Pitting Corrosion | Materials And Corrosion Control

Damage Description

Affected Materials

Critical Factors

Affected Units or Equipment

Appearance or Morphology of Damage

Prevention/Mitigation

·         3 coats system: APCS-2A or APCS-2C (dry film thickness not exceeding 20 mils)

·         1 coat system: APCS-2E, APCS-2F or APCS-2G (dry film thickness 20 mils minimum)

·         Use APCS-4 for external protection.

·         Corrosion inhibitor will provide protection to the vessel portion immersed in liquid (bottom portion)

Inspection and  Monitoring

·         Perform Internal visual inspection during T&I

·         Evaluate new technology for online external inspection for internal coating. Consider installing on-line mobiletex CP system after approval by CSD.

Inspection Frequency

·         Inspect bottom nozzles every 30 months

Key Performance Indicators (KPIs)

·         Inhibitor residual versus target & % compliance?

·         Corrosion inhibitor dosage rate ± 1 GPD This is an integrity operating window

·         Pitting penetration rate?

·         Number of leaks (by corrosion) per year

·         Number of OSI points with remaining life <10 years

Plant Integrity Windows (PIWs)

·         H₂S/CO₂: 0.27

·         Operating/Design pressure: 400/605 psig

·         Operating/Design Temperature: 110 (Winter)-180 (Summer)/235°F

Competencies and Training

·         e-COE 101 Corrosion Basics

·         e-COE 701 Corrosion & Corrosion Prevention

·         PEW 407 Corrosion Technology

·         COE 104 Chemical Treatment For Producing Operations

Coating Courses

·         COE 108 Protective Coatings

·         CTG 300 Corporate Inspection Coatings Program

·         CTG 107 Coatings Refresher

·         Cathodic Protection Courses

·         COE 107 Cathodic Protection

·         EIN 200 Cathodic Protection

NDT Courses

·         COE 109 Nondestructive Testing and inspection

·         NDT 103 Ultrasonic Testing Thickness Gauging

·         NDT 106/104 Visual Testing level I/II

·         NDT 203 Ultrasonic Testing Shear Wave Level II

Process Courses

·         CHE 108 Hydrocarbon Process Design & Modeling or
CHE 109 Hydrocarbon processing for Non-Chemical Engineers

·         CHE 104 Process Separation & Vessel Design

·         e-course: Gas Oil Separation Plant(GOSP)1-Descrption

·         e-course: Gas Oil Separation Plant(GOSP)2-Troupleshoot

Reference Resources (Standards/GIs/BPs)

·         SAEP-20 Equipment Inspection Schedule

·         SAEP-1135 On Stream Inspection Administration