RMGA Pipeline Operations and Maintenance 3

Question 1

What is the primary hazard associated with natural gas accumulation in an enclosed space?

Accepted Answer

Asphyxiation due to oxygen displacement and explosion risk

Answer

Corrosion of structural materials

Answer

Increased ambient temperature

Answer

Contamination of groundwater

Question 2

What action should a pipeline operator take when excavation damage exposes a pipeline?

Accepted Answer

Immediately stop work, evacuate, and notify the operator

Answer

Continue excavation and document the finding later

Answer

Cover the pipe and resume work

Answer

Increase operating pressure to test pipe integrity

Question 3

What is the Lower Explosive Limit (LEL) of natural gas (methane) in air?

Accepted Answer

5%

Answer

1%

Answer

10%

Answer

15%

Question 4

What is the function of a check valve in a natural gas system?

Accepted Answer

To allow flow in one direction only

Answer

To regulate pressure to a set point

Answer

To measure volumetric flow

Answer

To remove liquids from the gas stream

Question 5

Which tool is used to locate underground pipelines before excavation in the US?

Accepted Answer

811 one-call system

Answer

911 emergency services

Answer

PHMSA incident hotline

Answer

State environmental agency hotline

Question 6

What type of corrosion occurs when two dissimilar metals are connected in a moist environment?

Accepted Answer

Galvanic corrosion

Answer

Concentration cell corrosion

Answer

Crevice corrosion

Answer

Erosion corrosion