Sectioned-model Hopkinson-Ferranti steam valve, made by Ferranti Ltd, with wooden stand.

One of Sebastian de Ferranti's most successful projects as an independent engineer was a Steam Valve. Ferranti's experiments with high pressure steam for his turbines showed conventional stop valves to be inefficient. Ferranti's valve was smaller but, by compressing the steam through the valve, did not reduce the amount of steam passed through it. The advantages were that the smaller valve halved possible leaking, reduced warping and was quicker to open and close. The successful stop-valve manufacturer, Hopkinson of Huddersfield, licensed the production of the valve, paying Mr Ferranti a 7.5% royalty on all sales. This sectioned model, made by Hopkinsons, clearly shows the mechanism and the reducing bore of the stream pipe.