API RP 575-2020 PDF

Full title and description

Inspection Practices for Atmospheric and Low‑pressure Storage Tanks — API Recommended Practice RP 575, Fourth Edition (API RP 575:2020). This recommended practice provides guidance, recommended inspection methods and frequencies, repair and recordkeeping practices, and safety considerations for aboveground atmospheric and low‑pressure storage tanks used in petroleum and related industries.

Abstract

API RP 575:2020 (4th ed.) summarizes inspection objectives and procedures for atmospheric and low‑pressure storage tanks (designed to operate at pressures from atmospheric up to low‑pressure service, commonly cited as up to 15 psig), including types of deterioration, recommended inspection intervals, nondestructive examination (NDE) techniques, acceptance criteria for defects, methods of repair and documentation practices. The RP is intended to supplement API Std 653 and other design standards.

General information

• Status: Superseded — the 2020 edition (API RP 575:2020) was later superseded by a 2024 edition (API RP 575:2024).
• Publication date: 1 July 2020 (Fourth Edition).
• Publisher: American Petroleum Institute (API).
• ICS / categories: Petroleum and related technologies — storage tanks / fuels (ICS 75 family; storage/equipment for petroleum).
• Edition / version: 4th edition (API RP 575:2020).
• Number of pages: 116 pages.

Scope

This recommended practice addresses inspection practices for aboveground atmospheric and low‑pressure storage tanks — generally tanks designed to operate at pressures from atmospheric up to low‑pressure service (commonly referenced as up to 15 psig). It covers tank types and configurations, causes and mechanisms of deterioration, inspection planning and frequency, visual and NDE examination methods, evaluation of remaining strength, inspection of repairs and attachments, recordkeeping and reporting, and safety during inspection activities. The document is intended to supplement API Std 653 and applies primarily to tanks constructed to API design standards (for example API Std 650, API Std 620, API Spec 12C).

Key topics and requirements

• Definitions and classification of atmospheric and low‑pressure storage tanks and common design types (fixed roof, external/internal floating roof, cone/flat bottom, etc.).
• Causes of deterioration (external and internal corrosion, weld and seam deterioration, mechanical damage, brittle fracture potential, vapor and product interactions).
• Inspection planning: risk‑based considerations, inspection frequency guidance, pre‑inspection preparation and safe access.
• Inspection methods: visual, ultrasonic thickness measurement, radiography, magnetic particle, dye penetrant, multi‑echo UT for thin plates, floor and shell examinations, roof and floating roof inspection techniques.
• Evaluation and acceptance criteria for corrosion, leaks, cracks and mechanical deterioration; guidance for repair, reinforcement and continued service or retirement.
• Documentation: recommended records, inspection reports, repair records and data for integrity management.
• Coordination with related standards and regulations (API Std 653, API Std 650, API Std 620, OSHA requirements referenced).

Typical use and users

Primary users include tank owners and operators, inspection and integrity engineers, NDE technicians, maintenance and reliability personnel, facility safety managers, consultants, and regulators. The RP is used to develop inspection programs, plan and perform inspections, evaluate tank condition, determine repair actions, and produce inspection reports and records that support safe, compliant tank operation.

Related standards

Commonly referenced or related documents include API Std 653 (Tank Inspection, Repair, Alteration, and Reconstruction), API Std 650 (Welded Tanks for Oil Storage), API Std 620 (Design and Construction of Large, Welded, Low‑Pressure Storage Tanks), API Spec 12C/12A (tank construction), API RP 571 (Damage Mechanisms Affecting Fixed Equipment in the Refining Industry), and applicable OSHA regulations. API RP 575 is intended to supplement API Std 653 for in‑service inspection practices.

Keywords

API RP 575; inspection practices; atmospheric storage tanks; low‑pressure tanks; aboveground storage tanks (AST); inspection frequency; nondestructive examination (NDE); corrosion; floating roof; tank repair; API Std 653; tank integrity.

FAQ

Q: What is this standard?

A: API RP 575:2020 is the American Petroleum Institute’s Recommended Practice titled "Inspection Practices for Atmospheric and Low‑pressure Storage Tanks" (4th edition, published 1 July 2020). It provides recommended inspection methods, frequencies, evaluation criteria, repair guidance and recordkeeping for aboveground atmospheric and low‑pressure storage tanks.

Q: What does it cover?

A: It covers inspection planning and objectives, inspection methods (visual and NDE), common tank deterioration mechanisms, inspection intervals and prioritization, evaluation of defects, repair and maintenance practices, inspection of repairs and attachments, and documentation needed for tank integrity management. It is intended to supplement design and maintenance standards such as API Std 653.

Q: Who typically uses it?

A: Tank owners/operators, inspection engineers, NDE technicians, maintenance and reliability teams, safety managers, consultants and regulators use the RP to develop inspection programs, perform and evaluate inspections, and document tank condition and repair decisions.

Q: Is it current or superseded?

A: The 2020 (4th) edition was published 1 July 2020. It has since been superseded by a 2024 edition (API RP 575:2024); users should consult the latest edition for current requirements and any changes.

Q: Is it part of a series?

A: Yes — API RP 575 is part of API’s suite of standards and recommended practices addressing storage‑tank design, inspection and integrity (commonly used alongside API Std 650, API Std 620, API Std 653 and other API RPs and standards). The RP references and supplements related API standards and industry regulations.

Q: What are the key keywords?

A: Storage tank inspection, atmospheric tanks, low‑pressure tanks, NDE, corrosion, floating roof, tank repair, API RP 575, tank integrity, API Std 653.