Contractor Practice Exam Questions

CA D40 Service Station Equipment Contractor Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• Which of the following is the primary responsibility of a D-40

contractor?

• Building residential homes
• Installing electrical wiring
• Installing and maintaining service station equipment
• Landscaping service stations

Rationale: D-40 contractors specialize in service station equipment

installation and maintenance.

• What type of pump is commonly used in modern fuel dispensing

systems?

• Centrifugal pump
• Submersible turbine pump
• Piston pump
• Gear pump

Rationale: Submersible turbine pumps are standard in service stations

for dispensing fuel safely and efficiently.

• Which safety device prevents fuel overflow at service stations?
• Pressure relief valve
• Flow meter
• Automatic shutoff nozzle
• Expansion tank 1 / 3

Rationale: Automatic shutoff nozzles prevent overfilling by stopping

fuel flow when the tank is full.

• What is the minimum recommended distance between a fuel dispenser

and a building?

• 3 feet
• 5 feet
• 10 feet
• 15 feet

Rationale: Safety codes typically require at least 10 feet between

dispensers and nearby structures to reduce fire risk.

• Which of the following is a requirement for underground storage tanks

(USTs)?

• Must be above ground
• No corrosion protection needed
• Corrosion protection and leak detection systems
• Only installed in residential areas

Rationale: USTs must have corrosion protection and leak detection to

prevent environmental contamination.

• Which component measures the volume of fuel dispensed?
• Pressure regulator
• Check valve
• Flow meter
• Pump motor

Rationale: Flow meters accurately measure the quantity of fuel

delivered.

• What type of piping is typically used for underground fuel distribution?

A) PVC

• Fiberglass or steel with corrosion protection
• Copper
• Aluminum

Rationale: Corrosion-protected steel or fiberglass piping ensures

durability and safety underground.

• What is the primary purpose of a vapor recovery system?
• Increase fuel flow
• Reduce pump noise
• Capture fuel vapors to prevent air pollution
• Improve fuel color 2 / 3

Rationale: Vapor recovery systems prevent release of volatile organic

compounds (VOCs) into the atmosphere.

• When installing a fuel dispenser, which of the following must be

grounded?

• Only the nozzle
• Only the tank
• Both dispenser and tank
• No grounding required

Rationale: Grounding prevents static electricity buildup, reducing fire

hazards.

• Which inspection is required before putting a new UST into

service?

• Visual inspection only
• Leak testing and pressure testing
• Painting the tank
• Checking fuel color

Rationale: USTs must be leak-tested and pressure-tested to ensure

integrity before operation.

• What type of fire suppression system is commonly installed near

fuel dispensers?

• Sprinkler for residential use
• Foam system for offices
• Dry chemical or foam system for flammable liquids
• Water-only hose system

Rationale: Dry chemical or foam systems are effective at extinguishing

fuel fires safely.

• How often should service station equipment be inspected for

leaks?

• Every 5 years
• Only when installed
• Annually or per local regulations
• Never

Rationale: Regular inspections are required to ensure compliance and

prevent environmental hazards.

• Which of the following is a common cause of fuel dispenser

malfunction?

• Cold weather
• / 3