machinery. They are members of the API 618 sub-task force on pulsation and vibration control. The document discusses changes to pulsation and vibration control requirements in the proposed 5th edition of API 618 for reciprocating compressors. It introduces different design philosophies for pulsation control and discusses challenges with relying solely on mechanical analysis for design. Accurately predicting mechanical natural frequencies is difficult due to uncertainties, and small components can experience high vibration even if main piping vibration is low. The document advocates for