ASME B31.5-2022 PDF

Full title and description

ASME B31.5-2022 — Refrigeration Piping and Heat Transfer Components. This Code Section provides requirements for refrigerant piping, heat transfer components, and secondary coolant piping (including materials, design, fabrication, assembly, erection, testing and inspection) for low-temperature applications down to −320°F (−196°C).

Abstract

ASME B31.5-2022 is the 2022 edition of the ASME piping Code section that addresses safe practice and minimum requirements for refrigeration and heat‑transfer piping systems and their associated components. It clarifies applicability, materials selection, pressure/temperature limits, joining methods, flange and bolting requirements, inspection and testing procedures, and special provisions for low‑temperature and secondary coolant systems.

General information

• Status: Active / Current.
• Publication date: 2022 (edition published/issued in 2022).
• Publisher: American Society of Mechanical Engineers (ASME).
• ICS / categories: Piping and pipeline systems (ICS 23.040 series), piping and couplings (ICS 23.100.40); generally classified under piping and heat‑transfer system categories.
• Edition / version: 2022 edition (ASME B31.5-2022).
• Number of pages: Approximately 104–106 pages (commonly listed as 106 pages in product listings).

Scope

B31.5 prescribes requirements for refrigerant piping, heat transfer components, and secondary coolant piping for temperatures as low as −320°F (−196°C), whether erected in the field or factory assembled. The Code excludes self‑contained/unit systems covered by recognized testing laboratories (for example UL), ordinary water piping, piping designed for external or internal gage pressure not exceeding 15 psi (105 kPa), and equipment such as pressure vessels, compressors, or pumps (although connecting piping starting at the first joint adjacent to such apparatus is covered).

Key topics and requirements

• Materials selection and allowable stresses for low‑temperature service.
• Design rules for piping and heat transfer components (pressure/temperature ratings, wall thickness, stress analysis).
• Fabrication, joining and welding requirements, and acceptable joining methods for refrigerants and secondary coolants.
• Assembly, erection, supports, anchors, and provisions for thermal movement and stresses.
• Flange facings, bolting requirements (including specific guidance for cast/grey/malleable iron flanges) and gasket considerations.
• Inspection, nondestructive examination, pressure testing, and installation acceptance criteria.
• Special provisions for secondary coolant systems and interfaces with equipment (first joint adjacent to compressors, pumps, vessels, etc.).
• Compatibility notes regarding other B31 Code sections and refrigeration industry standards.

Typical use and users

Used by mechanical engineers, piping designers, plant owners, refrigeration system manufacturers, fabricators, inspectors, regulators and contractors involved in designing, building, inspecting or maintaining refrigeration and low‑temperature piping and heat‑transfer systems. The Code is referenced where jurisdictional piping regulations require or permit ASME B31 application for refrigeration piping.

Related standards

ASME B31.5 is part of the ASME B31 piping series and is commonly used alongside ASME B31.1 (Power Piping) and ASME B31.3 (Process Piping) where systems interface. Refrigeration practice also references industry standards such as ANSI/ASHRAE standards for refrigeration safety and IIAR guidance (for ammonia systems), plus applicable UL listings and local plumbing/mechanical codes.

Keywords

ASME B31.5, refrigeration piping, heat transfer components, secondary coolant piping, low‑temperature piping, allowable stress, materials, flanges, bolting, welding, inspection, testing, piping code.

FAQ

Q: What is this standard?

A: ASME B31.5-2022 is the ASME Code Section that sets minimum requirements for refrigeration piping and heat‑transfer components used in low‑temperature and secondary coolant systems.

Q: What does it cover?

A: It covers materials, design, fabrication, joining, assembly, erection, supports, testing, inspection and special provisions for piping used with refrigerants and secondary coolants down to −320°F (−196°C), and specifies where the Code does and does not apply.

Q: Who typically uses it?

A: Mechanical/piping engineers, system designers, fabricators, manufacturers, inspectors, owners and regulators involved with refrigeration and cryogenic piping systems.

Q: Is it current or superseded?

A: The 2022 edition (ASME B31.5-2022) is the current published edition of B31.5; refer to ASME or authorized distributors for any later amendments, corrigenda, or reaffirmations.

Q: Is it part of a series?

A: Yes — it is one section of the ASME B31 series of piping Codes, each covering a different piping application (for example B31.1 for power piping and B31.3 for process piping).

Q: What are the key keywords?

A: Refrigeration piping, heat‑transfer components, secondary coolant, low‑temperature piping, ASME B31.5, materials, flanges, bolting, inspection, testing.