The mechanical analysis uses dynamic calculations to determine the natural frequencies of a piping system.  Natural frequencies are a function of temperature, piping configuration and size, stress, and support structure stiffness.  A mechanical analysis will be conducted using Caesar II to determine mechanical natural frequencies.  The first three piping natural frequency modes will be compared to the first two excitation (driver) frequencies to avoid mechanical resonance using an appropriate separation margin. 

This analysis requires an accurate piping model, including piping support stiffness if supports cannot be assumed rigid, to identify mechanical natural frequencies.  Once the analysis is conducted, Compression Dynamics will recommend modifications to bring the system into compliance with API 618.  If the separation margins cannot be reasonably achieved, Compression Dynamics has the ability to perform a forced response analysis, if required, to calculate the additional stresses due to natural frequency excitation.

Separation Margins for API 618 can difficult to navigate.  Compression Dynamics will work with your engineers and designers to achieve the appropriate level of system stiffness.