ASTM A691/A691M-19 (2025) PDF

Full title and description

Standard Specification for Carbon and Alloy Steel Pipe, Electric-Fusion-Welded for High-Pressure Service at High Temperatures. This specification covers electric-fusion-welded (with filler metal added) carbon and alloy steel pipe fabricated from pressure‑vessel‑quality plate in a range of grades and strength levels suitable for high‑pressure, high‑temperature service. The standard defines grades, class designations (based on heat treatment, radiography, and pressure testing), manufacturing and welding requirements, and required mechanical and examination tests.

Abstract

ASTM A691/A691M establishes requirements for electric‑fusion‑welded carbon and alloy steel pipe intended for high‑pressure service at elevated temperatures. It prescribes allowable materials, welding procedure and reinforcement, heat treatment classes, mechanical testing (tension, bend, pressure), optional radiographic examination and supplementary requirements, and dimensional limits. The specification is published in both inch‑pound and SI versions and is supplied as A691/A691M‑19 with reapproval in 2025.

General information

• Status: Active (reapproved).
• Publication date: January 9, 2025 (designation A691/A691M‑19, reaffirmed/reissued 2025).
• Publisher: ASTM International.
• ICS / categories: 23.040.10 — Iron and steel pipes.
• Edition / version: A691/A691M‑19 (2019 edition, reapproved/issued 2025 as A691/A691M‑19(2025)).
• Number of pages: 6 pages.

Scope

The specification covers electric‑fusion‑welded pipe made with filler metal from pressure‑vessel‑quality plate intended for high‑pressure service at high temperatures. Heat treatment of the pipe may be required or omitted depending on the class and desired properties. The standard nominally applies to pipes 16 in. (400 mm) outside diameter and larger with wall thicknesses up to 3 in. (75 mm), although other dimensions may be furnished if all requirements are met. Classes designate heat treatment, radiographic examination, and pressure testing options; supplementary requirements allow for additional testing or controls when needed.

Key topics and requirements

• Material: carbon and alloy steel pipe produced from pressure‑vessel‑quality plate.
• Welding: electric‑fusion welding with filler metal (manual or automatic) and requirement for smooth, positively reinforced weld reinforcement.
• Class designations: Classes defined by type of heat treatment on the finished pipe (none, stress relieved, normalized, normalized & tempered, quenched & tempered), radiography, and pressure testing (examples include Classes 10–53 in the specification).
• Mechanical tests: mandatory tension, bend, and pressure (hydrostatic) tests on welds and joints as specified.
• Examination: radiographic examination when specified by class; removal/repair of unacceptable surface imperfections by grinding or machining, with blending of depressions.
• Heat treatment: procedures and acceptance criteria for various classes to attain required mechanical properties.
• Units: published in inch‑pound and SI (M) units; values in each system are to be used independently.
• Supplementary requirements: optional additional tests and controls, including repair welding controls and extra examinations when requested by purchaser.

Typical use and users

Used by manufacturers and fabricators of welded pressure piping for power generation, petrochemical and refinery plants, industrial high‑temperature pressure systems, and pressure vessel manufacturers. Typical users include piping/materials engineers, procurement specialists, quality and inspection personnel, welders and welding procedure developers, and standards/compliance engineers specifying pipe for high‑pressure, high‑temperature service.

Related standards

Relevant companion and referenced documents commonly used with A691/A691M include ASTM A20/A20M (selection guidelines for pressure‑vessel materials), ASTM A335 (seamless ferritic alloy‑steel pipe for high‑temperature service), ASTM A387 (pressure‑vessel plate, alloy steel), and applicable ASME code sections (for example code requirements for high‑temperature pressure piping). Users often consult these and other ASTM and ASME standards for material selection, code compliance, and complementary test methods.

Keywords

ASTM A691, A691M, electric‑fusion‑welded, EFW, carbon steel pipe, alloy steel pipe, high‑pressure, high‑temperature, pressure‑vessel plate, weld radiography, heat treatment, tension test, bend test, hydrostatic test, pipe classes.

FAQ

Q: What is this standard?

A: ASTM A691/A691M is a specification for carbon and alloy steel pipe produced by electric‑fusion welding with filler metal, intended for high‑pressure service at elevated temperatures.

Q: What does it cover?

A: It covers material grades and classes of EFW pipe made from pressure‑vessel‑quality plate, welding and weld reinforcement requirements, heat treatment classes, required mechanical tests (tension, bend, pressure), optional radiography and supplementary requirements, and dimensional and unit conventions.

Q: Who typically uses it?

A: Pipe manufacturers, fabricators, plant and piping engineers, inspectors, purchasers specifying high‑temperature/high‑pressure piping, and organizations needing welded alloy or carbon steel pipe for pressure service.

Q: Is it current or superseded?

A: The designation is A691/A691M‑19 with a 2025 reissue/reapproval (presented as A691/A691M‑19(2025)). It is an active standard; users should confirm the latest status and any amendments or revisions before procurement or design.

Q: Is it part of a series?

A: It is one of several ASTM pipe specifications addressing welded and seamless steels for elevated temperature and pressure service and is commonly used alongside related ASTM and ASME standards (for example A335, A387, and A20/A20M) and applicable ASME code rules.

Q: What are the key keywords?

A: Electric‑fusion‑welded, EFW, alloy steel pipe, carbon steel pipe, high pressure, high temperature, weld radiography, heat treatment, pressure test, pressure‑vessel plate.