Gabrial,
You have not filled up sufficient process description here so it is very difficult to help u in understanding the system. It is not expected a steady considerable flow of oil in reservoir from hydrocyclone. That is why there is no level control. However I suppose there is high and low...
Inlet Guide Vane Regulate the mass flow through compressor. IGV changes the pressure as first stage impeller sees. By throttling IGV, pressure drop is increased causing density to drop and reduction in mass flow is achieved. IGVs are required to improve over all efficiency of compressor when...