Figure 1 – Typical PFD for an Instrument Air Supply System Figure-1 depicts a typical process flow diagram (PFD) for instrument air supply system. As shown in figure-1, instrument air supply system is typically comprised of filters, compressors, knock out drums, aftercoolers, intercoolers and air drying (dehumidifying) packages. Air used for instrument air systems is … Continue reading Typical PFD for Instrument Air Supply System