An unfortunate state of affairs is the existence of multiple52 “standard” conditions of pressure
and temperature defined by different organizations. In the previous example, 14.7 PSIA was assumed
to be the “standard” atmospheric pressure, and 60 degrees Fahrenheit (519.67 degrees Rankine) was
assumed to be the “standard” ambient temperature. This conforms to the API (American Petroleum
Institute) standards in the United States of America, but it does not conform to other standards
in America or in Europe. The ASME (American Society of Mechanical Engineers) uses 14.7 PSIA
and 68 degrees Fahrenheit (527.67 degrees Rankine) as their “standard” conditions for calculating
SCFM. In Europe, the PNEUROP agency has standardized with the American CAGI (Compressed
Air and Gas Institute) organization on 14.5 PSIA and 68 degrees Fahrenheit being the “standard”
conditions