ICC Natural Gas Systems and Safety 1 — Questions and Answers
Question 1: Under 49 CFR Part 192, what is the minimum cover depth required for natural gas distribution pipelines installed in normal soil conditions?
- 12 inches
- 18 inches
- 24 inches (Correct answer)
- 30 inches
Correct answer: 24 inches
49 CFR Part 192 requires a minimum of 24 inches of cover for natural gas distribution lines installed in normal soil to provide adequate protection from surface loads and third-party damage.
Question 2: Which Illinois regulatory body has primary jurisdiction over the safety of natural gas pipelines operated by public utilities in the state?
- Illinois Environmental Protection Agency
- Illinois Commerce Commission (Correct answer)
- Illinois Department of Natural Resources
- Illinois State Fire Marshal
Correct answer: Illinois Commerce Commission
The Illinois Commerce Commission (ICC) has primary jurisdiction over natural gas pipeline safety for public utilities operating in Illinois, adopting and enforcing federal pipeline safety standards.
Question 3: Before placing a new natural gas service line in service, what strength test must be performed according to 49 CFR Part 192?
- Hydrostatic test at 1.1 times operating pressure
- Pneumatic test at 1.5 times maximum allowable operating pressure (MAOP) (Correct answer)
- Leak test at operating pressure for 24 hours
- Visual inspection at standard operating pressure
Correct answer: Pneumatic test at 1.5 times maximum allowable operating pressure (MAOP)
New natural gas service lines must be tested to a minimum of 1.5 times the MAOP as a strength test before being placed in service, ensuring structural integrity under maximum expected conditions.
Question 4: Which pipe material is prohibited from use in new natural gas distribution main or service line installations?
- Polyethylene (PE) pipe
- Steel pipe
- Cast iron pipe (Correct answer)
- Copper tubing for service lines
Correct answer: Cast iron pipe
Cast iron pipe is prohibited for new natural gas installations due to its brittleness and susceptibility to cracking; 49 CFR Part 192 does not permit cast iron for new construction.
Question 5: In Illinois, what must a contractor do before beginning any excavation that could affect underground natural gas facilities?
- Obtain a permit from the ICC
- Call JULIE (811) at least 48 hours before digging (Correct answer)
- Contact the property owner only
- Install warning signs and proceed carefully
Correct answer: Call JULIE (811) at least 48 hours before digging
Illinois law requires all excavators to call JULIE (Joint Utility Locating Information for Excavators) at 811 at least 48 hours before digging to have underground utilities located and marked.
Question 6: What is the primary purpose of cathodic protection installed on buried steel natural gas pipelines?
- To prevent corrosion caused by soil moisture and stray electrical currents (Correct answer)
- To regulate gas pressure within the distribution system
- To monitor gas flow rates at remote locations
- To automatically detect and report gas leaks
Correct answer: To prevent corrosion caused by soil moisture and stray electrical currents
Cathodic protection uses electrochemical principles to counteract the corrosion of buried steel pipe caused by soil moisture, oxygen, and stray electrical currents, extending pipeline service life.
Question 7: Under ICC-adopted pipeline safety regulations, how frequently must operators conduct leak surveys on natural gas distribution lines in business districts?
- Annually
- Every two years
- Twice per year (Correct answer)
- Every five years
Correct answer: Twice per year
49 CFR Part 192 requires leak surveys in business districts at least twice per calendar year, with intervals not exceeding 7.5 months, due to higher risk from dense infrastructure and population.
ICC Natural Gas Systems and Safety 1
Under 49 CFR Part 192, what is the minimum cover depth required for natural gas distribution pipelines installed in normal soil conditions?