Page 1 of 134
New Mexico MHD-3Y Gas Yardline Installer
Endorsement Exam QUESTIONS AND DETAILED
SOLUTIONS JUST RELEASED
New Mexico MHD-3Y Gas Yardline Installer Endorsement Exam
10 MOST-TESTED EXAM COVERAGE AREAS
1. Gas Yardline Scope, Licensing & Responsibilities — MHD-3Y scope, endorsement requirements,
permitted work, installer responsibilities, licensing limits, permits, inspections, and when work
must be performed under the proper authorization.
2. Gas Piping Materials & Approved Components — Approved pipe and tubing, fittings,
connectors, valves, regulators, transitions, corrosion-resistant materials, listed components,
joining methods, and proper component selection.
3. Gas Yardline Layout & Installation — Routing, burial, protection, support, transitions, sleeves,
clearances, installation near structures, protection from physical damage, and proper
connection to manufactured homes.
4. Gas Sizing & Pressure — Gas demand, pipe sizing, developed length, pressure, pressure drop,
appliance demand, regulator operation, and selecting an appropriate pipe size.
5. Trenching, Burial & Underground Protection — Trench preparation, depth requirements, soil
conditions, protection from damage, underground joints, warning methods, backfill, and
inspection before covering.
6. Gas Valves, Regulators & Appliance Connections — Shutoff valves, regulators, appliance
connectors, sediment traps where required, appliance connections, valve accessibility, and safe
isolation of gas supplies.
7. Pressure Testing, Leak Testing & Commissioning — Test preparation, test medium, test
pressure and duration according to the applicable code, isolating components that cannot
withstand the test, leak detection, and restoring service.
8. Gas Safety, Combustion & Ventilation — Combustion air, ventilation, gas leaks, ignition sources,
carbon monoxide hazards, appliance operation, emergency shutoff, and safe work practices.
9. Manufactured Home Gas Systems & Connections — Connecting the yardline to the
manufactured home's gas system, appliance supply, home gas piping, LP/natural-gas
considerations, and proper transition between systems.
10. Codes, Permits, Inspection & Compliance — New Mexico MHD rules, applicable adopted fuel-
gas requirements, permits, inspection procedures, documentation, violations, corrections, and
installer compliance. MHD also identifies its manufactured-housing rules and federal
manufactured-home regulations among examination reference materials. (NMRLD)
1.
, Page 2 of 134
What New Mexico license classification receives an expanded scope to install gas yardlines serving
manufactured homes after obtaining the required endorsement?
A. MHD-1
B. MHD-2
C. MHD-3Y
D. MHD-3E
Answer: C
Rationale: The MHD-3Y classification specifically extends the MHD-3 scope to installation of gas
yardlines serving manufactured homes. (NMRLD)
2.
Before an MHD-3 licensee installs gas yardlines to manufactured homes, what additional authorization
must the installer obtain from the division?
A. Electrical permit
B. Gas yardline endorsement
C. Foundation certificate
D. Dealer license
, Page 3 of 134
Answer: B
Rationale: New Mexico describes the MHD-3Y scope as an MHD-3 license extended by the appropriate
gas yardline endorsement. (NMRLD)
3.
What is the main purpose of a gas yardline installed between the gas supply and a manufactured home?
A. Supply electrical power
B. Carry fuel gas to the manufactured home
C. Carry wastewater away
D. Supply drinking water
Answer: B
Rationale: A gas yardline carries fuel gas from the supply point toward the manufactured home's gas
piping system.
4.
Why should an installer verify the required permit before beginning a gas yardline installation project?
, Page 4 of 134
A. Permits replace pressure testing
B. Permits establish compliance and allow required inspection
C. Permits determine appliance efficiency
D. Permits eliminate code requirements
Answer: B
Rationale: Permits and inspections help the authority verify that regulated installation work complies
with applicable requirements.
5.
Which New Mexico agency administers the manufactured housing licensing program that includes the
MHD-3Y endorsement?
A. Department of Transportation
B. Regulation and Licensing Department
C. Department of Agriculture
D. Environmental Protection Agency
Answer: B
New Mexico MHD-3Y Gas Yardline Installer
Endorsement Exam QUESTIONS AND DETAILED
SOLUTIONS JUST RELEASED
New Mexico MHD-3Y Gas Yardline Installer Endorsement Exam
10 MOST-TESTED EXAM COVERAGE AREAS
1. Gas Yardline Scope, Licensing & Responsibilities — MHD-3Y scope, endorsement requirements,
permitted work, installer responsibilities, licensing limits, permits, inspections, and when work
must be performed under the proper authorization.
2. Gas Piping Materials & Approved Components — Approved pipe and tubing, fittings,
connectors, valves, regulators, transitions, corrosion-resistant materials, listed components,
joining methods, and proper component selection.
3. Gas Yardline Layout & Installation — Routing, burial, protection, support, transitions, sleeves,
clearances, installation near structures, protection from physical damage, and proper
connection to manufactured homes.
4. Gas Sizing & Pressure — Gas demand, pipe sizing, developed length, pressure, pressure drop,
appliance demand, regulator operation, and selecting an appropriate pipe size.
5. Trenching, Burial & Underground Protection — Trench preparation, depth requirements, soil
conditions, protection from damage, underground joints, warning methods, backfill, and
inspection before covering.
6. Gas Valves, Regulators & Appliance Connections — Shutoff valves, regulators, appliance
connectors, sediment traps where required, appliance connections, valve accessibility, and safe
isolation of gas supplies.
7. Pressure Testing, Leak Testing & Commissioning — Test preparation, test medium, test
pressure and duration according to the applicable code, isolating components that cannot
withstand the test, leak detection, and restoring service.
8. Gas Safety, Combustion & Ventilation — Combustion air, ventilation, gas leaks, ignition sources,
carbon monoxide hazards, appliance operation, emergency shutoff, and safe work practices.
9. Manufactured Home Gas Systems & Connections — Connecting the yardline to the
manufactured home's gas system, appliance supply, home gas piping, LP/natural-gas
considerations, and proper transition between systems.
10. Codes, Permits, Inspection & Compliance — New Mexico MHD rules, applicable adopted fuel-
gas requirements, permits, inspection procedures, documentation, violations, corrections, and
installer compliance. MHD also identifies its manufactured-housing rules and federal
manufactured-home regulations among examination reference materials. (NMRLD)
1.
, Page 2 of 134
What New Mexico license classification receives an expanded scope to install gas yardlines serving
manufactured homes after obtaining the required endorsement?
A. MHD-1
B. MHD-2
C. MHD-3Y
D. MHD-3E
Answer: C
Rationale: The MHD-3Y classification specifically extends the MHD-3 scope to installation of gas
yardlines serving manufactured homes. (NMRLD)
2.
Before an MHD-3 licensee installs gas yardlines to manufactured homes, what additional authorization
must the installer obtain from the division?
A. Electrical permit
B. Gas yardline endorsement
C. Foundation certificate
D. Dealer license
, Page 3 of 134
Answer: B
Rationale: New Mexico describes the MHD-3Y scope as an MHD-3 license extended by the appropriate
gas yardline endorsement. (NMRLD)
3.
What is the main purpose of a gas yardline installed between the gas supply and a manufactured home?
A. Supply electrical power
B. Carry fuel gas to the manufactured home
C. Carry wastewater away
D. Supply drinking water
Answer: B
Rationale: A gas yardline carries fuel gas from the supply point toward the manufactured home's gas
piping system.
4.
Why should an installer verify the required permit before beginning a gas yardline installation project?
, Page 4 of 134
A. Permits replace pressure testing
B. Permits establish compliance and allow required inspection
C. Permits determine appliance efficiency
D. Permits eliminate code requirements
Answer: B
Rationale: Permits and inspections help the authority verify that regulated installation work complies
with applicable requirements.
5.
Which New Mexico agency administers the manufactured housing licensing program that includes the
MHD-3Y endorsement?
A. Department of Transportation
B. Regulation and Licensing Department
C. Department of Agriculture
D. Environmental Protection Agency
Answer: B
