This manual provides guidance on generally available methods for using quarter-turn valves as well as their cavitation, ?ow, and torque characteristics. Questions about speci?c situations or applicability of speci?c valves and values should be directed to the manufacturers or suppliers. Information in this manual is useful for technicians and engineers who want a basic understanding of the calculations associated with the use and speci?cation of quarter-turn valves. The valve torque, ?ow, and cavitation coe?cients given are typical but generic values covering a variety of products. Actual ?ow, cavitation, or torque coe?cients for a particular manufacturer's valve should be used in calculations for a speci?c valve and application to obtain the highest calculation accuracy.