Single stage Vs 2 stage comp rack

Dear all,

We have built compressor rack 2 stage compressors and single stage compressors of Bitzer brand, using R22 operating at -35 / 45 deg C SST/SCT. However, I find the vibration level for the 2 stage compressor is greater than of single stage.

Anybody has good idea why is this the case and any good solution to minimise vibration level for 2 stage rack.

For both cases, I did not use vibration eliminator at both discharge and suction line for each compressors. And the outcome is vibration level for 2 stage comp is greater

rgds,
Kevin