Dears,

recently I met a vibration issue on rotary screw compressor's piping system (both suction and discharge lines). the compressor's RPM=3550. and alarm point from vendor is 8.5mm/s.
Over 20% time run above alarm point, Ucl=10.5 mm/s. and trip point: 21-22mm/s. friction will be considered due to one elbow with +Y restraint were designed.(close to compressor nozzle)

but I didn't do any dynamic analysis before. based above information, would you like to advise me which type dynamic analysis will be the best choice? how to decide/set control parameter such as:(1) cut-off frequency: is 50 reasonable or not (2)Max. No. of Eigenvalues Calculated (3) stiffness factor for friction (1000 is ok or not)....

and how to estimate the natrure frequency of piping system? which range should be acceptable? what should I do?

Thanks per advance for your great help and explanation.


Regards
Jason