ASPE CPD Study Questions AH and
Answers Graded A+
Front - Correct answer-Back
What is the specific weight of water? - Correct answer-62.4 lbs per cubic foot
What happens in a storm and sanitary system after it passes the water test? -
Correct answer-A smoke pressure test is recommended with a smoke pressure of 1
in wc to prove the system gas tight.
Is an air test acceptable for a storm and sanitary system? - Correct answer-Yes, if a
water test is not possible, at a pressure of 5 psi, are tests are impractical and costly
What are the testing procedures for the storm and sanitary system? - Correct
answer-A water test upon completion of the rough piping and prior to concealment
of 10 ft wc minimum (except the topmost 10 feet of pipe), not to exceed 100 ft wc.
If system is higher than 100 feet, test plugs must be installed to facilitate testing,
rarely are more than 7 stories tested at one time. A peppermint oil test may also be
done with 2 oz of peppermint oil and 10 qt boiling water, and searching for
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,peppermint smell at leaks, however it is difficult to pinpoint the leak by this
method
The maximum length from the vent connection to any future drain outlet is
required by code, why, how long is the distance (listed in the book), and what’s
the exception? - Correct answer-To prevent a dead end where slime, sludge and
fungi can grow, 2 feet, unless the piping must be extended to an accessible location
for a cleanout
A sanitary tee may be used in the vertical but what may not be used in the vertical
and why? - Correct answer-A double sanitary tee because the possibility of flow
crossover and excessive pressures when one branch is discharging and the other
isn’t are possible
What are the slopes of pipe inside the building that correspond to 2 fps velocity? -
Correct answer-1/4 in per foot for 3 in and smaller 1/8 in per foot for larger pipe all
elbows, taps, tees etc are tapped at a pitch of 1/4” per foot
Where should cleanouts be provided? - Correct answer-1) Inside or outside the
building at the point of exit (use a wye branch) 2) at every change in direction
greater than 45 degrees 3) every 50 feet for piping 4” and less, and 100 ft for
larger piping 4) underground piping larger than 10 in should be provided with
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,manholes at every change in direction and every 150 feet 5) at the base of all
stacks 6) as required by code
What size cleanouts are provided in piping? - Correct answer-Piping up to 4
inches, the cleanout is the same size as the pipe. Piping greater than 4 inches, 4
inch cleanouts are adequate.
What should be installed in the house drain if there is a danger of backflow of
sewage into the building? Whats the difference? - Correct answer-A backwater
valve or a combination BWV with manually operated gate valve. The BWV does
not interfere with the airflow throughout the system, and the gate valve is
recommended where there is a history of backflow as a positive means of
protection.
Branch connections to the house drain should be made where and why? - Correct
answer-At the upper portion of the pipe (above the 1/2 - 2/3 full mark) because: 1)
there is a lower chance of stoppages in the branch 2) there is less flow interference
at the point of connection 3) When there is no flow in the branch, the full area of
the pipe is available to relieve pneumatic pressure fluctuations in the house drain
How many fixture units are equivalent to 1 gpm continuous or semicontinuous
flow and what are examples of these types of flow? - Correct answer-2 FUs, sump
pumps, ejectors, air conditioning equipment, water cooled, equipment, etc
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, What minimum slopes are required for building drains and why? - Correct answer-
3 in pipe and smaller: 1/4 in/ft 4-6 in pipe: 1/8 in/ft 8 in pipe and larger: 1/16 in/ft
to maintain 2 fps scouring action if low flow fixtures are present, 1/4 in/ft for all is
a good idea
House drains are designed to flow how full? - Correct answer-1/2 full to 3/4 full
max under uniform flow conditions
What is a house (building) drain? - Correct answer-The lowest piping of a gravity
drainage system that receives the discharge from soil, waste, and other drainage
pipes inside the building that extends a short distance from the building and
conveys the drainage to the building sewer
What is the measurement from horizontal that separates horizontal and vertical
drainage stacks? - Correct answer-45 degrees
Does an interior drainage stack that offsets 45 degrees or less from the vertical
require a change in size? - Correct answer-No. Any more than a 45 degree offset
requires sizing the offset as a house drain.
What is a branch interval? - Correct answer-A building story or a distance between
two branch connections greater than 8 feet apart.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
Answers Graded A+
Front - Correct answer-Back
What is the specific weight of water? - Correct answer-62.4 lbs per cubic foot
What happens in a storm and sanitary system after it passes the water test? -
Correct answer-A smoke pressure test is recommended with a smoke pressure of 1
in wc to prove the system gas tight.
Is an air test acceptable for a storm and sanitary system? - Correct answer-Yes, if a
water test is not possible, at a pressure of 5 psi, are tests are impractical and costly
What are the testing procedures for the storm and sanitary system? - Correct
answer-A water test upon completion of the rough piping and prior to concealment
of 10 ft wc minimum (except the topmost 10 feet of pipe), not to exceed 100 ft wc.
If system is higher than 100 feet, test plugs must be installed to facilitate testing,
rarely are more than 7 stories tested at one time. A peppermint oil test may also be
done with 2 oz of peppermint oil and 10 qt boiling water, and searching for
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,peppermint smell at leaks, however it is difficult to pinpoint the leak by this
method
The maximum length from the vent connection to any future drain outlet is
required by code, why, how long is the distance (listed in the book), and what’s
the exception? - Correct answer-To prevent a dead end where slime, sludge and
fungi can grow, 2 feet, unless the piping must be extended to an accessible location
for a cleanout
A sanitary tee may be used in the vertical but what may not be used in the vertical
and why? - Correct answer-A double sanitary tee because the possibility of flow
crossover and excessive pressures when one branch is discharging and the other
isn’t are possible
What are the slopes of pipe inside the building that correspond to 2 fps velocity? -
Correct answer-1/4 in per foot for 3 in and smaller 1/8 in per foot for larger pipe all
elbows, taps, tees etc are tapped at a pitch of 1/4” per foot
Where should cleanouts be provided? - Correct answer-1) Inside or outside the
building at the point of exit (use a wye branch) 2) at every change in direction
greater than 45 degrees 3) every 50 feet for piping 4” and less, and 100 ft for
larger piping 4) underground piping larger than 10 in should be provided with
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
,manholes at every change in direction and every 150 feet 5) at the base of all
stacks 6) as required by code
What size cleanouts are provided in piping? - Correct answer-Piping up to 4
inches, the cleanout is the same size as the pipe. Piping greater than 4 inches, 4
inch cleanouts are adequate.
What should be installed in the house drain if there is a danger of backflow of
sewage into the building? Whats the difference? - Correct answer-A backwater
valve or a combination BWV with manually operated gate valve. The BWV does
not interfere with the airflow throughout the system, and the gate valve is
recommended where there is a history of backflow as a positive means of
protection.
Branch connections to the house drain should be made where and why? - Correct
answer-At the upper portion of the pipe (above the 1/2 - 2/3 full mark) because: 1)
there is a lower chance of stoppages in the branch 2) there is less flow interference
at the point of connection 3) When there is no flow in the branch, the full area of
the pipe is available to relieve pneumatic pressure fluctuations in the house drain
How many fixture units are equivalent to 1 gpm continuous or semicontinuous
flow and what are examples of these types of flow? - Correct answer-2 FUs, sump
pumps, ejectors, air conditioning equipment, water cooled, equipment, etc
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, What minimum slopes are required for building drains and why? - Correct answer-
3 in pipe and smaller: 1/4 in/ft 4-6 in pipe: 1/8 in/ft 8 in pipe and larger: 1/16 in/ft
to maintain 2 fps scouring action if low flow fixtures are present, 1/4 in/ft for all is
a good idea
House drains are designed to flow how full? - Correct answer-1/2 full to 3/4 full
max under uniform flow conditions
What is a house (building) drain? - Correct answer-The lowest piping of a gravity
drainage system that receives the discharge from soil, waste, and other drainage
pipes inside the building that extends a short distance from the building and
conveys the drainage to the building sewer
What is the measurement from horizontal that separates horizontal and vertical
drainage stacks? - Correct answer-45 degrees
Does an interior drainage stack that offsets 45 degrees or less from the vertical
require a change in size? - Correct answer-No. Any more than a 45 degree offset
requires sizing the offset as a house drain.
What is a branch interval? - Correct answer-A building story or a distance between
two branch connections greater than 8 feet apart.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
