CONCEPT DEMONSTRATION
66Phillips 66Vessel Integrity Intelligence
← Vessel Registry

V-1031 — Wet H2S Gas Drum V-1031

Amine Treating Unit · Wet H2S Gas service · Installed Aug 30, 1992 (34 yrs in service)

Medium
Current Min. Thickness
0.610 in
t-min 0.460 in
Measured Corrosion Rate
0.50 mpy
ML-predicted: 0.15 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 Efficiency1.00
Design Pressure413 psig
Design Temperature299 °F
Operating Pressure262 psig
Operating Temperature215 °F
Diameter44 in
Nominal Thickness0.631 in
Corrosion Allowance0.1250 in
H2S / Chloride902 / 239 ppm
Flow Velocity21.6 ft/s
Process pH6.88
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
0.10 mpy
Predicted corrosion rate under these conditions (-0.40 mpy vs. current measured rate)
Implied Remaining Life
60+ yrs
Implied Reinspection Interval
10.0 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 — Wet H2S Damage (SSC/HIC)

API 571 §4.5.1

Hydrogen-induced cracking (HIC) and sulfide stress cracking (SSC) in carbon/low-alloy steel exposed to wet H2S service. Not detectable by thickness monitoring alone.

Recommended inspection approach: Wet fluorescent magnetic particle (WFMT) and UT shear-wave/AUBT surveys in addition to routine UT thickness, per API RP 571 and NACE SP0296.

This mechanism is crack-dominant — thickness monitoring alone will not detect it. See Standards & Documentation for the full NDE requirement.

Inspection History

UT thickness readings, most recent first

DateMethodCML CountAvg ThicknessMin CML Thickness
Aug 22, 2026UT Spot40.6261 in0.6104 in
Sep 11, 2025UT Grid + RT40.6280 in0.6226 in
Jan 4, 2024UT Grid (API 572)40.6233 in0.6110 in
Feb 3, 2021UT Grid + RT40.6255 in0.6165 in
May 9, 2019UT Grid (API 572)40.6245 in0.6092 in
Jun 9, 2017UT Grid + RT40.6295 in0.6226 in
Sep 27, 2015UT Grid + RT40.6263 in0.6084 in
Jan 14, 2014UT Grid (API 572)40.6285 in0.6215 in
Aug 9, 2011UT Spot40.6300 in0.6157 in
Jul 15, 2008UT Grid (API 572)40.6329 in0.6225 in
Dec 10, 2005UT Grid (API 572)40.6284 in0.6113 in
Sep 25, 2002UT Grid + RT40.6271 in0.6110 in
Dec 28, 1999UT Spot40.6301 in0.6137 in
Dec 24, 1996UT Spot40.6276 in0.6160 in
Apr 27, 1994UT Grid (API 572)40.6294 in0.6206 in