Kansas Standard Master Plumber with Gas
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the minimum distance a gas meter should be installed
from a building opening, such as a window or door?
A. 12 inches
B. 18 inches
C. 24 inches
D. 36 inches
C. 24 inches
Rationale: According to standard plumbing and gas codes, gas meters
must be installed at least 24 inches away from any building openings to
prevent gas accumulation from entering the building and creating a
hazard.
, 2. When joining black steel pipe for gas, which method is generally
approved for threaded joints?
A. Welding
B. Thread sealant approved for gas
C. Silicone caulk
D. PVC cement
B. Thread sealant approved for gas
Rationale: Gas piping requires joints that are leak-proof. Approved pipe
thread sealants (often PTFE-based) are used for black steel threaded
pipe to ensure gas-tight connections.
3. What type of venting is required for a Category I natural draft gas
water heater?
A. Direct vent
B. Mechanical draft
C. Gravity vent to the outdoors
D. Power vent
C. Gravity vent to the outdoors
Rationale: Category I natural draft water heaters rely on gravity to vent
combustion gases, meaning a properly sized vertical or slightly inclined
vent to the outdoors is required.
, 4. What is the purpose of a drip leg (sediment trap) in a gas line?
A. To reduce water in the line
B. To catch debris and moisture before it enters the appliance
C. To increase pressure in the line
D. To serve as a shutoff point
B. To catch debris and moisture before it enters the appliance
Rationale: Sediment traps prevent dirt and moisture in the gas line from
damaging or clogging appliances by collecting them in a trap installed
near the appliance inlet.
5. Which of the following is an approved material for underground
gas piping?
A. PVC Schedule 40
B. Polyethylene (PE)
C. Copper Type K
D. Galvanized steel
B. Polyethylene (PE)
Rationale: PE gas piping is approved for underground natural gas and
propane service due to its corrosion resistance and flexibility. PVC and
galvanized steel are not permitted underground for gas.
6. When testing a gas line for leaks with air or gas, what is the
maximum test pressure allowed for residential piping?
, A. 1 psi
B. 5 psi
C. 10 psi
D. 15 psi
B. 5 psi
Rationale: The standard maximum allowable test pressure for
residential gas piping using air or inert gas is 5 psi. Exceeding this can
damage the system and create unsafe conditions.
7. In a multi-story building, where should the gas shutoff be located
for a water heater?
A. In the basement only
B. Within sight of the appliance
C. At the street entrance
D. On the roof
B. Within sight of the appliance
Rationale: Gas shutoff valves are required to be within sight of the
appliance they serve to allow quick and safe disconnection during
maintenance or emergencies.
8. What is the minimum slope required for a horizontal gas vent
connector?
A. 1/4 inch per foot upward toward the vent
Exam Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the minimum distance a gas meter should be installed
from a building opening, such as a window or door?
A. 12 inches
B. 18 inches
C. 24 inches
D. 36 inches
C. 24 inches
Rationale: According to standard plumbing and gas codes, gas meters
must be installed at least 24 inches away from any building openings to
prevent gas accumulation from entering the building and creating a
hazard.
, 2. When joining black steel pipe for gas, which method is generally
approved for threaded joints?
A. Welding
B. Thread sealant approved for gas
C. Silicone caulk
D. PVC cement
B. Thread sealant approved for gas
Rationale: Gas piping requires joints that are leak-proof. Approved pipe
thread sealants (often PTFE-based) are used for black steel threaded
pipe to ensure gas-tight connections.
3. What type of venting is required for a Category I natural draft gas
water heater?
A. Direct vent
B. Mechanical draft
C. Gravity vent to the outdoors
D. Power vent
C. Gravity vent to the outdoors
Rationale: Category I natural draft water heaters rely on gravity to vent
combustion gases, meaning a properly sized vertical or slightly inclined
vent to the outdoors is required.
, 4. What is the purpose of a drip leg (sediment trap) in a gas line?
A. To reduce water in the line
B. To catch debris and moisture before it enters the appliance
C. To increase pressure in the line
D. To serve as a shutoff point
B. To catch debris and moisture before it enters the appliance
Rationale: Sediment traps prevent dirt and moisture in the gas line from
damaging or clogging appliances by collecting them in a trap installed
near the appliance inlet.
5. Which of the following is an approved material for underground
gas piping?
A. PVC Schedule 40
B. Polyethylene (PE)
C. Copper Type K
D. Galvanized steel
B. Polyethylene (PE)
Rationale: PE gas piping is approved for underground natural gas and
propane service due to its corrosion resistance and flexibility. PVC and
galvanized steel are not permitted underground for gas.
6. When testing a gas line for leaks with air or gas, what is the
maximum test pressure allowed for residential piping?
, A. 1 psi
B. 5 psi
C. 10 psi
D. 15 psi
B. 5 psi
Rationale: The standard maximum allowable test pressure for
residential gas piping using air or inert gas is 5 psi. Exceeding this can
damage the system and create unsafe conditions.
7. In a multi-story building, where should the gas shutoff be located
for a water heater?
A. In the basement only
B. Within sight of the appliance
C. At the street entrance
D. On the roof
B. Within sight of the appliance
Rationale: Gas shutoff valves are required to be within sight of the
appliance they serve to allow quick and safe disconnection during
maintenance or emergencies.
8. What is the minimum slope required for a horizontal gas vent
connector?
A. 1/4 inch per foot upward toward the vent
