Eliminate expansion joints in piping systems

An approach is presented for designing complex integrated mechanical systems such as fluid catalytic cracking units (FCCUs). This method can result in the elimination of expansion joints from interconnecting standpipes and other associated piping systems. The technique can be used with new and revamped facilities, and may be applied to any piping system subject to mechanical stresses where expansion loops cannot be tolerated. Significant savings are generated by eliminating the investment costs of the expansion joints and associated maintenance needs. Also, under certain conditions, slide valves may be relocated to the spaces previously used for the expansion joints. Slide valves control the flow of solids via a plate that slides across an opening. These are large valves that are hydraulically driven. Such a redesign can increase the driving force for catalyst circulation, boosting throughput, and offering a payback of only a few months.