CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
← Vessel Registry

V-1331 — Vacuum Resid Vessel V-1331

Fluid Catalytic Cracker · Vacuum Resid service · Installed Aug 25, 2013 (13 yrs in service)

Medium
Current Min. Thickness
1.747 in
t-min 1.723 in
Measured Corrosion Rate
6.32 mpy
ML-predicted: 10.02 mpy
Remaining Life
3.7 yrs
Next Inspection Due
Jul 4, 2028
Interval: 1.9 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. 1
Joint Efficiency0.85
Design Pressure520 psig
Design Temperature304 °F
Operating Pressure451 psig
Operating Temperature278 °F
Diameter92 in
Nominal Thickness1.850 in
Corrosion Allowance0.0938 in
H2S / Chloride18 / 50 ppm
Flow Velocity6.5 ft/s
Process pH6.09
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
10.45 mpy
Predicted corrosion rate under these conditions (+4.13 mpy vs. current measured rate)
Implied Remaining Life
2.3 yrs
Implied Reinspection Interval
1.1 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 — High-Temperature Sulfidation

API 571 §4.2.11

Reaction of sulfur compounds with steel at high temperature (>500°F) in the absence of water; rate governed by sulfur content, temperature, alloy content.

Recommended inspection approach: UT thickness per Modified McConomy-curve risk ranking; RT/UT at known high-rate locations identified by process simulation.

Inspection History

UT thickness readings, most recent first

DateMethodCML CountAvg ThicknessMin CML Thickness
Aug 22, 2026UT Spot81.7655 in1.7466 in
Dec 26, 2024UT Grid (API 572)81.7779 in1.7732 in
Jul 14, 2023UT Spot81.7871 in1.7695 in
Jan 6, 2021UT Grid + RT81.8011 in1.7829 in
Apr 23, 2019UT Grid (API 572)81.8102 in1.8051 in
Mar 20, 2017UT Spot81.8228 in1.8175 in
Sep 28, 2015UT Grid + RT81.8364 in1.8287 in