Natural Gas Systems and Safety Flashcards

What is the typical operating pressure range for natural gas transmission pipelines that feed into distribution systems?

Answer: 200 psig or higher

Natural gas transmission pipelines typically operate at 200 psig or higher (often 200–1,500 psig) to efficiently move large volumes of gas over long distances before pressure is reduced at regulator stations.

When a natural gas main is taken out of service for repairs, what procedure is required before work begins?

Answer: Purge the main with inert gas and follow proper isolation and lockout/tagout procedures

Mains taken out of service must be purged of residual gas using inert gas (such as nitrogen) and properly isolated through lockout/tagout to prevent ignition hazards during repair operations.

Who bears legal responsibility for locating and physically marking the position of underground natural gas facilities prior to excavation under Illinois law?

Answer: The natural gas utility (pipeline operator)

Under Illinois' JULIE One-Call law, the pipeline operator (natural gas utility) is responsible for locating and marking the position of its underground facilities in response to a dig notice.

What is the primary purpose of a metallic tracer wire installed alongside polyethylene natural gas pipe during installation?

Answer: To enable electromagnetic location of the non-metallic pipe by locating equipment

Tracer wire provides a metallic signal path so that electronic pipe-locating equipment can detect and trace the non-conductive PE pipe underground, which is critical for safe future excavation near the line.

Under 49 CFR Part 192, how long must an operator retain the pressure test records for a natural gas pipeline?

Answer: For the life of the pipeline

49 CFR Part 192 requires that pressure test records be retained for the useful life of the pipeline so that the original strength qualification can be verified throughout the facility's operational history.

When natural gas service is restored to multiple customers following a system outage, what is required before the restoration is considered complete?

Answer: Having a qualified technician relight pilot lights and check gas appliances at each service location

When gas is restored after an outage affecting multiple customers, a qualified technician must visit each premise to relight pilots, verify appliances are operating safely, and ensure no gas has accumulated indoors.

Under ICC regulations aligned with 49 CFR Part 192, what is required of natural gas pipeline operators regarding emergency response plans?

Answer: Operators must maintain written emergency procedures and conduct annual training for all personnel with emergency responsibilities

49 CFR Part 192 Subpart M requires operators to maintain written emergency plans covering multiple scenarios and to train all personnel who have emergency responsibilities at least once each calendar year.