ET 500 Two-Stage Piston Compressor Unit
1 trolley,  2 drive motor,  3 2nd compressor stage,  4 piston compressor,  5 1st compressor stage,  6 intermediate reservoir,  7 resistance thermometer,  8 switch box with digital displays,  9 differential pressure transmitter,  10 intake damper,  11 nozzle,  12 manometer,  13 silencer,  14 control valve,  15 safety valve,  16 pressure vessel 2nd stage,  17 pressure transmitter