ASPE CPD EXAM AH LATEST
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
How many fixture units are equivalent to 1 gpm of pump discharge (in an ejector
system)? - ANSWERS-2 FUs
QUESTION 2
When an ejector vent is connected to the building venting system, how is the
addtional load on the vent pipe calculated? - ANSWERS-By converting the gpm
discharge rate into FU.
QUESTION 3
Ejector basins should not retain the waste discharge for a period exceeding how
long? - ANSWERS-12 hours
QUESTION 4
In an ejector basin, the high and low water levels should be maintained where and
why? - ANSWERS-The high water level should be at least 3 inches below the
invert of the entering piping to prevent backflow and allow air circulation. The low
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, ASPE CPD EXAM AH LATEST
water level should be at least 6 inches above the bottom of the basin to ensure the
suction intake of the pump is covered by water.
QUESTION 5
What is the minimum run time on an ejector system to avoid excessive pump
cycling? - ANSWERS-5 minutes of pump capacity between high and low water
levels
QUESTION 6
In an ejector system, how is the length of run measured and what its the minimum
size? - ANSWERS-From the pump outlet to the highest point, it should be at least
the same size as the pump discharge outlet. (after this point, the piping is sized as
required for the gravity house drain)
QUESTION 7
What is the recommended design velocity for flow in an ejector system? -
ANSWERS-5 - 10 fps.
QUESTION 8
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, ASPE CPD EXAM AH LATEST
How do you determine the head of the ejector pump? - ANSWERS-Add the static
head, measured from the low water line in the receiver up to the highest point
pumped, and the friction head loss in the discharge piping and fittings.
QUESTION 9
In a duplex sewage ejector system, each pump is sized to satisfy what condition? -
ANSWERS-Peak inflow.
QUESTION 10
What is used to size the ejector pump? - ANSWERS-Use the water supply fixture
unit method to determine flow into the receiver, then total FU is converted to GPM
using a table.
QUESTION 11
When are pneumatic-type ejectors commonly used? - ANSWERS-When the
discharge rate is 100 GPM or less, when large solids must be handled, where
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, ASPE CPD EXAM AH LATEST
ground conditions are such that the space below the floor is restricted, where
compressed air is readily available, and in explosion proof conditions.
QUESTION 12
What two types of lifting devices are employed for the automatic discharge of
sump or ejector basin contents? - ANSWERS-1) Centrifugal pumps 2) Pneumatic
ejectors
QUESTION 13
A sump handles what? - ANSWERS-Clear waste water (sump basin not airtight,
needs no venting)
QUESTION 14
An ejector handles what? - ANSWERS-Sewage (ejector basin is airtight and
requires venting)
QUESTION 15
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4
ANSWER ALL QUESTIONS IN THIS SECTION
QUESTION 1
How many fixture units are equivalent to 1 gpm of pump discharge (in an ejector
system)? - ANSWERS-2 FUs
QUESTION 2
When an ejector vent is connected to the building venting system, how is the
addtional load on the vent pipe calculated? - ANSWERS-By converting the gpm
discharge rate into FU.
QUESTION 3
Ejector basins should not retain the waste discharge for a period exceeding how
long? - ANSWERS-12 hours
QUESTION 4
In an ejector basin, the high and low water levels should be maintained where and
why? - ANSWERS-The high water level should be at least 3 inches below the
invert of the entering piping to prevent backflow and allow air circulation. The low
END OF
PAGE
1
, ASPE CPD EXAM AH LATEST
water level should be at least 6 inches above the bottom of the basin to ensure the
suction intake of the pump is covered by water.
QUESTION 5
What is the minimum run time on an ejector system to avoid excessive pump
cycling? - ANSWERS-5 minutes of pump capacity between high and low water
levels
QUESTION 6
In an ejector system, how is the length of run measured and what its the minimum
size? - ANSWERS-From the pump outlet to the highest point, it should be at least
the same size as the pump discharge outlet. (after this point, the piping is sized as
required for the gravity house drain)
QUESTION 7
What is the recommended design velocity for flow in an ejector system? -
ANSWERS-5 - 10 fps.
QUESTION 8
END OF
PAGE
2
, ASPE CPD EXAM AH LATEST
How do you determine the head of the ejector pump? - ANSWERS-Add the static
head, measured from the low water line in the receiver up to the highest point
pumped, and the friction head loss in the discharge piping and fittings.
QUESTION 9
In a duplex sewage ejector system, each pump is sized to satisfy what condition? -
ANSWERS-Peak inflow.
QUESTION 10
What is used to size the ejector pump? - ANSWERS-Use the water supply fixture
unit method to determine flow into the receiver, then total FU is converted to GPM
using a table.
QUESTION 11
When are pneumatic-type ejectors commonly used? - ANSWERS-When the
discharge rate is 100 GPM or less, when large solids must be handled, where
END OF
PAGE
3
, ASPE CPD EXAM AH LATEST
ground conditions are such that the space below the floor is restricted, where
compressed air is readily available, and in explosion proof conditions.
QUESTION 12
What two types of lifting devices are employed for the automatic discharge of
sump or ejector basin contents? - ANSWERS-1) Centrifugal pumps 2) Pneumatic
ejectors
QUESTION 13
A sump handles what? - ANSWERS-Clear waste water (sump basin not airtight,
needs no venting)
QUESTION 14
An ejector handles what? - ANSWERS-Sewage (ejector basin is airtight and
requires venting)
QUESTION 15
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PAGE
4
