ASPE CPD AH EXAM/ASPE CPD AH EXAM
QUESTIONS AND CORRECT DETAILED ANSWERS
LATEST UPDATES 2025-2026 (VERIFIED ANSWERS)
ASPE CPD STUDY QUESTIONS AH EXAM ALREADY
GRADED A+
What is a simplified expression for the increase in pressure caused by hydraulic
shock? - ANSWER-The Jackowski Formula
What are the most common causes of hydraulic shock? - ANSWER-The starting
and stopping of pumps, improper check valves, rapid closure of valves; particularly
the last 15 percent of movement.
What are some effects of hydraulic shock? - ANSWER-Expand and burst pipe,
weakened joints, leaks, vibration, broken hangers, valve and faucet wear, ruptured
tanks and heaters, damage to meters, gauges, and temperature regulators, and
accelerated deterioration of the entire piping system. Hydraulic shock can occur
without water hammer, destroying a system before danger is recognized.
,What is water hammer? - ANSWER-The noise created by pipes moving as a result
of hydraulic shock.
What is hydraulic shock? - ANSWER-Hydraulic shock occurs when fluid flowing
through pipe is subjected to a sudden and rapid change in velocity, such as may be
caused by a quick closing valve. The kinetic energy of the fluid is converted into a
dynamic pressure wave (which may travel at rates as high as 3,000 miles/hr.). The
longer the pipe and the faster the velocity, the greater the pressure wave (surge).
This pressure wave produces an impact, travelling back and forth until it is
dissipated. When pipe is not adequately supported, this wave causes the pipe to
vibrate or hit against building structure.
Name some adverse effects of high velocity flow in piping: - ANSWER-Noise,
cavitation, increase danger of hydraulic shock and water hammer, increase erosion
and corrosion.
What maximum velocity should never be exceeded? - ANSWER-10 fps
What should always be of prime importance to the plumbing designer? -
ANSWER-The maximum velocity of water flow in the piping during periods of peak
demand.
What other factor has an effect on pressure drop through a fitting? - ANSWER-
Velocity
,What is the rule of thumb for determining equivalent length of piping in design
phase? - ANSWER-Assume 50 percent of the developed length as an allowance for
fittings and valves.
What are the average values for the coefficient of friction for brass and copper
and for steel? - ANSWER-0.02 for brass and copper, and 0.04 for steel
What equation is used to determine friction head loss? - ANSWER-The Darcy
Equation
How does friction head loss relate to velocity? - ANSWER-Friction head loss varies
approximately with the square of the velocity.
Friction head loss is directly proportional to...? - ANSWER-The roughness and
length of the pipe.
Friction head loss is inversely proportional to...? - ANSWER-The diameter of the
pipe.
Name the four things that affect head loss due to friction - ANSWER-"1. The
density and temperature of the fluid 2. The roughness of the pipe 3. The length of
the run 4. The velocity of the fluid"
What is flow (or residual) pressure? - ANSWER-The pressure measured at any
point while water is flowing (this is the pressure read on a pressure gauge installed
in the piping.) Flow pressure can be ignored in plumbing calcs.
, What is friction head and which equation do you use to find it? - ANSWER-Friction
head is the pressure loss along the line of flow caused by the friction produced by
flowing water. You use Bernoulli’s equation to solve for it.
Front - ANSWER-Back
What is the specific weight of water? - ANSWER-62.4 lbs. per cubic foot
What happens in a storm and sanitary system after it passes the water test? -
ANSWER-A smoke pressure test is recommended with a smoke pressure of 1 in
wk. to prove the system gas tight.
Is an air test acceptable for a storm and sanitary system? - 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? - ANSWER-A
water test upon completion of the rough piping and prior to concealment of 10 ft
wk. minimum (except the topmost 10 feet of pipe), not to exceed 100 ft wk. 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
QUESTIONS AND CORRECT DETAILED ANSWERS
LATEST UPDATES 2025-2026 (VERIFIED ANSWERS)
ASPE CPD STUDY QUESTIONS AH EXAM ALREADY
GRADED A+
What is a simplified expression for the increase in pressure caused by hydraulic
shock? - ANSWER-The Jackowski Formula
What are the most common causes of hydraulic shock? - ANSWER-The starting
and stopping of pumps, improper check valves, rapid closure of valves; particularly
the last 15 percent of movement.
What are some effects of hydraulic shock? - ANSWER-Expand and burst pipe,
weakened joints, leaks, vibration, broken hangers, valve and faucet wear, ruptured
tanks and heaters, damage to meters, gauges, and temperature regulators, and
accelerated deterioration of the entire piping system. Hydraulic shock can occur
without water hammer, destroying a system before danger is recognized.
,What is water hammer? - ANSWER-The noise created by pipes moving as a result
of hydraulic shock.
What is hydraulic shock? - ANSWER-Hydraulic shock occurs when fluid flowing
through pipe is subjected to a sudden and rapid change in velocity, such as may be
caused by a quick closing valve. The kinetic energy of the fluid is converted into a
dynamic pressure wave (which may travel at rates as high as 3,000 miles/hr.). The
longer the pipe and the faster the velocity, the greater the pressure wave (surge).
This pressure wave produces an impact, travelling back and forth until it is
dissipated. When pipe is not adequately supported, this wave causes the pipe to
vibrate or hit against building structure.
Name some adverse effects of high velocity flow in piping: - ANSWER-Noise,
cavitation, increase danger of hydraulic shock and water hammer, increase erosion
and corrosion.
What maximum velocity should never be exceeded? - ANSWER-10 fps
What should always be of prime importance to the plumbing designer? -
ANSWER-The maximum velocity of water flow in the piping during periods of peak
demand.
What other factor has an effect on pressure drop through a fitting? - ANSWER-
Velocity
,What is the rule of thumb for determining equivalent length of piping in design
phase? - ANSWER-Assume 50 percent of the developed length as an allowance for
fittings and valves.
What are the average values for the coefficient of friction for brass and copper
and for steel? - ANSWER-0.02 for brass and copper, and 0.04 for steel
What equation is used to determine friction head loss? - ANSWER-The Darcy
Equation
How does friction head loss relate to velocity? - ANSWER-Friction head loss varies
approximately with the square of the velocity.
Friction head loss is directly proportional to...? - ANSWER-The roughness and
length of the pipe.
Friction head loss is inversely proportional to...? - ANSWER-The diameter of the
pipe.
Name the four things that affect head loss due to friction - ANSWER-"1. The
density and temperature of the fluid 2. The roughness of the pipe 3. The length of
the run 4. The velocity of the fluid"
What is flow (or residual) pressure? - ANSWER-The pressure measured at any
point while water is flowing (this is the pressure read on a pressure gauge installed
in the piping.) Flow pressure can be ignored in plumbing calcs.
, What is friction head and which equation do you use to find it? - ANSWER-Friction
head is the pressure loss along the line of flow caused by the friction produced by
flowing water. You use Bernoulli’s equation to solve for it.
Front - ANSWER-Back
What is the specific weight of water? - ANSWER-62.4 lbs. per cubic foot
What happens in a storm and sanitary system after it passes the water test? -
ANSWER-A smoke pressure test is recommended with a smoke pressure of 1 in
wk. to prove the system gas tight.
Is an air test acceptable for a storm and sanitary system? - 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? - ANSWER-A
water test upon completion of the rough piping and prior to concealment of 10 ft
wk. minimum (except the topmost 10 feet of pipe), not to exceed 100 ft wk. 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
