API Spec 6A-2018 (2022) PDF

Full title and description

API SPEC 6A:2018 — Specification for Wellhead and Tree Equipment (Twenty‑First Edition) with Addendum 3 (2022). This entry refers to the 2018 base specification (21st edition) and the August 2022 addendum that amends selected technical, quality and product requirements for wellhead and Christmas‑tree equipment used in the petroleum and natural gas industries.

Abstract

API Spec 6A establishes performance, dimensional and functional interchangeability, design, materials, testing, inspection, welding, marking, handling, storage, shipment, purchasing, repair and remanufacture requirements for wellhead and tree (Christmas‑tree) equipment. Addendum 3 (2022) provides targeted amendments to the 2018 (21st) edition—clarifying product definitions, updating quality/acceptance rules and adding or revising limited product requirements. The addendum is published by the American Petroleum Institute.

General information

• Status: Amendment to API SPEC 6A:2018 (Addendum 3:2022). (Note: the 2018 base document and its addenda/errata have continued to be updated; later errata/addenda were published after 2022.)
• Publication date: Base standard (21st ed.) — 2018 (published Oct/Nov 2018). Addendum 3 — published 1 August 2022 (Addendum 3:2022).
• Publisher: American Petroleum Institute (API).
• ICS / categories: Petroleum and natural gas industries — drilling/production and pressure‑containment equipment (commonly referenced under ICS groups for drilling/extraction and petroleum production equipment).
• Edition / version: 21st Edition (API SPEC 6A:2018) plus Addendum 3 (2022).
• Number of pages: Base specification: commonly published as ~408–413 pages depending on publisher/redline; Addendum 3 (2022): 16 pages.

Scope

Applies to the design, manufacture, testing, inspection, marking, handling, storage, shipment, purchasing, repair and remanufacture of wellhead and tree (Christmas‑tree) equipment used in oil and gas drilling and production. Typical covered items include wellhead housings, spools, connectors, ring gaskets, valves (gate/plug/ball and safety valves), chokes, actuators, casing and tubing hangers, adapters, and related assemblies. Addendum 3 introduces targeted technical clarifications and limited new/updated product requirements to the 2018 edition.

Key topics and requirements

• Product definition updates and reorganization of product‑specific requirements (clarifying which requirements apply to specific equipment families).
• Quality and acceptance criteria (grouped by activity rather than dispersed by PSL), including updates to material, heat treatment and records control expectations.
• Revised sizing tables and figures (SI and USC unit sets) and clearer interchangeability/dimensional requirements.
• Updates to PSL (Product Specification Level) assignments and minimum PSL requirements tied to pressure rating and material class; targeted PSL 4 for critical service equipment.
• Addition, removal or reclassification of specific product items and annex material (e.g., incorporation/withdrawal of certain annexes; introduction of boarding shutdown valves as a product in the 21st edition and later clarifications in addenda).
• Factory acceptance testing (FAT), marking and monogram program implications clarified or reorganized in the main 2018 document with consequential adjustments in subsequent addenda.

Typical use and users

Used by manufacturers, purchasers, quality and inspection engineers, procurement teams, design engineers, test houses, service companies and certification bodies in upstream oil & gas to specify, supply, verify or certify wellhead and Christmas‑tree equipment for onshore and offshore applications. It is commonly referenced in procurement contracts, vendor drawings, shop test procedures and API Monogram licensing.

Related standards

Commonly referenced standards and documents include API repair/remanufacture guidance (e.g., API STD 6AR), relevant ASME and ISO documents for threads/flanges/welding/testing, NACE (corrosion) documents and material specifications used across wellhead equipment standards. The 21st edition also aligns with or references ISO 10423 and a range of API errata and addenda that have been issued since 2018.

Keywords

API 6A, wellhead, Christmas tree, tree equipment, wellhead equipment, valve, choke, PSL, product specification level, API Monogram, addendum 2022, Addendum 3, pressure‑containing equipment, inspection, FAT, material class.

FAQ

Q: What is this standard?

A: API SPEC 6A is the American Petroleum Institute’s specification that sets technical requirements for wellhead and Christmas‑tree (tree) equipment; the 2018 document is the 21st edition and Addendum 3 (2022) is a 16‑page amendment to that edition.

Q: What does it cover?

A: It covers design, materials, performance, dimensional interchangeability, testing, inspection, welding, marking, handling, storage, shipment, purchasing, repair and remanufacture requirements for a broad set of wellhead and tree components (flanges, connectors, valves, chokes, hangers, actuators, etc.). Addendum 3 supplies targeted clarifications and specific product updates to the 2018 edition.

Q: Who typically uses it?

A: Manufacturers, designers, quality/control inspectors, procurement professionals, test laboratories, certification bodies (API Monogram licensees) and operators in upstream oil & gas who buy, produce, inspect or certify wellhead and tree equipment.

Q: Is it current or superseded?

A: The 2018 base document remains the 21st edition; Addendum 3 (2022) is an amendment issued in 2022. Note that API has continued issuing errata and further addenda after 2022 (for example Addendum 4 and multiple errata in later years), so users should check the API catalogue or API Compass for the most current consolidated status and to confirm whether a later erratum or addendum affects the specific clauses they rely on.

Q: Is it part of a series?

A: Yes — API 6A is part of the API product family addressing drilling and production equipment; related documents include API repair/remanufacture standards (e.g., API STD 6AR), various API recommended practices and numerous referenced ASME/ISO/NACE standards. The 6A document itself is maintained via errata and addenda (the 21st edition plus subsequent addenda).

Q: What are the key keywords?

A: Wellhead, Christmas tree, API 6A, PSL (Product Specification Level), pressure rating, material class, monogram, valve, choke, Addendum 3 (2022).