Water distribution system operation and maintenance test review correct 100%

Water distribution system operation and maintenance test review correct 100% What is the purpose of water distribution systems? - ANSWER To deliver adequate quantities of water at sufficient pressure at all times under continually changing conditions while at the same time protecting water quality What is the purpose of vacuum, pressure-relief, and pressure-reducing valves? - ANSWER To prevent pipe damage from negative or excessively high pressures Under what conditions is the solid-sheeting shoring method used? When it is necessary to - ANSWER excavate in materials that will not stand in a vertical position When making pipe extensions, why are wet taps preferred over dry taps? - ANSWER Because any time the pressure in a pipeline is removed, contamination may more easily enter that line What problem can occur when air gets into the water in a pipeline and the air collects forming pockets of air? - ANSWER Air pockets can increase the resistance to flow or stop the flow of water completely What is the advantage of the Venturi type of water meter? - ANSWER extremely accurate at low flows What could be the source of supply for a water distribution system? - ANSWER Purchased water connection, wells, treatment plant clear well Water distribution system mains are laid out in what types of systems? - ANSWER Grid, loop, tree(branching)