ASPE CPD Study Questions and
answers 100% correct
What is the specific weight of water? - CORRECT ANSWERS 62.4 lbs per
cubic foot
What happens in a storm and sanitary system after it passes the water test? -
CORRECT ANSWERS 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
ANSWERS 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 ANSWERS 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 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 2
FUs, sump pumps, ejectors, air conditioning equipment, water cooled,
equipment, etc
What minimum slopes are required for building drains and why? - CORRECT
ANSWERS 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 ANSWERS 1/2 full
to 3/4 full max under uniform flow conditions
What is a house (building) drain? - CORRECT ANSWERS 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 ANSWERS 45 degrees
Does an interior drainage stack that offsets 45 degrees or less from the
vertical require a change in size? - CORRECT ANSWERS No. Any more than
a 45 degree offset requires sizing the offset as a house drain.
What is a branch interval? - CORRECT ANSWERS A building story or a
distance between two branch connections greater than 8 feet apart.
, Describe the procedure for sizing interior drainage stacks. - CORRECT
ANSWERS 1) First size the horizontal branches connecting to the stack 2)
Determine the minimum size that will accept each branch at one branch
interval 3) Total all fixture units connected to the stack, and determine the
size. The minimum size must be at least equal to the largest diameter
required at the base. You may reduce in size at upper branch intervals, but
never by more than 1/2 the largest size.
What is the total recommended maximum permissible flow in a stack? -
CORRECT ANSWERS 7/24 of the total cross sectional area of the stack.
Where should and shouldn’t you connect branch connections to stack
offsets? - CORRECT ANSWERS Not to the horizontal offset to the stack if at
all possible, unless its at least 10 pipe diameters downstream, and ideally 2
feet above the offset or 2 feet below to avoid pressure fluctuations.
What can minimize hydraulic jump? - CORRECT ANSWERS Increasing the
slope of the horizontal drain. Connecting to a horizontal drain that is larger
than the stack.
Any offset of the stack greater than what can cause hydraulic jump? -
CORRECT ANSWERS 45 degrees
When does terminal velocity occur in a drainage stack? - CORRECT
ANSWERS It is achieved at approximately 10 - 15 fps and this velocity is
achieved within 10 - 15 feet of fall from the point of entry.
A drainage stack should never be designed for a capacity greater than what
and why? - CORRECT ANSWERS One-thrid full, because the pressure
fluctuations in the system could greatly exceed the maximum 1 in water
column criterion and lose their seal by siphonage blowout
answers 100% correct
What is the specific weight of water? - CORRECT ANSWERS 62.4 lbs per
cubic foot
What happens in a storm and sanitary system after it passes the water test? -
CORRECT ANSWERS 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
ANSWERS 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 ANSWERS 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 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 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 ANSWERS 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 ANSWERS 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 ANSWERS 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 ANSWERS 2
FUs, sump pumps, ejectors, air conditioning equipment, water cooled,
equipment, etc
What minimum slopes are required for building drains and why? - CORRECT
ANSWERS 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 ANSWERS 1/2 full
to 3/4 full max under uniform flow conditions
What is a house (building) drain? - CORRECT ANSWERS 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 ANSWERS 45 degrees
Does an interior drainage stack that offsets 45 degrees or less from the
vertical require a change in size? - CORRECT ANSWERS No. Any more than
a 45 degree offset requires sizing the offset as a house drain.
What is a branch interval? - CORRECT ANSWERS A building story or a
distance between two branch connections greater than 8 feet apart.
, Describe the procedure for sizing interior drainage stacks. - CORRECT
ANSWERS 1) First size the horizontal branches connecting to the stack 2)
Determine the minimum size that will accept each branch at one branch
interval 3) Total all fixture units connected to the stack, and determine the
size. The minimum size must be at least equal to the largest diameter
required at the base. You may reduce in size at upper branch intervals, but
never by more than 1/2 the largest size.
What is the total recommended maximum permissible flow in a stack? -
CORRECT ANSWERS 7/24 of the total cross sectional area of the stack.
Where should and shouldn’t you connect branch connections to stack
offsets? - CORRECT ANSWERS Not to the horizontal offset to the stack if at
all possible, unless its at least 10 pipe diameters downstream, and ideally 2
feet above the offset or 2 feet below to avoid pressure fluctuations.
What can minimize hydraulic jump? - CORRECT ANSWERS Increasing the
slope of the horizontal drain. Connecting to a horizontal drain that is larger
than the stack.
Any offset of the stack greater than what can cause hydraulic jump? -
CORRECT ANSWERS 45 degrees
When does terminal velocity occur in a drainage stack? - CORRECT
ANSWERS It is achieved at approximately 10 - 15 fps and this velocity is
achieved within 10 - 15 feet of fall from the point of entry.
A drainage stack should never be designed for a capacity greater than what
and why? - CORRECT ANSWERS One-thrid full, because the pressure
fluctuations in the system could greatly exceed the maximum 1 in water
column criterion and lose their seal by siphonage blowout
