Current practice in the selection of intake gates

Increasing competitiveness has led to an intense effort to reduce the costs of hydromechanical equipment. However, this should never result in increased risk for the installation. In reviewing current practice in the selection of intake gates, the author emphasizes that safety aspects should take priority over the equipment capital costs. Various methods for filling the penstock are evaluated: partial opening of the gate; the use of bypass valves installed in the gate; or valves and piping embedded in the concrete. The advantages, disadvantages and operational risks of the use of vertical lift gates with upstream and downstream skinplate and seals are discussed. The alternatives of installation of emergency gates, either in the upstream side or the downstream side of Kaplan and bulb turbines, are also analysed.