ISO 20421-1:2019/Amd 1:2022

Overview

ISO 20421-1:2019/Amd 1:2022 is an international standard focusing on cryogenic vessels, specifically large transportable vacuum-insulated vessels. This amendment updates the design, fabrication, inspection, and testing requirements that ensure these specialized vessels meet stringent safety and performance criteria. Developed by ISO Technical Committee ISO/TC 220, the standard addresses critical parameters for vessels used in transporting and storing cryogenic liquids under vacuum insulation.

This document guides manufacturers, inspectors, and engineers toward compliance with internationally recognized best practices, enhancing reliability and safety in cryogenic vessel applications.

Key Topics

• Design Specifications
  Detailed requirements for calculating minimum wall thicknesses based on vessel diameter and material properties, emphasizing safety against internal and external pressures. The amendment revises criteria for materials, including tensile strength and elongation factors used in thickness calculations.

• Material Requirements
  Reference materials characterized by strength and elongation product values guide minimum thickness and fabrication practices. The standard defines minimum thicknesses for various alloys including austenitic stainless steel, ferritic stainless steel, aluminum alloys, and pure aluminum.

• Inspection and Testing
  Procedures and safety factors for inspecting vessel integrity to prevent buckling and failure during service. The amendment updates safety factors related to out-of-roundness tolerances and establishes distinct values depending on vessel geometry (cylindrical shells, spherical regions, and knuckle regions).

• Fabrication Guidelines
  Instructions to ensure structural robustness during the manufacturing process, including forming, welding, and applying vacuum insulation without compromising the vessel’s strength or vacuum integrity.

Applications

ISO 20421-1:2019/Amd 1:2022 applies predominantly to industries requiring safe and efficient transportation and storage of cryogenic substances, including:

• Liquefied gases transport: Large vacuum-insulated vessels designed pursuant to this standard are essential for moving gases like liquid nitrogen, oxygen, argon, and LNG safely over long distances.

• Industrial Gas Supply: Gas manufacturers and distributors rely on compliant cryogenic vessels for storage and delivery systems to customers in healthcare, manufacturing, and research.

• Energy Sector: With increasing use of liquefied natural gas (LNG), adhering to this standard ensures vessels meet the demanding conditions of energy transport and storage.

• Scientific Research: Laboratories handling cryogenic fluids benefit from vessels designed and tested according to this ISO amendment for improved safety.

Using these standards helps minimize risks associated with vessel failure due to material inadequacies or improper fabrication and supports global harmonization in cryogenic vessel quality.

Related Standards

ISO 20421-1:2019/Amd 1:2022 is part of the larger ISO 20421 series covering cryogenic vessels. For those working with vacuum-insulated transportable vessels or related cryogenic storage solutions, also consider:

• ISO 20421-2 – Addresses additional parts of cryogenic vessels, including operational requirements.
• ISO 11120 – Specifies requirements for reusable transportable cryogenic cylinders.
• ISO 13458 – Defines testing methods for cryogenic vessels.
• ISO/IEC Directives, Part 1 and Part 2 – Outline development and editorial rules applicable to ISO standards creation and amendments.

Applying ISO 20421-1:2019/Amd 1:2022 alongside these complementary standards ensures a comprehensive approach to cryogenic vessel safety, performance, and regulatory compliance.

Keywords: cryogenic vessels, vacuum-insulated transportable vessels, ISO 20421-1 amendment, cryogenic vessel design, vessel fabrication standards, inspection and testing, minimum wall thickness, cryogenic storage, LNG transport safety, stainless steel cryogenic tanks, aluminum cryogenic vessels, international standards for cryogenic equipment.