I do that, but there is still air in the whip. I know this because when I shut the system down I purge the air down to 1150 psi, then I drain out all the condensation. I bleed out any remaining air (via the purge valve on the whip) but there is still air in the whip, because at that point if I open the fill valve air comes out. My question is should I open the fill valve and let that air escape or keep it in there.
Have a look at this schematic, it's from
this website:
The compressed air comes from the last stage on the compressor and enters the aftercooler. This is a long airline behind the fan of the compressor. Next it goes through a NRV (non-return valve), through a filter and finally a PMV (pressure maintenance valve).
The NRV prevents air to flow back to the compressor when the condensate is drained.
The PMV prevents air to flow towards the filling hose when the pressure is too low (<140bar).
Note that in this picture, one should place the NRV
after the last separator
if this separator is drained every 15 minutes and stays open when the compressor has stopped.
The Air Filter thus stays pressurized all the time and cannot exchange air with the environment.
If you place the filter material (molecular sieve) out in the open air, it would slowly saturate with the moisture that is naturally present in air. This is also the reason why new filters are vacuum sealed.
So:
- leave the filter pressurized
- completely drain the fill whip and completely drain all condensate collectors
