V-1231 — Rich MDEA Amine Drum V-1231

Hydrocracker · Rich MDEA Amine service · Installed Aug 31, 1988 (38 yrs in service)

High

Current Min. Thickness

0.152 in

t-min 0.334 in

Measured Corrosion Rate

8.83 mpy

ML-predicted: 8.61 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 Pressure229 psig

Design Temperature275 °F

Operating Pressure161 psig

Operating Temperature254 °F

Diameter41 in

Nominal Thickness0.508 in

Corrosion Allowance0.1250 in

H2S / Chloride1316 / 273 ppm

Flow Velocity14.4 ft/s

Process pH7.45

InsulatedNo

Corrosion & Remaining-Life What-If

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

Operating Temperature254°F

H2S Concentration1316 ppm

Chloride Concentration273 ppm

Flow Velocity14.4 ft/s

Process pH7.45

Insulated (CUI potential)

MaterialDamage Mechanism

Live Prediction — What-If Model

13.29 mpy

Predicted corrosion rate under these conditions (+4.46 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 — Amine Corrosion

API 571 §4.2.4

Localized corrosion in amine treating services, accelerated by high velocity, heat-stable salts, and CO2/H2S loading.

Recommended inspection approach: UT thickness at high-turbulence points (elbows, tees, reboiler returns); monitor amine quality (HSAS, degradation products).

Inspection History

UT thickness readings, most recent first

Date	Method	CML Count	Avg Thickness	Min CML Thickness
Aug 22, 2026	UT Grid + RT	6	0.1670 in	0.1518 in
Jul 31, 2026	UT Spot	6	0.1670 in	0.1528 in
Aug 31, 2024	UT Grid (API 572)	6	0.1670 in	0.1489 in
Nov 19, 2021	UT Grid + RT	6	0.1670 in	0.1642 in
Feb 12, 2019	UT Grid + RT	6	0.1670 in	0.1610 in
Jul 13, 2017	UT Spot	6	0.1670 in	0.1589 in
Feb 3, 2016	UT Spot	6	0.1670 in	0.1474 in
Jul 4, 2014	UT Grid + RT	6	0.1670 in	0.1652 in
Nov 14, 2011	UT Grid (API 572)	6	0.1670 in	0.1512 in
Apr 27, 2010	UT Grid (API 572)	6	0.1670 in	0.1570 in
Jan 22, 2008	UT Spot	6	0.1963 in	0.1797 in
Oct 18, 2004	UT Grid + RT	6	0.2459 in	0.2428 in
May 10, 2002	UT Spot	6	0.2884 in	0.2698 in
Aug 27, 2000	UT Grid + RT	6	0.3172 in	0.3046 in
Oct 1, 1998	UT Spot	6	0.3457 in	0.3298 in
Feb 14, 1996	UT Spot	6	0.3868 in	0.3725 in
May 24, 1993	UT Grid + RT	6	0.4315 in	0.4243 in
Aug 3, 1991	UT Grid + RT	6	0.4614 in	0.4529 in