ABSTRACT
A penstock is a pipe that conveys the flow from the forebay to the turbine. The penstock pipe starts downstream of the forebay where the ground profile is much steeper than the headrace alignment. The potential energy of the water at the forebay is converted into kinetic energy at the turbine via the penstock pipe. Because the flow is conveyed under pressure, it is important for the pipe design to be safe. Cases have been reported in which the penstock pipes have burst. Because the penstock is on steep ground slopes, such a pipe burst can instantaneously cause landslides and other stability problems. Furthermore, penstock installation is often challenging and requires safe and careful work as shown in Figure 7.1. Sometimes a long pipeline is used to convey water from the headworks to the forebay; in such cases, the penstock is referred to as the headrace pipe.
