CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
← Vessel Registry

V-1259 — Atmospheric Gas Oil Drum V-1259

Fluid Catalytic Cracker · Atmospheric Gas Oil service · Installed Aug 24, 2018 (8 yrs in service)

High
Current Min. Thickness
1.286 in
t-min 1.270 in
Measured Corrosion Rate
11.40 mpy
ML-predicted: 14.10 mpy
Remaining Life
1.4 yrs
Next Inspection Due
Apr 25, 2027
Interval: 0.7 yrs (API 510)

UT Thickness Trend

Minimum CML reading per inspection vs. ASME Sec. VIII t-min

Vessel Specification

MaterialSA-387-11 Cl.2 (1.25Cr-0.5Mo)
Design CodeASME BPVC Section VIII, Div. 1
Joint Efficiency1.00
Design Pressure548 psig
Design Temperature409 °F
Operating Pressure430 psig
Operating Temperature299 °F
Diameter81 in
Nominal Thickness1.390 in
Corrosion Allowance0.0625 in
H2S / Chloride13 / 286 ppm
Flow Velocity15.4 ft/s
Process pH7.97
InsulatedNo

Corrosion & Remaining-Life What-If

Adjust operating conditions to see the live model-predicted corrosion rate and implied remaining life

Live Prediction — What-If Model
14.11 mpy
Predicted corrosion rate under these conditions (+2.71 mpy vs. current measured rate)
Implied Remaining Life
1.1 yrs
Implied Reinspection Interval
0.5 yrs

What-if model: standardized Ridge regression, R² 0.56 on held-out fleet data (3.25 mpy MAE). Runs entirely client-side for instant feedback — see Model Insights for the full fleet-scale ensemble model used for official predictions.

Governing Damage Mechanism — Naphthenic Acid Corrosion

API 571 §4.2.10

Aggressive, velocity-assisted corrosion in high-TAN crude fractions, most severe 450–750°F; low-alloy/carbon steel is far more susceptible than Mo-bearing or 316 SS.

Recommended inspection approach: UT thickness at high-velocity/turbulent locations; feed TAN monitoring; consider alloy upgrade per API 571 guidance.

Inspection History

UT thickness readings, most recent first

DateMethodCML CountAvg ThicknessMin CML Thickness
Aug 22, 2026UT Grid (API 572)41.2972 in1.2857 in
May 10, 2026UT Spot41.3020 in1.2870 in
Mar 22, 2023UT Grid + RT41.3384 in1.3242 in
Dec 19, 2020UT Spot41.3609 in1.3511 in