V-1275 — Boiler Feed Water Drum V-1275

Amine Treating Unit · Boiler Feed Water service · Installed Sep 1, 1984 (42 yrs in service)

Medium

Current Min. Thickness

0.564 in

t-min 0.727 in

Measured Corrosion Rate

7.26 mpy

ML-predicted: 6.83 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 Efficiency0.85

Design Pressure513 psig

Design Temperature649 °F

Operating Pressure322 psig

Operating Temperature471 °F

Diameter42 in

Nominal Thickness0.875 in

Corrosion Allowance0.0938 in

H2S / Chloride48 / 29 ppm

Flow Velocity7.3 ft/s

Process pH4.81

InsulatedNo

Corrosion & Remaining-Life What-If

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

Operating Temperature471°F

H2S Concentration48 ppm

Chloride Concentration29 ppm

Flow Velocity7.3 ft/s

Process pH4.81

Insulated (CUI potential)

MaterialDamage Mechanism

Live Prediction — What-If Model

6.47 mpy

Predicted corrosion rate under these conditions (-0.79 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 Spot	8	0.5731 in	0.5636 in
Mar 27, 2025	UT Grid (API 572)	8	0.5789 in	0.5770 in
Apr 20, 2022	UT Grid + RT	8	0.6015 in	0.5861 in
Apr 12, 2019	UT Spot	8	0.6258 in	0.6190 in
Sep 25, 2017	UT Grid + RT	8	0.6362 in	0.6345 in
Feb 19, 2015	UT Grid + RT	8	0.6549 in	0.6393 in
Sep 23, 2013	UT Spot	8	0.6651 in	0.6594 in
Aug 6, 2011	UT Grid + RT	8	0.6787 in	0.6768 in
May 26, 2009	UT Grid + RT	8	0.6933 in	0.6763 in
Feb 22, 2007	UT Spot	8	0.7129 in	0.6990 in
Dec 5, 2003	UT Grid (API 572)	8	0.7347 in	0.7150 in
Jul 5, 2002	UT Grid + RT	8	0.7449 in	0.7260 in
May 27, 1999	UT Spot	8	0.7664 in	0.7614 in
Jul 4, 1996	UT Grid + RT	8	0.7870 in	0.7690 in
Jan 22, 1994	UT Grid + RT	8	0.8086 in	0.8008 in
Jan 10, 1991	UT Spot	8	0.8314 in	0.8153 in
Mar 23, 1988	UT Grid (API 572)	8	0.8513 in	0.8509 in
May 11, 1986	UT Grid (API 572)	8	0.8634 in	0.8598 in