CROSS-CONNECTION & BACKFLOW
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS 100%
CORRECT RATED A+
What is a cross-connection?
Answer: Any arrangement of pipes, fittings, fixtures, or devices that connects a
non-potable system to a potable water system. It is a physical link between the
potable water supply and a source of pollution or contamination.
How are cross-connections classified?
Answer:
1. Direct or permanent (hard plumbed)
2. Indirect or temporary (e.g., a garden hose next to a chemical barrel)
What is an actual cross-connection?
Answer: Any arrangement of pipes, fittings, or devices that connects a potable
water supply directly to a non-potable source at all times.
What is backflow?
Answer: A hydraulic condition caused by a difference in pressure, where non-
potable water or other liquids flow into a potable water system.
What is backpressure?
Answer: A type of backflow where the pressure produced by a pump, boiler, or
other equipment is greater than the water supply pressure.
What is backsiphonage?
Answer: A type of backflow where the pressure in the distribution system is lower
, than atmospheric pressure, allowing contamination to enter the water system
through a cross-connection
POTENTIAL CROSS-CONNECTION -ANSWER✔✔any arrangement of pipes,
fittings, or devices that indirectly connects a potable water supply to a non-potable
source. This connection may not be present at all times, but it is always there
potentially.
AIR GAP -ANSWER✔✔Safest& simplest way to prevent cross connection.
Physical separation, not a device. Designed for high hazard.
in plumbing, the unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe or outlet supplying water to a tank,
plumbing fixture, or other container and the overflow rim of that container.
REDUCED PRESSURE ZONE BACKFLOW-PREVENTER (RPZ) -
ANSWER✔✔a mechanical device consisting of two independently operating,
spring loaded check valves with a reduced pressure zone (differential relief valve)
between the check valves. Designed to provide maximum protection against both
Backpressure and backsiphonage. Can be used for low/high hazard. Don't install in
pits where relief valve may become submerged. Should not be installed where
vertical access is req'd
DOUBLE CHECK VALVE BACKFLOW-PREVENTER (DCVA) -
ANSWER✔✔a mechanical designed basically the same way as the reduce pressure
zone backflow-preventer but without the relief valve. If the Check valve #2 doesn't
fully seal, then Check valve #1 will "backup" the #2
VACUUM BREAKER -ANSWER✔✔mechanical device that allows air into the
piping system, thereby preventing backflow that could otherwise be cause by the
siphoning action created by a partial vacuum
QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS 100%
CORRECT RATED A+
What is a cross-connection?
Answer: Any arrangement of pipes, fittings, fixtures, or devices that connects a
non-potable system to a potable water system. It is a physical link between the
potable water supply and a source of pollution or contamination.
How are cross-connections classified?
Answer:
1. Direct or permanent (hard plumbed)
2. Indirect or temporary (e.g., a garden hose next to a chemical barrel)
What is an actual cross-connection?
Answer: Any arrangement of pipes, fittings, or devices that connects a potable
water supply directly to a non-potable source at all times.
What is backflow?
Answer: A hydraulic condition caused by a difference in pressure, where non-
potable water or other liquids flow into a potable water system.
What is backpressure?
Answer: A type of backflow where the pressure produced by a pump, boiler, or
other equipment is greater than the water supply pressure.
What is backsiphonage?
Answer: A type of backflow where the pressure in the distribution system is lower
, than atmospheric pressure, allowing contamination to enter the water system
through a cross-connection
POTENTIAL CROSS-CONNECTION -ANSWER✔✔any arrangement of pipes,
fittings, or devices that indirectly connects a potable water supply to a non-potable
source. This connection may not be present at all times, but it is always there
potentially.
AIR GAP -ANSWER✔✔Safest& simplest way to prevent cross connection.
Physical separation, not a device. Designed for high hazard.
in plumbing, the unobstructed vertical distance through the free atmosphere
between the lowest opening from any pipe or outlet supplying water to a tank,
plumbing fixture, or other container and the overflow rim of that container.
REDUCED PRESSURE ZONE BACKFLOW-PREVENTER (RPZ) -
ANSWER✔✔a mechanical device consisting of two independently operating,
spring loaded check valves with a reduced pressure zone (differential relief valve)
between the check valves. Designed to provide maximum protection against both
Backpressure and backsiphonage. Can be used for low/high hazard. Don't install in
pits where relief valve may become submerged. Should not be installed where
vertical access is req'd
DOUBLE CHECK VALVE BACKFLOW-PREVENTER (DCVA) -
ANSWER✔✔a mechanical designed basically the same way as the reduce pressure
zone backflow-preventer but without the relief valve. If the Check valve #2 doesn't
fully seal, then Check valve #1 will "backup" the #2
VACUUM BREAKER -ANSWER✔✔mechanical device that allows air into the
piping system, thereby preventing backflow that could otherwise be cause by the
siphoning action created by a partial vacuum
