1. Q: What is a common steel grade for high-pressure gas transmission spiral pipe?
A: API 5L X70 or X80 PSL2, offering high strength and good toughness.
2. Q: What is Charpy V-Notch (CVN) testing?
A: An impact test that measures the material's (and weld's) fracture toughness at specified temperatures, crucial for preventing brittle fracture.
3. Q: What is a typical end finish for pipeline spiral pipe?
A: Beveled ends for field welding, prepared to a specific angle (e.g., 30°) and land face according to the project welding procedure.
4. Q: What is Hardness Testing (e.g., HV10) required for per API 5L?
A: Primarily for the weld Heat-Affected Zone (HAZ) to ensure it does not exceed maximum limits, which helps prevent Hydrogen Induced Cracking (HIC) and Sulfide Stress Cracking (SSC).
5. Q: What environmental service might require supplemental testing like HIC/SSC?
A: Sour service (environments containing wet H2S), common in oil and gas production.
