1. Q: What is "NACE MR0175/ISO 15156" compliance?
A: It's a standard specifying material requirements for resistance to Sulfide Stress Cracking (SSC) in sour (H2S-containing) oil and gas production environments. Pipes for such services must be compliant.
2. Q: What is ASTM A105? Is it a pipe specification?
A: No, ASTM A105 is a specification for forgings (like flanges, fittings) made of carbon steel for use in pressure systems at ambient and higher-temperature service. It is often paired with piping specs like A106.
3. Q: What is the main difference between ASTM A106 Grade B and API 5L Grade B?
A: While chemistry and strength are similar, they are governed by different standards for different primary uses. A106 B is for fixed-plant high-temperature pressure applications. API 5L B is for pipeline transportation. Testing and some supplementary requirements differ.
4. Q: What is "Drift Expanding Test"?
A: It's a test where a conical mandrel (drift) is pushed through the pipe to verify its ability to be expanded and to check for soundness (no cracks or splits) up to a specified diameter increase.
5. Q: What causes "Decarburization" on the pipe surface, and is it always detrimental?
A: Decarburization is the loss of carbon from the surface layer due to reaction with oxygen/hydrogen at high temperatures during hot rolling or heat treatment. It creates a softer surface layer, which can be detrimental for applications requiring high surface strength or fatigue resistance, but is often acceptable for many general purposes.
