前言 Unit 1Passage 1Pipeline Basics Passage 2The Alaska Pipeline Unit 2Passage 1Types of Natural Gas Pipelines Passage 2The GIS Introduction Unit 3Passage 1In?line Inspections (Smart Pig) Passage 2Inspection of the Corrosion State of Underground Pipelines Unit 4Passage 1Pipeline Repairs Passage 2How to Recognize a Natural Gas Leak Unit 5Passage 1Reasons of Pipeline Corrosion Passage 2Pipe Coatings Unit 6Passage 1Valves Passage 2Gas Hydrate Primer Unit 7Passage 1Pipeline Construction (Ⅰ) Passage 2The Pipe Jacking (Ⅰ) Unit 8Passage 1Pipeline Construction (Ⅱ) Passage 2The Pipe Jacking (Ⅱ) Glossary