Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service

A335/A335M- 15: Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service

For engineers and designers pushing the boundaries of industrial processes, the integrity of materials under extreme conditions is paramount. ASTM A335/A335M- 15 provides the essential framework for specifying seamless ferritic alloy-steel pipe designed to withstand the rigors of high-temperature service, ensuring reliability and safety in critical applications.

What is A335/A335M- 15?

ASTM A335/A335M- 15 is an authoritative standard that defines the material and manufacturing requirements for seamless ferritic alloy-steel pipe intended for elevated temperature applications. Originating from ASTM International, this specification is the industry-leading document for selecting and procuring pipe that can reliably perform in demanding thermal environments. Its primary purpose is to establish a proven set of criteria to ensure the suitability of these specialized pipes for their intended service.

Scope & Purpose

This comprehensive standard governs the production and material properties of seamless ferritic alloy-steel pipe with nominal or minimum wall thickness. It covers pipes suitable for forming operations like bending and flanging, as well as for fusion welding. The scope explicitly includes various grades of ferritic steels with specific chemical compositions and mandates appropriate heat treatments. It does not cover welded pipe or pipe intended for services other than high-temperature applications.

Who Must Comply?

• • Primary audience: Materials Engineers, Mechanical Engineers, Design Engineers, Quality Control Inspectors, and Procurement Specialists.
• • Industries affected: Petroleum, Chemical Processing, Power Generation (including fossil fuel and nuclear), Manufacturing, and Aerospace.
• • Compliance nature: Voluntary, but often mandated by project specifications, contractual agreements, and regulatory bodies.
• • Enforcement: Typically enforced through third-party inspections, client audits, and certification bodies, ensuring adherence to the specified material requirements.

Key Requirements Overview

• • The standard requires that pipe be manufactured via a seamless process, ensuring material homogeneity.
• • Professionals must ensure the selected pipe grade conforms to the specified chemical composition ranges for alloying elements like chromium and molybdenum, critical for high-temperature strength.
• • Key provisions include mandatory heat treatment, such as annealing, normalizing, or post-weld heat treatment, to achieve the desired mechanical properties and microstructure for high-temperature service.
• • The specification mandates specific mechanical testing, including tensile and impact tests (where applicable), to verify performance under operational stresses.
• • Non-destructive examination requirements, often referencing other ASTM standards, are crucial for detecting defects and ensuring structural integrity.

Related Standards & References

ASTM A335/A335M- 15 frequently works in conjunction with ASTM A999/A999M, "Standard Specification for General Requirements for Alloy and Stainless Steel Pipe," which outlines common requirements applicable to many pipe specifications. For welding considerations, AWS A5.5/A5.5M, "Specification for Low-Alloy Steel Electrodes for Shielded Metal Arc Welding," provides complementary material specifications for joining these high-temperature alloys. Additionally, ASME B36.10M, "Welded and Seamless Wrought Steel Pipe,"