ESDU 83046 provides simple techniques and data for the estimation of the wave speeds in fluids contained in lined or unlined circular pipes, unlined non-circular pipes, lined or unlined circular tunnels and buried circular pipes. The data are applicable to liquids, gases, liquid/gas mixtures and liquid/solid mixtures. Some typical values of the bulk modulus, density and speed of sound of some common liquids, necessary for the estimation of the wave speeds in the contained bodies of the liquids, are included. Data are also given for water and steam over a range of temperatures and pressures. Fluid transients are the pressure changes that propagate through a contained fluid following a disturbance, such as a change in the flow rate, and are also known as pressure surges, hydraulic transients and, in water applications, waterhammer. The magnitude of the pressure changes is proportional to the speed of propagation, or wave speed, of the pressure waves.