CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
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V-1266 — Steam Column V-1266

Sulfur Recovery Unit · Steam service · Installed Aug 31, 1989 (37 yrs in service)

High
Current Min. Thickness
3.146 in
t-min 3.164 in
Measured Corrosion Rate
2.75 mpy
ML-predicted: 4.69 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-240-304L Stainless
Design CodeASME BPVC Section VIII, Div. 2
Joint Efficiency0.85
Design Pressure638 psig
Design Temperature594 °F
Operating Pressure443 psig
Operating Temperature497 °F
Diameter137 in
Nominal Thickness3.270 in
Corrosion Allowance0.0625 in
H2S / Chloride46 / 206 ppm
Flow Velocity3.2 ft/s
Process pH5.33
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
7.62 mpy
Predicted corrosion rate under these conditions (+4.87 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 — Corrosion Under Insulation (CUI)

API 571 §4.3.5

Localized external corrosion beneath insulation where moisture is trapped, most severe in the 140–250°F operating band.

Recommended inspection approach: Insulation removal at high-risk locations (nozzles, low points), profile radiography, or guided-wave UT screening per API 570/RP 583.

Inspection History

UT thickness readings, most recent first

DateMethodCML CountAvg ThicknessMin CML Thickness
Aug 22, 2026UT Grid (API 572)43.1659 in3.1462 in
Apr 4, 2026UT Grid (API 572)43.1729 in3.1688 in
Jun 13, 2023UT Grid (API 572)43.1735 in3.1683 in
Jan 7, 2022UT Spot43.1824 in3.1650 in
Mar 31, 2020UT Grid + RT43.1857 in3.1769 in
Apr 7, 2017UT Spot43.1947 in3.1842 in
Dec 31, 2013UT Grid (API 572)43.2023 in3.1989 in
Jun 30, 2011UT Grid (API 572)43.2106 in3.2026 in
Jan 24, 2009UT Spot43.2166 in3.2075 in
Mar 6, 2006UT Spot43.2237 in3.2227 in
Dec 25, 2002UT Grid + RT43.2343 in3.2192 in
Nov 29, 1999UT Spot43.2397 in3.2308 in
Jan 19, 1997UT Spot43.2489 in3.2385 in
Mar 8, 1995UT Grid (API 572)43.2573 in3.2464 in
Jun 13, 1993UT Grid + RT43.2567 in3.2555 in
May 14, 1991UT Grid (API 572)43.2662 in3.2560 in