Improvements in motor operated gate valve design and prediction models for nuclear power plant systems. SBIR Phase 1, Final report, September 1990--April 1991

This research is aimed at improving the performance of a gate valves at nuclear power plants by developing improved predictive models and by identifying design improvements that overcome problems/limitations of the current gate valve designs. Phase 1 research is aimed at developing improved operating thrust models for the most common types of gate valves in use at US nuclear power plants. The research completed under Phase 1 addresses shortcomings in the current motor operated gate valve performance models by investigating localized contact stresses under disc tilting caused by fluid flow, by predicting inertial thrust overshoot, and by providing a comprehensive review of friction/galling data for gate valves. Instrumented valve test data provided by Duke Power Company were used to make limited comparisons with the analytical predictions. The areas that require systematic testing to further refine the predictive models are identified.