API St 650-2020 (2021) PDF

Full title and description

St API St 650-2020 (2021) — original: API Std 650:2020, "Welded Tanks for Oil Storage" (13th edition). The reference labeled "(2021)" commonly denotes the 2020 edition as issued with errata/incorporated errata published in 2021 (often shown as "Includes Errata 1:2021"). This document specifies minimum requirements for the materials, design, fabrication, erection and inspection of aboveground, vertical, cylindrical, welded storage tanks for internal pressures approximating atmospheric pressure.

Abstract

API Std 650 establishes requirements and guidance for the design, materials, fabrication, welding, erection, testing and inspection of aboveground welded storage tanks (open- and closed-top) used to store petroleum and petroleum products at pressures approximating atmospheric pressure. The standard includes provisions for shell and roof designs, bottoms and foundations, nozzles and appurtenances, welding and inspection requirements, corrosion allowances, floating roofs and specific annexes covering optional design and construction details.

General information

• Status: Superseded (the 2020 edition with Errata 1:2021 is a historical edition; a later API Std 650 edition has since been published).
• Publication date: Original edition published March 1, 2020; errata/incorporated errata issued January 14, 2021 (commonly referenced as the 2020 edition (2021) when errata are applied).
• Publisher: American Petroleum Institute (API).
• ICS / categories: Classified under petroleum and storage-tank related categories within the ICS system (typical subject area: petroleum and related technologies — storage tanks and handling equipment).
• Edition / version: 13th edition — API Std 650:2020 (includes Errata 1:2021 where noted).
• Number of pages: The 2020 edition with Errata 1:2021 is published as a comprehensive document of approximately 515 pages.

Scope

Applies to the design, material selection, fabrication, erection, examination, inspection and testing of vertical, cylindrical, aboveground, welded storage tanks (open- and closed-top) intended for petroleum and petroleum products stored at pressures approximating atmospheric pressure. The standard covers tanks of a wide range of sizes and capacities and contains mandatory requirements and informative annexes for specialized conditions (for example, floating roofs, seismic design, shop-assembled tanks and small-capacity tanks).

Key topics and requirements

• Design principles for shell, roof and bottom plates (minimum thickness calculations and corrosion allowance).
• Material specifications and permitted steel grades for plate, forgings and fittings.
• Welding procedures, welder qualification, joint types and radiographic/other NDT requirements.
• Foundation and anchoring recommendations, including settlement and load considerations.
• Inspection, testing and commissioning: hydrostatic testing, leak testing, visual and NDT inspection regimes.
• Requirements for floating roofs and internal components, including sealing and rim space practices.
• Provisions for secondary design drivers: seismic design, wind loads, thermal effects and overpressure considerations when applicable.
• Annexes covering optional design methods, shop-assembled tanks and small-capacity tank guidance.

Typical use and users

Used by tank designers, tank fabricators, site erectors, inspection and quality assurance personnel, asset owners/operators, engineers specifying storage tanks for refineries, terminals, bulk storage facilities and petrochemical sites. Also used by regulatory bodies, procurement teams and maintenance groups for specification, acceptance and repair planning of aboveground welded storage tanks.

Related standards

Commonly referenced with and complementary to other industry documents such as API Std 620 (large, low-pressure tanks), API Std 653 (tank inspection, repair, alteration and reconstruction), API RP 577 (welding guidelines), API RP 2350 (overfill prevention), and relevant NFPA and ASME documents addressing fire protection, piping and pressure equipment. These documents are often cross-referenced within API Std 650 and used together on storage-tank projects.

Keywords

API 650, Welded tanks, Oil storage tanks, Aboveground storage tanks, Tank design, Tank fabrication, Welding, Inspection, Corrosion allowance, Floating roof, Foundation, NDT, Tank erection

FAQ

Q: What is this standard?

A: API Std 650 is the American Petroleum Institute standard that sets minimum requirements for the design, materials, fabrication, erection and inspection of vertical, cylindrical, aboveground welded storage tanks used for petroleum and related products.

Q: What does it cover?

A: It covers structural design of shell, roof and bottom; material specifications; welding and weld inspection; foundations and anchoring; testing and commissioning; special considerations such as floating roofs, seismic and wind loading, and informative annexes for optional designs and small/shop-assembled tanks.

Q: Who typically uses it?

A: Tank designers, fabricators, erectors, inspectors, owners/operators of storage facilities, procurement/specification engineers, and regulatory/standards compliance personnel.

Q: Is it current or superseded?

A: The 2020 edition (with Errata 1:2021) is a historical edition and has subsequently been superseded by a later API Std 650 edition; users should confirm and use the most recent edition applicable to their project or regulatory requirement.

Q: Is it part of a series?

A: API Std 650 is part of API’s tank and storage guidance suite and is commonly used alongside API Std 620 (large low-pressure tanks), API Std 653 (inspection & repair), and other API recommended practices and standards that cover related topics (welding, overfill prevention, measurement and safety).

Q: What are the key keywords?

A: API 650; welded tanks; oil storage; storage tank design; welding and NDT; floating roofs; corrosion allowance; tank inspection.