BCG & BCP Configuration FAQs
Answers to common questions regarding Configuring Bulk Calculations – Gas (BCG) and – Petroleum (BCP) for LPG / NGL products on your systems
How are the two reading group indicators defined, that control the LPG vapor space calculations?
LPG calculations support two vapor space scenarios. For each scenario, one indicator is relevant.
Scenario A: You perform an opening and a closing dip measurement (e.g. for a loading process shore-to-ship) to determine the transferred mass of LPG (e.g. by using SAP Tank Management and implementing your delta calculation logic in a SAP Tank Management BAdI):
Summary: In this scenario, you perform two calculations (opening and closing dip calculation) with the “Apply vapor corr. (tank dip)” indicator set. The transferred mass is calculated by subtraction.
Our LPG conversion group does not allow entry of a test temperature to correct the LPG density to base. How can we solve this requirement?
Many of the MQCI LPG Q7** template conversion groups are configured such that the product base density (in vacuo) can be entered directly without a need to enter a second so-called test temperature to correct a test density to base. This is described in more detail in the BCP Reference Manual, Chapter 6.10.Example:
If required, you can easily extend your LPG reading group and add the test temperature (technical name OBSTSTMETT) and then also change the name of the input parameter OBSTSTDENS from base density to e.g. test density.
We do not require the hydrometer correction. Can we remove it from our conversion group configuration?
The hydrometer correction may only be required, if you enter an observed density that is determined with a glass hydrometer. If you utilize an ASTM D1250-04 implementation, you may simply remove the hydrometer function (and reading group parameter):
ASTM D1250-80 implementations contain a built-in (by measurement standard definition) hydrometer correction logic, which requires that you actively turn the correction off if not required – read note 000026 for all important details.
We enter pressure values for gas calculations. Are these values absolute or gauge pressure values?
QuantityWare BCS implementations for LPG/NGL, LNG and natural gas support both the data entry of absolute and gauge pressure values. The conversion group configuration can be made to support entry of either gauge or absolute pressure values – by adding dedicated MQCI pressure calculation functions to the conversion group function module sequence.
Read Note 000078 for additional details.
My customer requires ASTM Table 1 UoM conversion factors. What are the configuration steps?
For MQCI conversion groups, you simply activate the ASTM Table 1 conversion factors in the conversion group detail settings:
With the QuantityWare BCS templates, ASTM Table 1 conversion factors are delivered, which are accessible in your client 045 after activation of the relevant BC set. Read Note 000055 for all important additional configuration details.
We utilize an LPG conversion group with SAP Tank Management. Why is the vapor mass not considered for volume UoM?
Vapor space calculations are defined in measurement standard ISO 6578. The calculation simply adds the vapor mass (and vapor energy or weight) to the appropriate liquid mass, energy and weight quantity (in any given UoM). Volume quantities are not updated with the liquid volume quantity equivalent to the vapor mass and do contain the liquid product quantity value only (in any given volume UoM). Thus, it is important that the base UoM in the material master is either a mass, weight or energy UoM.
Read the working paper “LPG vapor space calculations” for all details.
My client wants to use MQCI conversion groups, where kg, lb, to, sto UoM are calculated as weights - is this possible?
Yes. The BCS template provides example conversion groups that are configured such that UoM of SAP dimension ID MASS are calculated as weights – which is the case for SAP QCI conversion groups if the air buoyancy indicator is set:
The LB value is the weight of the 10 000 gallon of product. The configuration to achieve this requires 2 (plus 1) steps:
You assign the SAP Dimension IDs for weight (and mass) DIMID.
You assign marker function /QTYW/MQCI_WEIGHT_MASS to the MQCI model function sequence.