Water Distribution Questions and Answers with Verified Solutions

ater Distribution Questions and Answers with Verified Solutions The term aquifer refers to? Water bearing strata The use of a well supply as a source normally results in? Water of consistent quality Maximum Safe Yield of a water source is? The quantity of water that can be taken from a source of supply over a period of years without depleting the source permanently Movement of water through the ground is called? Percolation The inlet into a pump is generally called? Suction The rotating element in a centrifugal pump is commonly called? impeller Pumps are primed to? replace air with water inside the pump The joints in the rings of pump packing should be? staggered A vertical turbine is an example of a? centrifugal pump Which type of pump is most commonly used for high capacity wells? centrifugal The maximum practical suction lift of a properly engineered centrifugal pump is about? 15-25 ft An altitude vale is used to? regulate the water surface level in a water storage tank Leakage from a packing gland should be approximately? 10 drops/min Enclosed, open, semi-open are terms used for the designation and selection of? impellers Which of the following is a positive displacement pump? reciprocating Pumps must be lubricated? in accordance with manufactures specifications An operator hears a "pinging" sound coming from a pump, a possible cause is? cavitation The size of water mains, pumping stations, and storage tanks is primarily determined by? Fire protection requirements Firefighting may cause low pressure in an area of the distribution system. This low pressure might lead to? contamination of the system by back-siphonage Whenever possible the end of a distribution system should be __________ to prevent taste and odor problems? looped Cathodic protection means protection against? corrosion Proper alignment between two shafts can be checked using? straight edge & feeler gauge Friction in a pipeline can cause? loss of pressure Surface water treatment plants must monitor turbidity how often? every 4 hours An invert pipe is located? at the inside bottom of the pipe The three common types of plastic pipes are listed PVC, PE, & PB. These names refer to the? composition of the pipe The carring capacity of water mains is often reduced by? tuberculation What is the main reason for preventing cave-ins? to prevent injury or loss of life Distribution system pressure (even during fighting demands) should not be allowed to drop below _______ psi? 20 psi When employees are working in a trench 5 ft deep or more, an adequate means of exit, such as a ladder or steps, must be located no more than_________ ft away from them. 25 ft A trench must be shored if it is ______ ft or more? 5 ft A portable ladder must extend at least ______ ft above the upper surface of an excavated trench? 3 ft green pipe or green markings on the floor for construction projects would indicate what kind of pipe line? sewer line purple pipe or purple markings on the floor for a construction project would indicate what kind of pipe line? reclaimed or recycled line blue pipe or blue markings on the floor for a construction project would indicate what kind of pipe line? potable line (drinking water line) orange markings on the floor or orange spray paint for construction projects would indicate what kind of equipment in the ground? communication lines red markings on the floor or red spray paint for construction projects would indicate what kind of equipment in the ground? electrical lines