WATER DISTRIBUTION TEST 4 GRADED A+

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WATER DISTRIBUTION TEST 4 GRADED A+ What the primary objective of water distribution operators deliver safe and pleasant drinking water to the consumers what should the distribution operator do if ... there is a complaint about the water? record the info and have the problem investigated and notify the person complained and what corrective was taken. Most accidents result from carelessness and negligence why are adequate and reliable records very important? to document the effectiveness of your operation an greater obligation rest with whom, and why? operators because of the great number who drink the water from the distribution system purpose of the a water storage facility? provide a sufficient amount of water to average or peak demand.,needs for fire protection, industrial uses and reserve storage where are storage tanks are found in the distribution closest to the users, where higher pressure are needed and where land is available. what signifies and standpipes? the height is greater than their diameter where are standing pipes are located? high ground and near well field or point in the distribution system why are stand pipes preferred over elevated storage? easy to maintain, more accessible safer and less objectionable from aesthetic viewpoint Hydropneumatic or pressure tank are used mostly in what type of plant? small system wells, they are pressure vessels caution with the pressures relief valve. hydropneumatic or pressure tank should have what amount of air to operate sufficient. 2/3 or 1/3 air, otherwise cause the starting and stopping of the pumps causing damage. why should pressure tanks have a sight glass? to observe water to air ratio what is an disadvantage of pressure tanks? not enough storage to meet demand in cause of power outage, and little time to do maintenance what are surge tanks? protect water line due too excessive surge pressure, also use to control water hammer and regulate the flow of water where should surge tanks be located? close as possible to activity that create water hammering. name procedure for storage operating a storage tank. fill all tanks during off peak hours, maintaining specified psi at critical points in distribution. Disadvantage of Variable speed pumps? Costly to operate. what normal operation procedure that can reduce cost? time-of day concept, pumps are only used during the off peak hours of electrical usage. 10pm6am what can eliminate taste and odor problems in a storage tank. periodally allow it to empty and be refilled. the purpose of altitude-control valve? prevent overflow from the storage tank, maintain a constant water level as long as water pressure in distribution is adequate. what is the simplest way to control level in storage? electrodes, but most problem arise when they are hard to reach and they get corroded. what is ultrasonic signals in storage tanks? transmitter sends a continues high-frequency to a receiver and when the water cover it the signal is broken. what are pressure switch in storage tanks? response to changes in pressure in the tank to control pumps what is the main problem with radio frequencies? bad weather and lighting cause voltage interferes or disrupts Name item needed to operate a centrifugal pump. impeller submerged in water, never operate until prime. what is JTU's Jackson turbidimeter is a Visual method 3 type of maintenance ? preventive, predictive, and corrective what's corrective maintenance? a problem already exist to be repaired how long should the outside or inside of painted pipes or tanks last? outside should last 5 yrs and 3-5 yrs. inside a tank. when is the best time to take out of service a storage tank in most cases? october - April two type of paints for refurnishing storage tanks. short life coating-protection for 6 yrs., long life-10yrs. before entering a tank what oxygen is safe? 19.5-23.5 oxygen name some items that increase corrosion dissolve oxygen, carbon dioxide, dissolved minerals, salts. Electrical control of corrosion is Cathodic protection what is known as a corrosion inhibitor? any substance that promotes film formation on the surface to be protected, example: lime, soda ash, and caustic soda when pH is above equilibrium what coating is form? calcium carbonate to form on the surface protecting it from corrosion what chemical that is commonly used in corrosion control? Sodium Hexamethphosphate(polyphosphate) tie up a variety of ions what is the commonly used feed rate for polyphosphates? no more than 5 mg/L what is the key to a successful cathodic protection program? replacement of sacrificial anodes , inspected at least yearly(made of mg & zn) when spraying a tank how many people should be available? 1 in the tank and 2 backups people for assistance if emergency After chlorinating with 200 ppm of a tank, what is the procedure for filling it with water. let stand for least 30 minutes, fill with water with residual of 3.0 mg/L and let stand for 3-6 hours, then take BACT-T samples. what are other methods to disinfect a new tank? fill up tank with at least 10mg/L of water for 24hrs. Name a stipulation concerning disinfecting a new tank? first time newly constructed tank, 50 ppm (instead of 3ppm) when placing a tank back in service for 24 hours. what disinfection method is used for different size storage tanks. tank over 100,000 gal. use gaseous chlorine, below 100,000 gal. us HTH when divers are used to inspect a tank what is the proper procedure? they need to be disinfected with 200 mg/L name procedures to prevent icing in storage tanks. flow rate into and out adjusted to allow circulation 50% variation within 24 hrs. or used air bubble to circulate water how often maintenance should be done on storage tanks? covered tanks every 3-5 yrs. and uncovered annually or twice a year. most booster pump are connected to service high elevation and controlled by? solenoid switch to altitude valve. what are regulator stations main function? reduce psi and maintain even acceptable psi down stream. what is excessive psi and what's normal psi in the system? 100 and 60-90 how often should you operate and overhaul regulator station? once a month and inspected annually record of data, date of installation, start up data, failure, and service performed on equipment should be record on what? nameplate what type of ventilation is necessary storage facility force-draft Hydraulic transients are commonly called? surge, shock or water hammer the major hydraulic concerns of a water distribution system are whether water will flow, & in what direction water should be delivered with a working pressure of? 35 what would be the absolute psi in distribution system? 20 roughness inside a pipe is called? C-factor, high the factor the smoother the pipe when do you will never used thrust block or kickers? when the pipe joints are fixed(welded) water hammer surges in the pipeline resulting from rapid increase or decrease in water flow. what are surge chambers? tank connect to the pipe to lessen the shock of water hammering in commercial districts what is the desired psi? 75 Minimum size pipe commonly used today? 6 inches what is the absolute minimum size pipe installed? 4 inches Dead end exceeding 1000 ft what should be the pipe size 6" dead end exceeding 2000 ft. what should be the pipe size 8" Valve in the distribution should be installed every 1000 ft. hydrant in the distribution should be installed every 500 ft. why type of material is commonly used in transmission lines concrete with steel cylinder where are distribution storage located? close as possible to the center of use. Ideally, the intake and outlet should be located where on storage tanks. opposite sides when a single reservoir is taken out of service the psi shouldn't be allowed to drop below? 20 what type of valve is install on the booster pump? check valve on the discharge side water distribution systems are laid out in grid, loop and tree(branching) most type of pipe layout? grid what is cathodic protection? electrical system for prevention of rust, and corrosion. class of working pressure are commonly use? 4, and 100,200,250 psi what causes shear breakage of water pipes? earthquakes what causes beam breakage? unevenly supported along it length min desirable pipe diameter is 6 " pipes should certainly not be less than 4" ductile iron pipe replace what type of pipe in water system? cast-iron pipe why used ductile iron pipe over cast-iron pipe? it will resist bending and twisting without breaking ductile iron is lined in the inside to prevent what? tuberculation- formation of small mounds of corrosion product. a lined pipe may have__________ the friction loss of an unlined pipe. 1/2 what can protect external pipe corrosion bituminous coatings, and polyethylene wrap when using concrete pipe what is the difference when it concern prestressed can withstand 250 psi and without stressed only 50 psi asbestos cement is immune to what? electrolysis can not tuberculate as do metal pipe. disadvantage of AC Pipe low flexural strength break when it is bent three types of plastic pipes general in usage? PVC, PE and PB, (pvc can reach up to 16") for pipes 24" or larger which pipe is recommended? reinforced concrete pipe what type of joints is most commonly used today? push-on(bell & spigot pipe) steel metal pipe is susceptible to corrosion what is used to protect it? cement mortar,, cold applied mastic, or coal tar enamel. R/W stands for what? right of ways how to check for metal pipe damage? tap with hammer, if it doesn't ring or hum it is damage when installing pipe where should the pipe be laid down for proper installation? along the trench opposite of the excavated material when stacking up plastic pipe it shouldn't be exposed to sunlight for more than how many days? 30 water mains need at least ________ of cover over the top of the pipe 30 inches trenches should be how wide for pipe installation? 1 to 2 ft. wider than diameter of the pipe [Show More]

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