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 2 pounds per square inch (0.14 bar). Since 1977, the American Society of Mechanical Engineers PVHO committee has published standards governing the construction of a number of PVHO applications. The current design standard is PVHO-1-2023.[1] The current code for maintenance and operation guidances is ASME PVHO-2-2019.[2] Similar standards are published by a range of national and international standards organisations.