Water distribution grades 3 & 4
what is the net positive suction head available given the following data? will the pump cavitate if the net positive suction head required is 18.4 ft 1.11 ft/in = Hg atmospheric pressure = 29.8in Hg static suction lift = 15.1ft friction head loss = 0.6ft vapor pressure at 12 degrees F = 0.50ft
17ft
what is the commonly accepted water velocity in water mains at a maximum flow?
2-4 ft (sec(0.6-1.2 m/sec))
how many times higher than the normal operation pressure should the pressure rating of distribution system piping be?
2.5-4.0 times
how many gallons per minute should a flowmeter register if a 10.0 in diameter main is to be flushed at 5.10 ft/sec
1.250 gpm
what is the maximum contaminant levels for arsenic
10 micrometers/L
a storage tank has a capacity of 34.0ft. currently there are 22.89ft of water in the tank. what would the scada reading be on the board in milliamps (mA) for a 4 mA to 20-mA signal?
14.8 mA
according to the us environmental protection agency's primary drinking water standards, what is the maximum contaminant level for alpha particles
15 pCi/L
according to the us environmental protection agency's primary drinking water standards, what is the maximum contaminant level goal for copper
3 mg/L
what is the motor horsepower, if 200 horsepower is required to run a pump with a motor efficacy of 88% and a pump efficacy of 74%
310 mhp
a tank 84.0ft in diameter and 24.25ft high at the overflow requires disinfection. how much 12.5% sodium hypochlorite that is 9.59 lb/gal will be requied for a dosage of 50.0 mg/L?
350 gal
water systems are required to achieve at least (blank) removal and inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer
4 log
a well that is 210ft in depth and 14.0in in diameter requires disinfection. the depth to water from the top of the casing is 91ft. if the designed dose is 50.0 mg/L, what is the number of pounds and ounces of sodium hypochlorite
43 oz of NaOCl
when converting from US pipe sizes, what is considered the metric equivalent of 0.25 in?
8 mm
automatic control
a system in which equipment is controlled entirely by machines or computers without human intervention under normal conditions
scanning
a technique of checking the value of each of several instruments, one after another. used to monitor more than one instrument over a single channel
polling
a technique of monitoring several instruments over a single communications channel with a receiver that periodically asks each instrument to send current status
pulse-duration modulation
a telemetry-signaling protocol in which the time that a signal pulse remains on varies with the value of the parameter being measured
remote manual control
a type of system control in which personnel in a central location manually operate the switches and levers to control equipment at a distant site
direct manual control
a type of system control in which personnel manually operate the switches and levers to control equipment from the physical location of the equipment
duplexing
a type of telemetry in which a single line allows the operator to send the instrument signals that are received at the central location back to a remote site
rural water system
a water system that has been established to se3rve widely spaced homes and communities in areas having no available water of very poor quality
purchased water system
a water system that purchases water from another water system and so generally provides only distribution and minimal treatment
groundwater system
a water system using wells, springs, or infiltration galleries as its source of supply
head loss
amount of energy used by water in moving from one location to another
relay
an electrical device in which an input signal, usually of low power, is used to operate a switch that controls another circuit, often of higher power.
solenoid
an electrical device that consist of a coil of wire wrapped around a moveable iron core. when a current is passed through the coil, the core moves, activating mechanical levers or switches.
piezometric surface
an imaginary surface to which groundwater rises under hydrostatic pressure, to produce springs
proportional control
automatic control in which a valve or motor is activated slightly to respond to small variations in the system, but activated at a greater rate to respond to larger variations
Per-capita water use
average day demand divided by number of residents connected to the water system.
how is the wire-to-water efficiency obtained
by multiplying the motor and pump efficiencies together
what is the formula for calculating chlorine demands
chlorine demand(mg/L) + chlorine residual(mg/L) = chlorine dosage(mg/L)
analog
continuously variable, as applied to signals, instruments, or controls
the (blank) is the outlet or high pressure, side of a pump
discharge side
grid systems
distribution system layout in which all ends of the mains are connected to eliminate dead ends
arterial loop system
distribution system layout involving a complete loop of arterial mains around the area being served with branched mains protecting inward, such a systems minimizes dead ends
tree system
distribution system layout that centers around a single arterial main, which decreases in size with length. branches are taken off at right angles, with subbranches from each branch
what is the formula to convert milligrams per liter concentration to pounds per day
feed rate (dosage) (flowrate) (conversion factor)
the size and capacity of a water distribution system is based largely on?
fire demand
in what type of water distribution layout are all ends of the mains connected to eliminate deadends?
grid system
what type of water systems uses wells, springs, or infiltration galleries as its source of supply?
ground water system
what is the term for the amount of energy used by water in moving from one location to another
head loss
friction head loss
head lost by water flowing in a stream or conduct as a result of disturbance set up by the contact between the moving water and its containing conduct and intermolecular friction
secondary instrumentation
instruments that respond to and display information form primary instruments
what is the term for the water use during the 24 hours of highest demand during the year?
maximum day demand
what term refers to the highest level of disinfectant allowed in drinking water
maximum residual disinfectant level
disinfection by-products (DBPs)
new chemical compounds that are formed by the reaction of disinfectants with organic compounds in water. At high concentrations many DBPs are considered a danger to human health
if a water system collects at least 40 samples per month for there analyses of total coliforms, what percentage of total coliform positive samples are acceptable for the system to remain in compliance with the maximum contaminant level for total coliforms?
no more than 5%
continuous chlorine residual monitoring is required where the water enters the distribution system under the surface water treatment rule when the
population served is >3,300 people
which of the following is the most common cause for surges in the distribution system
power failure shutting down a pump suddenly
Static Pressure
pressure that exists in water although the water does not flow
Fire flow
the rate of flow usually measured in gallons per minute(gpm) or liters per minute(L/min) that can be delivered from a water distribution system at a specified residual pressure for firefighting. when delivery is to fire depts. pumpers are specified residual pressure is generally 20psi (140 Kpa)
WIRE-TO-WATER EFFICIENCY
the ratio of the total power input to a motor and pump assembly, to the power output expressed as a percent, the combined efficiency of the pump and motor
control terminal unit
the receiver in a digital signal system
Velocity
the speed at which water moves, measured in ft/sec or m/sec
total static head
the total height that the pump must lift the water when moving it from one point to another, the vertical distance from the suction free water surface
average day demand
the total system water use for 1 year divided by 365 days in a year.
a water system using conventional filtration treatment does not have to use enhanced coagulation to achieve the total organic carbon (TOC) percent removal if?
the treated water quarterly running average TOC is less than 2.0 mg/l
Maximum day demand
the water during the 24 hours of highest demand during the year
A regulated organic contaminant concentration that exceeds the MCL
tier 2 violation requiring public notification with 30 days
regarding fire flow, mains smaller that 6 in (150 mm) should be used only
to a complete a grid
what are the basic components of every telemetry system?
transmitter, transmission channel, and receiver
A(n) (blank) layout centers around a single arterial main, which decreases in size with length
tree system
digital
varying in precise steps as applied to signals or instrumentation and control devices
surface water systems
water that is located atop Earth's surface (river, lakes, soil moisture, atmospheric water vapor)
on-off differential control
A mode of controlling equipment in which the equipment is turned fully on when a measured parameter reaches a preset value, then turned fully off when it returns to another preset value.
Surge pressure
A momentary increase of water pressure in a pipeline due to a sudden change in water velocity or direction of flow
pump center line
An imaginary line through the center of a pump
The pressure during fireflow conditions should not drop below?
B. 20 psi (138 KPa)
what is plotted on the horizontal scale(x-axis) of a pump curve?
Capacity (flow rate)
What type of distribution system configuration has smaller mains that generally terminate as deadends?
D. Tree system
Hydrostatic Pressure
Pressure exerted by water at rest
Dynamic Pressure
Pressure that exists in water as moving energy
what is the formula for calculating the quantity of water that flows through a pipe?
Q= A x V or quantity of water= cross sectional area of pipe x velocity of flow
variable frequency
Relating to a type of telemetry signal in which the frequency of the signal varies as the parameter being monitored varies.
regulations that govern US water supply and treatment are developed by the US environment protection agency under which act?
Safe drinking water act
dynamic suction head
The energy head available on the inlet side of a pumping system, reduced from the static suction head by the amount of friction and minor losses.
Water Hammer
The potentially damaging slam, bang, or shudder that occurs in a pipe when a sudden change in water velocity (usually as a result of someone too-rapidly starting a pump or operating a valve) creates a great increase in water pressure.
direct-wire control
a system for controlling equipment at a site by running wires from the equipment to the onsite control panel
pump characteristic curve
a curve or curves showing the interaction of speed, dynamic head, capacity, brake, horsepower, and efficiency of a pump
instantaneous flow rate
a flow rate of water measured at once particular instant, such as by a metering device involving the cross sectional area of the channel pipe and the velocity of the water at that instant
semiautomatic control
a form of a system control equipment in which many actions are taken automatically but some situations require human intervention, under normal conditions
voltage
a measure of electrical potential / in telemetry, a type of signal in which the electromotive force varies as the parameter being measured varies
supervisory control and data acquisition
a methodology involving equipment that both acquires data on an operation and provides limited to total control of equipment in response to the data
what type of water system is established to serve widely spaced homes and communities in areas having no available ground water or having very poor quality?
rural water system
dynamic water system
the description of a water system when water is moving through the system
static water system
the description of a water system when water is not moving through the system
static suction lift
the difference in elevation between the pump center line of a pump and the free water surface of the liquid being pumped in a static suction lift measurement, the piezometric surface of the water at the suction side of the bump is lower than th pump, otherwise static suction head is measured
dynamic discharge head
the difference in height from the pump center line a the pump discharge to the point on the HGL directly above it
minor head loss
the energy losses that result from the resistance to flow as water passes through valves, fittings, inlets, and outlets of a piping system
current
the flow rate of electricity measure in amperes / in telemetry, a signal whose amperage varies as a parameter being measured varies
pressure
the force on a unit area of water
Peak hour demand
the greatest volume of water in an hour that must be supplied by a water system during any particular time period, such as a year to meet customer demand
suction side
the inlet or low-pressure side of a pump
Maximum contaminant level (MCL)
the maximum permissible level of a contaminant in water as specified in the regulations of the Safe Drinking Water Act
power in hydraulics or electricity
the measure of the amount of work done in a given period of time, the rate of doing work measured in watts or horsepower
work
the operation of a force over a specific distance
discharge side
the outlet or high pressure side of a pump
receiver
the part of a meter that converts the signal from the sensor into a form that can be read by the operator, also called the receiver-indicator / in a telemetry system the device that converts the signal from the transmission channel into a form that the indicator can respond to
indicator
the part of an instrument that displays information about a system being monitored, generally either an analog or digital display
