https://www.england.nhs.uk/wp-content/uploads/2021/05/HTM_02-01_Part_A.pdf

Hi Ariel

I good starting point is the HTM (health technical memorandum) 02-01 Medical gas pipeline systems.
Link above.
This is whats used in Uk hospitals.
Richard

Richard Aldridge
Lead Technologist
Adult Critical care unit
Royal London Hospital
Whitechapel Road
London E1 1BB
Tel 0203 59 40302