Hello fellow mechanics.....i have recently replaced a 80hp refcomp compressor with a 90hp Handbell screw compressor.Reason for the replacement was refcomp is no longer in the United States and i needed parts/gaskets etc.Long story short i have a high pitch noise throughout the discharge line all the way to the evap condensor tower.I installed vibration eliminators on both the discharge and liquid line at the chiller.Still cant get rid of the noise in the discharge line.Im installing a vfd Friday to finish the quoted job and hoping this will help the hi noise pitch.It sounds like hi pitch sand in the discharge line....any ideas.: