Blundell Wavin P3259 pipe friction slide rule 1969 England

This all plastic slide rule was made by Blundell from England in 1969 with designation P3259. It was specially produced for use with the product if the Wavin Company and was designed by A.D. Calthorpe. In 1969 the patent was still pending. It was used for calculating 4 pipe line variables (length, pressure loss, flow rate and diameter). It has a metric and Imperial Unit side. It comes with the original faux leather case as well as with the instructions card. Everything is complete and in very good condition with minimal signs of use and age. It measures ca. 34 cm or 12 inches long. Do check the video below on how to work your vintage man tool: slide rule operation instructions!