With an increasing number of vendor supplied design tools for the calculation of packing hydraulics, the basis of these design methods needs to be reliable-reflecting industrial operating conditions as closely as possible. Currently however, different vendor supplied design tools predict different results for some very similar packing types. This paper sets out to determine a reliable model for the hydraulic calculation of I-Rings(TM) (IMTP(TM) equivalent). I-Ring sizes from #15 to #70 were tested in the air-water system at medium to high liquid loads in the Sulzer Chemtech facilities. In addition, distillation tests with standard test mixtures under total reflux conditions were conducted. Based on these experimental data points, the model originally developed for structured packing was adapted for random packing. The capacity and pressure drop calculated by the model compared with the experimental data points were within +/- 4% and +/-20% respectively.