Failure analysis of a high strength low alloy 0.15C–1.25Cr–1Mo–0.25V steel pressure vessel

• The premature failure of 0.15C–1.25Cr–1Mo–0.25V steel tank occurred.
• The failure reported at 109 bar during proof pressure test.
• Welding defect/lack of fusion as culprit for such failure.
• This caused the tank failure at pressure below to its design level occurred.