API Spec 12B-2020 (2024) PDF

Full title and description

API SPEC 12B:2020 — Specification for Bolted Tanks for Storage of Production Liquids (Seventeenth Edition). This specification sets requirements for the materials, design, fabrication, erection and testing of vertical, cylindrical, aboveground, bolted steel storage tanks used in production service; the 2020 edition is published with an official errata/technical correction issued in 2024.

Abstract

This specification provides minimum requirements and guidance for the safe, economical design and manufacture of bolted steel tanks used to store crude petroleum and other production liquids at approximately atmospheric pressure. Topics include material selection, plate and bolting details, shell and roof design, venting, access (walkways, ladders), erection, inspection and testing; annexes cover bolting specifications and recommendations for ordering and installation.

General information

• Status: Current — 2020 edition with Errata 1 (2024) in force.
• Publication date: 16 December 2020 (original edition); Errata/Inc. Errata 1 published November 2024.
• Publisher: American Petroleum Institute (API).
• ICS / categories: 23.020.10 — Stationary containers and tanks (petroleum storage and related technologies).
• Edition / version: Seventeenth edition (API Spec 12B:2020); amended by INC ERR 1:2024.
• Number of pages: 32 pages (main document) plus errata pages.

Scope

This specification applies to vertical, cylindrical, aboveground, closed- and open-top bolted steel tanks of standard sizes and capacities used in production service for storing crude petroleum and other production liquids at pressures approximating atmospheric. It addresses materials, design rules, fabrication, bolting, venting, inspection and testing, and provides normative annexes for bolting and for access features. The standard is intended for use by purchasers, manufacturers and fabricators to ensure interchangeability and safe operation of production storage tanks.

Key topics and requirements

• Material specifications for shell plates, gaskets and bolting (mechanical and chemical requirements).
• Design rules for shell, roof and base, including allowable stresses and thickness tables.
• Bolting design, bolt grade and torque/assembly recommendations (normative annex on tank bolting).
• Venting and pressure-relief provisions appropriate for atmospheric/near‑atmospheric service.
• Requirements for walkways, stairways, ladders and access (fabrication and safety-related clearances).
• Erection, alignment, leak‑tightness checks, hydrostatic testing and post‑erection inspection.
• Marking, documentation and acceptance/rejection criteria for fabricated tanks.

Typical use and users

Used by oilfield operators, tank manufacturers and fabricators, procurement and quality engineers, site construction teams, inspection and maintenance personnel, and regulatory/compliance staff. The standard is referenced in procurement specifications for production-area storage tanks and in inspection/maintenance procedures for aboveground bolted tanks.

Related standards

Other API and industry documents commonly used with API Spec 12B include API Spec 12D (field‑welded tanks), API Spec 12F (shop‑welded tanks), API Spec 12P (FRP tanks), API 12R1 (installation, operation, maintenance and inspection guidance), and API RP 2021 (management of atmospheric storage tank fires). National and international tank design standards (EN/ISO equivalents) and local building/installation codes may also be referenced.

Keywords

bolted tanks, storage tanks, production liquids, API Spec 12B, tank bolting, venting, hydrostatic testing, tank erection, aboveground storage, tank inspection

FAQ

Q: What is this standard?

A: API SPEC 12B:2020 is the American Petroleum Institute’s specification for bolted steel tanks used to store production liquids; it defines material, design, fabrication, bolting and testing requirements for aboveground, vertical, cylindrical bolted tanks.

Q: What does it cover?

A: It covers the full lifecycle of bolted production tanks from material selection and design rules through fabrication, bolting, erection, venting, inspection and testing, including normative annexes for bolting and access features.

Q: Who typically uses it?

A: Tank manufacturers, purchasers, site construction and erection teams, operations and maintenance engineers, and third‑party inspectors and regulators involved in production‑service storage tanks.

Q: Is it current or superseded?

A: The 2020 edition is current and has been amended by an official errata/technical correction issued in 2024 (INC ERR 1:2024); users should apply the errata together with the 2020 text.

Q: Is it part of a series?

A: Yes — API Spec 12B is part of the API “12” family of standards for storage tanks (examples: API Spec 12D, 12F, 12P, and related guidance such as API 12R1). These documents address different construction methods and materials for production‑service tanks.

Q: What are the key keywords?

A: Bolted tanks; storage tanks; production liquids; tank bolting; venting; hydrostatic test; API 12B; aboveground tanks.