Blundell Blakeborough P3695 valve sizing pockets slide rule 1960 England

This plastic slide rule was made by Blundell from England in the 1960’s with designation P3695. It was specially produced for the Blakeborough brand, known for their quality valves. This slide rules calculates liquids by volume and weight, set to the flow coefficient, including factors like steam/gas vorm, pressure drop and gravity. using settings on the back as well. It comes with the original (non signed) leather sleeve. The slide rule has 2 sides and 1 comes originally with one cursor, which can be used on the back as well when needed. Everything is complete and in great condition with minimal signs of use and age. It measures ca. 20 cm or 8 inches long. Do check the video below on how to work your vintage man tool: slide rule operation instructions!