4.1 PERC GAS QUESTIONS AND
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT RATED
A+ ||UPDATED 2026/2027
Effective system load is used to determine the amount of propane required to
operate appliances at a reduced demand and assumes the customers appliances
_____ -ANSWER ✔✔ Operate at full demand only during typical operating
cycles, for example, during a clothes drying cycle or when cooking. Also that
they do not operate simultaneously.
Frost penetration depth in the soil is important to consider when selecting _____. -
ANSWER ✔✔ Underground tanks
The two deciding factors for sizing underground tanks are the effective demand of
all existing and anticipated future gas appliances and _____. -ANSWER ✔✔ The
maximum anticipated soil frost penetration depth.
Aboveground tanks with less than _____ gallons water capacity may be placed
next to a building and must be at least _____ ft horizontally from any building
opening that is below the level of discharge. -ANSWER ✔✔ 125 gallons and 5
feet
The primary factors affecting the rate or extent of corrosion for propane storage
containers and vapor distribution piping are _____. -ANSWER ✔✔Type of metal
and environment in which metal is exposed.
Two commonly used cathodic protection methods are _____. -ANSWER
✔✔Sacrificial anodes and impressed current systems.
To prevent regulator freeze-up due to vent blockage caused by ice formation or
condensation, the regulator should be mounted so that the _____ to allow drainage
of moisture that forms above the diaphragm. -ANSWER ✔✔Vent points
downward
For a residential vapor distribution system involving a first- and second-stage
regulator, the highest Btu/hr output capacity for a single first-stage regulator is not
sufficient to meet total gas demand of the system. What is the best solution? -
ANSWER ✔✔Install two first-stage regulators in a parallel installation.
, A circular meter index commonly has four dials that record the volume of gas
used. When reading the dials of a circular index, start with the dial _____. -
ANSWER ✔✔furthest to the right and proceed left.
All of the following are examples of physical defects that would disallow a
container to be refilled: -ANSWER ✔✔1) Bulging
2) Cracks
3) Damage to the cylinder foot rings
ASME tanks used for LP-gas storage that have a water capacity of 125 gallons or
greater cannot be transported over a public roadway when filled to more than
_____ of their water capacity. -ANSWER ✔✔Must be under 5% water capacity to
transport over public roadways.
The steps to performing a leak test are as follows: Step 1: Select a leak checking
device; Step 2: Choose an appropriate place in the plant to perform the inspection;
Step 3: _____; Step 4: Use a leak detector to test for leaks. -ANSWER
✔✔Pressurize the container
If you are transporting cylinders or tanks containing propane, you must carry a
_____. -ANSWER ✔✔Shipping papers, a hazmat certificate of registration, and
emergency response information.
What are procedures for loading and securing propane cylinders on a vehicle? -
ANSWER ✔✔1) Park your vehicle at the dock or on the level ground before
moving the dolly and cylinder into the lift gate.
2) Take precautions before operating the lift gate, including centering the load on
the lift gate to help prevent it from tilting or falling.
3) Load and position the cylinders on the vehicle so that each cylinder's pressure
relief valve is in direct communication with the vapor space at all times and secure
them in this position.
What must be performed before excavating underground tanks and piping? -
ANSWER ✔✔1) Confirm the locations of underground utilities.
2) Confirm the locations of customer-owned underground systems
3) Ensure that the buried tank or piping will not interfere with pre-installed utilities
or systems.
ANSWERS WITH COMPLETE
SOLUTIONS 100% CORRECT RATED
A+ ||UPDATED 2026/2027
Effective system load is used to determine the amount of propane required to
operate appliances at a reduced demand and assumes the customers appliances
_____ -ANSWER ✔✔ Operate at full demand only during typical operating
cycles, for example, during a clothes drying cycle or when cooking. Also that
they do not operate simultaneously.
Frost penetration depth in the soil is important to consider when selecting _____. -
ANSWER ✔✔ Underground tanks
The two deciding factors for sizing underground tanks are the effective demand of
all existing and anticipated future gas appliances and _____. -ANSWER ✔✔ The
maximum anticipated soil frost penetration depth.
Aboveground tanks with less than _____ gallons water capacity may be placed
next to a building and must be at least _____ ft horizontally from any building
opening that is below the level of discharge. -ANSWER ✔✔ 125 gallons and 5
feet
The primary factors affecting the rate or extent of corrosion for propane storage
containers and vapor distribution piping are _____. -ANSWER ✔✔Type of metal
and environment in which metal is exposed.
Two commonly used cathodic protection methods are _____. -ANSWER
✔✔Sacrificial anodes and impressed current systems.
To prevent regulator freeze-up due to vent blockage caused by ice formation or
condensation, the regulator should be mounted so that the _____ to allow drainage
of moisture that forms above the diaphragm. -ANSWER ✔✔Vent points
downward
For a residential vapor distribution system involving a first- and second-stage
regulator, the highest Btu/hr output capacity for a single first-stage regulator is not
sufficient to meet total gas demand of the system. What is the best solution? -
ANSWER ✔✔Install two first-stage regulators in a parallel installation.
, A circular meter index commonly has four dials that record the volume of gas
used. When reading the dials of a circular index, start with the dial _____. -
ANSWER ✔✔furthest to the right and proceed left.
All of the following are examples of physical defects that would disallow a
container to be refilled: -ANSWER ✔✔1) Bulging
2) Cracks
3) Damage to the cylinder foot rings
ASME tanks used for LP-gas storage that have a water capacity of 125 gallons or
greater cannot be transported over a public roadway when filled to more than
_____ of their water capacity. -ANSWER ✔✔Must be under 5% water capacity to
transport over public roadways.
The steps to performing a leak test are as follows: Step 1: Select a leak checking
device; Step 2: Choose an appropriate place in the plant to perform the inspection;
Step 3: _____; Step 4: Use a leak detector to test for leaks. -ANSWER
✔✔Pressurize the container
If you are transporting cylinders or tanks containing propane, you must carry a
_____. -ANSWER ✔✔Shipping papers, a hazmat certificate of registration, and
emergency response information.
What are procedures for loading and securing propane cylinders on a vehicle? -
ANSWER ✔✔1) Park your vehicle at the dock or on the level ground before
moving the dolly and cylinder into the lift gate.
2) Take precautions before operating the lift gate, including centering the load on
the lift gate to help prevent it from tilting or falling.
3) Load and position the cylinders on the vehicle so that each cylinder's pressure
relief valve is in direct communication with the vapor space at all times and secure
them in this position.
What must be performed before excavating underground tanks and piping? -
ANSWER ✔✔1) Confirm the locations of underground utilities.
2) Confirm the locations of customer-owned underground systems
3) Ensure that the buried tank or piping will not interfere with pre-installed utilities
or systems.
