V-1083 — Catalyst Slurry Vessel V-1083

Fluid Catalytic Cracker · Catalyst Slurry service · Installed Aug 30, 1993 (33 yrs in service)

Low-Medium

Current Min. Thickness

0.698 in

t-min 0.589 in

Measured Corrosion Rate

0.51 mpy

ML-predicted: 0.69 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 Pressure211 psig

Design Temperature240 °F

Operating Pressure143 psig

Operating Temperature147 °F

Diameter111 in

Nominal Thickness0.725 in

Corrosion Allowance0.0625 in

H2S / Chloride48 / 173 ppm

Flow Velocity19.5 ft/s

Process pH8.86

InsulatedYes

Corrosion & Remaining-Life What-If

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

Operating Temperature147°F

H2S Concentration48 ppm

Chloride Concentration173 ppm

Flow Velocity19.5 ft/s

Process pH8.86

Insulated (CUI potential)

MaterialDamage Mechanism

Live Prediction — What-If Model

0.10 mpy

Predicted corrosion rate under these conditions (-0.41 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	6	0.7106 in	0.6980 in
Sep 3, 2024	UT Grid + RT	6	0.7096 in	0.6973 in
Oct 22, 2022	UT Grid (API 572)	6	0.7118 in	0.7040 in
Apr 3, 2021	UT Grid + RT	6	0.7101 in	0.6945 in
Feb 3, 2019	UT Spot	6	0.7124 in	0.6992 in
Jul 28, 2016	UT Spot	6	0.7120 in	0.6966 in
Jan 19, 2015	UT Grid (API 572)	6	0.7120 in	0.6967 in
Apr 11, 2013	UT Grid (API 572)	6	0.7188 in	0.6991 in
Oct 26, 2011	UT Grid + RT	6	0.7164 in	0.7115 in
Aug 28, 2009	UT Grid + RT	6	0.7161 in	0.7057 in
Aug 6, 2007	UT Spot	6	0.7176 in	0.7145 in
Oct 18, 2004	UT Spot	6	0.7212 in	0.7119 in
Aug 27, 2002	UT Spot	6	0.7207 in	0.7042 in
Jan 21, 2000	UT Grid + RT	6	0.7254 in	0.7185 in
Aug 14, 1998	UT Spot	6	0.7202 in	0.7070 in
Jun 10, 1996	UT Spot	6	0.7252 in	0.7243 in