1. What is ASTM A671 CJP ?
A: ASTM A671 is a standard for electric-fusion-welded steel pipes designed for low-temperature service. "CJP" stands for Complete Joint Penetration, indicating the weld fully penetrates the pipe wall thickness for high-stress applications.
2. What does "115 Class 30" mean?
A:
"115": Specifies the material grade (carbon-manganese steel), with minimum yield strength of 65 ksi (448 MPa) and tensile strength of 115 ksi (793 MPa).
"Class 30": Indicates the operating temperature rating, suitable for -30°F (-34°C) environments.
3. Key manufacturing requirements?
A: Pipes must be:
Welded via submerged arc welding (SAW) or electric resistance welding (ERW).
Heat-treated by normalizing or quenching and tempering to ensure toughness.
Tested for 100% radiography (RT) to validate weld integrity.
4. What tests are mandatory?
A: Required tests include:
Tensile test (for strength verification).
Charpy V-notch impact test at -30°F (to confirm low-T toughness).
Hydrostatic test at 2.4x design pressure.
Optional: Hardness test per NACE MR0175 for sour service.
5. Typical applications?
A: Used in cryogenic, offshore, and high-pressure systems, such as:
LNG export terminals.
Ethylene processing plants.
Arctic pipeline infrastructure.
