These ratios were in general design practice for single phase flow prior to about 1970. With the development of appropriate software for incremental analysis to equalize pressure drop in the various flow paths through and around baffles, such generalized design practice became obsolete to the expert practitioner. I was using a sliderule the last time I applied such practice. If you can estimate a large variance from these ratios for a single phase fluid, your equipment MIGHT benefit from an expert analysis with contemporary software.
