Repair

Module from the Storage Tank Engineering Curriculum curriculum.

Module 10 - Repair and Alteration (API 653 Sec 9) · Learning Objectives · 1. Distinguish repair vs alteration per API 653 3.32/3.1 · 2. Apply patch plate size limits (14"x14" lap, < 20% bottom) · 3. Design section replacement for entire course segment · 4. Apply hot-tapping for in-service nozzle addition per API 2201 · 5. Hydrotest tank to 100% of liquid level after major repair or alteration · Repair Method Selection

Repair Type	Scope	Hydrotest Req	Design Review	Typical Use	Ref
Lap patch plate (shell)	Up to 12 in sq	Not normally	Routine	Small corrosion	API 653 9.10
Insert (butt) patch	Large area	Required	Yes	Major	API 653 9.10
Course replacement	Entire course segment	Required	Yes	Bottom course	API 653 9.11
Bottom repair (lap patch)	<20% bottom area	Optional	Yes	General corrosion	API 653 9.10
Bottom replacement	>20% or full	Required	Full alteration	Old tank	API 653 9.11
Shell nozzle addition	New nozzle	Required local	Alteration	New piping	API 653 9.12
Shell jacking (to raise)	Full tank	Not required	Detailed plan	Install liner	API 653 9.13

Source: Storage_Tank_Engineering_Curriculum_v1.xlsx · Sheet: Repair

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