Backflow Questions and Answers
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Actual Cross Connection ✔✔Any arrangement of pipes, fittings, or devices that connects a
potable water supply DIRECTLY to a non-potable source at all times.
Air Gap ✔✔In
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Backflow Questions and Answers
Already Passed
Actual Cross Connection ✔✔Any arrangement of pipes, fittings, or devices that connects a
potable water supply DIRECTLY to a non-potable source at all times.
Air Gap ✔✔In plumbing, the unobstructed vertical distance though the free atmosphere between
the lowest opening from any pipe or outlet supplying water to a tank, plumbing fixtures. or other
container, and the over flow rom of that container.
Atmospheric Vacuum Breaker ✔✔A mechanical device consisting of a float check valve and an
air-inlet port designed to prevent backsphonage.
Auxiliary Supply ✔✔Any water source or system other than the potable water supply, that may
be available in the building or premises.
Backflow ✔✔A hydraulic condition, caused by a difference in pressures in which non-potable
water or other fluids flow into a potable water system.
Back Pressure ✔✔A backflow condition in which a pump, elevated tank, boiler, or other means
results in a downstream pressure greater than the supply pressure.
Backsiphonage ✔✔A backflow condition in which the pressure in the distribution system is less
than atmospheric pressure.
Bypass ✔✔In cross-connection control, any pipe arrangement that passes water around a
protective device causing it to be ineffective
Carrier ✔✔A human or animal that carries disease germs and can pass them to another person
without getting the disease himself.
Check Valve ✔✔A valve designed to open in the direction of normal flow and close with the
reversal of flow.
Cross Connection ✔✔Any arrangement of pipes, fittings, fixtures, or devices that connects a
non-potable system to a portable water system,
Double Check Valve Assembly ✔✔A testable mechanical device consisting of two
independently operating, spring-loaded check valves.
Dystenery ✔✔A disease (sometimes waterborne) caused by pathogenic microorganisms and
characterized by severe diarrhea with a passage of mucus and blood.
Feed Water ✔✔Water is added to a commercial or industrial system and subsequently used by
the system, such as water that is fed to a boiler to produce steam.
Gastroenteritis ✔✔An intestinal disease caused by pathogenic microorganisms which involves
inflammation of the stomach and intestines. Symptoms are diarrhea, pain, and nausea.
Hepatitis ✔✔An inflammation of the liver caused by a pathogenic virus . Symptoms are
jaundice, general weakness, nausea and the presence of dark urine.
Hose Bibb ✔✔A faucet to which a hose may be attached.
Incubation Period ✔✔The time period that elapses between the time a person is exposed to some
disease and the time that a person shows the first sign or symptom of the disease.
Overflow Level ✔✔The maximum height that water or liquid will rise in the receptacle before it
flows over the rim.
Potable Water ✔✔Safe for human consumption.
Potential Cross Connection ✔✔Any arrangement of pipes, fittings, or devices INDIRECTLY
connects a potable water supply to a non-potable source.
Pressure Vacuum Breaker ✔✔A device designed to prevent backsiphonge, consisting of one
independently operating spring-loaded check valve and an independently operating spring loaded
air-inlet valve.
Reduced Pressure Zone Backflow Preventer ✔✔A mechanical device consisting of two
independent operating, spring-loaded check valves with reduced pressure zone between check
valves.
RPBP ✔✔A shortened name for a reduced pressure backflow preventer.
Salmonellosis ✔✔A disease caused by pathogenic bacteria (often associated chicken) which
affects the intestinal tract. The primary symptom is diarrhea.
Two types of Backflow ✔✔1. Backpressure
2. Backsiphonge
Toxic ✔✔Substances that cause illness or death is called.
Biological Pollutant ✔✔organism that does not cause illnesses
Example of Biological Pollutant ✔✔Yeast or Yogurt
Examples of Biological Contaminants ✔✔1. Ecoli
2.Giarian
Example of Chemical Pollutant ✔✔1. Iron
2. Calcium
3. Sulfer
Examples of Chemical Contaminants ✔✔1.Antifreeze
2. Gas
Who has primary responsibility if there is a backflow incident and contaminated/polluted water
enters the distribution system? ✔✔Water Pervayor
What steps should a utility company be allowed to take if a customer, with a cross-connection,
refuses to install a backflow prevention assembly? ✔✔discontinue water service
If the volume of a gas is held constant and temperature increases, what will happen to the
pressure? ✔✔Increases
How far up a column can water be siphoned in a perfect vacuum? ✔✔33.9 Inches
Water traveling at a high velocity past or through a small opening can cause backsiphonge by
what effect? ✔✔Venturi Effect
How can you break a siphonge action? ✔✔Introduce air into the system.
A column of water one foot high generates how many psi? ✔✔.433
One psi equals ✔✔2.31 feet or 27 3/4 inches
40 psi equals how many feet of water ✔✔92.4 inches
A column of water 100 feet in height equals how many psi? ✔✔43.3 inches
What single household item allows most residential backflows to occur? ✔✔Garden Hose
The appropriate height of an air gap is ✔✔Twice the diameter of the pipe above the flood rim the
vessel, min of lunch.
What is the correct height to install a AVB ✔✔6 Inches above the highest down stream point
The biggest disadvantage with using an air gap is ✔✔easy to nullify
According to USC what type of protection does a PVB provide ✔✔1. backisphonge
2. Pollutant
3. Containment
According to USC what is the correct heigh to install a PVB ✔✔Min of 12 inches above highest
down stream point.
What type of protection does DCVA provide ✔✔Pollutant, Backpressure, and Backisphonge
What is the max psi drop allowed across a DCVA ✔✔10psi
What is the max psi drop allowed across an RP ✔✔Varries by size
What is the minimum spring tension on the relief valve RPBP/RPZ ✔✔has to open 2 psi
When testing the check valve #2 in the RP under the backpressure, how does the tester know if
the check holds? ✔✔Should not drop pressure
Why are backflow preventers often installed in parallel? ✔✔To allow constant flow of water
during repair
What are the installation criteria for an AVB? ✔✔6 inches abouve heighest down stream point
Under what hazard conditions and backflow conditions can an air gap be used? ✔✔any and all
conditions
Under what circumstances should you allow only the use of an air gap? ✔✔radioactive
materials, sewage
What is the minimum pressure drop required for a spring loaded, soft seated check valve?
✔✔1.0 psid
What is the difference between PVB and AVB ✔✔PVB is testable AVB is not-testable
AVB Float check / PVB Spring check
Where is the #1 test cock located on an RPZ or DC ✔✔on the first shut off valve, upstream valve
1
Where is the relief valve of an RP located? ✔✔Check #1 and Check #2
Where is the #2 test cock located on a DC ✔✔Shut off #1 and Check #1
Water pressure fluctuations will cause the relief valve of an RPBP to intermittently ✔✔split /
discharge
What federal law made water purveyors responsible for water quality all the way to "the last free
flowing tap" ✔✔SAFE DRINKING ACT OF 1986
What are some of the criteria for an "approved" prevention assembly? ✔✔Test cocks must be
properly located and resilient shut off valve properly located and resilient check valve resilient
If you approach an RPZ and discover that it is dripping from the relief what should you do?
✔✔contact the owner, can not test.
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