NEW MEXICO LP-5 PROPANE
INSTALLATION, SERVICE & REPAIR
LICENSE ULTIMATE STUDY GUIDE
This definitive study bank delivers highly realistic practice
questions specifically modeled after the 2026 New Mexico LP-5
trade license blueprint. Each multiple-choice question features
exact, italicized answers alongside deeply detailed, bolded
rationales that break down crucial NFPA 54 and NFPA 58 safety
standards. It is the ultimate high-yield study resource engineered
to help apprentices, plumbers, and gas technicians master
complex clearance codes, combustion calculations, and
troubleshooting principles to pass their state certification exam on
the very first attempt.
1. What is the minimum required distance
between a 500-gallon ASME LP-gas container
and an important building or line of adjoining
property?
A) 10 feet
B) 25 feet
C) 50 feet
D) 3 feet
Answer: B) 25 feet
Rationale: According to NFPA 58 regulations
governing LP-gas container storage, ASME
containers with a water capacity between 501
and 2,000 gallons require a minimum separation
distance of 25 feet from buildings, lines of
adjoining property, and important structures.
,2. Which specific grade of copper tubing is
mandatory for underground LP-gas piping
systems?
A) Type M
B) Type L
C) Type K
D) Type DWV
Answer: C) Type K
Rationale: NFPA 54 and New Mexico code
adaptations mandate that copper tubing installed
underground must be Type K or Type L, with
Type K heavily preferred and required for
harsher soil burial due to its thicker wall profile
and superior corrosion resistance.
3. What is the maximum permitted filling limit by
weight for an LP-gas cylinder with a water
capacity of 100 pounds?
A) 42 pounds
B) 80 pounds
C) 100 pounds
D) 42.4 pounds
Answer: A) 42 pounds
Rationale: Propane cylinders are generally filled
to roughly 42% of their total water capacity
weight to account for liquid thermal expansion,
preventing hazardous overpressurization.
,4. During a pressure test on a newly installed LP-
gas piping system operating at standard low
pressure, what is the minimum duration the
pressure must be held?
A) 5 minutes
B) 10 minutes
C) 30 minutes
D) 60 minutes
Answer: B) 10 minutes
Rationale: NFPA 54 specifies that for standard
low-pressure residential gas piping systems, the
pressure test must last a minimum of 10 minutes
without showing any drop on the gauge.
5. What color must the flame of a correctly
adjusted LP-gas burner be?
A) Bright yellow
B) Solid orange
C) Blue with a soft inner cone
D) Greenish-blue with sparks
Answer: C) Blue with a soft inner cone
Rationale: A clean blue flame with a distinct
inner cone indicates complete combustion. A
yellow or orange flame indicates incomplete
combustion, which produces hazardous carbon
monoxide.
, 6. Which tool must a technician use to safely
check an LP-gas joint for small leaks?
A) An open flame lighter
B) A calibrated combustible gas leak detector
C) A water-only spray bottle
D) A sulfur stick
Answer: B) A calibrated combustible gas leak
detector
Rationale: Electronic combustible gas detectors
or certified non-corrosive leak detection
solutions are the only approved and safe
methods for locating gas leaks. Open flames are
strictly prohibited.
7. What is the primary chemical compound found
in commercial-grade Liquefied Petroleum Gas?
A) Methane
B) Butane
C) Propane
D) Ethane
Answer: C) Propane
Rationale: While LP-gas can technically include
butane blends, commercial LP-gas utilized
across North America for heating and cooking
consists predominantly of propane (C₃H₈).
INSTALLATION, SERVICE & REPAIR
LICENSE ULTIMATE STUDY GUIDE
This definitive study bank delivers highly realistic practice
questions specifically modeled after the 2026 New Mexico LP-5
trade license blueprint. Each multiple-choice question features
exact, italicized answers alongside deeply detailed, bolded
rationales that break down crucial NFPA 54 and NFPA 58 safety
standards. It is the ultimate high-yield study resource engineered
to help apprentices, plumbers, and gas technicians master
complex clearance codes, combustion calculations, and
troubleshooting principles to pass their state certification exam on
the very first attempt.
1. What is the minimum required distance
between a 500-gallon ASME LP-gas container
and an important building or line of adjoining
property?
A) 10 feet
B) 25 feet
C) 50 feet
D) 3 feet
Answer: B) 25 feet
Rationale: According to NFPA 58 regulations
governing LP-gas container storage, ASME
containers with a water capacity between 501
and 2,000 gallons require a minimum separation
distance of 25 feet from buildings, lines of
adjoining property, and important structures.
,2. Which specific grade of copper tubing is
mandatory for underground LP-gas piping
systems?
A) Type M
B) Type L
C) Type K
D) Type DWV
Answer: C) Type K
Rationale: NFPA 54 and New Mexico code
adaptations mandate that copper tubing installed
underground must be Type K or Type L, with
Type K heavily preferred and required for
harsher soil burial due to its thicker wall profile
and superior corrosion resistance.
3. What is the maximum permitted filling limit by
weight for an LP-gas cylinder with a water
capacity of 100 pounds?
A) 42 pounds
B) 80 pounds
C) 100 pounds
D) 42.4 pounds
Answer: A) 42 pounds
Rationale: Propane cylinders are generally filled
to roughly 42% of their total water capacity
weight to account for liquid thermal expansion,
preventing hazardous overpressurization.
,4. During a pressure test on a newly installed LP-
gas piping system operating at standard low
pressure, what is the minimum duration the
pressure must be held?
A) 5 minutes
B) 10 minutes
C) 30 minutes
D) 60 minutes
Answer: B) 10 minutes
Rationale: NFPA 54 specifies that for standard
low-pressure residential gas piping systems, the
pressure test must last a minimum of 10 minutes
without showing any drop on the gauge.
5. What color must the flame of a correctly
adjusted LP-gas burner be?
A) Bright yellow
B) Solid orange
C) Blue with a soft inner cone
D) Greenish-blue with sparks
Answer: C) Blue with a soft inner cone
Rationale: A clean blue flame with a distinct
inner cone indicates complete combustion. A
yellow or orange flame indicates incomplete
combustion, which produces hazardous carbon
monoxide.
, 6. Which tool must a technician use to safely
check an LP-gas joint for small leaks?
A) An open flame lighter
B) A calibrated combustible gas leak detector
C) A water-only spray bottle
D) A sulfur stick
Answer: B) A calibrated combustible gas leak
detector
Rationale: Electronic combustible gas detectors
or certified non-corrosive leak detection
solutions are the only approved and safe
methods for locating gas leaks. Open flames are
strictly prohibited.
7. What is the primary chemical compound found
in commercial-grade Liquefied Petroleum Gas?
A) Methane
B) Butane
C) Propane
D) Ethane
Answer: C) Propane
Rationale: While LP-gas can technically include
butane blends, commercial LP-gas utilized
across North America for heating and cooking
consists predominantly of propane (C₃H₈).
