Texas LP-Gas Dispensing Exam | Texas Propane Dispenser Certification Study Guide & Exam Prep 2026/2027 | Railroad Commission of Texas Motor/Mobile Fuel Dispenser, LP-Gas Safety Rules, Propane Dispensing Operations, ASME Motor Fuel Containers, Autogas Refu

Texas LP-Gas Dispensing Exam | Texas
Propane Dispenser Certification Study Guide &
Exam Prep 2026/2027 | Railroad Commission
of Texas Motor/Mobile Fuel Dispenser, LP-Gas
Safety Rules, Propane Dispensing Operations,
ASME Motor Fuel Containers, Autogas
Refueling, Cylinder Safety, Fuel Dispenser
Procedures, Inspection, Emergency Response,
Practice Questions, Answers & Detailed
Rationales
Question 1: According to the Texas LP-Gas regulations, what is the maximum
allowable working pressure for a typical ASME horizontal storage tank used
for propane?
A. 100 psi
B. 150 psi
C. 250 psi
D. 300 psi
CORRECT ANSWER: C. 250 psi
Rationale: ASME horizontal storage tanks for LP-Gas are typically designed for a
maximum allowable working pressure of 250 psi, which accounts for the vapor pressure
of propane at elevated temperatures.


Question 2: When conducting a leak test on an LP-Gas system, what is the
maximum allowable pressure drop over a 10-minute period?
A. 1% of the test pressure
B. 5% of the test pressure
C. 10% of the test pressure
D. 15% of the test pressure
CORRECT ANSWER: A. 1% of the test pressure
Rationale: A pressure drop of 1% or less over 10 minutes indicates a system with no
significant leaks, ensuring safe operation as per Texas safety standards.


Question 3: What is the minimum required distance between an LP-Gas
container and a building opening below grade?
A. 5 feet
B. 10 feet

,C. 15 feet
D. 20 feet
CORRECT ANSWER: B. 10 feet
Rationale: A 10-foot minimum separation from building openings below grade prevents
gas accumulation near structures and is mandated by Texas LP-Gas rules for safety.


Question 4: At what pressure does the safety relief valve on a typical LP-Gas
cargo tank start to open?
A. 200 psi
B. 250 psi
C. 300 psi
D. 375 psi
CORRECT ANSWER: D. 375 psi
Rationale: Relief valves on cargo tanks are set to open at 375 psi to prevent over-
pressurization during transport, aligning with DOT and Texas regulations.


Question 5: Which type of piping is prohibited for use in LP-Gas liquid service
in Texas?
A. Black iron
B. Galvanized steel
C. Copper tubing
D. Stainless steel
CORRECT ANSWER: B. Galvanized steel
Rationale: Galvanized steel can flake, leading to clogged orifices and is prohibited in
liquid LP-Gas service; black iron or copper are acceptable alternatives.


Question 6: A 1,000-gallon aboveground propane tank must have a minimum
distance from a property line of how many feet?
A. 10 feet
B. 25 feet
C. 50 feet
D. 100 feet
CORRECT ANSWER: B. 25 feet
Rationale: A 25-foot setback from property lines is required for aboveground tanks over
500 gallons, reducing fire exposure risks.

,Question 7: What is the required frequency for hydrostatic testing of an ASME
propane tank that is 30 years old?
A. Every 5 years
B. Every 10 years
C. Every 15 years
D. Every 20 years
CORRECT ANSWER: B. Every 10 years
Rationale: Older tanks require hydrostatic testing every 10 years to ensure structural
integrity, as specified in Texas administrative code.


Question 8: If a dispenser hose shows visible cracking, what action must be
taken immediately?
A. Apply sealant
B. Replace the hose
C. Tape the cracks
D. Reduce pressure
CORRECT ANSWER: B. Replace the hose
Rationale: Cracks compromise hose integrity and can lead to catastrophic failure;
immediate replacement is mandated to maintain safe dispensing operations.


Question 9: During a pre-dispensing inspection, what odor threshold must an
operator be able to detect?
A. One-tenth of the lower explosive limit
B. One-fifth of the lower explosive limit
C. One-half of the lower explosive limit
D. Full lower explosive limit
CORRECT ANSWER: A. One-tenth of the lower explosive limit
Rationale: Odorant must be detectable at one-tenth of the LEL to provide early warning;
operators must verify this during daily checks.


Question 10: What is the maximum filling density for a propane cylinder by
weight?
A. 42%
B. 50%
C. 80%
D. 85%
CORRECT ANSWER: C. 80%

, Rationale: Filling density is limited to 80% to allow for liquid expansion, preventing
hydraulic rupture of the cylinder.


Question 11: A delivery truck must have a fire extinguisher rated at a
minimum of what?
A. 5-B:C
B. 10-B:C
C. 20-B:C
D. 40-B:C
CORRECT ANSWER: C. 20-B:C
Rationale: Texas LP-Gas rules require a minimum 20-B:C extinguisher on delivery
vehicles to handle flammable liquid and electrical fires.


Question 12: In a bulk plant, where must the emergency shutdown switch be
located?
A. Inside the office
B. Near the loading rack
C. At the main gate
D. Adjacent to the tank
CORRECT ANSWER: C. At the main gate
Rationale: The emergency shutdown must be accessible at the main gate for rapid
activation by emergency personnel.


Question 13: How often must an LP-Gas dispenser calibration be verified?
A. Monthly
B. Quarterly
C. Annually
D. Biannually
CORRECT ANSWER: C. Annually
Rationale: Annual verification ensures accurate metering for consumer protection and
tax compliance.


Question 14: What is the minimum pipe diameter for a vapor line in a 100,000
BTU/hr system?
A. 1/4 inch
B. 3/8 inch