Emerson SZV22 Manuale Utente

These procedures describe how to drain oil from the system and to replace the oil after draining.

Under normal operation, the Compressor and oil circuit remain under pressure when the Compressor 
is turned off. This pressure can be used to drain most of the oil. It is also possible to use the gas supply 
pressure to force oil out of the Compressor Module. In some cases it may necessary to pressurize the 
module with an inert gas to remove the oil.

1.  Turn the knob on the backseating control valve fully counterclockwise.

2.  Connect the backseating control valve to the Schrader valve near the bottom of the fi rst-stage oil 

separator, shown in Figure 16.

3.  Connect one end of the oil transfer hose to the backseating control valve.

4.  Place the free end of the hose into a suitable container and turn the knob on the backseating control 

valve clockwise to open the Schrader valve and open the oil transfer hose ball valve. 

5.  Leave the valves open until the oil stops fl owing and gas comes out of the hose; close the valves.

6.  Relocate the hose to the Schrader valve on the inlet of one Compressor and repeat Steps 5 and 6. 

Repeat for the other Compressor on the Compressor Module.

7.  Move the hose to the Schrader valve on the oil cooler and repeat Steps 5 and 6.

8.  Close the valves, remove the service hose and replace the protective caps on all Schrader valves.

9.  Note the volume of oil that has been drained from the Compressor Module; replace the oil as 

described in the next section, Replacing Oil on page 24.