Refer to Figure 200-12 for a chart of capacity vs. pressure for horizontally- and vertically-split centrifugal compressors.
Normally, manufacturers do not design a compressor to match an application, they fit the application to one of a series of existing compressor casings or frame sizes. Therefore, check the manufacturer’s bulletins for data required to make selection estimates. Figure 200-24 provides data for a series of compressor casings based on a comparison of data from the industry.
In addition, the minimum discharge CFM (DCFM) should be considered. Current impeller designs limit impeller inlet CFM to approximately 300-500 ICFM. Thus, process conditions resulting in a discharge volume of less than approximately 250 DCFM may be unacceptable.