blurred backround Hydrogren storage

Updated Cryogenic Hydrogen Storage Standards: CGA H-3 Now Available

CGA would like to announce the release of CGA H-3:2024, Standard for Cryogenic Hydrogen Storage, fourth edition.  This publication contains the suggested minimum design and performance requirements for shop-fabricated, vacuum-insulated cryogenic tanks (vertical and horizontal) intended for above ground storage of liquid hydrogen.

This publication applies to liquid hydrogen storage tanks with maximum allowable working pressures (MAWP) up to and including 175 psi (1210 kPa). Tanks less than 1000 gal (3785 L) gross volume or greater than 25 000 gal (94 600 L) gross volume and all transportable containers are excluded. Tanks outside these pressure and volume constraints may also meet the requirements of this standard when agreed upon by the purchaser/manufacturer and the authority having jurisdiction (AHJ). This standard does not include operation and installation requirements or emergency response information.

The fourth edition includes editorial updates from the third edition.

CGA H-3 is an important standard because of the increasing storage of liquid hydrogen for use as liquid or gaseous hydrogen. It is important that storage tanks operate safely and efficiently to reduce the evaporation and loss of hydrogen.

CGA H-3 provides detailed technical requirements for the following aspects of storage tanks:

  • Tank design and manufacturing criteria
  • Inner vessel
  • Outer jacket
  • Annular space piping and insulation
  • External piping
  • Cleaning
  • Painting
  • Testing
  • Inspection
  • Shipment

CGA H-3 incudes two informational appendices:

  • Appendix A provides typical tank fabrication and design parameters, such as dimensions, shipping envelopes, liquid withdrawal capacity, and pressure building sizing,
  • Appendix B provides examples of tank piping flow diagrams to provide methods of operating and maintaining tanks safely. One important part of tank maintenance is the periodic replacement of main pressure relief devices (PRDs).  This appendix shows designs that allow the removal of those devices while keeping the service personnel safe, such as dual vent stacks or isolation valves for PRDs. Another design feature is the addition of control valves for feeding hydrogen to high pressure reciprocating pumps.

CGA H-3 is going through the final stages of designation as an American National Standard (ANS) and will be identified as ANSI/CGA H-3.  An ANS must be approved by a broad-based consensus body consisting of members from organizations and people in addition to CGA members.  Only one ANS is allowed for a given subject matter, so this means that CGA owns the ANS for the material in ANSI/CGA H-3.