Depending on the size of the NRL the liquid line and discharge lines are equipped with isolating valves. The liquid line valve can be closed, the compressor section can be pumped down to one or two pounds, the hot gas line valve can be closed. The remaining refrigerant pressure can be vented. The compressor repairs can be made as per good refrigerant practice. Evacuate the compressor section add a small charge of refrigerant to raise the pressure to one or two lbs. Open up the isolating valves and restart the unit.
