Updated from the 2001 edition, this new manual has expanded equations for eccentricity torque, added torque sign conventions and double offset disc design variables. Water operators receive complete information about the versatile butterfly valve in drinking water service. Engineers and technicians will gain a basic understanding of calculations for operating torque, head loss, and cavitation. Coverage includes valve design, torque, head loss, cavitation, testing, noise, and vibration. (Replaces ISBN 9781583210413)