ISO 21013-3-2016 PDF

Full title and description

ISO 21013-3:2016 — Cryogenic vessels — Pressure‑relief accessories for cryogenic service — Part 3: Sizing and capacity determination. This part gives calculation methods to determine the required mass‑flow to be relieved and provides recommendations for pressure‑relief devices and sizing for cryogenic vessels and cryostats.

Abstract

ISO 21013-3:2016 specifies separate calculation procedures for determining the contributing mass flow to be relieved for a range of cryogenic vessel conditions (vacuum‑insulated vessels with intact insulation under normal vacuum, with pressure‑build up system operating, loss of vacuum and fire exposure, etc.). It requires good engineering practice where no specific calculation method is provided, and includes recommendations in an informative annex for pressure relief arrangements for cryostats.

General information

• Status: Published (International Standard).
• Publication date: May 2016.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 23.020.40 (Cryogenic vessels).
• Edition / version: Edition 2 (2016).
• Number of pages: 35.

(General information items above are taken from the ISO bibliographic entry for ISO 21013‑3:2016.)

Scope

Gives calculation methods to determine the required mass flow to be discharged for specified situations affecting cryogenic vessels: vacuum‑insulated vessels with intact insulation under normal vacuum, cases with active pressure‑build up systems, loss of vacuum or damaged insulation (including fire exposure) and related conditions. Where no specific calculation method is provided for a condition, the standard requires application of sound engineering practice based on established physical theory. Annex A contains recommendations for pressure‑relief arrangements for cryostats.

Key topics and requirements

• Calculation methods for sizing relief devices and determining required discharge mass flow for multiple cryogenic failure/operational scenarios.
• Treatment of vacuum‑insulated vessels (intact vacuum, vacuum loss) and effects of ambient/inner vessel temperatures on relieving conditions.
• Requirements to use good engineering practice and theoretical physical data where explicit methods are not provided.
• Informative recommendations (Annex A) for selection and arrangement of pressure‑relief accessories for cryostats.

Typical use and users

Used by designers and manufacturers of cryogenic vessels and storage systems, safety and process engineers, testing and inspection bodies, certification/approval authorities, and standards committees to size and specify pressure‑relief devices (valves, bursting discs, assemblies) for cryogenic service and to document safety analyses.

Related standards

ISO 21013 is a multipart series covering pressure‑relief accessories for cryogenic service. Key related parts include: ISO 21013‑1 (Reclosable pressure‑relief valves) — current edition ISO 21013‑1:2021; ISO 21013‑1 also has an amendment (2024). ISO 21013‑2 (Non‑reclosable devices / bursting discs, buckling pins) — latest edition published 2025 (ISO 21013‑2:2025); methods for determining device capacity for a particular vessel are referenced to Part 3. ISO 21013‑4 (Pilot‑operated pressure relief devices) — ISO 21013‑4:2012 with Amendment 1:2019 covers pilot‑operated devices for cryogenic service.

Keywords

cryogenic vessels; pressure‑relief accessories; relief sizing; capacity determination; vacuum insulation; mass flow; safety devices; cryostats; bursting disc; pressure‑relief valve.

FAQ

Q: What is this standard?

A: ISO 21013‑3:2016 is Part 3 of the ISO 21013 series and provides methods for sizing and determining the capacity (required discharge mass flow) of pressure‑relief accessories used in cryogenic vessels.

Q: What does it cover?

A: It covers calculation procedures for different vessel conditions (intact vacuum, vacuum loss, fire exposure, pressure build‑up systems in operation) and gives informative recommendations for relief arrangements; where no explicit method applies it requires use of sound engineering practice.

Q: Who typically uses it?

A: Mechanical and process engineers, cryogenic equipment manufacturers, safety assessors, testing laboratories, and regulatory or certification bodies involved with cryogenic storage and transfer systems.

Q: Is it current or superseded?

A: ISO 21013‑3:2016 is a published international standard (Edition 2, 2016). The ISO bibliographic record indicates the part is under the normal review cycle and a draft revision (ISO/DIS 21013‑3) has been prepared; users should check for any newer edition or DIS release if they need the absolute latest revision.

Q: Is it part of a series?

A: Yes — it is part of the ISO 21013 series on pressure‑relief accessories for cryogenic service (Parts 1, 2, 3, 4). Part 1 covers reclosable valves, Part 2 non‑reclosable devices, Part 3 sizing (this document), and Part 4 pilot‑operated devices.

Q: What are the key keywords?

A: Cryogenic vessels; pressure relief; sizing; capacity determination; vacuum insulation; mass flow; relief devices; cryostats.