Modeling Suction and Discharge piping in a compressor station

I have a basic question regarding modeling piping in a compressor station.

Typically, the compressor is installed first and properly levelled and grouted.  The pipe (discharge and suction) is installed next and all adjustments to the piping are performed until the mating faces of the pipes and the compressor nozzles are accurately aligned. At this point all the gravity load from the empty pipe is carried by the supports on the pipes and no load is transferred to compressor nozzle. After assuring that the pipe and the nozzles are accurately aligned, the pipe is connecetd to the compressor nozzles. At this instant no load from the pipe is carried by the compressor nozzle. When the system is in operation the compressor nozzle will be subjected to all the loads (temperature, pressure, gas in the pipe) that occur in the system subsequent to the initial connection bewteen the pipe and the nozzle. How is this scenario correctly modeled so that when the reactions are printed, it will show zero reactions at the compressor nozzle?  Thanks.