The occurance of pressure surge, waterhammer or pressure transient propagation within any fluid/conduit system is normal and frequent event that accompanies any change in the system operating condition. The aim of any study of unsteady flow must therefore be to understand the mechanisms of such transient propagation so that the possible severity of any event may be determined and suitable design decisions taken. This text provides the knowledge needed by engineers for an understanding of the governing mechanisms and methods of analysis and control of pressure transients. The book discusses the causes, and develops the theory, of transient propagation, and the dependance of transient severity upon fluid and conduit properties and the mode of system operation.