V-1250 — Catalyst Slurry Column V-1250

Delayed Coker · Catalyst Slurry service · Installed Aug 29, 1996 (30 yrs in service)

Low-Medium

Current Min. Thickness

0.765 in

t-min 0.627 in

Measured Corrosion Rate

0.50 mpy

ML-predicted: 1.78 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 Pressure177 psig

Design Temperature217 °F

Operating Pressure97 psig

Operating Temperature173 °F

Diameter141 in

Nominal Thickness0.796 in

Corrosion Allowance0.1250 in

H2S / Chloride37 / 70 ppm

Flow Velocity21.5 ft/s

Process pH6.04

InsulatedNo

Corrosion & Remaining-Life What-If

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

Operating Temperature173°F

H2S Concentration37 ppm

Chloride Concentration70 ppm

Flow Velocity21.5 ft/s

Process pH6.04

Insulated (CUI potential)

MaterialDamage Mechanism

Live Prediction — What-If Model

2.30 mpy

Predicted corrosion rate under these conditions (+1.80 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 — Erosion-Corrosion

API 571 §4.2.13

Mechanical removal of protective scale by high-velocity flow or entrained solids, accelerating the underlying corrosion mechanism.

Recommended inspection approach: UT thickness at flow-direction changes (elbows, reducers); review process velocity against API RP 14E erosional velocity limits.

Inspection History

UT thickness readings, most recent first

Date	Method	CML Count	Avg Thickness	Min CML Thickness
Aug 22, 2026	UT Grid + RT	4	0.7777 in	0.7655 in
Apr 20, 2026	UT Spot	4	0.7782 in	0.7630 in
Aug 31, 2023	UT Grid + RT	4	0.7825 in	0.7694 in
Dec 3, 2020	UT Grid (API 572)	4	0.7841 in	0.7822 in
Nov 24, 2018	UT Grid (API 572)	4	0.7877 in	0.7681 in
Jul 14, 2016	UT Grid + RT	4	0.7852 in	0.7722 in
Jan 26, 2014	UT Grid (API 572)	4	0.7853 in	0.7726 in
Apr 28, 2011	UT Grid (API 572)	4	0.7898 in	0.7885 in
Jul 3, 2008	UT Grid + RT	4	0.7901 in	0.7794 in
Dec 21, 2005	UT Spot	4	0.7892 in	0.7848 in
Nov 26, 2003	UT Grid + RT	4	0.7944 in	0.7773 in
Oct 27, 2000	UT Spot	4	0.7900 in	0.7715 in
Mar 12, 1998	UT Grid + RT	4	0.7931 in	0.7765 in