API MPMS CH 11.2.5

Description

Methods used for calculation of the correction factor for pressure effects such as Chapter 11.2.1-1984 (now superseded by Chapter 11.1-2004) and Chapter 11.2.2-1986 require knowledge of the equilibrium bubble point pressure (vapor pressure) at the measured conditions. However, the vapor pressure of the process liquid is generally not measured. The vapor pressure can also be calculated form compositional information, but the composition is not always measured for natural gas liquids (NGLs). Therefore, a correlation for the vapor pressure of NGLs is based upon normally measured properties is required and is documented in this publication.