REDUCTION OF PEAK DYNAMIC LOADS ON PUMPING UNITS OF MAIN CANAL STATIONS.

The characteristic feature of the layouts of pumping stations of main canals with axial- and diagonal-flow pumps is the absence of gates on the discharge pipe of the pump. At such stations the pump is started on a water-free pipeline, and upon stopping the pump is separated from the forebay of the station by means of a siphon outlet or gate located in the forebay. The water is drained from the pressure pipeline through the pump into the lower pool, causing overspeeding of the pumping unit in the opposite direction and an increase of the dynamic loads on elements of the pump and structural elements of the station. The following suggestions were made to eliminate the unfavorable overspeeding regime. 1. Start and stop the pump on a specially provided no-load outlet from the pressure conduit with a closed gate on the pressure conduit behind the no-load outlet. 2. Use various brakes for complete stopping of the pumps or considerably reducing the rotational speed of the pump.