Copper and alloys of copper are not applicable for refrigeration, plan
ts with NH3 refrigerant. The use of new oils in NH3-systems, the discu
ssion about dry piston compressor concept and the possible use of NH3
at smeller capacities lead to new test in the sector of material stabi
lity for NH3-systems. The tests for copper and its alloys show a remar
kable good stability.