V-1085 — Sour Water Drum V-1085

Amine Treating Unit · Sour Water service · Installed Aug 29, 1998 (28 yrs in service)

Critical

Current Min. Thickness

0.447 in

t-min 0.456 in

Measured Corrosion Rate

3.97 mpy

ML-predicted: 3.93 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-387-11 Cl.2 (1.25Cr-0.5Mo)

Design CodeASME BPVC Section VIII, Div. 2

Joint Efficiency1.00

Design Pressure334 psig

Design Temperature256 °F

Operating Pressure278 psig

Operating Temperature196 °F

Diameter48 in

Nominal Thickness0.576 in

Corrosion Allowance0.0938 in

H2S / Chloride654 / 193 ppm

Flow Velocity19.9 ft/s

Process pH5.89

InsulatedYes

Corrosion & Remaining-Life What-If

Adjust operating conditions to see the live model-predicted corrosion rate and implied remaining life

Operating Temperature196°F

H2S Concentration654 ppm

Chloride Concentration193 ppm

Flow Velocity19.9 ft/s

Process pH5.89

Insulated (CUI potential)

MaterialDamage Mechanism

Live Prediction — What-If Model

5.29 mpy

Predicted corrosion rate under these conditions (+1.32 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 — General Corrosion

API 571 §4.2.1

Uniform thinning across the surface due to the process environment. Rate depends on fluid chemistry, temperature, and velocity.

Recommended inspection approach: UT thickness grid at fixed CMLs per API 510/572; trend over time to establish long-term rate.

Inspection History

UT thickness readings, most recent first

Date	Method	CML Count	Avg Thickness	Min CML Thickness
Aug 22, 2026	UT Grid + RT	6	0.4664 in	0.4470 in
May 26, 2026	UT Grid (API 572)	6	0.4646 in	0.4517 in
Sep 23, 2023	UT Spot	6	0.4758 in	0.4653 in
Mar 29, 2021	UT Grid + RT	6	0.4869 in	0.4677 in
Jul 1, 2018	UT Spot	6	0.4960 in	0.4779 in
Jun 7, 2015	UT Grid (API 572)	6	0.5124 in	0.5072 in
Feb 25, 2013	UT Spot	6	0.5172 in	0.5052 in
Jun 9, 2011	UT Grid + RT	6	0.5265 in	0.5248 in
Jan 9, 2009	UT Grid + RT	6	0.5334 in	0.5231 in
Jun 8, 2006	UT Grid (API 572)	6	0.5470 in	0.5412 in
Nov 6, 2003	UT Spot	6	0.5573 in	0.5482 in
Jun 6, 2002	UT Grid + RT	6	0.5601 in	0.5550 in
Sep 28, 2000	UT Grid (API 572)	6	0.5666 in	0.5552 in