ICC Natural Gas Systems and Safety 3

Question 1

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

Accepted Answer

200 psig or higher

Answer

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.

Question 2

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

Accepted Answer

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

Answer

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.

Question 3

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

Accepted Answer

The natural gas utility (pipeline operator)

Answer

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.

Question 4

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

Accepted Answer

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

Answer

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.

Question 5

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

Accepted Answer

For the life of the pipeline

Answer

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.

ICC - Illinois Commerce Commission Certified Contractor Practice Test

ICC - Illinois Commerce Commission Certified Contractor Practice Test

ICC Natural Gas Systems and Safety 3