Fundamentals of Pipe Stress Engineering

A: The full restraint assumption drives you straight to σ = E·α·ΔT, and the arithmetic lands at 200,000 MPa × 12×10⁻⁶ × 80. Option B sounds reasonable if you're used to allowable stress checks, but modulus isn't reduced by a design factor. Option C imports buried pipeline logic; there's no soil here, just steel between anchors. Option D reflects an operational assumption that isn't stated and quietly halves the load without justification.

A: Free water plus CO₂, even at low mol%, keeps sweet corrosion on the table offshore. Option B catches engineers who equate any sulfur with SSC, but the chemistry and hardness thresholds aren't there. Option C belongs to furnaces, not 60 °C gas. Option D is a classic stainless issue; ferritic carbon steel doesn't fail that way.

A: High cyclic displacement finds the weakest stiffness discontinuity, usually small-bore take-offs. Option B sounds dramatic but ignores material ductility and the fact that stress often redistributes before rupture. Option C confuses thermal stress with hydraulic behavior. Option D assumes velocity changes that the missing loop doesn't create.

A: Expansion stress is displacement-driven, so flexibility fixes it. Option B helps sustained stress but barely moves the expansion range. Option C feels confident yet misses that allowable expansion stress in B31.3 is weakly tied to SMYS. Option D trades one limit state for another and doesn't touch thermal movement.