Investigation into the effect of manufacturing variations on the performance of a high-performance servo valve

The project was an investigation into the effect of manufacturing variations on the performance of small high-performance servo valves. In association with the project a survey of the instrumentation used was conducted. This instrumentation had been developed by the Servo Valve Section of the English Electric Aviation Co. Ltd, (Stevenage). The manufacturing variations which affect the performance of a valve are those which control the shape of the metering edges, and the relative positions of the metering edges. It was the study of the effects of these variations that the work of the project was concentrated [on]. The final product of the project was a computer programme which predicted the performance of a particular four-way hydraulic valve for which practical results were available.