CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
← Vessel Registry

V-1280 — Vacuum Gas Oil Column V-1280

Crude Distillation Unit · Vacuum Gas Oil service · Installed Aug 28, 2000 (26 yrs in service)

Low-Medium
Current Min. Thickness
1.935 in
t-min 1.826 in
Measured Corrosion Rate
0.88 mpy
ML-predicted: 1.73 mpy
Remaining Life
60+ yrs
Next Inspection Due
Aug 19, 2036
Interval: 10.0 yrs (API 510)

UT Thickness Trend

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

Vessel Specification

MaterialSA-516-70 Carbon Steel
Design CodeASME BPVC Section VIII, Div. 2
Joint Efficiency0.85
Design Pressure504 psig
Design Temperature137 °F
Operating Pressure317 psig
Operating Temperature119 °F
Diameter121 in
Nominal Thickness1.961 in
Corrosion Allowance0.0625 in
H2S / Chloride38 / 11 ppm
Flow Velocity11.5 ft/s
Process pH8.00
InsulatedYes

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
5.51 mpy
Predicted corrosion rate under these conditions (+4.63 mpy vs. current measured rate)
Implied Remaining Life
19.8 yrs
Implied Reinspection Interval
9.9 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 + RT61.9374 in1.9352 in
Jul 16, 2024UT Grid + RT61.9422 in1.9236 in
Jan 22, 2023UT Grid + RT61.9409 in1.9319 in
Jan 29, 2020UT Grid + RT61.9436 in1.9394 in
May 8, 2017UT Spot61.9476 in1.9298 in
Apr 9, 2014UT Spot61.9457 in1.9404 in
Jan 6, 2012UT Grid (API 572)61.9530 in1.9352 in
Dec 3, 2009UT Grid (API 572)61.9497 in1.9315 in
Nov 15, 2006UT Grid (API 572)61.9558 in1.9422 in
Oct 9, 2004UT Grid (API 572)61.9584 in1.9387 in
May 3, 2002UT Spot61.9602 in1.9433 in