Expansion ratio

The expansion ratio of a liquefied and cryogenic substance is the volume of a given amount of that substance in liquid form compared to the volume of the same amount of substance in gaseous form, at room temperature and normal atmospheric pressure.{{cite book | title = Emergency Characterization of Unknown Materials | author = Rick Houghton | publisher = CRC Press | year = 2007 | isbn = 978-0-8493-7968-0 | url = https://books.google.com/books?id=GA_0smWGxwwC&q=liquid+gas+%22Expansion+ratio%22&pg=PA22 }}

If a sufficient amount of liquid is vaporized within a closed container, it produces pressures that can rupture the pressure vessel. Hence the use of pressure relief valves and vent valves are important.[http://www.airproducts.com/nr/rdonlyres/38000ecf-e07b-4288-8ff9-73699c70c882/0/safetygram27.pdf Safetygram-27 Cryogenic Liquid Containers] {{webarchive|url=https://web.archive.org/web/20081207051502/http://www.airproducts.com/NR/rdonlyres/38000ECF-E07B-4288-8FF9-73699C70C882/0/safetygram27.pdf |date=2008-12-07 }}

The expansion ratio of liquefied and cryogenic from the boiling point to ambient is:

• nitrogen – 1 to 696
• liquid helium – 1 to 745
• argon – 1 to 842
• liquid hydrogen – 1 to 850
• liquid oxygen – 1 to 860
• neon – Neon has the highest expansion ratio with 1 to 1445.{{cite book|others=Compressed Gas Association|title=Handbook of Compressed Gases|url=https://books.google.com/books?id=5EfhBwAAQBAJ&pg=PA82|accessdate=27 July 2022|date=2012-12-06|publisher=Springer Science & Business Media|isbn=9781461306733|page=76}}{{cite web| url = http://www.lindecanada.com/en/aboutboc/safety/cryogenic_liquids/characteristics.php| archive-url = https://web.archive.org/web/20120218125124/http://www.lindecanada.com/en/aboutboc/safety/cryogenic_liquids/characteristics.php |archive-date = 2012-02-18| title = Characteristics| publisher = The Linde Group}}