Aspects of the invention are associated with the discovery of methods for operating rotary valves that reduce or minimize wear of the seal sheet, which is often the limiting factor in overall processing capability of the valve. The control of certain parameters associated with the rotary valve operation, and particularly the seating pressure of the seal sheet (e.g., the dome pressure), can extend the useful life of the seal sheet, thereby avoiding excessive maintenance and downtime costs. In preferred embodiments, control is on a real time basis.