API 653

Module from the Storage Tank Engineering Curriculum curriculum.

Module 9 - API 653 Inspection · Learning Objectives · 1. Apply API 653 monthly/external/internal inspection intervals · 2. Schedule external inspection every 5 years; internal every 10 or RBI · 3. Perform Magnetic Flux Leakage (MFL) on bottom plates during internal · 4. Measure settlement (differential, out-of-plane) per App B · 5. Complete fitness-for-service assessment per App B/App C for thin areas · API 653 Inspection Intervals

Inspection Type	Max Interval	Triggers	Who	Notes	Ref
Routine monthly	Monthly	Per procedure	Operator	External walk-around	API 653 6.3.1
External formal	5 yr	Age & service	Certified inspector	Documented report	API 653 6.3.2
UT shell thickness	5 yr or less	Condition	Certified or contracted	CML UT readings	API 653 6.3.3
Internal inspection	10 yr or Half RL	Bottom CR	Certified + services	Floor scan MFL	API 653 6.4
RBI-based	Per risk	Consequence/likelihood	RBI team	Extended possible	API 580, API 653 6.4.2.2

Source: Storage_Tank_Engineering_Curriculum_v1.xlsx · Sheet: API 653

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