CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
← Vessel Registry

V-1112 — Atmospheric Gas Oil Column V-1112

Sulfur Recovery Unit · Atmospheric Gas Oil service · Installed Aug 31, 1989 (37 yrs in service)

High
Current Min. Thickness
1.175 in
t-min 1.762 in
Measured Corrosion Rate
19.71 mpy
ML-predicted: 18.60 mpy
Remaining Life
0.0 yrs
Next Inspection Due
Feb 20, 2027
Interval: 0.5 yrs (API 510)

UT Thickness Trend

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

Vessel Specification

MaterialSA-240-316L Stainless
Design CodeASME BPVC Section VIII, Div. 2
Joint Efficiency0.85
Design Pressure427 psig
Design Temperature462 °F
Operating Pressure251 psig
Operating Temperature305 °F
Diameter115 in
Nominal Thickness1.911 in
Corrosion Allowance0.0938 in
H2S / Chloride20 / 152 ppm
Flow Velocity20.6 ft/s
Process pH6.99
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
15.84 mpy
Predicted corrosion rate under these conditions (-3.87 mpy vs. current measured rate)
Implied Remaining Life
0.0 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)61.1802 in1.1752 in
May 9, 2025UT Grid + RT61.2048 in1.1897 in
Feb 2, 2023UT Grid + RT61.2530 in1.2477 in
Jul 20, 2020UT Spot61.3040 in1.2939 in
Jun 8, 2018UT Spot61.3447 in1.3360 in
Jan 27, 2016UT Spot61.3910 in1.3837 in
Nov 28, 2013UT Grid (API 572)61.4311 in1.4184 in
Apr 28, 2011UT Spot61.4859 in1.4848 in
Apr 2, 2009UT Grid (API 572)61.5254 in1.5112 in
Sep 18, 2007UT Spot61.5546 in1.5525 in
Nov 26, 2004UT Spot61.6082 in1.6005 in
Jun 29, 2002UT Grid + RT61.6555 in1.6416 in
Jan 1, 2000UT Grid (API 572)61.7062 in1.6952 in
Aug 29, 1997UT Grid + RT61.7521 in1.7471 in
Jul 31, 1994UT Grid (API 572)61.8143 in1.8001 in
Dec 31, 1991UT Grid + RT61.8669 in1.8654 in