Water Distribution 1

Head is measured in - Correct Ans-feet A plat is - Correct Ans-A map Which type of valve will prevent the collapse of a pipe - Correct Ans-Air-and-vaccume relief valve The highest degree of protection of a coated steel pipe is - Correct Ans-cathodic protection At which time of day is the age of the water stored in the distribution system the highest? - Correct Ans-In the morning One of chlorines advantages is that it - Correct Ans-has a persistent residual Chlorine gas is _____ times heavier than air. - Correct Ans-2.5 After a water storage tank has been chlorinated, which bacteriological test must prove negative before the tank is put back into service. - Correct Ans-Coliform test Which is the best and most reliable way of finding a very small chlorine leak? - Correct Ans-Use a chlorine gas detector and place it near any area suspected of leaking. The minimum required free chlorine residual anywhere in the distribution system is - Correct Ans-a detectable level First draw samples for the analysis of lead and copper water must be collected from taps where the water has stood motionless in the plumbing for at least - Correct Ans-6 hours Samples collected for cloakrooms are collected in plastic bottles that must contain - Correct Ans-Sodium thiosulfate The volume of a sample for coliform compliance is - Correct Ans-100 ml If a water sample is not analyzed immediately for chlorine residual, it is acceptable to be analyzed within - Correct Ans-15 minutes The heart of a pump is called the - Correct Ans-impeller Which device serves the same function as the packing - Correct Ans-Mechanical seal Which is used to stop air leakage into the casing around the pump shaft - Correct Ans-seals Which is at the top of a stuffing box? - Correct Ans-Packing gland Which assembly holds the lantern ring and packing? - Correct Ans-Stuffing box Why is it important to monitor the speed of a variable speed pump? - Correct Ans-To prevent cavitation from occurring Which basic electrical unit is used to measure a materials opposition of flow of electricity? - Correct Ans-Ohm The first oil change on a pump should be done - Correct Ans-After a month of operation How often should the temperature of centrifugal pump motor bearings be checked with a thermometer? - Correct Ans-Once a month All sensors that respond to liquid pressure will preform poorly if _______ enters the air sensor - Correct Ans-Air Which agency sets limits on the concentration levels of harmful contaminants in potable water distributed to costumers? - Correct Ans-United States Environmental Protection Agency Which violations are most serious? - Correct Ans-Tier 1 A positive fecal coliform test must be reported to the primacy agency within 24 hours - Correct Ans-24 hours The number of monthly distribution system bacteriological samples is required is - Correct Ans-based on the population served Which is the approximate angle of response for average soils when using the sloping method for the prevention of cave ins? - Correct Ans-1.0 : 1.0 At what time of day is the age of the water stored in a distribution system the lowest? - Correct Ans-Late Evening Which type of maps should not overlap each other? - Correct Ans-Sectional maps Which of the following is a joint for ductile iron piping? - Correct Ans-Flexible ball joint The amount of feet in energy required to overcome resistance to flow in a pipe is called - Correct Ans-friction head The fire insurance underwriters recommend that no main should have a diameter less than - Correct Ans-6 inches Water velocities in a pipe should be limited to 5 ft/sec in order to - Correct Ans-minimize friction loss Which of the following is a type of joint in polyvinyl chloride piping? - Correct Ans-Bell and spigot type Which of the following is a type of joint in polyethylene piping? - Correct Ans-Thermal butt-fusion Which of the following is a type of joint for ductile iron piping? - Correct Ans-Flanged joint The height of the water in three differently shaped tanks is 22.4 feet. In which tank is the psi at the bottom the highest? - Correct Ans-It will be the same in all three tanks A water tank has a glass tube on its side showing the water level of the tank. What is its surface called? - Correct Ans-Piezometric surface Minor head losses are caused by - Correct Ans-Sudden changes in direction or velocity of flow Water mains should primarily be sized based on - Correct Ans-Adequate fire flow at a appropriate pressure The most desirable residential pressure ranges from - Correct Ans-50-75 psi Which is pipe strength expressed in? - Correct Ans-Tensile and flexural strength The resistance of a material to longitudinal pulling forces before it breaks is called - Correct Ans-Tensile Strength Most water systems use fire hydrants with two nozzles with diameters of ______ and one nozzle with a diameter of ____ - Correct Ans-2.5 in and 4.5 in Which type of pipe is durable and strong, has high flexural strength and good corrosion resistance, and is easily tapped? - Correct Ans-Ductile iron which of the following is a joint for concrete piping? - Correct Ans-Bell and spigot type Precipitative softening water treatment plants try to end up with distribution system water that is - Correct Ans-Slightly scale forming Which is a closed fire line? - Correct Ans-Unmetered connection for fire protection system Comprehensive maps of medium to large systems generally have scales ranging from - Correct Ans-500 to 1000 feet to 1 inch Sectional maps generally have scales ranging from - Correct Ans-50 to 100 ft to 1 inch Which type of centrifugal pumps are the most common? - Correct Ans-Radial flow impellers Name two types of joints for steel piping - Correct Ans-Expansion joint and rubber gasket joint The pressure during fire flow conditions should not drop below - Correct Ans-20 psi Which type of distribution system configuration has smaller mains that generally terminate as dead ends? - Correct Ans-Tree system