ISO 91:2017 pdf free. Petroleum and related products — Temperature and pressure volume correction factors (petroleum measurement tables) and standard reference conditions.
ISO 91:2017 refers to temperature volume correction factors, which allow users to convert volumes, measured at ambient conditions, to those at reference conditions for transactional purposes.
ISO 91:2017 also refers to compressibility factors required to correct hydrocarbon volumes measured under pressure to the corresponding volumes at the equilibrium pressure for the measured temperature.
Custody transfer of crude petroleum and its products are generally transacted in volumetric quantities. Since crude oils and petroleum products have relatively high coefficients of thermal expansion and compressibility, volumes are corrected to standard conditions of temperature and pressure in order to provide a meaningful and consistent basis for measurement. The definition of standard reference conditions is therefore of fundamental Importance in measurement, calculation and accounting of petroleum quantities.
In the early 1970s, it was demonstrated that the previously published tables were not satisfactorily applicable to many crude oils of current economic importance. A revised standard was published in 1980 by the American Petroleum Institute as the API Manual of Petroleum Measurement Standards (MPMS) Chapter 11.! (also designated API/Standard 2540, ASTM D1250-80 and IP 200/80) following the development of a new database by API in cooperation with the US NBS. This study Included the examination of 463 samples of crude oil and refined products. The crude oil samples represented 67 % of world production in 1974. The 1980 standard also constituted a major conceptual departure from previous versions in the recognition of the use of computers in the petroleum industry. The actual standard represented by API MPMS Chapter 11.1-1980/ASTM 1)1250-80/IP 200/80 was neither the hardcopy printed tables nor the set of equations used to represent the density data, but was an explicit implementation procedure used to develop computer subroutines. The standardization of an implementation procedure implied the standardization of the set of mathematical expressions, including calculational sequence and round-off procedures, used within the computer code. Adherence to the procedures given in API MPMS Chapter 1 l.1-1980/ASTM D1250-80/IP 200/80 was an attempt to ensure that all computers and computer codes meeting the stated specifications and restrictions would be able to produce identical results. Hence, the published implementation procedures were the primary standard, the distributed subroutines the secondary standard, and the published tables produced for convenience.ISO 91:2017 pdf free download.