Many of the problems encountered in fluidized bed operations can be linked to spargers and grid plates. Gas maldistribution, high attrition and erosion due to spargers and grid plates often results in frequent and premature shut down of the unit and replacement of some, if not all, of the components. Fortunately, these failures can be managed. Understanding the jet hydrodynamics from spargers and grid plates is critical in designing and operating a reliable sparger. Jet penetration, jet flow reversal and bubble hydrodynamics all contribute to the performance and reliability of fluidized beds. Using such criteria as pressure drop, orifice pitch and jet penetration length is a good start, but experimental and CFD results suggest that additional criteria need to be added.