API RP 572, Inspection of Pressure Vessels is a recommended practice developed and published by the American Petroleum Institute (API) that covers the inspection of pressure vessels, including those with a design pressure under 15 psig, and the standards for their construction and maintenance. In addition, API RP 572 also discusses, with relation to pressure vessels, the reasons for inspection, causes of deterioration, the frequency and methods of inspection, methods of repair, and preparation of records and reports. The document was originally published in 1992, with the most recent fourth edition published in December of 2016.

Whereas API 510 defines requirements and expectations for inspection of pressure vessels, this recommended practice is intended to supplement API 510 by providing practical knowledge on inspection practices to pressure vessel inspectors.It covers a large variety of topics related to the inspection of pressure vessels including safety precautions, thickness measurements, both internal and external inspections, and special methods of detecting mechanical damage. 

To be most effective, this recommended practice requires knowledge of other API standards and practices. Some of these standards include, but are not limited to:

• API 510, Pressure Vessel Inspection Code, 
• API RP 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, and 
• API RP 574, Inspection Practices for Piping System Components. 

It is also helpful to have a general familiarity with the ASME Boiler and Pressure Vessel Code, Section VIII: Pressure Vessels when using API RP 572.

API RP 572 Contents

In addition to typical document sections such as Scope and Terms and Definitions, API RP 572 contains the following sections:

• Introduction to Pressure Vessels: methods and materials of construction, internal components and equipment, uses of pressure vessels, and design/construction standards.
• Reasons for Inspection: general, safety, reliability, and regulatory requirements.
• Inspection Plans: inspection for specific types of damage, developing inspection plans, reviewing and updating inspection plans, and risk-based inspection.
• Frequency and Extent of Inspection
• Safety Precautions and Preparatory Work
• Inspection Methods and Limitations: thickness measurements, external and internal inspections, special methods of detecting mechanical damage, metallurgical changes and in-situ metal analysis, and testing.
• Condition Assessment and Repair: visual inspection, thickness measurements, remaining life, and methods of repair for pressure vessels and supporting equipment.
• Records and Reports

The document also includes three informative annexes (“Exchangers,” “Towers,” and “Sample Record Forms”).

Related Topics

• API 560 - Fired Heaters for General Refinery Service
• API 579-1/ASME FFS-1 - Fitness-For-Service (FFS)
• API 594 - Check Valves: Flanged, Lug, Wafer, and Butt-Welding
• API 620 - Design and Construction of Large, Welded, Low-Pressure Storage Tanks
• API 650 - Welded Tanks for Oil Storage
• API 660 - Shell-and-Tube Heat Exchangers
• API 661 - Petroleum, Petrochemical, and Natural Gas Industries Air-Cooled Heat Exchangers
• API RP 1160 - Managing System Integrity for Hazardous Liquid Pipelines
• API RP 1173 - Pipeline Safety Management Systems
• API RP 1176 - Assessment and Management of Cracking in Pipelines
• API RP 1188 - Hazardous Liquid Pipeline Facilities Integrity Management
• API RP 538 - Industrial Fired Boilers for General Refinery and Petrochemical Service
• API RP 571 - Damage Mechanisms Affecting Fixed Equipment in the Refining Industry
• API RP 573 - Inspection of Fired Boilers and Heaters
• API RP 574 - Inspection Practices for Piping System Components
• API RP 575 - Inspection Practices for Atmospheric and Low Pressure Storage Tanks
• API RP 576 - Inspection of Pressure-Relieving Devices
• API RP 577 - Welding Processes, Inspection, and Metallurgy
• API RP 578 - Material Verification for New and Existing Alloy Piping
• API RP 580 - Risk Based Inspection (RBI)
• API RP 581 - Risk Based Inspection Technology
• API RP 583 - Corrosion Under Insulation and Fireproofing
• API RP 584 - Integrity Operating Windows
• API RP 585 - Pressure Equipment Integrity Incident Investigation
• API RP 651 - Cathodic Protection of Aboveground Petroleum Storage Tanks
• API RP 75 - Safety and Environmental Management System for Offshore Operations
• API RP 751 - Safe Operation of Hydrofluoric Acid Alkylation Units
• API RP 754 - Process Safety Performance Indicators for the Refining and Petrochemical Industries
• API RP 934 - Materials and Fabrication of Heavy Wall Pressure Vessels for High-Pressure Hydrogen Ser
• API RP 939-C - Guidelines for Avoiding Sulfidation (Sulfidic) Corrosion Failures in Oil Refineries
• API RP 941 - Steels for Hydrogen Service at Elevated Temperatures and Pressures
• API RP 970 - Corrosion Control Documents
• International Organization for Standardization (ISO)

Relevant Links

• API Standards Homepage
• Purchase Document

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