CALIFORNIA CSST EXAM PREP
ACTUAL EXAM QUESTIONS AND
VERIFIED ANSWERS WITH
RATIONALES GRADED A+
LATEST
1. Which of the following is the most critical step before beginning a CSST gas
line installation?
A. Cutting the tubing to length
B. Verifying the pipe material type
C. Shutting off the gas supply and ensuring no leaks
D. Installing pipe supports every 6 feet
Answer: C
Rationale: Safety regulations mandate shutting off the gas supply before any
installation to prevent accidental leaks or explosions. Verification of pipe type and
proper supports are important, but ensuring the gas is off is critical.
2. CSST tubing must be bonded and grounded to reduce the risk of:
A. Corrosion
B. Electrical shock and lightning damage
C. Freezing in cold weather
D. Pressure loss
Answer: B
Rationale: Bonding and grounding CSST is required to prevent electrical
discharge damage, including lightning strikes, which can puncture the tubing and
cause gas leaks.
,3. Which tool is recommended for cutting CSST to the proper length?
A. Reciprocating saw
B. Hacksaw or tubing cutter designed for stainless steel
C. Angle grinder
D. Pipe torch
Answer: B
Rationale: CSST must be cut cleanly using a hacksaw or tubing cutter designed
for stainless steel to prevent jagged edges that could compromise fittings.
4. What is the minimum required distance CSST must maintain from sharp edges
of framing or metal studs?
A. 0 inches
B. 1/4 inch
C. 1/2 inch
D. 1 inch
Answer: B
Rationale: Manufacturers and California code require at least 1/4 inch clearance
from sharp edges to prevent abrasion and potential leaks.
5. When installing CSST through walls or floors, the tubing must always be:
A. Painted to match the surroundings
B. Sleeved with a protective material
C. Bent as sharply as possible to save space
D. Left unprotected if passing through wood
Answer: B
Rationale: CSST passing through walls, floors, or studs must be sleeved with
protective material to prevent abrasion that could lead to leaks.
,6. The maximum allowable operating pressure for residential CSST systems is
typically:
A. 0.5 psi
B. 5 psi
C. 60 psi
D. 125 psi
Answer: B
Rationale: Residential CSST systems are designed for low-pressure natural gas
systems, usually around 5 psi. Exceeding this can compromise tubing integrity.
7. Which statement is correct regarding CSST fittings?
A. Threaded fittings are preferred over compression fittings
B. Only manufacturer-approved fittings should be used
C. Any standard gas fitting can be adapted to CSST
D. Fittings do not need to be checked for leaks after installation
Answer: B
Rationale: Using only manufacturer-approved fittings ensures proper seal integrity
and compliance with safety standards. Improper fittings can lead to leaks.
8. What is the purpose of a CSST drip leg (sediment trap)?
A. To reduce water in the gas supply
B. To regulate gas pressure
C. To catch sediment and moisture from the gas line
D. To bond the tubing to the ground
Answer: C
Rationale: A drip leg prevents debris or moisture from entering gas appliances,
which could damage equipment or cause inefficient operation.
, 9. When bending CSST, the installer must ensure that the bend radius is:
A. As tight as needed to fit the space
B. At least the manufacturer’s recommended minimum radius
C. Twice the diameter of the tubing
D. Not necessary; CSST can bend freely
Answer: B
Rationale: Adhering to the manufacturer’s minimum bend radius prevents kinking
or weakening the tubing, which could compromise safety.
10. Which of the following is required when testing a newly installed CSST system
for leaks?
A. Visual inspection only
B. Soap solution or approved gas leak detection fluid
C. Lighting a match near joints
D. Pressurizing the system above 60 psi
Answer: B
Rationale: Soap solution or approved gas detectors allow safe identification of
leaks without risk of ignition.
11. CSST should never be installed in direct contact with:
A. Copper tubing
B. Electrical wiring
C. Sharp metal edges or unprotected steel
D. Wooden studs
Answer: C
Rationale: Direct contact with sharp metal edges can abrade the tubing, creating
potential leak points.
ACTUAL EXAM QUESTIONS AND
VERIFIED ANSWERS WITH
RATIONALES GRADED A+
LATEST
1. Which of the following is the most critical step before beginning a CSST gas
line installation?
A. Cutting the tubing to length
B. Verifying the pipe material type
C. Shutting off the gas supply and ensuring no leaks
D. Installing pipe supports every 6 feet
Answer: C
Rationale: Safety regulations mandate shutting off the gas supply before any
installation to prevent accidental leaks or explosions. Verification of pipe type and
proper supports are important, but ensuring the gas is off is critical.
2. CSST tubing must be bonded and grounded to reduce the risk of:
A. Corrosion
B. Electrical shock and lightning damage
C. Freezing in cold weather
D. Pressure loss
Answer: B
Rationale: Bonding and grounding CSST is required to prevent electrical
discharge damage, including lightning strikes, which can puncture the tubing and
cause gas leaks.
,3. Which tool is recommended for cutting CSST to the proper length?
A. Reciprocating saw
B. Hacksaw or tubing cutter designed for stainless steel
C. Angle grinder
D. Pipe torch
Answer: B
Rationale: CSST must be cut cleanly using a hacksaw or tubing cutter designed
for stainless steel to prevent jagged edges that could compromise fittings.
4. What is the minimum required distance CSST must maintain from sharp edges
of framing or metal studs?
A. 0 inches
B. 1/4 inch
C. 1/2 inch
D. 1 inch
Answer: B
Rationale: Manufacturers and California code require at least 1/4 inch clearance
from sharp edges to prevent abrasion and potential leaks.
5. When installing CSST through walls or floors, the tubing must always be:
A. Painted to match the surroundings
B. Sleeved with a protective material
C. Bent as sharply as possible to save space
D. Left unprotected if passing through wood
Answer: B
Rationale: CSST passing through walls, floors, or studs must be sleeved with
protective material to prevent abrasion that could lead to leaks.
,6. The maximum allowable operating pressure for residential CSST systems is
typically:
A. 0.5 psi
B. 5 psi
C. 60 psi
D. 125 psi
Answer: B
Rationale: Residential CSST systems are designed for low-pressure natural gas
systems, usually around 5 psi. Exceeding this can compromise tubing integrity.
7. Which statement is correct regarding CSST fittings?
A. Threaded fittings are preferred over compression fittings
B. Only manufacturer-approved fittings should be used
C. Any standard gas fitting can be adapted to CSST
D. Fittings do not need to be checked for leaks after installation
Answer: B
Rationale: Using only manufacturer-approved fittings ensures proper seal integrity
and compliance with safety standards. Improper fittings can lead to leaks.
8. What is the purpose of a CSST drip leg (sediment trap)?
A. To reduce water in the gas supply
B. To regulate gas pressure
C. To catch sediment and moisture from the gas line
D. To bond the tubing to the ground
Answer: C
Rationale: A drip leg prevents debris or moisture from entering gas appliances,
which could damage equipment or cause inefficient operation.
, 9. When bending CSST, the installer must ensure that the bend radius is:
A. As tight as needed to fit the space
B. At least the manufacturer’s recommended minimum radius
C. Twice the diameter of the tubing
D. Not necessary; CSST can bend freely
Answer: B
Rationale: Adhering to the manufacturer’s minimum bend radius prevents kinking
or weakening the tubing, which could compromise safety.
10. Which of the following is required when testing a newly installed CSST system
for leaks?
A. Visual inspection only
B. Soap solution or approved gas leak detection fluid
C. Lighting a match near joints
D. Pressurizing the system above 60 psi
Answer: B
Rationale: Soap solution or approved gas detectors allow safe identification of
leaks without risk of ignition.
11. CSST should never be installed in direct contact with:
A. Copper tubing
B. Electrical wiring
C. Sharp metal edges or unprotected steel
D. Wooden studs
Answer: C
Rationale: Direct contact with sharp metal edges can abrade the tubing, creating
potential leak points.
