A full-scale computational fluid dynamics (CFD) model has been developed to investigate the complex flows in a product fill valve that is used for packaging liquid products. Detailed investigations of pressure, velocity and wall shear stress distribution were made to examine the effect of current valve design on CIP (cleaning in place), smooth operation and product-filling rate. The model revealed several key areas that can be improved for better CIP and increased filling rate of the valve. Formation of reverse flow was observed at the outlet and comparatively low shear stresses were observed at the wall regions, causing reduction in filling rate and poor CIP performance of the valve. Cavitation occurs in two regions, within the flow domain, causing an objectionable sound level of the device and a reduction in filling efficiency. Finally, several possible modifications have been suggested to eliminate these problems, which will enhance the product quality, reduce the operating cost, and improve the performance of the valve through better CIP performance. (c) 2007 Elsevier Ltd. All rights reserved.