Unit description and problem identification V-38, commissioned in 2009, is constructed from SA 516 Gr. 60 carbon steel with a shell thickness of 32 mm. It operates at 7.5-8.5 kg/ cm² and 40-60°C, with a design pressure of 22 kg/ cm² and a temperature of 120°C. Two pressure safety valves (PSVs) protect the vessel, set at 10.5 kg/cm²g. absorber (VH V10) and the medium-pressure amine absorber (VH V8) and feeds it to the ARU (see Figure 1 ). Prior inspections in 2014 and 2017 revealed minor pitting, fabrication marks, and deposits, but no serious damage. The vessel was not inspected during 2020 due to COVID-19. In 2024, more than 300 blisters were discovered on shell courses 2 and 3, covering ~6 m² below The drum receives rich MDEA from the high-pressure amine the inlet nozzle (see Figure 2b ). Thickness in blistered zones was reduced to 10-11 mm. Cracks were found at long and circumferential seams during phased array ultrasonic testing (PAUT) scans. Fitness for
TORISPHERICAL D’END (TYP.)
2-LIFTING LUG 180˚ APART
DISTRIBUTOR
ML v2350
LADDER RUNG
W3
SKO
Figure 2a V-38 schematic
documented, with solutions including improved distributor design, internal cladding, and periodic inspection programmes. This case reinforces existing knowledge by illustrating how inlet flow dynamics and material selection contributed to the failure of an unlined amine flash drum.
Service (FFS) Level I per API 579 Part 7 failed the vessel. Level III confirmed it was unfit for service in its current state. Inspection and failure analysis Inspection was performed by TCR Advanced using: PAUT of circumferential and longitudinal
Refining India
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