So far, very few design correlations for interstage flow in MSF plants have been published, and their validation for a broad range of conditions is absent. Based on all experimental data with small-scale MSF units that was available to us, correlations for the orifice coefficient were developed for a wide range of flow and flashing conditions, in stages without and with downstream baffles, and a draft was presented at a past IDA congress. This paper recorrelates them in a much better way. These correlations are the first to use such a large amount of data, and the first to employ appropriate dimensionless variables. While their standard error and correlation coefficient are satisfactory, we note that the data came from a variety of sources and for channel widths of at most 0.53 m. Consequently, they should be used with some caution, and further extensive well-instrumented experiments are highly recommended.