Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 1

Transcription

1 Instruction manual HIMS / HTG and vapour pressure (P3) measurement July 2014 Part no Rev. 2 Enraf B.V. P.O. Box AV Delft Netherlands Tel. : Fax : hfs-tac-support@honeywell.com Website: : Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 1

2 Copyright 2014 Enraf B.V. All rights reserved. Reproduction in any form without the prior consent of Enraf B.V. is not allowed. This manual is for information only. The contents, descriptions and specifications are subject to change without notice. Enraf B.V. accepts no responsibility for any errors that may appear in this manual. The warranty terms and conditions applicable in the country of purchase in respect to Enraf B.V. products are available from your supplier. Please retain them with your proof of purchase. Page 2 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

3 Preface Preface This manual is intended for technicians involved with the commissioning and service of the Honeywell Enraf gauges with the optional HCU board or ICU_HPI board installed for the function of HIMS (Hybrid Inventory Measurement System), HTG (Hydrostatic Tank Gauge) and vapour pressure measurement with pressure transmitter P3. A description preceding the technical procedures gives the technical information necessary to understand its functioning. It is recommended to read this description prior to performing any of the procedures. Safety and prevention of damage Refer to the chapter Safety in the instruction manual of the applicable instrument (servo/radar gauge or indicator) for detailed safety instructions. "Warnings", "Cautions", and "Notes" have been used throughout this manual to bring special matters to the immediate attention of the reader. A Warning concerns danger to the safety of the technician or user; A Caution draws attention to an action which may damage the equipment; A Note points out a statement deserving more emphasis than the general text, but does not deserve a "Warning" or a "Caution". The sequence of steps in a procedure may also be important from the point of view of personal safety and prevention of damage; it is therefore advised not to change the sequence of procedural steps or alter a procedure. Legal aspects The information in this manual is the copyright property of Enraf B.V., Netherlands. Enraf B.V. disclaims any responsibility for personal injury or damage to equipment caused by: Deviation from any of the prescribed procedures; Execution of activities that are not prescribed; Neglect of the general safety precautions for handling tools, use of electricity and microwave radiation. EC declaration of conformity The Honeywell Enraf instrument, in which the optional HCU or ICU_HPI board is installed, is in conformity with the protection requirements of EC Council Directive 93/68/EEC. Refer to the CE declaration of conformity delivered with the instrument. Additional information Please do not hesitate to contact Enraf or its representative if you require additional information. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 3

4 Table of contents Table of contents Preface Introduction HCU board ICU_HPI board Overview of functions HCU compatibility Replacement or adding optional board in 854 ATG or 854 XTG servo gauges Replacement or adding optional board in 873 SmartRadar Replacement or adding optional board in 877 FDI Field Display & Interface Optional functions in this manual HIMS Introduction into HIMS HIMS calculations Corrections for ambient air and vapour density Commissioning of HIMS system Selecting pressure and density dimension Tank and gauge data Set-up and configuration of the pressure transmitters Zero calibration of the pressure transmitters Compensation for pressure transmitter P1 position Operation Display Manual inputs Data items HTG Introduction into HTG HTG calculations Volume and Mass calculations Corrections for ambient air and vapour density Commissioning Selecting pressure and density dimension Tank and gauge data Alarm settings Ullage readout Set-up and configuration of the pressure transmitters Zero calibration of the pressure transmitters Compensation for pressure transmitter P1 - P2 distance Operation Display Manual inputs Data items Page 4 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

5 Table of contents 4 Vapour pressure (P3) measurement Introduction into vapour pressure measurement Commissioning Selecting pressure dimension Gauge data Set-up and configuration of the pressure transmitter Zero calibration of the pressure transmitter Operation Display Manual input Data items Maintenance and troubleshooting Maintenance Troubleshooting HIMS Troubleshooting HTG Troubleshooting vapour pressure (P3) measurement Hydrostatic error request (item EH) Hydrostatic status request (item QF) HART device pointer (items VP and VV) Appendix A ASCII table Appendix B1 Assessment of distance LP for HIMS Appendix B2 Assessment of distance LP (and LS) for HTG Appendix C Local gravity constant (item LG) Appendix D Ambient air density (item RF) Appendix E Vapour density (items RG and RJ) Appendix F1 Define values for hydrostatic deformation (items IF and IL) for HIMS Appendix F2 Define values for hydrostatic deformation (items IF and IL) for HTG Appendix G SET-up and Configuration procedure for HART pressure transmitters with the HART Communicator model Appendix H Zero calibration of pressure transmitters Appendix J Related documents Index Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 5

6 Introduction 1 Introduction 1.1 HCU board The optional HCU board is used in Honeywell Enraf servo gauges 854 ATG, 854 XTG, 873 SmartRadar and Field Indicator 877 FDI to interface optional equipment as: spot temperature element; average temperature element; water bottom probe; pressure transmitters. and to provide for an analog level output. This option board has two HART channels: HART input 1, standard used for the Honeywell Enraf 762 VITO Interface; HART input 2, standard used for the connection of pressure transmitters for HIMS, HTG or vapour pressure measurement. Note 1: HTG: Hydrostatic Tank Gauging; only applicable with 877 FDI. HIMS is available with the level gauges (servo and radar). Vapour pressure measurement is mostly performed on pressurized vessels with the level gauges. Note 2: Standard, the 762 VITO Interface is connected to HART input 1 and pressure transmitters are connected to HART input 2 of the optional HCU board. It must be verified that the maximum values for current and power of the HCU option board HART input 2 circuit are not exceeding the maximum values of the connected HART pressure transmitters. If the values of HART input 2 circuit are too high, then connect the pressure transmitters to HART input 1 and the 762 VITO Interface to HART input 2 (only possible when HART input 1 is available). 1.2 ICU_HPI board The optional ICU_HPI board is used in Honeywell Enraf 973 SmartRadar LT, 971 SmartRadar LTi and 970 SmartRadar ATi to interface optional equipment as: spot temperature element; average temperature element; water bottom probe; pressure transmitters. Note: Analog level output with the 97x SmartRadar is provided by the optional ICU_HPO board. For a description of these functions, refer to section 1.1. The ICU_HPI board has the same input functions as the HCU board; the only difference is its shape, which makes it to fit in the 97x SmartRadar. Page 6 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

7 Introduction 1.3 Overview of functions The HCU / ICU_HPI option board has the following hardware channels: SPOT input: for spot temperature element (RTD) Pt100 HART input 1: for 762 VITO Interface HART input 2: for HART pressure transmitters and/or external water bottom probe 4-20 ma output: for analog level output (only with HCU option board) The hardware combinations, together with software emulations gives in total 8 different models according to the table below: Sales code for option Function with HCU and ICU_HPI option board Emulation mode B Spot temperature Pt100 TPU-2 / HSU C VITO temperature and/or water probe HPU J VITO temperature and/or water probe + HART device(s) HPU U Spot temperature + HART device(s) HSU V Analog level output MPU W Analog level output + VITO temperature and/or water probe HCU X Analog level output + VITO temperature probe MPU Y Analog level output + Spot temperature Pt100 + VITO temperature and/or water probe + HART device(s) HCU Notes: 1 Option codes: V, W and X are not available with the 970 / 971 / 973 SmartRadar types as the analog level output is provided by the ICU_HPO option board. 2 Please note that with option code Y in the 970 / 971 / 973 SmartRadar types, the analog level output is provided by the ICU_HPO option board. 3 Option code Y is not available in the 854 XTG servo gauge. 4 Option code U can only be available in the 854 XTG servo gauge without connection for 977 TSI Tank Side Indicator (in 854 ATG connection for 977 TSI is possible). 5 HART devices can be: - HART pressure transmitters for HIMS / HTG configuration or vapour pressure measurement; - HART water bottom sensor e.g. Side mounted water probe. 6 With sales code Y (all HCU functions), the spot temperature measurement is disabled if the VITO temperature (and water) probe is present. 1.4 HCU compatibility The HCU board can be used to replace an existing optional board in the 854, 873 and 877 gauges. However, it requires some checking if more boards in the instrument must be updated or external equipment must be replaced. The HCU board can be used to replace the following optional boards: HPU board (for average temperature measurement, restricted to MTT or VITO probes only) HSU board (for spot temperature measurement, restricted to Pt100 RTD s only) Note: Read carefully the installation guide of the HCU board before starting to replace the existing option board. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 7

8 Introduction Replacement or adding optional board in 854 ATG or 854 XTG servo gauges The HCU optional board requires an XPU-2 board in the 854 ATG and 854 XTG servo gauges. If there is no XPU-2 board installed, then the installed XPU (or XPU-1) board must be replaced by an XPU-2 board. Notes: 1 When the HCU board is used to replace an optional board with average temperature measurement, please note the following: The 863 MRT with 862 MIR or the 864 MTT with 862 MIT temperature connection cannot be maintained. The 864 MTT can be connected to the 762 VITO-MTT Interface for connection to the HCU board; The 863 MRT can be connected to the 762 VITO-MRT Interface for connection to the HCU board. 2 The optional data transmission channel on the XPU-2 (i.s. channel for 977 TSI or RS-232C/RS-485 channel) is only possible when backplane-2 is installed. Backplane-2 is standard installed in instruments 854 ATG with series number: and higher; 854 XTG with series number: and higher Replacement or adding optional board in 873 SmartRadar The HCU optional board can be installed in the 873 SmartRadar without any problem. Refer to Note 1 section Replacement or adding optional board in 877 FDI Field Display & Interface The HCU optional board can be installed in an 877 FDI Field Display & Interface when there is an XPU or XPU-1 board. However, be informed that water bottom measurement with the VITO probe or Side mounted water probe is not possible. If this function is required, then the installed XPU (or XPU-1) board must be replaced by an XPU-2 board. Refer to note 1 in section Notes: 1 Please be aware that an XPU-2 board in the 877 FDI does not have the ability to listen to the Enraf Fieldbus signals. Hence, the Indicator functionality is not available. It will then function as an HTG or Stand Alone temperature gauge. 2 The optional data transmission channel on the XPU-2 (i.s. channel for 977 TSI or RS-232C/RS-485 channel) is only possible when backplane-2 is installed. Backplane-2 is standard installed in indicators 877 FDI with series number: and higher. 1.5 Optional functions in this manual This instruction manual describes the optional functions for: HIMS (Hybrid Inventory Measurement) chapter 2 HTG (Hydrostatic Tank Gauging) chapter 3 Vapour pressure (P3) measurement chapter 4 The optional functions for temperature and water bottom measured are described in the instruction manual: VITO interface and average temperature (and water) probes for 854 servo, 97x SmartRadar and 877 FDI. Page 8 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

9 HIMS 2 HIMS 2.1 Introduction into HIMS The HIMS (Hybrid Inventory Management System) combines the direct mass measurement as used with HTG (Hydrostatic Tank Gauging) with the level gauge principle to one powerful system. All tank quantities as level, volume, mass, density, etc. can be measured and calculated. For level measurement can be used the Honeywell Enraf series 854 ATG / XTG servo gauge or the Honeywell Enraf series SmartRadar gauge. The HIMS option is also available with the 877 FDI (Field Display & Interface). Pressure transmitters communicating with the HART protocol can be used HIMS calculations The pressure transmitters P1 and P3 used with an HIMS system are of the differential type. That means one side (low pressure side) is open to atmosphere. P3 is not required for tanks which are free vented to atmosphere and with floating roof tanks. A temperature measuring device is optional and only required when standard volume and reference density is to be calculated. The pressure measured by P1 is the result of the static liquid head above P1 (height h) and the pressure in the vapour space, measured by P3. The liquid height above P1 is the level (l), measured by the level gauge, minus the distance LP. LP represents the distance between the tank zero point (datum plate) and the zero point of P1. The observed density is calculated as: Figure 2.1 Principle HIMS configuration where: P7 : (P1 - P3) + corr. [Pa] P1 : pressure of pressure transmitter P1 [Pa] P3 : pressure of pressure transmitter P3 [Pa] corr. : for corrections, refer to section LP : distance zero point tank to zero point pressure transmitter P1 [m] LG : local gravity acceleration [m/s 2 ] Level : measured level from level gauge [m] The measured level and (optionally) temperature, and the calculated observed density are transmitted to the tank gauging system. The tank gauging system (a Honeywell Enraf Entis Pro system, Honeywell Enraf CIUPlus or other host system) needs the Tank Capacity Table and optionally the ASTM table to calculate the Gross Observed Volume, Mass, and optionally the Gross Standard Volume and reference density. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 9

10 HIMS Corrections for ambient air and vapour density Ambient air density correction The pressure at the atmospheric side measured by pressure transmitter P1, compared to P3, is increased by the column of air over the distance (LM - LP). Refer to figure 2.1. That is compensated in the calculated pressure P7 by the term: (LM - LP) x RF x LG [Pa] where: LM : distance zero point tank to zero point pressure transmitter P3 [m] LP : distance zero point tank to zero point pressure transmitter P1 [m] RF : ambient air density [kg/m 3 ] LG : local gravity acceleration [m/s 2 ] The default value for the ambient air density (item RF) is set at kg/m 3 (floating point format). Vapour density correction The vapour space above the product in a fixed roof tank consists of a mixture from air and product vapour. The density of this vapour mixture in the tank is different from the density of the air outside the tank. That is compensated in the calculated pressure P7 by the term: (LM - Level) x RG x LG [Pa] where: LM : distance zero point tank to zero point pressure transmitter P3 [m] Level : measured level from level gauge [m] RG : vapour density [kg/m 3 ] LG : local gravity acceleration [m/s 2 ] The default value for the vapour density (item RG) is set at 1.25 kg/m 3 (floating point format). Pressure P7 The pressure difference (P1 - P3), compensated for ambient air density and vapour density (item P7) is calculated as: P7 = (P1 - P3) + (LM - LP) x RF x LG - (LM - Level) x RG x LG [Pa] Density in air With the default values used in items RF and RG, the observed density is the density in vacuum. If the density value is required as density in air, then item RF must be set to 0, and from item RG the value of the ambient air density must be subtracted. The table below summarizes the values for items RF and RG for density in vacuum and density in air. HIMS density: in vacuum in air ambient air density (item RF) kg/m 3 (default) 0 kg/m 3 vapour density (item RG) 1.25 kg/m 3 (default) (RG - ambient air density) Page 10 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

11 HIMS 2.2 Commissioning of HIMS system For information how to program items, refer to the instruction manual of the used level gauge or to the instruction manual of the 847 Portable Enraf Terminal. For connection of the pressure transmitters to the instrument, refer to the installation guide of the used level gauge Selecting pressure and density dimension When the pressure and/or density dimension has to be changed from default, all items with related formats have to be changed and the values must be converted to the new dimension. Note: When the instrument is equipped with the XPU-2 board, then all dimension depended items will be automatically changed and the values will be automatically converted. Item Name Description W2= Protection level 2 Enter protection level 2 PI= Pressure dimension Selects the pressure dimension and converts the format. This item contains one character, which can be: P : Pa; format: sign X X X X X X separator X K : kpa; format: sign X X X X separator X X X I : psi; format: sign X X separator X X X X X S : psi; format: sign X X X separator X X X X Default set on: P [Pa] DI= Density dimension Selects the density dimension and converts the format. This item contains one character, which can be: K : kg/m 3 ; format: sign X X X X X separator X X A : API; format: sign X X X X separator X X X L : lbs/ft 3 ; format: sign X X X separator X X X X Default set on: K [kg/m 3 ]..= format depended items Not required with XPU-2 board. Program all pressure depended and/or density depended items to the new dimension. Refer to the table below for an overview of these items. EX Exit Exit protection level. Items from which the format depends on the pressure dimension (item PI) 29 M1 O2 H1 M2 O3 H2 M3 P0 H3 O1 PH Items from which the format depends on the density dimension (item DI) 28 HD DD DL DU Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 11

12 HIMS Tank and gauge data Figure 2.2 HIMS tank data Item Name Description W2= Protection level 2 Enter protection level 2 LM= Distance P3 - tank zero Format according to item LD. This distance is used in tank gas correction and ambient air density correction. If pressure transmitter P3 is not installed, use a value equal to the upper reference point. Alternatively, use the value of item TT (with servo level gauges), or item PR (with SmartRadar gauges). LN= Minimum HIMS level Format according to item LD. Default, item LN is set to 3.5 metres. The distance LN can be lowered to approximately 2 metres. The purpose is of LN is as follows: If the level drops below the setting of LN, the last valid density will be stored and used as the density value, as lower levels gives inaccurate density results. LP= Distance P1 - tank zero Format according to item LD. The setting of item LP directly influences the density calculation. It therefore must be assessed accurately. Refer to Appendix B1 for some methods to assess this distance. Page 12 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

13 HIMS Continue: Item Name Description PA= Available pressure transmitters LG= Local gravity RF= Ambient air density RG= Tank gas density HT= HIMS / HTG selection DL= Density lower limit DU= Density upper limit HD= Density alarm hysteresis Three characters; 123, or a - for the pressure transmitter which is not installed. For HIMS, item PA can be: 1-3 : Pressure transmitters P1 and P3 are installed; or : Pressure transmitter P1 is installed. Standard floating point format; units: m/s 2. Item LG must be set to the local gravity constant. Appendix C gives information about the local gravity constant. Standard floating point format; units: kg/m 3. Default, RF is set to E+01. Refer to Appendix D for more information about the ambient air density. Standard floating point format; units: kg/m 3. Default RG is set to E+01. Refer to Appendix E for more information about the vapour density. One character; either I (for HIMS) or T (for HTG). Check if item HT is set to I; if not change it. Format according to item DI. Low density alarm set point. Default value: [kg/m 3 ]. Format according to item DI. High density alarm set point. Default value: [kg/m 3 ]. Format according to item DI. Hysteresis around the density lower and density upper limits (items DL and DU). Default value: [kg/m 3 ]. M1= Minimum trip pressure P1 Format according to item PI. Sets a minimum trip pressure for pressure transmitter P1. Default value: [Pa]. M3= Minimum trip pressure P3 Format according to item PI. Sets a minimum trip pressure for pressure transmitter P3. Default value: [Pa]. H1= Maximum trip pressure P1 Format according to item PI. Sets a maximum trip pressure for pressure transmitter P1. Default value: [Pa]. H3= Maximum trip pressure P3 Format according to item PI. Sets a maximum trip pressure for pressure transmitter P3. Default value: [Pa]. PH= Pressure alarm hysteresis Format according to item PI. Hysteresis around the minimum and maximum trip pressures (items M1, M3, H1 and H3). Default value: [Pa]. EX Exit Exit protection level. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 13

14 HIMS Set-up and configuration of the pressure transmitters For the Set-up and Configuration of the pressure transmitters with the HART Communicator refer to Appendix G Zero calibration of the pressure transmitters For the zero calibration procedure of the pressure transmitters, refer to Appendix H Compensation for pressure transmitter P1 position The tank shell will bulge due to the hydrostatic pressure caused by the liquid stored in the tank. This can have an influence on the position of pressure transmitter P1 (refer to figure 2.3). The amount of movement of pressure transmitter P1 depends on the height of P1 above the bottom, the structure of the tank shell and the density of the product. In many cases, pressure transmitter P1 is located as low as possible to the tank bottom and the influence of tank shell bulging is negligible. However, in those cases where the influence is present, items IF and IL can be used to compensate for the position of pressure transmitter P1. Item IF (hydrostatic deformation factor) decreases distance LP for (IF) mm/m level above the level IL (hydrostatic deformation level). In formula: Figure 2.3 Tank shell bulging LP comp. = LP progr. - (Level - IL) x IF [m] where: LP comp. : LP compensated for hydrostatic tank deformation [m] LP progr. : the programmed value for LP [m] Level : measured level from level gauge [m] IL : hydrostatic deformation level (item IL) [m] IF : hydrostatic deformation factor (item IF) [mm/m] Item Name Description W2= Protection level 2 Enter protection level 2 IF= Hydrostatic deformation factor Standard floating point format; units: mm/m. Default value: E+00. When left at the default value, the hydrostatic deformation compensation is disabled. Refer to Appendix F1 for information how to obtain a correct setting for item IF. IL= Hydrostatic deformation level Format according to item LD. Default value: [m]. Item IL contains the level value above the hydrostatic deformation compensation becomes effective. Refer to Appendix F1 how to obtain a correct setting for item IL. EX Exit Exit protection level. Page 14 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

15 HIMS 2.3 Operation Display For operation of the display and the information on it, refer to the instruction manual of the applicable level gauge (or 877 FDI). Below, only an overview is given which display formats give information about the pressure and density measurement. Display format E F H Displayed information HIMS density Pressure P1 Pressure P Manual inputs For two quantities the operator can give a manual input by means of the PET (Portable Enraf Terminal), which are not protected by protection level 1 or 2. These quantities are: Item Name Description RJ= Manual tank gas density Standard floating point format; units: kg/m 3. The value must be preceded by one status character: V : Valid manual tank gas density I : Invalid manual tank gas density The tank gas density is used in the same way as with item RG. If the status of the manual tank gas density is valid (V), then the manual tank gas density (item RJ) is used. If the status of the manual tank gas density is invalid (I), then the value of item RG is used as tank gas density. P0= Manual pressure P3 Format according to item PI. The value must be preceded by one status character: V : Valid manual vapour pressure I : Invalid manual vapour pressure If there is no P3 pressure transmitter installed, and the vapour pressure can be assumed constant, a manual vapour pressure value can be entered. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 15

16 HIMS Data items Below, a summary is given of available data items. They contain measured and calculated data, verification data and error data. The verification data can be used to check the results of certain steps in the measuring sequence. The hydrostatic status indicates the validity of the measured / calculated data. The diagnostic data provides low level error information about the pressure measurement and density calculation. There is only one operational command with HIMS. Item P1 P3 P4 P7 DQ QQ N1 N3 Q1 Q3 QF Description Measured / calculated data Measured pressure of pressure transmitter P1 Measured pressure of pressure transmitter P3 P1 minus P3 (P1 - P3) compensated for ambient air density and vapour density Calculated HIMS density (preceded by 5 status characters of item QF) Abbreviated HIMS density (preceded by 1 status character) Serial number of pressure transmitter P1 Serial number of pressure transmitter P3 Temperature of pressure transmitter P1 (if available) Temperature of pressure transmitter P3 (if available) Hydrostatic status request (refer to section 5.6) VV Verification data Refer to description at section 5.7 EH FH H0 HE Diagnostic data Error HCU / ICU_HPI request (refer to section 5.5) Fatal HCU / ICU_HPI errors Last fatal HCU / ICU_HPI error HART communication errors Operational command: SR Stop HART request (used with HART communicator). Page 16 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

17 HTG 3 HTG 3.1 Introduction into HTG An HTG (Hydrostatic Tank Gauge) system measures the tank quantities by means of pressure transmitters. Depending on the configuration, one to three pressure transmitters are required. The pressure transmitters, communicating with the HART protocol, are connected to an 877 FDI (Field Display & Interface). Unlike level based tank gauges, as servo or radar, the HTG system is a direct mass measurement system. One pressure transmitter (P1), located at a shell nozzle near the bottom, is used to measure the liquid head. A second pressure transmitter (P2) is located approximately 2 to 2.5 metres (6 to 8 feet) above P1. If there exists a pressure in the vapour space, the vapour pressure must be measured with a separate pressure transmitter (P3). P3 is not required on a floating roof tank, or with a free vented cone roof tank HTG calculations The pressure transmitters used with an HTG system are of the differential type. That means one side (low pressure side) is open to atmosphere. A temperature measuring device is optional and only required when standard volume and reference density is to be calculated. The principle HTG formulas for level and observed density are: Observed density is calculated as: Level is calculated as: where: P1 : pressure of pressure transmitter P1 [Pa] Figure 3.1 Principle HTG configuration P2 : pressure of pressure transmitter P2 [Pa] P3 : pressure of pressure transmitter P3 [Pa] LG : local gravity acceleration [m/s 2 ] LS : distance zero point pressure transmitter P1 to P2 [m] LP : distance zero point pressure transmitter P1 to zero point tank [m] The calculated level and observed density and (optional) measured temperature are transmitted to the tank gauging system. The tank gauging system (an Honeywell Enraf Entis system, Honeywell Enraf CIUPlus or other host system) needs the Tank Capacity Table and (optionally) the ASTM table to calculate the Mass, Gross Observed Volume, and optionally the Gross Standard Volume and reference density. When the product density is known and does not change, pressure transmitter P2 is not required. The density will be a manual input value, from which the level can be calculated by: Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 17

18 HTG Volume and Mass calculations The standard HTG mass and volume calculations are: where: Vol. heel : Volume below the zero point of pressure transmitter P1 [m 3 ] Area eq. : Equivalent area over the (calculated) tank level [m 2 ] Honeywell Enraf transmits the calculated HTG level and observed density values to the tank gauging system (Entis, CIUPlus or other host system). In the tank gauging system the Gross Observed Volume is obtained from the level value via the tank capacity table. Then Mass is calculated as: Mass = Gross Observed Volume x Dens. obs. This is equivalent to the standard HTG mass calculation as is shown in the following conversion equations: Mass = Gross Observed Volume x Dens. obs. Mass = (Level x Area eq. ) x Dens. obs. Mass = (Level LP) x Area eq. x Dens. obs. + LP x Area eq. x Dens. obs. substitute of HTG level and density formulas gives: the above formula can be reduced to: which is the standard HTG mass formula. Page 18 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

19 HTG Corrections for ambient air and vapour density Ambient air density The pressure at the atmospheric side measured by pressure transmitter P1, compared to P2 and to P3, is increased by the column of air over respectively the distances LS and (LM - LP). Refer to figure 2.1. That is compensated in the calculated pressures P7 and P8 by the terms: (LM - LP) x RF x LG [Pa] for P7 (P1 - P3) LS x RF x LG [Pa] for P8 (P1 - P2) where: LM : distance zero point pressure transmitter P3 to zero point tank [m] LP : distance zero point pressure transmitter P1 to zero point tank [m] LS : RF : LG : distance zero point pressure transmitter P1 ambient air density [kg/m 3 ] local gravity acceleration [m/s 2 ] to P2 The default value for the ambient air density (item RF) is set at: kg/m 3 (floating point format). [m] Vapour density correction The vapour space above the product in a fixed roof tank consists of a mixture from air and product vapour. The density of this vapour mixture in the tank is different from the density of the air outside the tank. That is compensated in the calculated pressure P7 by the term: (LM - Level) x RG x LG [Pa] where: LM : distance zero point pressure transmitter P3 to zero point tank [m] Level : calculated HTG level (item HQ) [m] RG : vapour density [kg/m 3 ] LG : local gravity acceleration [m/s 2 ] The default value for the vapour density (item RG) is set at: 1.25 kg/m 3 (floating point format). Pressures P7 and P8 The pressure differences (P1 - P3) and (P1 - P2), compensated for ambient air density and vapour density, are: P7 = (P1 - P3) + (LM - LP) x RF x LG - (LM - Level) x RG x LG P8 = (P1 - P2) + LS x RF x LG [Pa] [Pa] Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 19

20 HTG Density calculation The calculated density, corrected for ambient air density (item DQ) will then become: Level calculation The calculated level, corrected for ambient air density and vapour density (item HQ), becomes: Item HQ is non-explicit. However, after conversion the level (item HQ) can directly be obtained: Density in air With the default values used in items RF and RG, the observed density is the density in vacuum. If the density value is required as density in air, then item RF must be set to 0, and from item RG the value of the ambient air density must be subtracted. The table below summarizes the values for items RF and RG for density in vacuum and density in air. HTG Density in vacuum in air Ambient air density (item RF) kg/m 3 (default) 0 kg/m 3 Vapour density (item RG) 1.25 kg/m 3 (default) (RG ambient air density) Page 20 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

21 HTG 3.2 Commissioning For information how to program items, refer to the instruction manual 877 FDI or to the instruction manual of the 847 Portable Enraf Terminal. It is assumed that the basic settings for the 877 FDI are already programmed, according to the instruction manual 877 FDI. For connection of the pressure transmitters to the instrument, refer to the installation guide 877 FDI Selecting pressure and density dimension When the pressure and/or density dimension has to be changed from default, all items with related formats have to be changed and the values must be converted to the new dimension. Note: When the 877 FDI is equipped with the XPU-2 board, then all dimension depended items will be automatically changed and the values will be automatically converted. Item Name Description W2= Protection level 2 Enter protection level 2 PI= Pressure dimension Selects the pressure dimension and converts the format. This item contains one character, which can be: P : Pa; format: sign X X X X X X separator X K : kpa; format: sign X X X X separator X X X I : psi; format: sign X X separator X X X X X S : psi; format: sign X X X separator X X X X Default set on: P [Pa] DI= Density dimension Selects the density dimension and converts the format. This item contains one character, which can be: K : kg/m 3 ; format: sign X X X X X separator X X A : API; format: sign X X X X separator X X X L : lbs/ft 3 ; format: sign X X X separator X X X X Default set on: K [kg/m 3 ]..= format depended items Not required with XPU-2 board. Program all pressure depended and/or density depended items to the new dimension. Refer to the table below for an overview of these items. EX Exit Exit protection level. Items from which the format depends on the pressure dimension (item PI) 29 M1 O2 H1 M2 O3 H2 M3 P0 H3 O1 PH Items from which the format depends on the density dimension (item DI) 28 HD DD DL DU Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 21

22 HTG Tank and gauge data P3 AH P2 LM HH HA AH P1 LS LN LA LL Tank zero (datum plate) LP Figure 3.2 HTG tank data Item Name Description W2= Protection level 2 Enter protection level 2 LM= Distance P3 - tank zero Format according to item LD. This distance is used in tank gas correction and ambient air density correction. If pressure transmitter P3 is not installed, use a value equal to the upper reference point. LN= Minimum HTG level Format according to item LD. Default, item LN is set to 3.5 metres. The distance LN can be lowered to a level which is approximately 0.5 m (20") above the pressure transmitter P2. The purpose is of LN is as follows: If the level drops below the setting of LN, the last valid density will be stored and used as the density value. This is, because as the level drops below P2, density cannot be calculated anymore. LP= Distance P1 - tank zero LS= Distance P1 - P2 Format according to item LD. The setting of item LP influences the level and hence the volume calculation. It therefore must be assessed accurately. Refer to Appendix B2 for some methods to assess this distance. Format according to item LD. The distance between pressure transmitters P1 and P2 (item LS) is used in the level and density calculation. It can be directly measured by means of a measuring tape from flange to flange, or from the zero marks on both pressure transmitters. Refer to Appendix B2 for some other methods to assess this distance. Page 22 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

23 HTG Continue: Item Name Description PA= Available pressure transmitters LG= Local gravity RF= Ambient air density RG= Tank gas density HT= HIMS / HTG selection OB= Optional board selection Three characters; 123, or a - for the pressure transmitter which is not installed. For example, item PA can be set to: 123 : Pressure transmitters P1, P2 and P3 are installed; or 12 - : Pressure transmitters P1 and P2 are installed, etc. Standard floating point format; units: m/s 2. Item LG must be set to the local gravity constant. Appendix C gives information about the local gravity constant. Standard floating point format; units: kg/m 3. Default, RF is set to E+01. Refer to Appendix D for more information about the ambient air density. Standard floating point format; units: kg/m 3. Default RG is set to E+01. Refer to Appendix E for more information about the vapour density. One character; either I (for HIMS) or T (for HTG). Item HT must be set to: T. Three characters; selects the optional board. Must be set to: HPU for the optional HCU and ICU_HPI boards. IM= Indicator mode One character; selects the indicator mode of the 877 FDI. For HTG mode, item IM must be set to: H. DL= Density lower limit DU= Density upper limit HD= Density alarm hysteresis Format according to item DI. Low density alarm set point. Default value: [kg/m 3 ]. *) Format according to item DI. High density alarm set point. Default value: [kg/m 3 ]. *) Format according to item DI. Hysteresis around the density lower and density upper limits (items DL and DU). Default value: [kg/m 3 ]. M1= Minimum trip pressure P1 Format according to item PI. Sets a minimum trip pressure for pressure transmitter P1. Default value: [Pa]. M2= Minimum trip pressure P2 Format according to item PI. Sets a minimum trip pressure for pressure transmitter P2. Default value: [Pa]. M3= Minimum trip pressure P3 Format according to item PI. Sets a minimum trip pressure for pressure transmitter P3. Default value: [Pa]. *) Do enter a good estimate for the density upper limit (item DU) and density lower limit (item DL). These values are also used in the level calculation (and checking) when the tank is filled after a complete tank discharge whereby the level dropped below the P2 (and P1) pressure transmitter(s). Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 23

24 HTG Continue: Item Name Description H1= Maximum trip pressure P1 Format according to item PI. Sets a maximum trip pressure for pressure transmitter P1. Default value: [Pa]. H2= Maximum trip pressure P2 Format according to item PI. Sets a maximum trip pressure for pressure transmitter P2. Default value: [Pa]. H3= Maximum trip pressure P3 Format according to item PI. Sets a maximum trip pressure for pressure transmitter P3. Default value: [Pa]. PH= Pressure alarm hysteresis LU= Level status conversion Format according to item PI. Hysteresis around the minimum and maximum trip pressures (items M1, M2, M3, H1, H2 and H3). Default value: [Pa]. One character; default:? The character, specified in item LU, is used in the level status byte of the level record to the host to indicate a reduc level accuracy condition. Most Honeywell Enraf tank gauging systems accept the? character as reduced accuracy status. With the following conditions, the contents of item LU is placed in the level status: manual or last valid P3 used; manual or last valid density used; manual gas density used; level below minimum HTG (item LN). EX Exit Exit protection level Alarm settings Refer to figure 3.2. The high level alarm (HA) and low level alarm (LA) conditions are transmitted in the level alarm byte of the level record to the host. Item Name Description W1= Protection level 1 Enter protection level 1 AH= Level alarm hysteresis HA= High level alarm HH= High high level alarm LA= Low level alarm LL= Low low level alarm Format according to item LD. Sets level alarm hysteresis. Default value: (m). Format according to item LD. High level alarm set point. Default value: (m). Format according to item LD. High high level alarm set point. Default value: (m). Format according to item LD. Low level alarm set point. Default value: (m). Format according to item LD. Low low level alarm set point. Default value: (m). EX Exit Exit protection level. Page 24 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

25 HTG Ullage readout When an ullage reading is required, the two items shown below must be changed. The ullage value is also transmitted to the host via the two wire Enraf field bus. The ullage, or outage, measurement is referred to a zero point at the tank top (upper reference point). The level, or innage, measurement is referred to a zero point at the tank bottom (datum plate). Refer to figure 3.3. Note: The high and low level alarms are innage alarms. Hence, a high alarm condition occurs when there is a low ullage and visa verse. Figure 3.3 Upper reference value Item Name Description W2= Protection level 2 Enter protection level 2. UR= Upper reference Format according to item LD. Distance UR represents the distance from the i zero point (datum plate) to the upper reference point at a dip hatch (or other point at the tank top). DE= Level type One character; either I or U. I : for innage measurement (default) U : for ullage measurement. EX Exit Exit protection level Set-up and configuration of the pressure transmitters For the Set-up and Configuration of the pressure transmitters with the HART Communicator refer to Appendix G. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 25

26 HTG Zero calibration of the pressure transmitters For the zero calibration procedure of the pressure transmitters, refer to Appendix H Compensation for pressure transmitter P1 - P2 distance The tank shell will bulge due to the hydrostatic pressure caused by the liquid stored in the tank. This can have an influence on the position of pressure transmitters P1 and P2 (refer to figure 3.4). The amount of movement depends on the position of P1 and P2, the length of the ar (nozzle - ball valve), the structure of the tank shell and the density of the product. In some cases, the influence of the tank shell bulging is negligible. However, in those cases where the influence is present, several methods can be followed to limited the influence. Mechanical solution: U-bend or rigid bar (refer to Installation Info 003) Compensation for the distance P1 - P2 (item LS). This section describes how to compensate for the distance LS. Figure 3.4 Tank shell bulging Item IF (hydrostatic deformation factor) increases distance LS for (IF) mm/m level above the level IL (hydrostatic deformation level). In formula: LS comp. = LS progr. + (Level - IL) x IF [m] where: LS comp. : LS compensated for hydrostatic tank deformation [m] LS progr. : the programmed value for LS [m] Level : calculated HTG level (item HQ) [m] IL : hydrostatic deformation level [m] IF : hydrostatic deformation factor [mm/m] Item Name Description W2= Protection level 2 Enter protection level 2 IF= Hydrostatic deformation factor Standard floating point format; units: mm/m. Default value: E+00. When left at the default value, the hydrostatic deformation compensation is disabled. Refer to Appendix F2 for information how to obtain a correct setting for item IF. IL= Hydrostatic deformation level Format according to item LD. Default value: [m]. Item IL contains the level value above which the hydrostatic deformation compensation becomes effective. Refer to Appendix F2 for information how to obtain a correct setting for item IL. EX Exit Exit protection level Page 26 Instruction manual HIMS / HTG and vapour pressure (P3) measurement

27 HTG 3.3 Operation Display For operation of the display and the information on it, refer to the instruction manual 877 FDI. Below, only an overview is given which display formats give information about the level, pressure and density measurement. Display format A B E F G H Displayed information HTG level and temperature HTG level and status HTG density Pressure P1 Pressure P2 Pressure P Manual inputs For three quantities the operator can give a manual input by means of the PET (Portable Enraf Terminal), which are not protected by protection level 1 or 2. These quantities are: Item Name Description RJ= Manual tank gas density Standard floating point format; units: kg/m 3. The value must be preceded by one status character: V : Valid manual tank gas density I : Invalid manual tank gas density The tank gas density is used in the same way as with item RG. If the status of the manual tank gas density is valid (V), then the manual tank gas density (item RJ) is used. If the status of the manual tank gas density is invalid (I), then the value of item RG is used as tank gas density. P0= Manual pressure P3 Format according to item PI. The value must be preceded by one status character: V : Valid manual vapour pressure I : Invalid manual vapour pressure If there is no P3 pressure transmitter installed, and the vapour pressure can be assumed constant, a manual vapour pressure value can be entered. DD= Manual density Format according to item DI. The value must be preceded by one status character: V : Valid manual density I : Invalid manual density If there is no P2 pressure transmitter installed, and the product density can be assumed constant, a manual product density must be given. Note: The manual density is the observed density. Instruction manual HIMS / HTG and vapour pressure (P3) measurement Page 27