ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
What is a WAGD system? - ANSWER-Waste anaesthetic gas disposal system includes oilles/inert
vacuum producers, and is required at each anesthetizing location. It is violet colored and gas
specific. The minimum flow/Hg is determined by patient equipment requirements
What are the three levels and their ramifications in terms of potential patient risk if a medical
gas system fails? - ANSWER-Level 1: Places patients in imminent danger of morbidity or
mortality Level 2: Places patients at manageable risk for morbidity or mortality Level 3:
Terminates procedures but would not place patients at risk of morbidity or mortality
What is the definition of medical gases and can you name the 8 major gases? - ANSWER-Gases
that are used as part of a healthcare procedure other than for normal body functions. 1)
Oxygen, 2) Medical Air 3) Nitrous Oxide 4) Carbon dioxide 5) Nitrogen 6) Instrument Air 7)
Vacuum and 8) WAGD
What two methods of gas sizing may be used? - ANSWER-1) The longest length method sizes
the main from the meter to the farthest gas user (stay constant along the maximum horizontal
length). The same maximum length can be used for branches. 2) The branch length method
sizes the branches (not the main) based on their individual actual lengths from the meter.
1
, ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
What five factors are involved in the sizing of gas systems? - ANSWER-1) Allowable pressure
drop from meter to farthest outlet 2) Demand (load) in (ft^3/h) 3) Actual length of run (see
NFPA 54 National Fuel Gas Code for gas sizing tables) 4) Specific gravity of gas 5) Diversity factor
(or factor of usage) if allowed by code
What is the testing procedure for the gas piping? - ANSWER-The entire system should be
subjected to an air test for 10 min at a pressure that is twice the working pressure without
showing any loss of pressure.
What design considerations are there for gas piping within a building? - ANSWER-All risers
should be valved, and drips should be located at all low points in the building and at the base of
all risers. Connections from the mains should be from the top or side whenever possible, if
impossible, a connection can me made from the bottom with either a drip or a pitch down to
the main in the branch piping. Each piece of equipment should have a shutoff valve.
What range should the total pressure drop fall within from the gas meter to the farthest outlet?
- ANSWER-0.2 to 0.5 in wc, never exceeding 10 percent of the available gas pressure.
2
,Page 3 of 76
Describe the gas line coming into the building: - ANSWER-It must have a minimum cover of 2 ft
or greater, a curb valve should be installed at the tap off of the main, and a shutoff valve should
be installed within 2 ft of the point of entry into the building. The point of entry into the
building should be 10 feet away from any stairway.
Before commencing design of the system, the engineer should contact the local utility company
to determine what? - ANSWER-Their rules and regulations, the point at which the utility
company’s work ends and the contractors work begins, BTU value and pressure of gas
supplied, any special requirements
What is a special consideration for burying steel piping? - ANSWER-Protect it with a
corrosionresistant material (bitumastic paint, etc.)
What is the preferred material for gas piping, and when and what other materials can be used?
- ANSWER-Black steel is preferred, brass and copper can be used when the gas is not corrosive,
stainless steel and corrugated stainless steel may also be used. Underground services 6” and
larger can be cast iron, but it must be steel pipe entering the building. Don’t forget to use
plug or ball valves rated for gas service.
What special precautions must be used when designing LPG systems? - ANSWER-LPG cylinders
or appliances should not be located in pits, vaults, or basements unless they are mechanically
3
, ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
vented. When they are located in a room, vents must be provided at floor level. Exterior
locations may require proper separation of cylinders.
With regards to natural and manufactured gas and LPG, what is their density compared to air? -
ANSWER-Natural and manufactured gas is lighter than air, LPG is heavier than air.
How are propane and butane made available? - ANSWER-They come in cylinders at a pressure
of 80 to 120 psi.
Pressure threshold is deemed “high pressure” for natural and manufactured gas? -
ANSWER-2 psi. Low pressure gas is less than 2 psi, usually no greater than 0.5 psi (14 in wc). Gas
is distributed throughout the building at 0.5 psi and on occasion, 1 psi.
What is the name and heat content of the two types of LPG? - ANSWER-Propane: 2,500
BTU/ft^3 and Butane: 3,175 BTU/ft^3
What is the heat content and water content of manufactured gas? - ANSWER-540 BTU/ft^3 and
some water content, which may cause corrosion problems
4
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
What is a WAGD system? - ANSWER-Waste anaesthetic gas disposal system includes oilles/inert
vacuum producers, and is required at each anesthetizing location. It is violet colored and gas
specific. The minimum flow/Hg is determined by patient equipment requirements
What are the three levels and their ramifications in terms of potential patient risk if a medical
gas system fails? - ANSWER-Level 1: Places patients in imminent danger of morbidity or
mortality Level 2: Places patients at manageable risk for morbidity or mortality Level 3:
Terminates procedures but would not place patients at risk of morbidity or mortality
What is the definition of medical gases and can you name the 8 major gases? - ANSWER-Gases
that are used as part of a healthcare procedure other than for normal body functions. 1)
Oxygen, 2) Medical Air 3) Nitrous Oxide 4) Carbon dioxide 5) Nitrogen 6) Instrument Air 7)
Vacuum and 8) WAGD
What two methods of gas sizing may be used? - ANSWER-1) The longest length method sizes
the main from the meter to the farthest gas user (stay constant along the maximum horizontal
length). The same maximum length can be used for branches. 2) The branch length method
sizes the branches (not the main) based on their individual actual lengths from the meter.
1
, ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
What five factors are involved in the sizing of gas systems? - ANSWER-1) Allowable pressure
drop from meter to farthest outlet 2) Demand (load) in (ft^3/h) 3) Actual length of run (see
NFPA 54 National Fuel Gas Code for gas sizing tables) 4) Specific gravity of gas 5) Diversity factor
(or factor of usage) if allowed by code
What is the testing procedure for the gas piping? - ANSWER-The entire system should be
subjected to an air test for 10 min at a pressure that is twice the working pressure without
showing any loss of pressure.
What design considerations are there for gas piping within a building? - ANSWER-All risers
should be valved, and drips should be located at all low points in the building and at the base of
all risers. Connections from the mains should be from the top or side whenever possible, if
impossible, a connection can me made from the bottom with either a drip or a pitch down to
the main in the branch piping. Each piece of equipment should have a shutoff valve.
What range should the total pressure drop fall within from the gas meter to the farthest outlet?
- ANSWER-0.2 to 0.5 in wc, never exceeding 10 percent of the available gas pressure.
2
,Page 3 of 76
Describe the gas line coming into the building: - ANSWER-It must have a minimum cover of 2 ft
or greater, a curb valve should be installed at the tap off of the main, and a shutoff valve should
be installed within 2 ft of the point of entry into the building. The point of entry into the
building should be 10 feet away from any stairway.
Before commencing design of the system, the engineer should contact the local utility company
to determine what? - ANSWER-Their rules and regulations, the point at which the utility
company’s work ends and the contractors work begins, BTU value and pressure of gas
supplied, any special requirements
What is a special consideration for burying steel piping? - ANSWER-Protect it with a
corrosionresistant material (bitumastic paint, etc.)
What is the preferred material for gas piping, and when and what other materials can be used?
- ANSWER-Black steel is preferred, brass and copper can be used when the gas is not corrosive,
stainless steel and corrugated stainless steel may also be used. Underground services 6” and
larger can be cast iron, but it must be steel pipe entering the building. Don’t forget to use
plug or ball valves rated for gas service.
What special precautions must be used when designing LPG systems? - ANSWER-LPG cylinders
or appliances should not be located in pits, vaults, or basements unless they are mechanically
3
, ASPE CPD AH EXAM LATEST 2024-2025 COMPLETE
300 QUESTIONS AND DETAILED CORRECT
ANSWERS JUST RELEASED
vented. When they are located in a room, vents must be provided at floor level. Exterior
locations may require proper separation of cylinders.
With regards to natural and manufactured gas and LPG, what is their density compared to air? -
ANSWER-Natural and manufactured gas is lighter than air, LPG is heavier than air.
How are propane and butane made available? - ANSWER-They come in cylinders at a pressure
of 80 to 120 psi.
Pressure threshold is deemed “high pressure” for natural and manufactured gas? -
ANSWER-2 psi. Low pressure gas is less than 2 psi, usually no greater than 0.5 psi (14 in wc). Gas
is distributed throughout the building at 0.5 psi and on occasion, 1 psi.
What is the name and heat content of the two types of LPG? - ANSWER-Propane: 2,500
BTU/ft^3 and Butane: 3,175 BTU/ft^3
What is the heat content and water content of manufactured gas? - ANSWER-540 BTU/ft^3 and
some water content, which may cause corrosion problems
4
