Spirit flow-x Function Reference

Function Reference

Certified flow calculations

Flow and batch calculations

Worksheet functions

Product

Flow-X Function Reference

Reference number

01-0110-1

Revision

A.6

Date

April 2015

Authors

J.C.H.M. van Dal

Disclaimer

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Flow-X─ Function Reference

1-3

Table of contents

Chapter 1 - Document Control ---------------------------------------------------------------------------------- 1-7

Revision Coding -------------------------------------------------------------------------------------------- 1-7 Revision History -------------------------------------------------------------------------------------------- 1-7

Chapter 2 - Introduction ------------------------------------------------------------------------------------------ 2-9

Flow-X Function Library ---------------------------------------------------------------------------------- 2-9 API Petroleum Measurement Tables ----------------------------------------------------------------- 2-9

History--------------------------------------------------------------------------------------------------------------------- 2-9 Volume correction for pressure ----------------------------------------------------------------------------------- 2-10 NGL and LPG tables -------------------------------------------------------------------------------------------------- 2-10 Overview of hydrocarbon liquid conversion standards ------------------------------------------------------ 2-11 Overview of the functions ------------------------------------------------------------------------------------------ 2-12 Hydrometer Correction ---------------------------------------------------------------------------------------------- 2-13 API-2540 Boundaries ------------------------------------------------------------------------------------------------ 2-13

Chapter 3 - Flow-X General functions------------------------------------------------------------------------- 3-17

fx2CellSelection ------------------------------------------------------------------------------------------ 3-17 fx3CellSelection ------------------------------------------------------------------------------------------ 3-19

fxAGA10_M ---------------------------------------------------------------------------------------------- 3-22 fxAGA10ex_M ------------------------------------------------------------------------------------------- 3-24

fxAGA3_C-------------------------------------------------------------------------------------------------- 3-27 fxAGA5_C-------------------------------------------------------------------------------------------------- 3-33 fxAGA8_C-------------------------------------------------------------------------------------------------- 3-34 fxAGA8_M ------------------------------------------------------------------------------------------------ 3-36 fxAGA8_Gross -------------------------------------------------------------------------------------------- 3-38 fxAPI_Dens15C_1952 ----------------------------------------------------------------------------------- 3-40 fxAPI_Dens15C_1980 ----------------------------------------------------------------------------------- 3-43

Chapter 4 - Flow-X General functions------------------------------------------------------------------------- 4-49

fx2CellSelection ------------------------------------------------------------------------------------------ 4-49 fx3CellSelection ------------------------------------------------------------------------------------------ 4-51

fxAGA10_M ---------------------------------------------------------------------------------------------- 4-54 fxAGA10ex_M ------------------------------------------------------------------------------------------- 4-56

fxAGA3_C-------------------------------------------------------------------------------------------------- 4-59 fxAGA5_C-------------------------------------------------------------------------------------------------- 4-65 fxAGA8_C-------------------------------------------------------------------------------------------------- 4-66 fxAGA8_M ------------------------------------------------------------------------------------------------ 4-68 fxAGA8_Gross -------------------------------------------------------------------------------------------- 4-70 fxAPI_Dens15C_1952 ----------------------------------------------------------------------------------- 4-72 fxAPI_Dens15C_1980 ----------------------------------------------------------------------------------- 4-75 fxAPI_Dens15C_NGL_LPG ----------------------------------------------------------------------------- 4-81 fxAPI_Dens20C_NGL_LPG ----------------------------------------------------------------------------- 4-86 fxAPI_Gravity60F_1952 -------------------------------------------------------------------------------- 4-92 fxAPI_Gravity60F_1980 -------------------------------------------------------------------------------- 4-95 fxAPI_MPMS_11_2_1 --------------------------------------------------------------------------------- 4-100 fxAPI_MPMS_11_2_1M ------------------------------------------------------------------------------- 4-102 fxAPI_MPMS_11_2_2 --------------------------------------------------------------------------------- 4-104 fxAPI_MPMS_11_2_2M ------------------------------------------------------------------------------- 4-106 fxAPI_MPMS_11_3_2_1 ------------------------------------------------------------------------------ 4-108 fxAPI_MPMS_11_3_3_2 ------------------------------------------------------------------------------ 4-109 fxAPI_RD60F_1980 ------------------------------------------------------------------------------------- 4-111 fxAPI_SG60F_1952 ------------------------------------------------------------------------------------- 4-117

1-4 Flow-X─ Function Reference

fxAPI_RD60F_NGL_LPG ------------------------------------------------------------------------------- 4-120 fxAPI_Table5_1952 ------------------------------------------------------------------------------------ 4-125 fxAPI_Table5_1980 ------------------------------------------------------------------------------------ 4-126 fxAPI_Table5_2004 ------------------------------------------------------------------------------------ 4-128 fxAPI_Table6_1952 ------------------------------------------------------------------------------------ 4-130 fxAPI_Table6_1980 ------------------------------------------------------------------------------------ 4-131 fxAPI_Table6_2004 ------------------------------------------------------------------------------------ 4-133 fxAPI_Table23_1952 ----------------------------------------------------------------------------------- 4-135 fxAPI_Table23_1980 ----------------------------------------------------------------------------------- 4-136 fxAPI_Table23_2004 ----------------------------------------------------------------------------------- 4-138 fxAPI_Table23E ----------------------------------------------------------------------------------------- 4-140 fxAPI_Table24_1952 ----------------------------------------------------------------------------------- 4-141 fxAPI_Table24_1980 ----------------------------------------------------------------------------------- 4-142 fxAPI_Table24_2004 ----------------------------------------------------------------------------------- 4-144 fxAPI_Table24E ----------------------------------------------------------------------------------------- 4-146 fxAPI_Table53_1952 ----------------------------------------------------------------------------------- 4-147 fxAPI_Table53_1980 ----------------------------------------------------------------------------------- 4-148 fxAPI_Table53_2004 ----------------------------------------------------------------------------------- 4-150 fxAPI_Table53E ----------------------------------------------------------------------------------------- 4-152 fxAPI_Table54_1952 ----------------------------------------------------------------------------------- 4-153 fxAPI_Table54_1980 ----------------------------------------------------------------------------------- 4-154 fxAPI_Table54_2004 ----------------------------------------------------------------------------------- 4-156 fxAPI_Table54E ----------------------------------------------------------------------------------------- 4-158 fxAPI_Table59_2004 ----------------------------------------------------------------------------------- 4-159 fxAPI_Table59E ----------------------------------------------------------------------------------------- 4-161 fxAPI_Table60_2004 ----------------------------------------------------------------------------------- 4-162 fxAPI_Table60E ----------------------------------------------------------------------------------------- 4-164 fxASTM_D1550_RD60 --------------------------------------------------------------------------------- 4-165 fxASTM_D1550_Ctl ------------------------------------------------------------------------------------ 4-167 fxASTM_D1555_Dens60F----------------------------------------------------------------------------- 4-168 fxASTM_D1555_Ctl ------------------------------------------------------------------------------------ 4-171 fxBatchFWA ---------------------------------------------------------------------------------------------- 4-173 fxBatchHistData----------------------------------------------------------------------------------------- 4-174 fxBatchLatch --------------------------------------------------------------------------------------------- 4-175 fxBatchMax ---------------------------------------------------------------------------------------------- 4-176 fxBatchMin ----------------------------------------------------------------------------------------------- 4-177 fxBatchTotal --------------------------------------------------------------------------------------------- 4-178 fxBatchTWA --------------------------------------------------------------------------------------------- 4-179 fxBatchWatch ------------------------------------------------------------------------------------------- 4-180 fxConvertUnit ------------------------------------------------------------------------------------------- 4-181 fxDeviationAlarm --------------------------------------------------------------------------------------- 4-182 NIST1045 ------------------------------------------------------------------------------------------------- 4-183 fxEthylene_IUPAC_C ----------------------------------------------------------------------------------- 4-184 fxEthylene_IUPAC_M ---------------------------------------------------------------------------------- 4-185 fxGasViscosity_2004 ----------------------------------------------------------------------------------- 4-186 fxGenerateReport -------------------------------------------------------------------------------------- 4-188 fxGERG2008_Gas --------------------------------------------------------------------------------------- 4-189 fxGERG2008_Flash ------------------------------------------------------------------------------------- 4-191 fxGPA_TP15---------------------------------------------------------------------------------------------- 4-193 fxGPA2172_96_C --------------------------------------------------------------------------------------- 4-195 fxGPA2172_96_M -------------------------------------------------------------------------------------- 4-198 fxGPA2172_09_C --------------------------------------------------------------------------------------- 4-201 fxGPA2172_09_M -------------------------------------------------------------------------------------- 4-204 fxIAPWS_IF97_C ---------------------------------------------------------------------------------------- 4-207 fxIAPWS_IF97_M --------------------------------------------------------------------------------------- 4-210 fxIndex ---------------------------------------------------------------------------------------------------- 4-213

Flow-X─ Function Reference

1-5

fxInterpolationCurve ---------------------------------------------------------------------------------- 4-214 fxISO5167_ISA1932Nozzle --------------------------------------------------------------------------- 4-216 fxISO5167_LongRadiusNozzle ----------------------------------------------------------------------- 4-219 fxISO5167_Orifice -------------------------------------------------------------------------------------- 4-222 fxISO5167_Venturi ------------------------------------------------------------------------------------- 4-229 fxISO5167_VenturiNozzle ---------------------------------------------------------------------------- 4-233 fxISO6976_1983_M ------------------------------------------------------------------------------------ 4-237 fxISO6976_1995_M ------------------------------------------------------------------------------------ 4-238 fxISO6976ex_1995_M --------------------------------------------------------------------------------- 4-240 fxKeypadFallback --------------------------------------------------------------------------------------- 4-244 fxKeypadFallbackArray -------------------------------------------------------------------------------- 4-245 fxLatch ---------------------------------------------------------------------------------------------------- 4-246 fxLimitAlarm --------------------------------------------------------------------------------------------- 4-247 fxMR113 -------------------------------------------------------------------------------------------------- 4-248 fxName --------------------------------------------------------------------------------------------------- 4-249 fxNX19_1962 -------------------------------------------------------------------------------------------- 4-250 fxNX19_M ------------------------------------------------------------------------------------------------ 4-252 fxPeriodFWA--------------------------------------------------------------------------------------------- 4-254 fxPeriodLatch -------------------------------------------------------------------------------------------- 4-255 fxPeriodMax --------------------------------------------------------------------------------------------- 4-256 fxPeriodMin---------------------------------------------------------------------------------------------- 4-257 fxPeriodTotal -------------------------------------------------------------------------------------------- 4-258 fxPeriodTWA -------------------------------------------------------------------------------------------- 4-260 fxPeriodWatch ------------------------------------------------------------------------------------------ 4-261 fxPID ------------------------------------------------------------------------------------------------------- 4-262 fxROCAlarm ---------------------------------------------------------------------------------------------- 4-269 fxSarasota_C --------------------------------------------------------------------------------------------- 4-269 fxSarasota_M -------------------------------------------------------------------------------------------- 4-271 fxSetOnChange ----------------------------------------------------------------------------------------- 4-273 fxSetOnCondition--------------------------------------------------------------------------------------- 4-273 fxSetOnEvent -------------------------------------------------------------------------------------------- 4-274 fxSetIndexOnChange ---------------------------------------------------------------------------------- 4-274 fxSetIndexOnCondition ------------------------------------------------------------------------------- 4-275 fxSetIndexOnEvent ------------------------------------------------------------------------------------- 4-276 fxSGERG_C ----------------------------------------------------------------------------------------------- 4-277 fxSGERG_M ---------------------------------------------------------------------------------------------- 4-279 fxSolartron_Gas_C ------------------------------------------------------------------------------------- 4-281 fxSolartron_Gas_M ------------------------------------------------------------------------------------ 4-284 fxSolartron_Liquid _C---------------------------------------------------------------------------------- 4-287 fxSolartron_Liquid_M --------------------------------------------------------------------------------- 4-290 fxSolartron_SG ------------------------------------------------------------------------------------------ 4-294 fxStatusAlarm ------------------------------------------------------------------------------------------- 4-295 fxTag ------------------------------------------------------------------------------------------------------- 4-295 fxTimer ---------------------------------------------------------------------------------------------------- 4-297 fxTotalizerDelta ----------------------------------------------------------------------------------------- 4-298 fxTotalizerRate ------------------------------------------------------------------------------------------ 4-300 fxUGC_C -------------------------------------------------------------------------------------------------- 4-302 fxUGC_M ------------------------------------------------------------------------------------------------- 4-304 fxWatchUpdate ----------------------------------------------------------------------------------------- 4-306 fxVCone_C ----------------------------------------------------------------------------------------------- 4-307 fxVCone_M ---------------------------------------------------------------------------------------------- 4-311

Chapter 5 - Flow-X IO Functions ----------------------------------------------------------------------------- 5-315

fxAnalogInput ------------------------------------------------------------------------------------------- 5-315 fxAnalogOutput ----------------------------------------------------------------------------------------- 5-316 fxSetAnalogOutput ------------------------------------------------------------------------------------- 5-316

1-6 Flow-X─ Function Reference

fxDigitalInput -------------------------------------------------------------------------------------------- 5-317 fxDigitalOutput ----------------------------------------------------------------------------------------- 5-318 fxSetDigitalOutput ------------------------------------------------------------------------------------- 5-319 fxFrequencyOutput ------------------------------------------------------------------------------------ 5-319 fxSetFrequencyOutput -------------------------------------------------------------------------------- 5-320 fxDoubleChronometry -------------------------------------------------------------------------------- 5-321 fxPulseInput --------------------------------------------------------------------------------------------- 5-324 fxResetPulseInputErrors ------------------------------------------------------------------------------ 5-327 fxPulseOutput ------------------------------------------------------------------------------------------- 5-328 fxSetPulseOutput --------------------------------------------------------------------------------------- 5-329 fxPT100Input -------------------------------------------------------------------------------------------- 5-329 fxRTDInput ----------------------------------------------------------------------------------------------- 5-330 fxPT100Table -------------------------------------------------------------------------------------------- 5-330 fxTimePeriodInput ------------------------------------------------------------------------------------- 5-332

Chapter 6 - Reference ------------------------------------------------------------------------------------------- 6-333

Unit Types ------------------------------------------------------------------------------------------------ 6-333 Terminology --------------------------------------------------------------------------------------------- 6-347 Standard composition --------------------------------------------------------------------------------- 6-348

Flow-X─ Function Reference

1-7

Document Control - Revision Coding

Chapter 1 - Document Control

Revision Coding

Our documents are supplied with a revision code. This code has the following format: <major revision letter>.<minor revision number>. Initially, the document has revision code A.0. When in the next release of the document minor changes were implemented, the minor revision number increases. When major changes have been implemented, the major revision number increments.

Example document:

A.0 First revision A.1 Second revision with minor changes implemented A.2 Third revision, with other minor changes B.0 Fourth revision, with (a) major change(s).

The revision coding will be modified for each new release of a document.

All software packages and software modules or components will be provided with a version number. This number consists of three parts: A release number, a major revision number and a minor revision number separated by decimal points. A release number identifies the generation number of the software, the major number refers to the main functionality of the program, seen from the user's point of view, while the minor revision number identify a new software version.

Example program:

1.01.001 Initial release

1.01.002 Minor change

1.02.001 Major change

2.01.001 Family change

Revision History

Revision A.0

Author : J.C.H.M. van Dal Date : April 2009

Initial, release

Revision A.1

Author : J.C.H.M. van Dal Date : June 2010

Added IUPAC Ethylene and IAWS-IF97 functions

Revision A.2

Author : I. Fiers Date : Aug 2012

Updated and corrected IO functions, moved to separate chapter.

1-8 Flow-X─ Function Reference

Document Control - Revision History

Revision A.3

Author : H. Rutjes Date : March 2013

Updated incorrect page-header in TOC. Removed PPRV output from fxPeriodLatch(..) function.

Revision A.4

Author : J.C.H.M. van Dal Date : July 2014

Added extended ISO6976 function that takes all 55 components of the standard Added GERG2004 and GERG2008 functions

Revision A.5

Author : J.C.H.M. van Dal Date : February 2015

Minor editorial changes

Revision A.6

Author : J.C.H.M. van Dal Date : April 2015

Added new natural gas viscosity calculation Added C11 – C21 components to the extended ISO6976 functions Added “Quarter circle” and “Conical entrance” orifice calculations

Revision A.7

Author : J.C.H.M. van Dal Date : September 2015

Added GSSSD method MR 113-03 function

Flow-X─ Function Reference

2-9

Introduction - Flow-X Function Library

Chapter 2 - Introduction

This document describes the spreadsheet functions for the Flow-X series of flow computers. It also provides background information on related standards and calculation methods used in the industry for quality and quantity measurement of hydrocarbon and other type of fluids. The document serves as a reference manual for application engineers who have in-depth knowledge of the configuration software used for programming the Flow-X products.

Flow-X Function Library

The Flow-X series of flow computer uses Microsoft Excel as its configuration environment. Each Flow-X application consists of a single Excel workbook that contains one or more worksheets. Flow-X functions are configured as regular Excel functions. By using the output of one function as an input (argument) in another function a complete calculation scheme can be made. Functions can be defined on multiple sheets in order to organize the application.

API Petroleum Measurement Tables

History

The first version of the API Petroleum Measurement Tables was published in 1952. In those days measurement readings were taken manually and the tables were used to convert the observed density or gravity at the observed temperature to the value at the reference temperature. So the table values were the actual standard. The 1952 Tables consists of 58 tables containing all kind of correction and conversion factors used in the measurement of hydrocarbon liquids. Each table deals with a particular conversion of units, correction of density, or correction of volume. The 1952 tables that have to do with the conversion of density and volume are: 5, 6, 23, 24, 53 and 54. Table 5, 6, 23 and 24 convert density or volume to or from to a reference temperature of 60°F, while tables 53 and 54 refer to 15°C. In 1980 a complete new set of tables was published together with computer routines to allow electronic devices to automatically calculate the volume conversion factors and API gravity / (relative) density at the reference temperature. Back then most electronic devices were not capable of performing double-precision floating point calculations, so the standard prescribed all kind of rounding and truncating rules to make sure that the calculations would always provide the same result. For the 1980 version the calculation procedures are the standard rather than the table values. In the 1980 version, which is also referred to as API-2540, the tables are divided into 3 product groups and a letter designation was used to distinguish between the sub-tables. "A" was used for crude oil, "B" for refined products and "C" for special applications. The 1980 tables, however, did not cover the LPGs and NGLs density ranges and the 1952 Tables were left valid for these products. Furthermore, the lubricating oil tables (designated as "D") were not complete at the time of the printing in 1980 and were released two years later. As opposed to the A, B and C tables no implementation procedures were defined for the D tables. In 1988 the Institute of Petroleum released its Paper No. 3 with tables 59 and 60 that are based on a reference temperature of 20°C. This resulted in the following Petroleum Measurement Tables dealing with the conversion of volume and density to and from a reference temperature.

2-10 Flow-X─ Function Reference

Introduction - API Petroleum Measurement Tables

Number

Title

5

API Gravity Reduction to 60°F

6

Reduction of Volume to 60°F Against API Gravity at 60°F

23

Reduction of Observed Specific Gravity to Specific Gravity 60/60°F

24

Reduction of Volume to 60o F Against Specific Gravity 60/60°F

53

Reduction of Observed Density to Density at 15°C

54

Reduction of Volume to 15°C Against Density at 15°C

59

Reduction of Observed Density to Density at 20°C

60

Reduction of Volume to 20°C Against Density at 20°C

In 2004 the API MPMS 11.1 1980 tables were superseded by a new set of tables primarily for the following reasons:

 API 11.1:2004 includes the correction for both temperature and pressure in one and the

same algorithm

 Taken into account the progress in electronics (and for other reasons) the complex

truncating and rounding rules were abandoned. Instead the calculation procedures use double-precision floating point math. The input and output values are still rounded in order to obtain consistent results.

 The convergence methods for the correction of observed density to base density have been

improved.

 On-line density measurement by densitometers became common practice, requiring the

pressure and temperature correction to be incorporated in one ands the same procedure

 The tables are extended in both temperature and density to cover lower temperatures and

higher densities.

 The previous standard used a significant digit format which resulted in 4 or 5 decimal places

depending on whether the observed temperature was above or below the reference temperature. The new standard prescribes 5 decimal places if or both cases.

 The IP paper No. 3 tables were added to accommodate conversion to 20°C.

Tables for lubricating oils including the implementation procedures are now part of the standard.

Volume correction for pressure

The API MPMS 11.1:1980 Tables only cover the correction for temperature. The correction for pressure was published in API MPMS standards 11.2.1 and 11.2.2. The correction for pressure is to the atmospheric pressure or, for products within the lower density range, to the equilibrium vapor pressure. To calculate the equilibrium vapor pressure an Addendum was added to API MPMS 11.2.2. This addendum is also known as GPA TP-15 (1988). In September 2007 the addendum was replaced by a new API standard 11.2.5 and at the same time GPA TP-15 (1988) was updated with a new 2007 revision.

NGL and LPG tables

For NGL and LPG products volume correction tables 24E and 23E (at 60 °F) were published in GPA TP-25 (1988), so the letter 'E" was used to distinguish the tables from the related API MPMS A, B, C and D tables. GPA TP-25 has been superseded by GPA TP-27 / API MPMS 11.2.4 (2007), which includes tables 53E, 54E, 59E and 60E to convert to 15°C and 20°C as well. All text from TP-25 is included without technical change, so TP-25 is still viable for conversion to and from 60 °F.

Flow-X─ Function Reference

2-11

Introduction - API Petroleum Measurement Tables

Overview of hydrocarbon liquid conversion standards

 ASTM-IP Petroleum Measurement Tables, Historical Edition, 1952  API MPMS Chapter 11.1 - 1980* (Temperature VCFs for Generalized Crude Oils, Refined

Products, and Lubricating Oils): Historical; Published in 14 separate volumes

Also known as

 API Standard 2540 (API-2540)  ASTM D1250  IP 200

 In 1982 chapters XIII and XIV were published containing tables 5D, 6D, 53D and

54D for lubricating oils.

 API MPMS Chapter 11.1 - 2004 (Temperature & Pressure VCFs for Generalized Crude Oils,

Refined Products and Lube Oils)

 API MPMS Chapter 11.2.1- 1984 (Compressibility Factors for Hydrocarbons: 0-90°API):

Historical: now incorporated into Chapter 11.1-2004

 API MPMS Chapter 11.2.1M- 1984 (Compressibility Factors for Hydrocarbons: 638-1074

kg/m3): Historical: now incorporated into Chapter 11.1-2004

 API MPMS Chapter 11.2.2 - 1984 (Compressibility Factors for Hydrocarbons: 0.350-0.637

Relative Density and –50°F to 140°F)

 API MPMS Chapter 11.2.2M - 1986 (Compressibility Factors for Hydrocarbons: 350-637

kg/m3 Density (15°C) and –46°C to 60°C)

 API MPMS Chapter 11.2.2A - 1984 (Addendum to Correlation of Vapor Pressure Correction

for NGL): Superseded by Chapter 11.2.5

 API Publication/GPA TP-25/ASTM Publication (Temperature Correction for the volume of

Light Hydrocarbons – Tables 24E and 23E: Superseded by API MPMS Chapter 11.2.4

GPA TP-25 was published in 1998 and replaced the 1952 tables 23, 24 for Light Hydrocarbon Liquids and GPA Technical Publication TP-16, which were previously used for volumetric measurement of LPG.

 API MPMS Chapter 11.2.4 - 2007 / GPA TP-27 / ASTM Publication (Temperature Correction

for the Volume of NGL and LPG – Tables 23E, 24E, 53E, 54E, 59E, 60E): Supersedes GPA TP25

 API MPMS Chapter 11.2.5 - 2007 / GPA TP-15 / ASTM Publication (A Simplified Vapor

Pressure Correlation for Commercial NGLs): Supersedes Addendum to Chapter 11.2.2 (11.2.2A)

 IP No. 3 - 1988 (Energy Institute (formerly Institute of Petroleum), Petroleum Measurement

Paper No 3 Computer Implementation Procedures for Correcting Densities and Volumes to 20 C. Superseded by IP No.3 - 1997

 IP No. 3 - 1997 (Energy Institute (formerly Institute of Petroleum), Petroleum Measurement

Paper No 3 Computer Implementation Procedures for Correcting Densities and Volumes to 20 C. Supersedes IP No.3 - 1988

 ISO 91-1 - 1982 Petroleum measurement tables Part 1: Tables based on reference

temperatures of 15 °C and 60 °F. Superseded by ISO 91-1 1992.

 ISO 91-1 - 1992 Petroleum measurement tables Part 1: Tables based on reference

temperatures of 15 °C and 60 °F. Supersedes ISO 91-1 1982.

 ISO 91-2 - 1991 Petroleum measurement tables Part 2: Tables based on reference

temperatures of 20 °C

 OIML R 63 - 1994 Petroleum measurement tables

2-12 Flow-X─ Function Reference

Introduction - API Petroleum Measurement Tables

Overview of the functions

The following table lists the volume conversion functions for hydrocarbon liquids as provided by the Flow-X series of flow computer.

Function

Temperature correction

Pressure correction

Input

Output

ASTM-IP Petroleum Measurement Tables 1952 - American Edition

API_Table23 (1952)

Table 23 - Specific Gravity Reduction to 60 °F

SG (T)

SG (60°F)

API_Table24 (1952)

Table 24 - Volume Reduction to 60 °F

SG (60°F)

Ctl

Crude Oils, Refined Products and Lubricating Oils (API MPMS 11.1:1980 / API-2540)

API_Table5 (1980)

API 11.1:1980 Tables 5A, 5B and 5D

API 11.2.1:1984

°API (T, P)

°API (60°F, Pe)

API_Table6 (1980)

API 11.1:1980 Tables 6A, 6B and 6D

API 11.2.1:1984

°API (60°F, Pe)

°API (T, P)

API_Table23 (1980)

API 11.1:1980 Tables 23A and 23B

API 11.2.1:1984

RD (T, P)

RD (60°F, Pe)

API_Table24 (1980)

API 11.1:1980 Tables 24A and 24B

API 11.2.1:1984

RD (60°F, Pe)

RD (T, P)

API_Table53 (1980)

API 11.1:1980 Tables 53A, 53B and 53D

API 11.2.1M:1984

Density (T, P)

Density (15°C, Pe)

API_Table54 (1980)

API 11.1:1980 Tables 54A, 54B and 54D

API 11.2.1M:1984

Density (15°C, Pe)

Density (T, P)

Crude Oils, Refined Products and Lubricating Oils (API MPMS 11.1:2004)

API_Table5 (2004)

API 11.1:2004

°API (T, P)

°API (60°F, 0 psig)

API_Table6 (2004)

API 11.1:2004

°API (60°F, 0 psig)

°API (T, P)

API_Table23 (2004)

API 11.1:2004

RD (T, P)

RD (60°F, 0 psig)

API_Table24 (2004)

API 11.1:2004

RD (60°F, 0 psig)

RD (T, P)

API_Table53 (2004)

API 11.1:2004

Density (T, P)

Density (15°C, 0 bar(g))

API_Table54 (2004)

API 11.1:2004

Density (15°C, 0 bar(g))

Density (T, P)

API_Table59 (2004)

API 11.1:2004

Density (T, P)

Density (20°C, 0 bar(g))

API_Table60 (2004)

API 11.1:2004

Density (20°C, 0 bar(g))

Density (T, P)

API_Table6C (2004)

API 11.1:2004

Not applicable

Thermal expansion coefficient at 60°F

Ctl

NGL and LPG (API 11.2.4)

API_Table23E

API 11.2.4: 2007 Table 23E

API 11.2.2:1986 GPA TP-15:1988 GPA TP-15:2007

RD (T, P)

RD (60°F, Pe)

Flow-X─ Function Reference

2-13

Introduction - API Petroleum Measurement Tables

API_Table24E

API 11.2.4: 2007 Table 24E

API 11.2.2:1986 GPA TP-15

RD (60°F, Pe)

RD (T, P)

API_Table53E

API 11.2.4: 2007 Table 53E

API 11.2.2:1986 GPA TP-15

Density (T, P)

Density (15°C, Pe)

API_Table54E

API 11.2.4: 2007 Table 53E

API 11.2.2:1986 GPA TP-15

Density (15°C, Pe)

Density (T, P)

API_Table59E

API 11.2.4: 2007 Table 59E

API 11.2.2M:1986 GPA TP-15

Density (T, P)

Density (20°C, Pe)

API_Table60E

API 11.2.4: 2007 Table 60E

API 11.2.2M:1986 GPA TP-15

Density (20°C, Pe)

Density (T, P)

Hydrometer Correction

The API MPMS 11.1 1980 Standard (API-2540) assumes that the API gravity or relative density is observed with a glass hydrometer. Therefore a correction may be applied for the change of volume of the glass hydrometer with temperature. The hydrometer correction applies for tables 5A, 5B, 23A, 23B, 53A and 53B. The 2004 standard does not include a correction for a glass hydrometer.

API-2540 Boundaries

API MPMS 11.1:1980 (API 2540) is based on published data that lie within the so-called 'Data' range. The other table values were obtained from extrapolation and lie within the 'Extrapolated' range. It is recommended not to use API-2540 outside the 'Data' and 'Extrapolated' ranges. For the lubricating oil tables no difference is made between data that is table values that are based on published data and table values that are determined by extrapolation.

Range

API Gravity [◦API]

Relative Density [-]

Density [kg/m3]

Temperature [◦F]

Temperature [◦C]

Data Range

0 .. 40 40 .. 50 50 .. 55

1.0760 .. 0.8250

0.8250 .. 0.7795

0.7795 .. 0.7585

1075.0 ..

824.0

824.0 .. 778.5

778.5 .. 758.0

0 .. 250 0 .. 200 0 .. 150

-18..120

-18..90

-18..60

Extrapolate d Range

0 .. 40 40 .. 50 50 .. 55 55 .. 100

1.0760 .. 0.8250

0.8250 .. 0.7795

0.7795 .. 0.7585

0.7585 .. 0.6110

1075.0 ..

824.0

824.0 .. 778.5

778.5 .. 758.0

758.0 .. 610.5

250 .. 300 200 .. 250 150 .. 200 0 .. 200

120..150

90..125

60..95

-18..95

Applies for:

Table 5A Table 6A

Table 23A Table 24A

Table 53A Table 54A

Table 5A Table 6A Table 23A Table 24A

Table 53A Table 54A

Range

API Gravity [°API]

Relative Density [-]

Density [kg/m3]

Temperature [°F]

Temperature [°C]

Data Range

0 .. 40 40 .. 50 50 .. 85

1.0760 .. 0.8250

0.8250 .. 0.7795

0.7795 .. 0.6535

1075.0 ..

824.0

824.0 .. 778.5

778.5 .. 653.0

0 .. 250 0 .. 200 0 .. 150

-18..120

-18..90

-18..60

Extrapolated Range

0 .. 40 40 .. 50 50 .. 85

1.0760 .. 0.8250

0.8250 .. 0.7795

0.7795 .. 0.6535

1075.0 ..

824.0

824.0 .. 778.5

778.5 .. 653.0

250 .. 300 200 .. 250 150 .. 200

120..150

90..125

60..95

2-14 Flow-X─ Function Reference

Introduction - API Petroleum Measurement Tables

Applies for:

Table 5B Table 6B

Table 23B Table 24B

Table 53B Table 54B

Table 5B Table 6B Table 23B Table 24B

Table 53B Table 54B

Range

API Gravity [°API]

Relative Density [-]

Density [kg/m3]

Temperature [°F]

Temperature [°C]

Data Range

-10..45

0.8..1.165

800..1164

0 .. 300

-20..+150

Applies for:

Table 5D Table 6D

Table 23D* Table 24D*

Table 53D Table 54D

Table 5D Table 6D Table 23D* Table 24D*

Table 53D Table 54D

* Values derived from Table 5D/6D

API-2540 - Rounding and truncating rules

For each table API Standard 2540 specifies an explicit 'Calculation Procedure' that includes the rounding and truncating of all the input, intermediate and output values. The 'Calculation Procedure' is considered to be the standard rather than the table values or a set of equations. The function provides the option to either apply the full API rounding and truncating requirements or to perform the calculation procedure without any rounding and truncating being applied. For tables 6A, 6B, 24A, 24B and 54A and 54B the standard makes a distinction between computational and table values for the calculated VCF. The table values are always rounded to 4 decimal places, Whereas the computational values has 4 decimal places when the VFC >=1 and 5 decimal places when the VCF < 1. When API rounding is enabled the convergence limit is set to the limit value as specified in the standard. When the API rounding is disabled the convergence limit is set to 0.00001 kg/m3 to obtain highest precision.

API-11.1:2004 Limits

Range

Density

Temperature

Pressure

Crude Oil

610.6..1163.5 kg/m3 @ 60°F

100..-10 API @ 60°F

0.61120..1.16464 RD @ 60°F

611.16..1163.79 kg/m3 @ 15°C

606.12..1161.15 kg/m3 @ 20°C

-58..302 °F

-50..150 °C

0..1500 psig

0..103.4 bar(g)

Refined products

610.6..1163.5 kg/m3 @ 60°F

100..-10 API @ 60°F

0.61120..1.16464 RD @ 60°F

611.16..1163.86 kg/m3 @ 15°C

606.12..1160.62 kg/m3 @ 20°C

-58..302 °F

-50..150 °C

0..1500 psig

0..103.4 bar(g)

Lubricating oils

800.9..1163.5 kg/m3 @ 60°F

45..-10 API @ 60°F

0.80168..1.1646 RD @ 60°F

801.25..1163.85 kg/m3 @ 15°C

798.11..1160.71 kg/m3 @ 20°C

-58..302 °F

-50..150 °C

0..1500 psig

0..103.4 bar(g)

Flow-X─ Function Reference

2-15

Introduction - API Petroleum Measurement Tables

API constants in US customary units

For the tables in US customary units the following constants apply (both for the 1980 and the 2004 tables):

Product

API Table

K0

K1

K2

Crude oil

A

341.0957

0.0

Gasoline

B

192.4571

0.2438

0.0

Transition area

B

1489.0670

0.0

-0.00186840

Jet fuels

B

330.3010

0.0

Fuel oils

B

103.8720

0.2701

0.0

Lubricating oils

D

0.0

0.34878

0.0

API constants in metric units

For the tables in metric units the following constants apply (both for the 1980 and the 2004 tables):

Product

API Table

K0

K1

K2

Crude oil

A

613.9723

0.0

Gasoline

B

346.4228

0.4388

0.0

Transition area

B

2680.3206

0.0

-0.00336312

Jet fuels

B

594.5418

0.0

Fuel oils

B

186.9696

0.4862

0.0

Lubricating oils

D

0.0

0.6278

0.0

2-16 Flow-X─ Function Reference

Introduction - API Petroleum Measurement Tables

This page is left blank intentionally.

Flow-X─ Function Reference

3-17

Flow-X General functions - fx2CellSelection

Chapter 3 - Flow-X General functions

This chapter lists all available Flow-X functions in alphabetical order.

fx2CellSelection

Description

The function selects between 2 input cells (e.g. differential pressure cells) based on the actual measured value and the failure status of each cell. The function can handle the following type of cell range configurations:

 Lo – Hi  Hi – Hi

Where ‘Lo’ means low range, ‘Mid’ mid range and ‘Hi’ high range.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Cell A value

Input value as percentage of span of cell A

Cell A status

Input status of cell A 0: Normal <> 0 : Failure

Cell B value

Input value as percentage of span of cell B

Cell B status

Input status of cell B 0: Normal <> 0 : Failure

Range type

For a description of the functionality refer to adjacent section ‘Logic’ 1: Lo Hi Cell A at low range Cell B at high range 2: Hi Hi Cell A and B at same range

RNGTYP

Auto switchback

For a description of the functionality refer to adjacent section ‘Logic’ 0: Disabled 1: Enabled

Switch-up percentage

Switch-up value expressed as percentage of span of the lower range

-

SWUPPERC

0..100

95 Switch-down percentage

Switch-down value expressed as percentage of span of the lower range

-

SWDNPERC

0..100

90

3-18 Flow-X─ Function Reference

Flow-X General functions - fx2CellSelection

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range

STS FIOOR

Selected cell number

1: Cell 1 2: Cell 2

SELNR

1 Selected cell status

0: Normal 1: Failure

SELSTS

0

Logic

The function will switch from one cell to another at the following conditions:

Range type = ‘Lo Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell B when cell A fails while cell B is healthy

When cell B is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell A when cell B fails and cell A is healthy

Range type = ‘Hi Hi’

When cell A is currently selected

 Select cell B when cell A value fails and cell B is healthy

When cell B is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell A when cell B fails and cell A is healthy.

Flow-X─ Function Reference

3-19

Flow-X General functions - fx3CellSelection

fx3CellSelection

Description

The function selects between 3 input cells (typically differential pressure cells) based on the actual measured value and the failure status of each cell. The function can handle the following type of cell range configurations:

 Lo – Mid – Hi  Lo – Hi – Hi  Hi – Hi – Hi

Where ‘Lo’ means low range, ‘Mid’ mid range and ‘Hi’ high range.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Cell A value

Input value as percentage of span of cell A

Cell A status

Input status of cell A 0: Normal <> 0 : Failure

Cell B value

Input value as percentage of span of cell B

Cell B status

Input status of cell B 0: Normal <> 0 : Failure

Cell C value

Input value as percentage of span of cell C

Cell C status

Input status of cell C 0: Normal <> 0 : Failure

Range type

For a description of the functionality refer to adjacent section ‘Logic’ 1: Lo Mid Hi Cell A at low range Cell B at mid range Cell C at high range 2: Lo Hi Hi Cell A at low range Cell B and C at high range 3: Hi Hi Hi Cell A, B and C at same range

RNGTYP

Auto switchback

For a description of the functionality refer to adjacent section ‘Logic’ 0: Disabled 1: Enabled

Switch-up percentage

Switch-up value expressed as percentage of span of the lower range Does not apply for selection type ‘Hi Hi Hi’

-

SWUPPERC

0..100

95

Switch-down percentage

Switch-down value expressed as percentage of span of the lower range Does not apply for selection type ‘Hi Hi Hi’

-

SWDNPERC

0..100

90

3-20 Flow-X─ Function Reference

Flow-X General functions - fx3CellSelection

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range

STS FIOOR

Selected cell number

1: Cell 1 2: Cell 2 3: Cell 3

SELNR

1 Selected cell status

0: Normal 1: Failure

SELSTS

0

Logic

The function will switch from one cell to another at the following conditions:

Range type = ‘Lo Mid Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell B when cell A fails while cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell C when cell B value is above or equal to the switch-up percentage of its range and

cell C is healthy

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell A when cell B fails while cell A is healthy  Select cell C when cell B and cell A fail and cell C is healthy

When cell C is currently selected

 Select cell B when cell B value is below or equal to the switch-down percentage of its range

and cell B is healthy

 Select cell B when cell C fails while cell B is healthy  Select cell A when cell C and cell B fail and cell A is healthy

Range type = ‘Lo Hi Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell C when cell A value is above or equal to the switch-up percentage of its range and

cell B fails and cell C is healthy.

 Select cell B when cell A fails while cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell C when cell B fails while cell C is healthy  Select cell A when cell B and cell C fail and cell A is healthy

Flow-X─ Function Reference

3-21

Flow-X General functions - fx3CellSelection

When cell C is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell B when cell B is healthy and ‘Auto switchback’ is enabled  Select cell A when cell C and cell B fail and cell A is healthy

Range type = ‘Hi Hi Hi’

When cell A is currently selected

 Select cell B when cell A value fails and cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell A when cell B fails and cell A is healthy  Select cell C when cell B and A fail and cell C is healthy

When cell C is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell B when cell B is healthy and cell A fails and ‘Auto switchback’ is enabled  Select cell A when cell C fails and cell A is healthy  Select cell B when cell C and A fail and cell B is healthy

3-22 Flow-X─ Function Reference

Flow-X General functions - fxAGA10_M

fxAGA10_M

The function calculates the speed of sound of a gas at the specified conditions of temperature and pressure using the formulae presented in the American Gas Association Report No 10.

Compliance

AGA Report No. 10 - Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, January 2003

Boundaries

The AGA-10 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-10 calculation has a higher uncertainty. Using the AGA-10 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended. The AGA-10 standard specifies the same limits as the AGA-8 standard. Refer to the fxAGA8 function for details on the actual limit values used by this function to set output ‘Range’.

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Observed pressure

bar(a)

0..2000

Temperature

Observed temperature

°C -

200..+400

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alam

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPOOR Speed of sound

m/s

SOS 0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

RANGE

OOR

0

Flow-X─ Function Reference

3-23

Flow-X General functions - fxAGA10_M

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA10 calculation is not recommended in this case)

Calculations

Calculations are as documented in the standard.

3-24 Flow-X─ Function Reference

Flow-X General functions - fxAGA10ex_M

fxAGA10ex_M

The extended AGA 10 function provides an extensive set of gas properties at the specified conditions of temperature and pressure using the formulae presented in the American Gas Association Report No 10.

Compliance

AGA Report No. 10 - Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, January 2003

Boundaries

The AGA-10 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-10 calculation has a higher uncertainty. Using the AGA-10 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended. The AGA-10 standard specifies the same limits as the AGA-8 standard. Refer to the fxAGA8 function for details on the actual limit values used by this function to set output ‘Range’.

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Observed pressure

bar(a)

0..2000

Temperature

Observed temperature

°C -

200..+400

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alam

Fall back

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +-

0.0001

STS FIOOR CALCERR NOCONV COMPOOR

Molecular weight

kg/kmol

MOLMASS

Molar density at base conditions

mol/m3

MOLDENSB

Molar density at flowing conditions

mol/m3

MOLDENSF

Mass density at base conditions

kg/m3

MASSDENSB

Mass density at flowing conditions

kg/m3

MASSDENSF

Flow-X─ Function Reference

3-25

Flow-X General functions - fxAGA10ex_M

Ideal gas relative density

- IRD

Real gas relative density

- RRD Velocity of sound

m/s

SOS

Compressibility at base conditions

- ZB

Compressibility at flowing conditions

- ZF Supercompressibility

- FPV

Ideal gas specific enthalpy

kJ/kg

MASSH0

Real gas specific enthalpy

kJ/kg

MASSH

Real gas specific entropy

kJ/kg/K

MASSS

Ideal gas isobaric heat capacity

kJ/kg/K

MASSCP0

Real gas isobaric heat capacity

kJ/kg/K

MASSCP

Real gas isochoric heat capacity

kJ/kg/K

MASSCV

Ideal gas isobaric heat capacity

kJ/kmol/K

MOLCP0

Real gas isobaric heat capacity

kJ/kmol/K

MOLCP

Real gas isochoric heat capacity

kJ/kmol/K

MOLCV Ratio of specific heats

- CPCV

Isentropic exponent

- KAPPA

Critical flow factor

- CRITC

Ideal gas specific enthalpy

kJ/kmol

MOLH0

Real gas specific enthalpy

kJ/kmol

MOLH

Isentropic perfect gas critical flow factor

- CI

Isentropic real gas critical flow factor

- CRI

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA10

RANGE

OOR

0

3-26 Flow-X─ Function Reference

Flow-X General functions - fxAGA10ex_M

calculation is not recommended in this case)

Calculations

Calculations are as documented in the standard.

Flow-X─ Function Reference

3-27

Flow-X General functions - fxAGA3_C

fxAGA3_C

Description

The function calculates the mass flow rate for Orifice pressure differential flow devices according to the AGA-3 standard for orifice meters with flange taps.

Compliance

 AGA Report No. 3 - Orifice Metering Measurement of fluid flow by means of pressure

differential devices, 1992

 API Manual of Petroleum Measurement Standards, Chapter 14 Natural Gas Fluids

Measurement, Section 3 - Concentric Square-edged Orifice Meters 1992.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Differential Pressure

Differential pressure over the primary flow device measured at the up- and downstream pressure tappings, which need to be in the positions as specified in the standard

inH2O @ 60°F

0..1000

0

Pressure

Down- or upstream pressure value of the fluid at metering conditions

psia 0..30000

0

Temperature

Down- or upstream temperature of the fluid at metering conditions

°F -

400..200 0

0 Density

Down or upstream density of the fluid at metering conditions

lbm/ft3

0..200

0

Dynamic Viscosity

Dynamic viscosity of the fluid

lbm/ft.s

DYNVI S

0..10

6.9e-6

Isentropic Exponent

Also referred to as  (kappa). For an ideal gas this coefficient is equal to the ratio of the specific heat capacity at constant pressure to the specific heat at constant volume. This ratio is commonly used when the real value is unknown.

-

KAPPA

0..10

1.3

Pipe Diameter

Internal diameter of the pipe at reference temperature

inches

PIPEDI AM

0..100

0

Pipe Expansion factor

The thermal expansion coefficient of the pipe material

1/°F

PIPEE XPF

0..1

6.2e-6

Pipe Reference temperature

The reference temperature that corresponds to the 'Pipe diameter' input value

°F

PIPER EFT -400..200 0

68 Orifice Diameter

Orifice diameter at reference temperature

inches

ORIFD IAM

0..100

0

Orifice Expansion factor

The thermal expansion coefficient of the orifice material Typical values are:

1/°F

ORIFE XPF

0..1

9.25e-6

Orifice Reference Temperature

The reference temperature that corresponds to the 'Orifice diameter' input value

°F

ORIFR EFT -400..200 0

68

3-28 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

Pressure Location

1: Upstream tapping

Input 'Pressure' represents the pressure at the upstream pressure tapping (p1). Since the absolute pressure is usually measured at the upstream tapping this is the most common setting.

2: Downstream tapping

Input 'Pressure' represents the pressure at the downstream tapping (p2).

-

PRESL OC

1

Temperature Location

1: Upstream tapping

Input 'Temperature' represents the upstream temperature (t1).

2: Downstream tapping

Input 'Temperature represents the temperature at the downstream tapping (t2).

3: Recovered pressure

Input 'Temperature' represents the downstream temperature at a location Where the pressure has fully recovered (t3). Since temperature measurement is usually downstream of the flow device this is the most common setting.

-

TEMP LOC

3

Temperature Correction

1: Use (1-)/

Isentropic expansion using (1-)/ as the temperature referral exponent

2: Use temperature exponent

Isentropic expansion using input 'Temperature Exponent' as the temperature referral exponent [-]

-

TEMP COR

1

Temperature Exponent

To correct the temperature from down- to upstream conditions (or vice versa) the formula (-1)/ (isentropic expansion) will be used when the input value is set to 0, else the input value will be used. For more details refer to section 'Temperature correction'.

TEMP EXP

0

Flow-X─ Function Reference

3-29

Flow-X General functions - fxAGA3_C

Density Location

This parameter specifies if and how the density should be corrected from downstream to upstream conditions. 1: Upstream tapping

Input 'Density' represents the density at the upstream pressure tapping (1).

2: Downstream tapping

Input 'Density' represents the density at the downstream tapping (2).

3: Recovered pressure

Input 'Density' represents the density downstream at a location Where the pressure has fully recovered (3).

-

DENSL OC

0

Density Exponent.

This factor is used when density correction is enabled. The formula 1/ will be used when the input value is set to 0, else the input value will be used. For more details refer to section function 'ISO5167- Orifice' 'Density correction'.

-

DENSE XP

0 Fluid

The type of fluid being measured 1: Gas 2: Liquid For liquid the expansion factor is set to 1, i.e. the fluid is considered to be incompressible.

-

FLUID

0

Drain hole

When input is > 0 then an additional correction on the orifice diameter will be applied to account for the drain hole, as explained further on.

in

DRAIN

0.. 100

0

Fpwl

Local Gravitational Correction Factor for Deadweight Calibrators used to calibrate differential and static pressure Instruments.

Directly applied on the calculated mass flow rate within each iteration.

-

FPWL

0.9..1.1

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

STS FIOOR CALCERR NOVONV

Mass flow rate

The calculated mass flow rate

klbm/hr

MASSR

0 Beta ratio

Orifice to pipe diameter

-

BETA

0

3-30 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

ratio at upstream temperature

Orifice diameter

At the upstream temperature

inches

ORIFUP

0 Pipe diameter

At the upstream temperature

inches

PIPEUP

0

Upstream pressure

Pressure at upstream tapping (p1)

psia

PRESUP

0

Pressure at downstream tapping

Pressure at downstream tapping (p2)

psia

PRESDN

0 Recovered downstream pressure

Fully recovered downstream pressure (p3)

psia

PRESREC

0 Upstream temperature

Temperature at upstream tapping (t1)

°F

TEMPUP

0

Temperature at downstream tapping

Temperature at downstream tapping (t2)

°F

TEMPDN

0

Downstream Temperature

'Fully recovered' downstream temperature (t3)

°F

TEMPREC

0 Upstream density

Density at upstream tapping (1)

lbm/ft3

DENSUP

0

Density at downstream tapping

Pressure at downstream tapping (2)

lbm/ft3

DENSDN

0 Downstream density

'Fully recovered' downstream density (3)

lbm/ft3

DENSREV

0

Reynolds number

The pipe Reynolds number, i.e. the Reynolds number upstream of the orifice and not the one within the device throat itself)

-

REYN

0

Discharge coefficient

- DISCF

0 Expansion Factor

- EXPFAC

0 Velocity of Approach

- VOA 0

Pressure out of range

0: Pressure is in valid range 1: Pressure is out of valid range

-

PRESOOR

0

Reynolds out of range

0: Reynolds number is in valid range 1: Reynolds number is out of valid range

-

REYNOO R

0

Diameter out of range

0: Device and pipe diameter and Beta ratio in valid range 1: Device diameter, pipe diameter and/or Beta ratio out of valid range

-

DIAMOO R

0

Calculations

The calculations are in accordance with the standard.

Flow-X─ Function Reference

3-31

Flow-X General functions - fxAGA3_C

Pressure correction

 The relation between the pressure at the upstream tapping p

1

and the pressure at the

downstream tapping (p2) is as following:

1000

12

units

Kppp



 The relation between the pressure at the upstream tapping and the downstream tapping is

as following:

LOSS

ppp 

13

   

unitsLOSS

Kpp 







2

1



 

4

1







E

EC

Where:

p1

Pressure at upstream tapping

psia

p2

Pressure at downstream tapping

psia

p3

Fully recovered downstream pressure

psia

p

Differential pressure

inH20 @ 60°F

p

LOSS

Pressure loss over the meter

psi

C

Discharge coefficient as calculated by the standard

-

α

Flow coefficient

-

β

Diameter ratio at the upstream pressure and temperature

-

E

Velocity of approach factor

-

K

units

Unit conversion factor to convert a value expressed in 'inH2O @60°F' to the corresponding expressed in 'psi' (conversion as specified in section 'Unit Types')

-

Temperature correction

 When input 'Temperature correction' is set to 1, then an isentropic expansion based on the

isentropic coefficient is applied:

 

67.45967.459

1

2

21





 





 









p

tt

 

67.45967.459

1

3

31





 





 









p

tt

3-32 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

 When input 'Temperature correction' is set to 2, then an isentropic expansion based on

input 'Temperature exponent' is applied:

 

67.45967.459

1

2

21





 





 





TE

K

p

tt

 

67.45967.459

1

3

31





 





 





TE

K

p

tt

Where:

t1

Upstream temperature

°F

t2

Temperature at the downstream tapping

°F

t3

Temperature at the fully recovered downstream pressure

°F

p1

Upstream pressure

psia

p2

Pressure at the downstream tapping

psia

p3

Fully recovered downstream pressure

psia



Isentropic exponent

-

KTE

Temperature exponent

-

Density correction

 When input 'Density exponent' = 0, then the following isentropic corrections are applied

(depending on the type of Density Correction)





1

2

1

21



 





 





p





1

3

1

31



 





 





p

 Else the value of input 'Density Exponent' is used

DE

K

p



 





 





2

1

21



DE

K

p



 





 





3

1

31



Where:

1

Upstream density

lbm/ft3

2

Density at the downstream tapping

lbm/ft3

3

Density at the fully recovered downstream pressure

lbm/ft3

p1

Upstream pressure

psia

p2

Pressure at the downstream tapping

psia

p3

Fully recovered downstream pressure

psia



Isentropic exponent

-

KDE

Density exponent

-

Flow-X─ Function Reference

3-33

Flow-X General functions - fxAGA5_C

fxAGA5_C

The AGA 5 standard defines methods to calculate the mass and volume based calorific values at 60°F and 14.73 psia for a natural gas based on known molar fractions of the non-hydrocarbon gas components.

Compliance

 A.G.A. Transmission Measurement Committee Report No. 5 (Fuel gas Energy Metering) 1981  A.G.A. Transmission Measurement Committee Report No. 5 (Fuel gas Energy Metering) 1996

(Reprinted 1999)

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Composition

Standard composition as defined in section 'Standard gas composition. Only the following components are considered by the calculation: N2 Nitrogen CO2 Carbon dioxide H2O Water H2S Hydrogen sulfide H2 Hydrogen CO Carbon monoxide O2 Oxygen He Helium

Sum of these fractions may not exceed 1

molar fraction

COMP

0..1

0

Specific Gravity

Molar Mass Ratio, i.e. ratio of the molar mass of the gas and of the molar mass of air (specified in AGA-5 as 28.9644 kg/kmol (lbm/lbmol))

-

SG

0..1

0

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error

STS FIOOR CALCERR

Calorific value mass

Mass based calorific value

Btu/lbm

CV_MASS

0

Calorific value volume

Volume calorific value at 60°F and 14.73 psia

Btu/scf

CV_VOL

0

Calculations

The Energy to Mass ratio is calculated according to Section III of the standard, which contains the calculation procedure for the gas mass to energy conversion. The equations based on the 'by volume' fractional values are used (and not the equations based on the 'by weight' values). The Energy to Volume ratio is calculated according to Section II of the standard, which contains the calculation procedure for the gas volume to energy conversion.

3-34 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_C

fxAGA8_C

The compressibility and density of a gas are calculated from the composition, temperature and pressure in accordance with the ‘Detail Characterization’ method outlined in the AGA-8 standard, with the input and output values in US Customary units.

Compliance

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994  ISO 12213 Natural gas — Calculation of compression factor — Part 2: Calculation using

molar-composition analysis, 1997

Boundaries

The AGA-8 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-8 calculation has a higher uncertainty. Using the AGA-8 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended.

Input value

Normal Range

Expanded Range

EU

Pressure

0 .. 20000

psia

Temperature

-200 .. +400

°F

Mole fraction of Methane

0.45 .. 1.00

0.00 .. 1.00

-

Mole fraction of Ethane

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Propane

0.00 .. 0.04

0.00 .. 0.12

-

Mole fraction of Butanes

0.00 .. 0.01

0.00 .. 0.06

-

Mole fraction of Pentanes

0.00 .. 0.003

0.00 .. 0.04

-

Mole fraction of Hexanes Plus

0.00 .. 0.002

*

-

Mole fraction of Carbon monoxide

0.00 .. 0.03

-

Mole fraction of Carbon dioxide

0.00 .. 0.30

0.00 .. 1.00

-

Mole fraction of Nitrogen

0.00 .. 0.50

0.00 .. 1.00

-

Mole fraction of Helium

0.00 .. 0.002

0.00 .. 0.03

-

Mole fraction of Argon

0.00 .. 0.00

0.00 .. 0.01

-

Mole fraction of Oxygen

0.00 .. 0.00

0.00 .. 0.21

-

Mole fraction of Hydrogen Sulphide

0.00 .. 0.0002

0.00 .. 1.00

-

Mole fraction of Hydrogen

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Water

0.00 .. 0.0005

*

-

* For these components the dew point temperature is the upper limit. Limit check is ignored for reason of simplicity.

Flow-X─ Function Reference

3-35

Flow-X General functions - fxAGA8_C

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Pressure value

psia 0..40000

1.01325

Temperature

Temperature value

°F -250..+800

0

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

0

neo-Pentane mode

Determines what to do when component neo-Pentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPERR

Compressibility factor

- Z 1 Mass Density

lb/ft3

MASDENS

0

Mole Density

lbmol/ ft3

MOLDENS

0

Molar Mass

lb/lbm ol

MOLMASS

0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA8 calculation is not recommended in this case)

RANGE

OOR

0

Calculations

The calculations are as documented in the standard.

3-36 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_M

fxAGA8_M

The compressibility and density of a gas are calculated from its composition, temperature and pressure in accordance with the ‘Detail Characterization’ method outlined in the AGA8 standard, with the input and output values in metric units.

Compliance

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994  ISO 12213 Natural gas — Calculation of compression factor — Part 2: Calculation using

molar-composition analysis, 1997

Boundaries

The AGA-8 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-8 calculation has a higher uncertainty. Using the AGA-8 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended.

Input value

Normal Range

Expanded Range

EU

Pressure

0 .. 1379

bar(a)

Temperature

-129 .. +204

°C

Mole fraction of Methane

0.45 .. 1.00

0.00 .. 1.00

-

Mole fraction of Ethane

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Propane

0.00 .. 0.04

0.00 .. 0.12

-

Mole fraction of Butanes

0.00 .. 0.01

0.00 .. 0.06

-

Mole fraction of Pentanes

0.00 .. 0.003

0.00 .. 0.04

-

Mole fraction of Hexanes Plus

0.00 .. 0.002

*

-

Mole fraction of Carbon monoxide

0.00 .. 0.03

-

Mole fraction of Carbon dioxide

0.00 .. 0.30

0.00 .. 1.00

-

Mole fraction of Nitrogen

0.00 .. 0.50

0.00 .. 1.00

-

Mole fraction of Helium

0.00 .. 0.002

0.00 .. 0.03

-

Mole fraction of Argon

0.00 .. 0.00

0.00 .. 0.01

-

Mole fraction of Oxygen

0.00 .. 0.00

0.00 .. 0.21

-

Mole fraction of Hydrogen Sulphide

0.00 .. 0.0002

0.00 .. 1.00

-

Mole fraction of Hydrogen

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Water

0.00 .. 0.0005

*

-

* For these components the dew point temperature is the upper limit. Limit check is ignored for reason of simplicity.

Flow-X─ Function Reference

3-37

Flow-X General functions - fxAGA8_M

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Pressure value

bar(a)

0..2800

1.01325

Temperature

Temperature value

°C -150..+450

0

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

0

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPERR Compressibility factor

- Z 1 Mass Density

kg/m3

MASDENS

0

Mole Density

kmol/m3

MOLDENS

0

Molar Mass

kg/kmol

MOLMASS

0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA8 calculation is not recommended in this case

RANGE

OOR

0

Calculations

The calculations are as documented in the standard.

3-38 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_Gross

fxAGA8_Gross

Description

This function calculates the compressibility factor in accordance with the AGA-8 Gross Characterization Method. Although the AGA-8 Gross Method is based on the Standard GERG Virial Equation Of State (SGERG) there are slight differences in the results.

Two different methods are specified by the standard. Method 1 takes the Pressure, Temperature, Specific Gravity (Relative Density), Carbon Dioxide content and Gross Heating Value (GHV) as inputs. Method 2 takes the same inputs except for the Nitrogen content instead of GHV.

Compliance

AGA 8, Second edition November 1992 - 2nd printing July 1994

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994

Boundaries

The AGA8 standard recommends using the Gross Characterization Method only when input conditions lie within the following range. For conditions outside this range the standard recommends to use the Detailed Characterization Method.

Input value

Normal Range

EU

Temperature

32..130

°F

Pressure

0 .. 1200

psia

Gross heating value

475 .. 1210

Btu/ft3

Relative density

0.554 .. 0.87

-

Carbon dioxide

0.00 .. 0.30

mol/mol

Nitrogen

0.00 .. 0.50

mol/mol

Function inputs and outputs

Function inputs

Remark

EU

Range

Default

Name

Optional tag name, tag description and tag group

Temperature

Observed temperature

°F

-250..+800

60

Pressure

Observed pressure

psia

0..40000

Relative density

Relative density at the corresponding reference temperature and pressure

-

0..2 0 RD reference temperature

Reference temperature for relative density

°F

-250 ..+800

60

RD reference pressure

Reference pressure for relative density

psia

0..40000

14.73

Gross heating value

Gross heating value at the corresponding reference temperature and pressure

Btu/ft3

0..2500

0

GHV reference temperature

Reference temperature for gross heating value

°F

-250 ..+800

60

GHV reference pressure

Reference pressure for gross heating value

psia

0..40000

14.73 Nitrogen

Nitrogen (N2) fraction

mol/mol

0..1

0

Carbon dioxide

Carbon dioxide (CO2) fraction

mol/mol

0..1

0

Method

Gross Characterization Method: 1: GHV, Relative Density, CO2 2: Relative Density, CO2, N2

Note: For Method 1 input ‘Nitrogen’ is not

- 0

Flow-X─ Function Reference

3-39

Flow-X General functions - fxAGA8_Gross

used, while for Method 2 inputs ‘Gross heating value’, ‘GHV reference temperature’ and ‘GHV reference pressure’ are not used.

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

STS FIOOR CALCERR NOCONV

Compressibility factor

- 1

Molar mass

lb/ lbmo l

0 Density

Density at observed pressure and temperature

lb/ft3 0

Range

0: In Normal Range

All components are within the range that is recommended by the standard

1: Out of Range

One or more inputs are outside the recommended range

RANGE

0

Calculations

The calculations are in accordance with the standard.

3-40 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1952

fxAPI_Dens15C_1952

Density (T, P) <--> Density (15°C, equilibrium pressure)

This function converts a density value at the observed temperature and pressure to the density at 15°C and the equilibrium pressure (typically 0 barg) or vice versa. The temperature conversion is according to ASTM-IP Petroleum Measurements Tables 1952 (Also known as API-1952 tables) Table 54.

Note: this function is a combination of the API 1952 Tables and API 11.2.1M. For the calculation from observed to standard conditions an iterative calculation is required. The rounding and truncating of input and intermediate values is implemented such that the example calculations as specified in both standards are exactly reproduced.

Compliance

 ASTM-IP Petroleum Measurement Tables, Metric Edition, Metric Units of Measurement,

1952

 API MPMS 11.2.1M - Compressibility Factors for Hydrocarbons: 638 - 1074 Kilograms per

Cubic Meter Range - First Edition, August 1984

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Observed Density

Depending on the conversion method this is the Density either at the observed temperature and observed pressure or at 15 °C and the equilibrium pressure

kg/m3

0..1300

0

Observed temperature

°C -

100..200

15 Observed pressure

bar(g)

-1..150

0

API 11.2.1 rounding

0: Disabled

The calculation of the compressibility factor F is performed with full precision

1: Enabled

API-MPMS 11.2.1 rounding and truncating rules are applied. The compressibility factor F is rounded to 3 decimal places as specified in the standard.

-

API1121R ND

0

Equilibrium pressure

The equilibrium pressure is considered to be 0 bar(g) for liquids which have an equilibrium pressure less than atmospheric pressure (in

bar(g)

EQUIPRES

0..150

0

Flow-X─ Function Reference

3-41

Flow-X General functions - fxAPI_Dens15C_1952

compliance with API MPMS

12.2 par. 12.2.5.4).

Conversion method

1: From observed to standard conditions 2: From standard to observed conditions

CONVERS ION

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

-

STS FIOOR CALCERR NOCONV

1

Output Density

Depending on the conversion method this is the Density either at 15 °C and the equilibrium pressure or at the observed temperature and observed pressure

kg/m3

DENS

0

CTL

Volume correction factor for temperature.

-

CTL 1

CPL

Volume correction factor for pressure Value will be rounded according to input 'API 11.2.1 rounding'

-

CPL 1 CTPL

Combined volume correction factor CTPL = CTL * CPL

-

CTPL 1

F

Compressibility factor

- F

0

CTL calc out of range

With respect to the standard used for the calculation of CTL the combination of input values is: 0: In Range 1: Out of Range

CTLOOR

0

CPL calc out of range

With respect to the standard used for the calculation of CPL the combination of input values is: 0: In Range 1: Out of Range

CPLOOR

0

Calculations

The calculations depend on the conversion method.

Conversion method 1: from observed to standard conditions. The function performs the following iterative algorithm to calculate the Density at standard conditions:

1. At the start of the iteration the initial value for Density at [15 C, equilibrium

pressure] is set to the Observed Density. The initial CPL value is set to 1.

2. The CTL value is determined from the Density at [15 C, equilibrium pressure]

according to API 1952 Table 54.

3. The Density at [15 C, equilibrium pressure] is calculated from the Observed

Density, the new CTL value and the CPL value from the previous iteration.

4. The compressibility factor is calculated according to API MPMS 11.2.1M from the

density at [15 C, equilibrium pressure] and the 'Observed temperature'. If API

11.2.1M rounding is enabled then the density and temperature are rounded and

3-42 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1952

the calculations are performed in accordance with the rounding and truncating rules of the standard.

5. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

6. The Density at [15C, equilibrium pressure] is calculated by dividing the Observed

Density by the CTL and the new CPL value.

7. Steps 2 through 6 are repeated taking the Density value from step 7 as the start

value for the next iteration until the absolute difference between two consecutive Density values is 0.0001.

Conversion method 2: from standard to observed conditions. The function performs straightforward calculations to determine the Density at observed conditions:

1. The CTL value is calculated according to API 1952 Table 54

2. The compressibility factor is calculated according to API MPMS 11.2.1M from

the input density and temperature'. If API 11.2.1M rounding is enabled then the input density and temperature are rounded and the calculations are performed in accordance with the rounding and truncating rules of the standard.

3. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

4. The output Density (at observed temperature and pressure) is calculated from

the input Density and the CTL and the CPL values.

Flow-X─ Function Reference

3-43

Flow-X General functions - fxAPI_Dens15C_1980

fxAPI_Dens15C_1980

Description

Density (T, P) <--> Density (15°C, equilibrium pressure)

This function converts a density value at the observed temperature and pressure to the density value at 15°C and the equilibrium pressure (typically 0 bar(g)) or vice versa. The temperature conversion is according to API-2540, Tables 53A/54A (Generalized Crude Oils) and 53B/54B (Refined Oil Products) and API MPMS 11.1 Chapter XIV Table 53D/54D: 1984 (Lubricating Oils), while the volume correction for pressure according to API MPMS 11.2.1M. An iterative calculation needs to be applied to convert the observed density to the value at base conditions.

Note: this function is a combination of API2540 and API 11.2.1M. For the calculation from observed to standard conditions an iterative calculation is required. The rounding and truncating of input and intermediate values is implemented such that the example calculations as specified in both standards are exactly reproduced.

Compliance

 API MPMS 11.1 Volume X (API Standard 2540) - Table 53A - Generalized Crude Oils,

Correction of Observed Density to Density at 15°C - First Edition, August 1980

 API MPMS 11.1 Volume X (API Standard 2540) - Table 54A - Generalized Crude Oils,

Correction of Volume to 15°C against Density at 15°C- First Edition, August 1980

 API MPMS 11.1 Volume X (API Standard 2540) - Table 53B - Generalized Products,

Correction of Observed Density to Density at 15°C - First Edition, August 1980

 API MPMS 11.1 Volume X (API Standard 2540) - Table 54B - Generalized Products,

Correction of Volume to 15°C against Density at 15°F - First Edition, August 1980

 API MPMS 11.1 Volume XIV - Table 53D - Generalized Lubricating Oils, Correction of

Observed Density to Density at 15°C - January 1982

 API MPMS 11.1 Volume XIV - Table 54D - Generalized Lubricating Oils, Correction of Volume

to 15°C against Density at 15°F - January 1982

 API MPMS 11.2.1M - Compressibility Factors for Hydrocarbons: 638 - 1074 Kilograms per

Cubic Meter Range - First Edition, August 1984

3-44 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1980

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Input density

Meaning depends on the input 'Conversion method'. 'Conversion method' = 1

Density at the observed temperature and pressure

'Conversion method' = 2

Density at 15 °C and the equilibrium pressure.

kg/m3

0..1300

0

Observed temperature

°C -100..200

15

Observed pressure

bar(g)

-1..150

0

Product

1: A - Crude Oil 2: B - Auto select

Selection based on density at 15 °C

3: B - Gasoline 4: B - Transition Area 5: B - Jet Fuels 6: B - Fuel Oil 7: D - Lubricating Oil

PRDTYP

1

API 2540 rounding

0: Disabled

The calculations are performed with full precision and the final CTL value is rounded as specified by input 'CTL decimal places'

1: Enabled for computational value

API-2540 rounding and truncating rules are applied and, in case of conversion method 2 (standard to observed), the computational value for CTL as specified in Table 54 is used, meaning that the CTL value has: 4 decimal places if CTL >=1 5 decimal places if CTL <

1.

2: Enabled for table value

API-2540 rounding and truncating rules are applied and, in case of conversion method 2 (standard to observed), the table value for CTL as specified in Table 54 meaning that the CTL value has 4 decimal places

API2540RND

-

0

Flow-X─ Function Reference

3-45

Flow-X General functions - fxAPI_Dens15C_1980

in all cases

3: Enabled with 5 decimal places

API-2540 rounding and truncating rules are applied, and, in case of conversion method 2 (standard to observed), the CTL value has 5 decimal places in all cases.

Note: although not strictly in accordance with the standard, this option is more commonly used than option 'Enabled for computational value'

Note: for conversion type 1

‘From observed to standard conditions’ the CTL factor is

rounded to 6 decimal places

when input ‘API 2540 rounding’

> 0, as in accordance with table

53.

Hydrometer correction

Only applies for conversion method

‘1: From observed to standard conditions’

0: Disabled 1: Enabled

-

HYDROCOR

0

API 11.2.1M rounding

0: Disabled

The calculation of the compressibility factor F is performed with full precision.

1: Enabled

API-MPMS 11.2.1M rounding and truncating rules are applied. The compressibility factor F is rounded to 3 decimal places as specified in the standard.

-

API1121RND

0

Equilibrium pressure

The equilibrium pressure is considered to be 0 bar(g) for liquids which have an equilibrium pressure less than atmospheric pressure (in compliance with API MPMS 12.2 par. 12.2.5.4)

bar(g)

EQUIPRES

0..150

0

Conversion method

1: From observed to standard conditions 2: From standard to observed conditions

CONVERSIO N

1

3-46 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1980

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

-

STS FIOOR CALCERR NOCONV

1

Output density

Meaning depends on the input 'Conversion method'. 'Conversion method' = 1

Density at 15 °C and the equilibrium pressure.

'Conversion method' = 2

Density at the observed temperature and pressure

kg/m3

DENS

0

CTL

Volume correction factor for temperature. Value will be rounded according to input 'API2540 rounding''

-

CTL 1

CPL

Volume correction factor for pressure Value will be rounded according to input 'API 11.2.1M rounding''

-

CPL 1 CTPL

Combined volume correction factor CTPL = CTL * CPL

-

CTPL 1 K0

Actual value of constant K0 used for CTL calculation

-

K0 0

K1

Actual value of constant K1 used for CTL calculation

-

K1 0

K2

Actual value of constant K2 used for CTL calculation

-

K2 0 Alpha

Thermal expansion factor

1/°C

ALPHA

0 F

Compressibility factor

- F

0

Product

When input 'Product' is 'B - Auto select', then the output is set to the actual selected product of tables 53B/54B (enumerative value as defined for input 'Product'), else the output is set equal to input 'Product'.

-

PRDCUR

0 CTL calc out of range

With respect to the standard used for the calculation of CTL the combination of input values is: 0: In Range 1: Out of Range

CTLOOR

0

CPL calc out of range

With respect to the standard used for the calculation of CPL the combination of input values is: 0: In Range 1: Out of Range

CPLOOR

0

Calculations

The calculations depend on the conversion method.

Conversion method 1: from observed to standard conditions. The function performs the following iterative algorithm to calculate the density at reference conditions:

Flow-X─ Function Reference

3-47

Flow-X General functions - fxAPI_Dens15C_1980

1. First the inputs are rounded in accordance with the API2540 standard, provided

that API2540 rounding is enabled.

2. The hydrometer correction on the input density is applied, provided that this

correction is enabled

3. At the start of the iteration the density at [15 C, equilibrium pressure] is set

equal to the observed density and the initial CPL value is set to 1.

4. When the type of product is set to ‘B – Auto select’ (automatic selection of the

refined product range) the K0, K1 and K2 factors are determined based on the density at [15 C, equilibrium pressure]. The Transition area is only taken in consideration in the 2nd iteration loop, as specified in the standard.

5. The Alpha factor is calculated according from the density at [15 C, equilibrium

pressure] and the K0, K1 and K2 factor. If API2540 rounding is enabled, then the intermediate results are rounded or truncated as specified API-2540 Table 53.

6. The CTL value is calculated according to API-2540 Table 53 from the Alpha factor

and the differential temperature (= observed temperature – 15°C). If API2540 rounding is enabled, then the intermediate results are rounded or truncated as specified API-2540 Table 53.

7. Depending on the type of API2540 rounding the calculated CTL value is rounded

to 6 decimal places or not rounded at all.

8. The density at [15 C, equilibrium pressure] is calculated by dividing the observed

density by the new CTL value and the CPL value from the previous iteration.

9. The compressibility factor is calculated according to API MPMS 11.2.1M from the

density at [15 C, equilibrium pressure] and the 'Observed temperature'. If API

11.2.1M rounding is enabled then the density and temperature are rounded and the calculations are performed in accordance with the rounding and truncating rules of the standard.

10. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

11. The density at [15C, equilibrium pressure] is calculated by dividing the observed

density by CTL and the new CPL value.

12. If API2540 rounding is enabled then the density at [15C, equilibrium pressure]

value is rounded to 3 decimal places as specified in the standard.

13. Steps 4 through 12 are repeated taking the density value from step 12 as the

starting value until the absolute difference between two consecutive density values is either 0.05 (or 0.07 for the transition area) or 0.000001, depending of API2540 rounding being enabled or not.

14. For refined products the entire iteration loop is repeated if the density at [15C,

equilibrium pressure] appears to be in a different product region than the observed input density. This is required because a different product region means different K0, K1 and K2 factors.

15. When API2540 rounding is enabled, the final density at [15C, equilibrium

pressure] is rounded to 1 decimal place.

Conversion method 2: from standard to observed conditions. The function performs straightforward calculations to determine the density at observed conditions:

1. First the inputs are rounded in accordance with the API2540 standard, provided

that API2540 rounding is enabled.

2. When the type of product is set to ‘B – Auto select’ (automatic selection of the

refined product range) the K0, K1 and K2 factors are determined based on the input density

3. The Alpha factor is calculated according from the input density and the K0, K1

and K2 factor. If API2540 rounding is enabled, then the intermediate results are rounded or truncated as specified API-2540 Table 54.

3-48 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1980

4. The CTL value is calculated according to API-2540 Table 54 from the Alpha factor

and the differential temperature (= observed temperature – 15°C If API2540 rounding is enabled, then the intermediate results are rounded or truncated as specified API-2540 Table 54.

5. Depending on the type of API2540 rounding the calculated CTL value is rounded

to 4 or 5 decimal places or not rounded at all.

6. The compressibility factor is calculated according to API MPMS 11.2.1M from the

input density and temperature'. If API 11.2.1M rounding is enabled then the input density and temperature are rounded and the calculations are performed in accordance with the rounding and truncating rules of the standard.

7. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

8. The density at [15C, equilibrium pressure] is calculated by multiplying the input

density by the CTL and the CPL values.

Flow-X─ Function Reference

4-49

Flow-X General functions - fx2CellSelection

Chapter 4 - Flow-X General functions

This chapter lists all available Flow-X functions in alphabetical order.

fx2CellSelection

Description

The function selects between 2 input cells (e.g. differential pressure cells) based on the actual measured value and the failure status of each cell. The function can handle the following type of cell range configurations:

 Lo – Hi  Hi – Hi

Where ‘Lo’ means low range, ‘Mid’ mid range and ‘Hi’ high range.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Cell A value

Input value as percentage of span of cell A

Cell A status

Input status of cell A 0: Normal <> 0 : Failure

Cell B value

Input value as percentage of span of cell B

Cell B status

Input status of cell B 0: Normal <> 0 : Failure

Range type

For a description of the functionality refer to adjacent section ‘Logic’ 1: Lo Hi Cell A at low range Cell B at high range 2: Hi Hi Cell A and B at same range

RNGTYP

Auto switchback

For a description of the functionality refer to adjacent section ‘Logic’ 0: Disabled 1: Enabled

Switch-up percentage

Switch-up value expressed as percentage of span of the lower range

-

SWUPPERC

0..100

95 Switch-down percentage

Switch-down value expressed as percentage of span of the lower range

-

SWDNPERC

0..100

90

4-50 Flow-X─ Function Reference

Flow-X General functions - fx2CellSelection

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range

STS FIOOR

Selected cell number

1: Cell 1 2: Cell 2

SELNR

1 Selected cell status

0: Normal 1: Failure

SELSTS

0

Logic

The function will switch from one cell to another at the following conditions:

Range type = ‘Lo Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell B when cell A fails while cell B is healthy

When cell B is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell A when cell B fails and cell A is healthy

Range type = ‘Hi Hi’

When cell A is currently selected

 Select cell B when cell A value fails and cell B is healthy

When cell B is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell A when cell B fails and cell A is healthy.

Flow-X─ Function Reference

4-51

Flow-X General functions - fx3CellSelection

fx3CellSelection

Description

The function selects between 3 input cells (typically differential pressure cells) based on the actual measured value and the failure status of each cell. The function can handle the following type of cell range configurations:

 Lo – Mid – Hi  Lo – Hi – Hi  Hi – Hi – Hi

Where ‘Lo’ means low range, ‘Mid’ mid range and ‘Hi’ high range.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Cell A value

Input value as percentage of span of cell A

Cell A status

Input status of cell A 0: Normal <> 0 : Failure

Cell B value

Input value as percentage of span of cell B

Cell B status

Input status of cell B 0: Normal <> 0 : Failure

Cell C value

Input value as percentage of span of cell C

Cell C status

Input status of cell C 0: Normal <> 0 : Failure

Range type

For a description of the functionality refer to adjacent section ‘Logic’ 1: Lo Mid Hi

Cell A at low range Cell B at mid range Cell C at high range

2: Lo Hi Hi

Cell A at low range Cell B and C at high range

3: Hi Hi Hi

Cell A, B and C at same range

RNGTYP

Auto switchback

For a description of the functionality refer to adjacent section ‘Logic’ 0: Disabled 1: Enabled

Switch-up percentage

Switch-up value expressed as percentage of span of the lower range Does not apply for selection type ‘Hi Hi Hi’

-

SWUPPERC

0..100

95

Switch-down percentage

Switch-down value expressed as percentage of span of the lower range Does not apply for selection type ‘Hi Hi Hi’

-

SWDNPERC

0..100

90

4-52 Flow-X─ Function Reference

Flow-X General functions - fx3CellSelection

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range

STS FIOOR

Selected cell number

1: Cell 1 2: Cell 2 3: Cell 3

SELNR

1 Selected cell status

0: Normal 1: Failure

SELSTS

0

Logic

The function will switch from one cell to another at the following conditions:

Range type = ‘Lo Mid Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell B when cell A fails while cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell C when cell B value is above or equal to the switch-up percentage of its range and

cell C is healthy

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell A when cell B fails while cell A is healthy  Select cell C when cell B and cell A fail and cell C is healthy

When cell C is currently selected

 Select cell B when cell B value is below or equal to the switch-down percentage of its range

and cell B is healthy

 Select cell B when cell C fails while cell B is healthy  Select cell A when cell C and cell B fail and cell A is healthy

Range type = ‘Lo Hi Hi’

When cell A is currently selected

 Select cell B when cell A value is above or equal to the switch-up percentage of its range and

cell B is healthy.

 Select cell C when cell A value is above or equal to the switch-up percentage of its range and

cell B fails and cell C is healthy.

 Select cell B when cell A fails while cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell C when cell B fails while cell C is healthy  Select cell A when cell B and cell C fail and cell A is healthy

Flow-X─ Function Reference

4-53

Flow-X General functions - fx3CellSelection

When cell C is currently selected

 Select cell A when cell A value is below or equal to the switch-down percentage of its range

and cell A is healthy

 Select cell B when cell B is healthy and ‘Auto switchback’ is enabled  Select cell A when cell C and cell B fail and cell A is healthy

Range type = ‘Hi Hi Hi’

When cell A is currently selected

 Select cell B when cell A value fails and cell B is healthy  Select cell C when cell A and cell B fail and cell C is healthy

When cell B is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell A when cell B fails and cell A is healthy  Select cell C when cell B and A fail and cell C is healthy

When cell C is currently selected

 Select cell A when cell A is healthy and ‘Auto switchback’ is enabled  Select cell B when cell B is healthy and cell A fails and ‘Auto switchback’ is enabled  Select cell A when cell C fails and cell A is healthy  Select cell B when cell C and A fail and cell B is healthy

4-54 Flow-X─ Function Reference

Flow-X General functions - fxAGA10_M

fxAGA10_M

The function calculates the speed of sound of a gas at the specified conditions of temperature and pressure using the formulae presented in the American Gas Association Report No 10.

Compliance

AGA Report No. 10 - Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, January 2003

Boundaries

The AGA-10 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-10 calculation has a higher uncertainty. Using the AGA-10 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended. The AGA-10 standard specifies the same limits as the AGA-8 standard. Refer to the fxAGA8 function for

details on the actual limit values used by this function to set output ‘Range’.

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Observed pressure

bar(a)

0..2000

Temperature

Observed temperature

°C -

200..+400

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alam

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to

1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPOOR

Speed of sound

m/s

SOS 0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs

RANGE

OOR

0

Flow-X─ Function Reference

4-55

Flow-X General functions - fxAGA10_M

values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA10 calculation is not recommended in this case)

Calculations

Calculations are as documented in the standard.

4-56 Flow-X─ Function Reference

Flow-X General functions - fxAGA10ex_M

fxAGA10ex_M

The extended AGA 10 function provides an extensive set of gas properties at the specified conditions of temperature and pressure using the formulae presented in the American Gas Association Report No 10.

Compliance

AGA Report No. 10 - Speed of Sound in Natural Gas and Other Related Hydrocarbon Gases, January 2003

Boundaries

The AGA-10 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-10 calculation has a higher uncertainty. Using the AGA-10 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended. The AGA-10 standard specifies the same limits as the AGA-8 standard. Refer to the fxAGA8 function for

details on the actual limit values used by this function to set output ‘Range’.

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Observed pressure

bar(a)

0..2000

Temperature

Observed temperature

°C -

200..+400

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alam

Fall back

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +-

0.0001

STS FIOOR CALCERR NOCONV COMPOOR

Molecular weight

kg/kmol

MOLMASS

Molar density at base conditions

mol/m3

MOLDENSB

Molar density at flowing conditions

mol/m3

MOLDENSF

Mass density at base conditions

kg/m3

MASSDENSB

Mass density at flowing conditions

kg/m3

MASSDENSF

Flow-X─ Function Reference

4-57

Flow-X General functions - fxAGA10ex_M

Ideal gas relative density

- IRD

Real gas relative density

- RRD Velocity of sound

m/s

SOS

Compressibility at base conditions

- ZB

Compressibility at flowing conditions

- ZF Supercompressibility

- FPV

Ideal gas specific enthalpy

kJ/kg

MASSH0

Real gas specific enthalpy

kJ/kg

MASSH

Real gas specific entropy

kJ/kg/K

MASSS

Ideal gas isobaric heat capacity

kJ/kg/K

MASSCP0

Real gas isobaric heat capacity

kJ/kg/K

MASSCP

Real gas isochoric heat capacity

kJ/kg/K

MASSCV

Ideal gas isobaric heat capacity

kJ/kmol/K

MOLCP0

Real gas isobaric heat capacity

kJ/kmol/K

MOLCP

Real gas isochoric heat capacity

kJ/kmol/K

MOLCV Ratio of specific heats

- CPCV

Isentropic exponent

- KAPPA

Critical flow factor

- CRITC

Ideal gas specific enthalpy

kJ/kmol

MOLH0

Real gas specific enthalpy

kJ/kmol

MOLH

Isentropic perfect gas critical flow factor

- CI

Isentropic real gas critical flow factor

- CRI

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA10

RANGE

OOR

0

4-58 Flow-X─ Function Reference

Flow-X General functions - fxAGA10ex_M

calculation is not recommended in this case)

Calculations

Calculations are as documented in the standard.

Flow-X─ Function Reference

4-59

Flow-X General functions - fxAGA3_C

fxAGA3_C

Description

The function calculates the mass flow rate for Orifice pressure differential flow devices according to the AGA-3 standard for orifice meters with flange taps.

Compliance

 AGA Report No. 3 - Orifice Metering Measurement of fluid flow by means of pressure

differential devices, 1992

 API Manual of Petroleum Measurement Standards, Chapter 14 Natural Gas Fluids

Measurement, Section 3 - Concentric Square-edged Orifice Meters 1992.

Function

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Differential Pressure

Differential pressure over the primary flow device measured at the up- and downstream pressure tappings, which need to be in the positions as specified in the standard

inH2O @ 60°F

0..1000

0

Pressure

Down- or upstream pressure value of the fluid at metering conditions

psia 0..30000

0

Temperature

Down- or upstream temperature of the fluid at metering conditions

°F -

400..200 0

0 Density

Down or upstream density of the fluid at metering conditions

lbm/ft3

0..200

0

Dynamic Viscosity

Dynamic viscosity of the fluid

lbm/ft.s

DYNVI S

0..10

6.9e-6

Isentropic Exponent

Also referred to as  (kappa). For an ideal gas this coefficient is equal to the ratio of the specific heat capacity at constant pressure to the specific heat at constant volume. This ratio is commonly used when the real value is unknown.

-

KAPPA

0..10

1.3

Pipe Diameter

Internal diameter of the pipe at reference temperature

inches

PIPEDI AM

0..100

0

Pipe Expansion factor

The thermal expansion coefficient of the pipe material

1/°F

PIPEE XPF

0..1

6.2e-6

Pipe Reference temperature

The reference temperature that corresponds to the 'Pipe diameter' input value

°F

PIPER EFT -400..200 0

68 Orifice Diameter

Orifice diameter at reference temperature

inches

ORIFD IAM

0..100

0

Orifice Expansion factor

The thermal expansion coefficient of the orifice material Typical values are:

1/°F

ORIFE XPF

0..1

9.25e-6

Orifice Reference Temperature

The reference temperature that corresponds to the 'Orifice diameter' input value

°F

ORIFR EFT -400..200 0

68

4-60 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

Pressure Location

1: Upstream tapping

Input 'Pressure' represents the pressure at the upstream pressure tapping (p1). Since the absolute pressure is usually measured at the upstream tapping this is the most common setting.

2: Downstream tapping

Input 'Pressure' represents the pressure at the downstream tapping (p2).

-

PRESL OC

1

Temperature Location

1: Upstream tapping

Input 'Temperature' represents the upstream temperature (t1).

2: Downstream tapping

Input 'Temperature represents the temperature at the downstream tapping (t2).

3: Recovered pressure

Input 'Temperature' represents the downstream temperature at a location Where the pressure has fully recovered (t3). Since temperature measurement is usually downstream of the flow device this is the most common setting.

-

TEMP LOC

3

Temperature Correction

1: Use (1-)/

Isentropic expansion using (1)/ as the temperature referral exponent

2: Use temperature exponent

Isentropic expansion using input 'Temperature Exponent' as the temperature referral exponent [-]

-

TEMP COR

1 Temperature Exponent

To correct the temperature from down- to upstream conditions (or vice versa) the formula (-1)/ (isentropic expansion) will be used when the input value is set to 0, else the input value will be used. For more details refer to section 'Temperature correction'.

TEMP EXP

0

Flow-X─ Function Reference

4-61

Flow-X General functions - fxAGA3_C

Density Location

This parameter specifies if and how the density should be corrected from downstream to upstream conditions. 1: Upstream tapping

Input 'Density' represents the density at the upstream pressure tapping (1).

2: Downstream tapping

Input 'Density' represents the density at the downstream tapping (2).

3: Recovered pressure

Input 'Density' represents the density downstream at a location Where the pressure has fully recovered (3).

-

DENSL OC

0

Density Exponent.

This factor is used when density correction is enabled. The formula 1/ will be used when the input value is set to 0, else the input value will be used. For more details refer to section function 'ISO5167- Orifice' 'Density correction'.

-

DENSE XP

0 Fluid

The type of fluid being measured 1: Gas 2: Liquid For liquid the expansion factor is set to 1, i.e. the fluid is considered to be incompressible.

-

FLUID

0

Drain hole

When input is > 0 then an additional correction on the orifice diameter will be applied to account for the drain hole, as explained further on.

in

DRAIN

0.. 100

0

Fpwl

Local Gravitational Correction Factor for Deadweight Calibrators used to calibrate differential and static pressure Instruments.

Directly applied on the calculated mass flow rate within each iteration.

-

FPWL

0.9..1.1

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

STS FIOOR CALCERR NOVONV

Mass flow rate

The calculated mass flow rate

klbm/h r

MASSR

0 Beta ratio

Orifice to pipe diameter ratio at upstream temperature

-

BETA

0 Orifice

At the upstream

inches

ORIFUP

0

4-62 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

diameter

temperature

Pipe diameter

At the upstream temperature

inches

PIPEUP

0 Upstream pressure

Pressure at upstream tapping (p1)

psia

PRESUP

0

Pressure at downstream tapping

Pressure at downstream tapping (p2)

psia

PRESDN

0

Recovered downstream pressure

Fully recovered downstream pressure (p3)

psia

PRESREC

0 Upstream temperature

Temperature at upstream tapping (t1)

°F

TEMPUP

0

Temperature at downstream tapping

Temperature at downstream tapping (t2)

°F

TEMPDN

0

Downstream Temperature

'Fully recovered' downstream temperature (t3)

°F

TEMPREC

0 Upstream density

Density at upstream tapping (1)

lbm/ft 3

DENSUP

0

Density at downstream tapping

Pressure at downstream tapping (2)

lbm/ft 3

DENSDN

0 Downstream density

'Fully recovered' downstream density (3)

lbm/ft 3

DENSREV

0

Reynolds number

The pipe Reynolds number, i.e. the Reynolds number upstream of the orifice and not the one within the device throat itself)

-

REYN

0

Discharge coefficient

- DISCF

0 Expansion Factor

- EXPFAC

0

Velocity of Approach

- VOA 0

Pressure out of range

0: Pressure is in valid range 1: Pressure is out of valid range

-

PRESOOR

0

Reynolds out of range

0: Reynolds number is in valid range 1: Reynolds number is out of valid range

-

REYNOOR

0

Diameter out of range

0: Device and pipe diameter and Beta ratio in valid range 1: Device diameter, pipe diameter and/or Beta ratio out of valid range

-

DIAMOOR

DIAMOO R

0

Calculations

The calculations are in accordance with the standard.

Flow-X─ Function Reference

4-63

Flow-X General functions - fxAGA3_C

Pressure correction

 The relation between the pressure at the upstream tapping p

1

and the pressure at the

downstream tapping (p2) is as following:

1000

12

units

Kppp



 The relation between the pressure at the upstream tapping and the downstream tapping is

as following:

LOSS

ppp 

13

   

unitsLOSS

Kpp 







2

1



 

4

1







E

EC

Where:

p1

Pressure at upstream tapping

psia

p2

Pressure at downstream tapping

psia

p3

Fully recovered downstream pressure

psia

p

Differential pressure

inH20 @ 60°F

p

LOSS

Pressure loss over the meter

psi

C

Discharge coefficient as calculated by the standard

-

α

Flow coefficient

-

β

Diameter ratio at the upstream pressure and temperature

-

E

Velocity of approach factor

-

K

units

Unit conversion factor to convert a value expressed in 'inH2O @60°F' to the corresponding expressed in 'psi' (conversion as specified in section 'Unit Types')

-

Temperature correction

 When input 'Temperature correction' is set to 1, then an isentropic expansion based on the

isentropic coefficient is applied:

 

67.45967.459

1

2

21





 





 









p

tt

4-64 Flow-X─ Function Reference

Flow-X General functions - fxAGA3_C

 

67.45967.459

1

3

31





 





 









p

tt

 When input 'Temperature correction' is set to 2, then an isentropic expansion based on

input 'Temperature exponent' is applied:

 

67.45967.459

1

2

21





 





 





TE

K

p

tt

 

67.45967.459

1

3

31





 





 





TE

K

p

tt

Where:

t1

Upstream temperature

°F

t2

Temperature at the downstream tapping

°F

t3

Temperature at the fully recovered downstream pressure

°F

p1

Upstream pressure

psia

p2

Pressure at the downstream tapping

psia

p3

Fully recovered downstream pressure

psia  Isentropic exponent

-

KTE

Temperature exponent

-

Density correction

 When input 'Density exponent' = 0, then the following isentropic corrections are applied

(depending on the type of Density Correction)





1

2

1

21



 





 





p





1

3

1

31



 





 





p

 Else the value of input 'Density Exponent' is used

DE

K

p



 





 





2

1

21



DE

K

p



 





 





3

1

31



Where:

1

Upstream density

lbm/ft3

2

Density at the downstream tapping

lbm/ft3

3

Density at the fully recovered downstream pressure

lbm/ft3

p1

Upstream pressure

psia

p2

Pressure at the downstream tapping

psia

p3

Fully recovered downstream pressure

psia



Isentropic exponent

-

KDE

Density exponent

-

Flow-X─ Function Reference

4-65

Flow-X General functions - fxAGA5_C

fxAGA5_C

The AGA 5 standard defines methods to calculate the mass and volume based calorific values at 60°F and 14.73 psia for a natural gas based on known molar fractions of the non-hydrocarbon gas components.

Compliance

 A.G.A. Transmission Measurement Committee Report No. 5 (Fuel gas Energy Metering) 1981  A.G.A. Transmission Measurement Committee Report No. 5 (Fuel gas Energy Metering) 1996

(Reprinted 1999)

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Composition

Standard composition as defined in section 'Standard gas composition. Only the following components are considered by the calculation: N2 Nitrogen CO2 Carbon dioxide H2O Water H2S Hydrogen sulfide H2 Hydrogen CO Carbon monoxide O2 Oxygen He Helium

Sum of these fractions may not exceed 1

molar fraction

COMP

0..1

0

Specific Gravity

Molar Mass Ratio, i.e. ratio of the molar mass of the gas and of the molar mass of air (specified in AGA-5 as 28.9644 kg/kmol (lbm/lbmol))

-

SG

0..1

0

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error

STS FIOOR CALCERR

Calorific value mass

Mass based calorific value

Btu/lbm

CV_MASS

0

Calorific value volume

Volume calorific value at 60°F and 14.73 psia

Btu/scf

CV_VOL

0

Calculations

The Energy to Mass ratio is calculated according to Section III of the standard, which contains the calculation procedure for the gas mass to energy conversion. The equations based on the 'by volume' fractional values are used (and not the equations based on the 'by weight' values). The Energy to Volume ratio is calculated according to Section II of the standard, which contains the calculation procedure for the gas volume to energy conversion.

4-66 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_C

fxAGA8_C

The compressibility and density of a gas are calculated from the composition, temperature and pressure in accordance with the ‘Detail Characterization’ method outlined in the AGA-8 standard, with the input and output values in US Customary units.

Compliance

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994  ISO 12213 Natural gas — Calculation of compression factor — Part 2: Calculation using

molar-composition analysis, 1997

Boundaries

The AGA-8 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-8 calculation has a higher uncertainty. Using the AGA-8 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended.

Input value

Normal Range

Expanded Range

EU

Pressure

0 .. 20000

psia

Temperature

-200 .. +400

°F

Mole fraction of Methane

0.45 .. 1.00

0.00 .. 1.00

-

Mole fraction of Ethane

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Propane

0.00 .. 0.04

0.00 .. 0.12

-

Mole fraction of Butanes

0.00 .. 0.01

0.00 .. 0.06

-

Mole fraction of Pentanes

0.00 .. 0.003

0.00 .. 0.04

-

Mole fraction of Hexanes Plus

0.00 .. 0.002

*

-

Mole fraction of Carbon monoxide

0.00 .. 0.03

-

Mole fraction of Carbon dioxide

0.00 .. 0.30

0.00 .. 1.00

-

Mole fraction of Nitrogen

0.00 .. 0.50

0.00 .. 1.00

-

Mole fraction of Helium

0.00 .. 0.002

0.00 .. 0.03

-

Mole fraction of Argon

0.00 .. 0.00

0.00 .. 0.01

-

Mole fraction of Oxygen

0.00 .. 0.00

0.00 .. 0.21

-

Mole fraction of Hydrogen Sulphide

0.00 .. 0.0002

0.00 .. 1.00

-

Mole fraction of Hydrogen

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Water

0.00 .. 0.0005

*

-

* For these components the dew point temperature is the upper limit. Limit check is ignored for reason of simplicity.

Flow-X─ Function Reference

4-67

Flow-X General functions - fxAGA8_C

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Pressure value

psia 0..40000

1.01325

Temperature

Temperature value

°F -250..+800

0

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

0

neo-Pentane mode

Determines what to do when component neo-Pentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_M ODE

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPERR

Compressibility factor

- Z 1 Mass Density

lb/ft3

MASDENS

0

Mole Density

lbmol/ ft3

MOLDENS

0 Molar Mass

lb/lbm ol

MOLMASS

0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA8 calculation is not recommended in this case)

RANGE

OOR

0

Calculations

The calculations are as documented in the standard.

4-68 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_M

fxAGA8_M

The compressibility and density of a gas are calculated from its composition, temperature and pressure in accordance with the ‘Detail Characterization’ method outlined in the AGA8 standard, with the input and output values in metric units.

Compliance

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994  ISO 12213 Natural gas — Calculation of compression factor — Part 2: Calculation using

molar-composition analysis, 1997

Boundaries

The AGA-8 calculation has defined uncertainty bounds for gas mixtures that lie within the 'Normal range'. Also an 'Expanded range' of gas mixtures is defined for which the AGA-8 calculation has a higher uncertainty. Using the AGA-8 calculation for gas mixtures that lie outside the 'Expanded range' is not recommended.

Input value

Normal Range

Expanded Range

EU

Pressure

0 .. 1379

bar(a)

Temperature

-129 .. +204

°C

Mole fraction of Methane

0.45 .. 1.00

0.00 .. 1.00

-

Mole fraction of Ethane

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Propane

0.00 .. 0.04

0.00 .. 0.12

-

Mole fraction of Butanes

0.00 .. 0.01

0.00 .. 0.06

-

Mole fraction of Pentanes

0.00 .. 0.003

0.00 .. 0.04

-

Mole fraction of Hexanes Plus

0.00 .. 0.002

*

-

Mole fraction of Carbon monoxide

0.00 .. 0.03

-

Mole fraction of Carbon dioxide

0.00 .. 0.30

0.00 .. 1.00

-

Mole fraction of Nitrogen

0.00 .. 0.50

0.00 .. 1.00

-

Mole fraction of Helium

0.00 .. 0.002

0.00 .. 0.03

-

Mole fraction of Argon

0.00 .. 0.00

0.00 .. 0.01

-

Mole fraction of Oxygen

0.00 .. 0.00

0.00 .. 0.21

-

Mole fraction of Hydrogen Sulphide

0.00 .. 0.0002

0.00 .. 1.00

-

Mole fraction of Hydrogen

0.00 .. 0.10

0.00 .. 1.00

-

Mole fraction of Water

0.00 .. 0.0005

*

-

* For these components the dew point temperature is the upper limit. Limit check is ignored for reason of simplicity.

Flow-X─ Function Reference

4-69

Flow-X General functions - fxAGA8_M

Function inputs and outputs

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Pressure

Pressure value

bar(a)

0..2800

1.01325

Temperature

Temperature value

°C -150..+450

0

Composition

Standard composition as defined in section 'Standard gas composition.

mol/mol

COMP

0..1

0

neo-Pentane mode

Determines what to do when component neoPentane is larger than zero 1: Add to i-Pentane 2: Add to n-Pentane 3: Neglect

-

NEOC5_MODE

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence 4: Mole fractions do not add up to 1.0 +- 0.0001

STS FIOOR CALCERR NOCONV COMPERR Compressibility factor

- Z 1 Mass Density

kg/m3

MASDENS

0

Mole Density

kmol/m3

MOLDENS

0

Molar Mass

kg/kmol

MOLMASS

0

Range

0: In Normal Range

All inputs are within the 'Normal Range'

1: In Extended Range

One or more inputs within the 'Extended Range, but none of the inputs outside the Extended rang (outputs values have higher uncertainty)

2: Out of Range

One or more inputs outside the 'Extended Range' (using the AGA8 calculation is not recommended in this case

RANGE

OOR

0

Calculations

The calculations are as documented in the standard.

4-70 Flow-X─ Function Reference

Flow-X General functions - fxAGA8_Gross

fxAGA8_Gross

Description

This function calculates the compressibility factor in accordance with the AGA-8 Gross Characterization Method. Although the AGA-8 Gross Method is based on the Standard GERG Virial Equation Of State (SGERG) there are slight differences in the results.

Two different methods are specified by the standard. Method 1 takes the Pressure, Temperature, Specific Gravity (Relative Density), Carbon Dioxide content and Gross Heating Value (GHV) as inputs. Method 2 takes the same inputs except for the Nitrogen content instead of GHV.

Compliance

AGA 8, Second edition November 1992 - 2nd printing July 1994

 AGA Report No. 8, Second edition November 1992 - 2nd printing July 1994  API MPMS 14.2, Second edition November 1992 - 2nd printing July 1994

Boundaries

The AGA8 standard recommends using the Gross Characterization Method only when input conditions lie within the following range. For conditions outside this range the standard recommends to use the Detailed Characterization Method.

Input value

Normal Range

EU

Temperature

32..130

°F

Pressure

0 .. 1200

psia

Gross heating value

475 .. 1210

Btu/ft3

Relative density

0.554 .. 0.87

-

Carbon dioxide

0.00 .. 0.30

mol/mol

Nitrogen

0.00 .. 0.50

mol/mol

Function inputs and outputs

Function inputs

Remark

EU

Range

Default

Name

Optional tag name, tag description and tag group

Temperature

Observed temperature

°F

-250..+800

60

Pressure

Observed pressure

psia

0..40000

Relative density

Relative density at the corresponding reference temperature and pressure

-

0..2

0

RD reference temperature

Reference temperature for relative density

°F

-250 ..+800

60

RD reference pressure

Reference pressure for relative density

psia

0..40000

14.73

Gross heating value

Gross heating value at the corresponding reference temperature and pressure

Btu/ft3

0..2500

0

GHV reference temperature

Reference temperature for gross heating value

°F

-250 ..+800

60

GHV reference pressure

Reference pressure for gross heating value

psia

0..40000

14.73 Nitrogen

Nitrogen (N2) fraction

mol/mol

0..1

0

Carbon dioxide

Carbon dioxide (CO2) fraction

mol/mol

0..1

0

Method

Gross Characterization Method: 1: GHV, Relative Density, CO2 2: Relative Density, CO2, N2

- 0

Flow-X─ Function Reference

4-71

Flow-X General functions - fxAGA8_Gross

Note: For Method 1 input ‘Nitrogen’ is not used, while for Method 2 inputs ‘Gross heating value’, ‘GHV reference temperature’ and ‘GHV reference pressure’ are not used.

Function outputs

Remark

EU

SW tag

Alarm

Fallbac k

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

STS FIOOR CALCERR NOCONV

Compressibility factor

- 1

Molar mass

lb/ lbmo l

0 Density

Density at observed pressure and temperature

lb/ft3 0

Range

0: In Normal Range

All components are within the range that is recommended by the standard

1: Out of Range

One or more inputs are outside the recommended range

RANG E

0

Calculations

The calculations are in accordance with the standard.

4-72 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1952

fxAPI_Dens15C_1952

Density (T, P) <--> Density (15°C, equilibrium pressure)

This function converts a density value at the observed temperature and pressure to the density at 15°C and the equilibrium pressure (typically 0 barg) or vice versa. The temperature conversion is according to ASTM-IP Petroleum Measurements Tables 1952 (Also known as API-1952 tables) Table 54.

Note: this function is a combination of the API 1952 Tables and API 11.2.1M. For the calculation from observed to standard conditions an iterative calculation is required. The rounding and truncating of input and intermediate values is implemented such that the example calculations as specified in both standards are exactly reproduced.

Compliance

 ASTM-IP Petroleum Measurement Tables, Metric Edition, Metric Units of Measurement,

1952

 API MPMS 11.2.1M - Compressibility Factors for Hydrocarbons: 638 - 1074 Kilograms per

Cubic Meter Range - First Edition, August 1984

Function inputs

Remark

EU

SW tag

Range

Default

Name

Optional tag name, tag description and tag group

Observed Density

Depending on the conversion method this is the Density either at the observed temperature and observed pressure or at 15 °C and the equilibrium pressure

kg/m3

0..1300

0

Observed temperature

°C -

100..200

15 Observed pressure

bar(g)

-1..150

0

API 11.2.1 rounding

0: Disabled

The calculation of the compressibility factor F is performed with full precision

1: Enabled

API-MPMS 11.2.1 rounding and truncating rules are applied. The compressibility factor F is rounded to 3 decimal places as specified in the standard.

-

API1121R ND

0

Equilibrium pressure

The equilibrium pressure is considered to be 0 bar(g) for liquids which have an equilibrium pressure less than atmospheric pressure (in compliance with API MPMS

12.2 par. 12.2.5.4).

bar(g)

EQUIPRES

0..150

0

Flow-X─ Function Reference

4-73

Flow-X General functions - fxAPI_Dens15C_1952

Conversion method

1: From observed to standard conditions 2: From standard to observed conditions

CONVERS ION

1

Function outputs

Remark

EU

SW tag

Alarm

Fallback

Status

0: Normal 1: Input argument out of range 2: Calculation error 3: No convergence

-

STS FIOOR CALCERR NOCONV

1

Output Density

Depending on the conversion method this is the Density either at 15 °C and the equilibrium pressure or at the observed temperature and observed pressure

kg/m3

DENS

0

CTL

Volume correction factor for temperature.

-

CTL 1

CPL

Volume correction factor for pressure Value will be rounded according to input 'API 11.2.1 rounding'

-

CPL 1 CTPL

Combined volume correction factor CTPL = CTL * CPL

-

CTPL 1

F

Compressibility factor

- F

0

CTL calc out of range

With respect to the standard used for the calculation of CTL the combination of input values is: 0: In Range 1: Out of Range

CTLOOR

0

CPL calc out of range

With respect to the standard used for the calculation of CPL the combination of input values is: 0: In Range 1: Out of Range

CPLOOR

0

Calculations

The calculations depend on the conversion method.

Conversion method 1: from observed to standard conditions. The function performs the following iterative algorithm to calculate the Density at standard conditions:

1. At the start of the iteration the initial value for Density at [15 C, equilibrium

pressure] is set to the Observed Density. The initial CPL value is set to 1.

2. The CTL value is determined from the Density at [15 C, equilibrium pressure]

according to API 1952 Table 54.

3. The Density at [15 C, equilibrium pressure] is calculated from the Observed

Density, the new CTL value and the CPL value from the previous iteration.

4. The compressibility factor is calculated according to API MPMS 11.2.1M from the

density at [15 C, equilibrium pressure] and the 'Observed temperature'. If API

11.2.1M rounding is enabled then the density and temperature are rounded and the calculations are performed in accordance with the rounding and truncating rules of the standard.

4-74 Flow-X─ Function Reference

Flow-X General functions - fxAPI_Dens15C_1952

5. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

6. The Density at [15C, equilibrium pressure] is calculated by dividing the Observed

Density by the CTL and the new CPL value.

7. Steps 2 through 6 are repeated taking the Density value from step 7 as the start

value for the next iteration until the absolute difference between two consecutive Density values is 0.0001.

Conversion method 2: from standard to observed conditions. The function performs straightforward calculations to determine the Density at observed conditions:

5. The CTL value is calculated according to API 1952 Table 54

6. The compressibility factor is calculated according to API MPMS 11.2.1M from

the input density and temperature'. If API 11.2.1M rounding is enabled then the input density and temperature are rounded and the calculations are performed in accordance with the rounding and truncating rules of the standard.

7. The CPL value is calculated from the compressibility factor and the 'Observed

pressure' and 'Equilibrium pressure' input values.

8. The output Density (at observed temperature and pressure) is calculated from

the input Density and the CTL and the CPL values.

Flow-X─ Function Reference

4-75