Pressure vessel for human occupancy

A Pressure vessel for human occupancy is a container that is intended to be occupied by one or more persons at a pressure which differs from ambient by at least . Since 1977, the American Society of Mechanical Engineers PVHO committee has published standards governing the construction of a number of structures which are defined as Pressure Vessels for Human Occupancy. The current standard is PVHO-1-2019. Similar standards are published by a range of national and international standards organisations.
List of PVHO types.
Nuclear reactor containments, aerospace cabins, caissons or mild hyperbaric chambers are not considered to be PVHOs according to the standard.