API STD 653- 5th Edition – Rules for Construction of Power Boilers

API 653 is a standard developed by the American Petroleum Institute (API) that provides guidelines for the inspection, repair, alteration, and reconstruction of aboveground storage tanks (ASTs) used in the petroleum and chemical industries. This standard is specifically focused on the maintenance and integrity of existing tanks.

Scope: API 653 applies to atmospheric storage tanks that operate at temperatures ranging from -40°F to 500°F (-40°C to 260°C) and have a maximum design pressure of not more than 2.5 psi (17 kPa). The standard covers both shop-built and field-erected tanks.

Key Features:

Inspection Requirements: API 653 outlines the inspection requirements for in-service ASTs. It covers visual, non-destructive, and other testing methods to assess the tank’s condition, including its foundation, shell, roof, and appurtenances.
Evaluation and Assessment: The standard provides criteria for evaluating the tank’s fitness for continued service. This involves assessing the condition of the tank materials, welds, corrosion rates, and other factors that may affect its integrity.
Repairs and Alterations: API 653 includes guidelines for performing repairs and alterations to existing tanks. It outlines the procedures for identifying and addressing issues such as corrosion, leaks, and structural deficiencies to ensure the continued safe operation of the tank.
Welding and Material Standards: The standard specifies requirements for welding procedures, qualifications, and materials used in repairs and alterations. This ensures that any work conducted on the tank meets specified quality and safety standards.
Inspection Records: API 653 emphasizes the importance of maintaining detailed records of inspections, repairs, and alterations. These records provide a historical perspective on the tank’s condition and serve as valuable documentation for regulatory compliance.
Out-of-Service Tanks: The standard provides recommendations for tanks that are temporarily or permanently taken out of service. It covers procedures for cleaning, purging, and securing tanks during periods of inactivity.

Industry Application: API 653 is widely utilized in the petroleum and chemical industries as a benchmark for the inspection and maintenance of aboveground storage tanks. Compliance with API 653 is often required by regulatory agencies, and the standard serves as a crucial tool for ensuring the ongoing integrity and safety of existing storage tank facilities. Tank owners, engineers, inspectors, and maintenance personnel refer to API 653 to develop and implement effective tank maintenance programs.