API RP 4G-2019 (2020) PDF

Full title and description

API RP 4G:2019 — Recommended Practice for Operation, Inspection, Maintenance, and Repair of Drilling and Well Servicing Structures (5th edition). The 2019 text is published with subsequent addenda; commonly distributed as API RP 4G:2019 including Addendum 1 (2020) and Addendum 2 (2020), which consolidate clarifications and editorial updates to the 2019 edition.

Abstract

This recommended practice provides guidelines and recommended procedures for the operation, inspection, maintenance, and repair of drilling and well‑servicing structures to maintain serviceability and safety. It covers masts/derricks, substructures and associated accessories, inspection categories and frequency, inspection methods (visual and NDT), repair and recertification criteria, and documentation/reporting templates.

General information

• Status: Current (consolidated edition published with addenda through 2020).
• Publication date: Fifth edition published 2019; consolidated with Addendum 1 and Addendum 2 (addenda dated 2020; consolidated reissue Sept 1, 2020).
• Publisher: American Petroleum Institute (API).
• ICS / categories: Petroleum and natural gas industries — drilling and extraction equipment (ICS area typically associated with codes for drilling/extraction equipment such as 75.180.x).
• Edition / version: 5th edition (2019) — includes Addendum 1 (2020) and Addendum 2 (2020); commonly referenced as API RP 4G:2019+ADD2:2020.
• Number of pages: Approximately 64 pages in the published PDF/print edition (consolidated with addenda).

Summary details above reflect the 2019 fifth edition and the consolidated 2020 addenda release.

Scope

Applies to drilling and well‑servicing structures used on land and offshore installations. The standard gives recommended practices for inspection classifications, inspection techniques (visual inspection, nondestructive testing, functional checks), maintenance and repair methods, acceptance criteria for structural members and attachments, and recertification procedures. It is intended to supplement manufacturer instructions and other API safety practices rather than replace them. Typical items covered include masts/derricks, substructures, platforms, ladders, braces, connection plates, fasteners and lifting attachments.

Key topics and requirements

• Inspection categories and intervals (Category I–IV inspections for different rig types and service conditions).
• Inspection procedures: visual inspection, dimensional checks, nondestructive testing (UT, MT, PT) where required.
• Acceptance and rejection criteria for load‑bearing members, welds, bolts, and fasteners.
• Maintenance, repair and corrective action guidance including approved repair methods and weld/bolting practices.
• Recertification and documentation requirements: inspection reports, tag/labeling and owner/operator records.
• Interfaces to related API guidance (hoisting equipment, wire rope, drilling equipment) and required references/annexes with checklists and forms.

These topics represent the principal obligations and procedures users must apply when following the recommended practice.

Typical use and users

Primary users are drilling contractors, rig owners and operators, maintenance and inspection service providers, rig safety and reliability engineers, third‑party inspection bodies, and regulatory/compliance teams. The document is used for routine inspection programs, pre‑use checks, major recertification campaigns, third‑party audits and establishing maintenance/repair procedures onshore and offshore.

Related standards

Commonly referenced standards and practices include API RP 8B (hoisting equipment inspection and maintenance), API RP 7L (drilling equipment), API RP 9B (wire rope care and use), API Spec 6A/16A (wellhead/BOP equipment), API RP 54 (occupational safety for drilling/servicing operations) and relevant ISO standards for drilling and lifting equipment. Users should apply the companion API documents where procedures or equipment overlap.

Keywords

drilling structures; derrick; mast; substructure; inspection; maintenance; repair; recertification; API RP 4G; inspection categories; nondestructive testing; rig safety; addenda 2020.

FAQ

Q: What is this standard?

A: API RP 4G is a Recommended Practice from the American Petroleum Institute providing guidance for the operation, inspection, maintenance and repair of drilling and well‑servicing structures (masts/derricks, substructures and accessories).

Q: What does it cover?

A: It covers inspection classifications and schedules, inspection methods (including visual and NDT), acceptance/rejection criteria for structural members and components, recommended repair methods, tagging/recertification and required documentation templates.

Q: Who typically uses it?

A: Drilling and well servicing contractors, rig owners/operators, inspection companies, safety and reliability engineers, maintenance teams and regulators use it to plan and execute inspections, repairs and recertification of drilling structures.

Q: Is it current or superseded?

A: The 5th edition was published in 2019 and has been issued with addenda in 2020; the consolidated release including Addendum 2 (dated 2020) is the commonly used/current consolidated version. Earlier editions (for example 2012) are superseded by the 2019 edition with 2020 addenda.

Q: Is it part of a series?

A: It forms part of API's family of exploration and production recommended practices and specifications addressing drilling equipment, hoisting and lifting, wire rope, well control and safety; users should consult adjacent API RPs and Specs where equipment or procedures overlap (for example API RP 8B, 7L, 9B, 54 and related specifications).

Q: What are the key keywords?

A: Drilling structures, mast, derrick, substructure, inspection, maintenance, repair, recertification, API RP 4G, NDT, inspection categories, addendum 2020.