OPERATIONAL SITUATION DURING DISCHARGE, LOOKING FOR OPINION REGARDING THIS MATTER

Good day to all my followers and readers, This time is to open a discussion reagring some typical operations that can occur during the discharge of a CBOB cargo, this a real scenario and some opinions differs regarding the way of how the line diplacements volumes has to be calculated. Here below a brief explanation of both scenarios: SCENARIO # 1: DISCHARGING CBOB PARCEL: The ship is arrives to Montreal for discharge two grades, CBOB and Premium Unleaded Gasoline (PUG), the 1st grade discharged was the CBOB, the shore line condition before discharge was as follows: a) A section related to the shore line was full of ULSD and its capacity was 20M3 approx, and other section of line was full of Regular Gasoline 30m3 approx, terminal decide to displace the two portion of the shore line using the product to be discharge by the ship in this way line will remain packed with CBOB. one 1st line displacement of 20m3 into a shore tank lets call it Tk-a, and a second shore line displacement of 30m3 into shore tank called "b" and after the two line displacement the full capacity of the shore line will be packed with CBOB. Then after completion of the line displacements the full discharge will go into TK-C. After completion of the discharge we had the following data to calculate our outturn figures: 1.- Open gauge and close gauge of TK-A (20m3 line displacement ULSD). 2.- Open gauge and close gauge of TK-B (30m3 line displacement RUG). 3.- Open Gauge and close gauge of TK-C (full CBOB discharge). Terminal has provide all the info regarding the product densities contained into all shore tanks for the open gauges and closing gauges. In this case the dilemma is the following: For shore quantity determination which densities we suppose to use to calculate the two shore line displacements? the ones provided by the terminal for the opening and closing gauges? or, we have to use the density corresponding to the product being discharge by the Vessel? (ship's density). I will wait for your commentaries regarding this matter, because I am in a big confusion with my supervisors regarding which densities to use and which don't, I am agree to use the densities provided by the terminal rather the ship's densities. I will wait for your commentaries regarding this matter. Have a nice weekend. Abelardo Eijesser

VESSEL EXPERIENCE FACTOR

The purpose of this bulletin is to clarify the position of IFIA member companies regarding the use and application of VEFs (Vessel Experience Factors). IFIA member companies are frequently asked to apply VEFs to vessel figures for the purpose of Custody Transfer where measurements determined by shore tank or meter are not available. Following the first issue of this bulletin in March 2002 the new standard, API MPMS Chapter 17.9/EI HM 49 Vessel Experience Factor (VEF) was issued in November 2005, “the Standard”. Appendix C in API MPMS Chapter 17.1 was withdrawn in March 2008. The VEF is primarily a loss control tool to help assess the validity of quantities derived from shore side (tanks, meters, etc.), off-shore installations or from other vessels. It should be recognized that quantities derived using vessel figures and the VEF will never have the measurement rigor of those from traditional static shore tank or meter measurements. For these reasons the Standard states that VEF adjusted vessel figures may be used for custody transfer where traditional measurements are either "not available, or are known to be inadequate". Although not well defined, "known to be inadequate" implies a general acceptance by all parties that due to poor design or obvious malfunction a shore tank or meter measurement cannot be relied upon. While in many situations when traditional measurements are questioned, a VEF adjusted vessel quantity may be the only available alternate measurement, the lack of statistics for precision and uncertainty cannot be overcome. Therefore, in these situations, it should not be automatically assumed that VEF adjusted vessel figures will provide any greater accuracy than the traditional measurements which they might replace. Limitations of the Vessel Experience Factor There are a number of factors which limit the overall accuracy of quantity calculations based on application of a VEF to vessel measurements. These factors are recognized in the Standard but a number of issues remain: • The voyage data used to compile a VEF must, by necessity, come from information supplied by the vessel. The inspector is rarely able to verify the accuracy of this data. • Most vessels only maintain records of load port data. Therefore, most vessel experience factors are load port experience factors (VEFL), even though they are frequently applied to discharge measurements. The Standard requires that data necessary for calculation of both load and discharge VEFs should be maintained by vessels. As vessels are commonly not aware of the shore outturn this data is not normally available. Data and information may be available from other reliable sources but not necessarily in sequential order. • Barge towing companies often do not maintain load or discharge records. Data may be available from other reliable sources, and which would include inspection companies and/or oil companies, but, again, not necessarily in sequential order. • There is considerable debate about whether VEFs calculated from “full” cargoes should be applied to part cargoes. The Standard allows for development of partial VEFs for “a specific set of compartments, or amount less than 75% of a vessel capacity”. However, this requires regular operation of the vessel in the same condition and it is extremely rare for there to be sufficient data to compile a partial VEF. The Standard states “if data to determine a partial cargo VEF is not available it is recommended to apply the full cargo VEF to each partial cargo”. Although the recommendation is clear the application of VEFs to part cargoes remains a contentious issue. As a consequence of the known limitations, the use of vessels figures adjusted by VEF to determine a Custody Transfer quantity (Bill of Lading or Outturn) is a commercial decision and can only be made with the agreement of the interested parties. This is clearly noted in the Standard. However it should be recognized that some regulatory authorities impose the use of a “correction” factor to vessel measurements that is not in keeping with the Standard and outside the control of inspection companies and their principals. Application of the Vessel Experience Factor Noting the above, it is recommended that IFIA member companies should calculate Custody Transfer figures by applying a VEF to vessel measurements as follows: • In accordance with the Standard, vessel experience factors will be applied for purposes of determining Custody Transfer quantities only “when agreed by interested parties”. • A full-vessel VEF will only be used for partial cargoes, as recommended in the Standard, where i) a partial VEF is not available or ii) the interested parties instruct that a full-vessel VEF is to be applied. • When data to determine a discharge VEF (VEFD) in accordance with the Standard is not available the Standard states that “a VEFL may be used”. However, in these circumstances, IFIA member companies may, with agreement of all interested parties, use data from other reliable sources to calculate a discharge VEF. Such data may not be sequential. • Where no agreement is obtained from interested parties with regard to application of a VEF for purposes of determining a Custody Transfer quantity, IFIA member companies should issue vessel figures with no factor applied.

FAME CONTAMINATION IN AVIATION FUEL

With increased levels of FAME being allowed in the EN590 Gas Oil (#2 Diesel) specification, the presence and concentration of FAME components in these cargoes may not be known by the vessel. This can create a major problem if a subsequent cargo is Aviation Fuel. Current Jet Fuel specifications have a very low tolerance to FAME and, although not currently reflected in specifications, AVGAS is also critical with regard to FAME as noted in the Energy Institute publication HM50 Guidelines for the cleaning of tanks and lines for marine tank vessels carrying petroleum or refined products. (HM50) Companies are sometimes asked to inspect ships tanks for cleanliness prior to receipt of cargo and to issue a respective Tank Inspection document. With increasing environmental restrictions, many of these inspections must be performed from deck level only as the tanks remain under inert gas. Any retained cargo must be determined by manual gauging and sampling through vapour control valves. It is therefore necessary to rely heavily on information provided by the vessel as to previous cargoes and tank cleaning methods. While IFIA members can review records of previous cargoes and tank cleaning methods they cannot attest to the accuracy of information provided by the vessel and clearly this may be critical in relation to FAME contamination of Aviation Fuel. IFIA members should report the conditions under which tank cleanliness and/or OBQ is determined and note where information is provided by the vessel. There is an inherent problem in obtaining uncontaminated samples from cargoes which follow Bio diesels as FAME has a tendency to adhere to internal surfaces. This may lead to increased concentrations at sampling points, as they are difficult to clean. HM50 states under section 2.12.7 that the cleaning regime employed by the vessel should include sampling equipment, stand pipes and stilling wells. However, the Inspector normally has to rely on cleaning information provided by the vessel and cannot verify whether this operation has been carried out. When a previous cargo has contained FAME and samples are drawn through the vessel sampling system their integrity may be in doubt due to the inherent difficulties in removing FAME residues from sampling fittings on the vessel. Therefore, in cases where analysis of samples obtained via closed or restricted systems indicates that FAME limits have been exceeded in a following cargo, it is recommended principals are advised accordingly and arrangements are made to take additional samples under open sampling conditions to confirm the results. The responsibility for cleanliness and suitability of the vessel rests with the vessel and its charterer. It is recommended that charterers confirm whether FAME has been present in previous cargoes and ensure that appropriate cleaning procedures are adopted prior to considering the vessel for the carriage of Aviation Fuel. Where part cargoes are involved charterers should treat any non-nominated cargo tanks carrying FAME or Bio diesel in the same manner as the nominated cargo tanks to avoid the possibility of cross-contamination. HM50 recommends three intermediate cargoes between FAME or Bio-diesel with a FAME content of 15% or above (B15) and an Aviation Fuel cargo, together with rigorous cleaning procedures for prior cargoes with lower FAME levels. IFIA members would consider the presence of FAME or Bio diesel in the three prior cargoes a reason to decline the vessel as fit for the loading of Aviation Fuel. Therefore, it is recommended that any charterer choosing to utilize such a vessel should inform the Inspector of its agreements with the vessel in advance of its arrival for inspection to reduce the chance of delay. There is significant evidence to show that shore loading systems can retain enough residual FAME to contaminate an Aviation Fuel cargo. It is therefore recommended that the party with contractual responsibility for the loading operation verify with the terminal that manifolds, loading arms and hoses have not been used to transfer FAME or Bio diesels for the last three operations. IFIA members are not in a position to obtain and verify such information and cannot accept any duty or responsibility in this regard.

Sampling & Testing Cargoes Blended On Board Marine Vessels

IFIA AC member companies are often assigned to inspect cargoes of petroleum that are blended on
board marine vessels at the loading port with the intention to meet certain contractual quality specifications of buyers and sellers. These cargoes are usually blended from two or more shore tanks, each containing a different component. The target composition of the final blend is typically based on a composite of shore tank samples, proportionally blended in a loading port laboratory. Shippers and receivers then rely on agitation of the cargo during proportional transfer into each of the vessel’s tanks to mix all of the components to contract quality specifications.
IFIA AC members’ experience has consistently indicated that, for many physical reasons, thorough
mixing of these components does not always occur as intended. Therefore, when the blended cargo
reaches the discharge port, manual samples taken from the vessel do not yield the same test results that were obtained at the loading port.

The American Petroleum Institute (API), in its Manual of Petroleum Measurement Standards (MPMS),
has recognized the difficulties of obtaining representative samples from cargoes that are not uniform throughout their profile and cross-section in a tank. API MPMS Chapter 8.1.8.3.3.1 states that “A running/all-levels sample is not necessarily representative (because of the difficulties of ensuring proportional filling of the sampler).” API MPMS Chapter 17.1.9.7 Note: states that “...on blended cargoes, vessel tank samples often will not be representative of proportional hand-blended samples that were tested at the port of loading.”
All work performed by IFIA AC member companies is subject to regulatory audit for conformance to
industry standards. Therefore, consistent with API and ASTM standards, IFIA AC member companies
have resolved to take the following position:
1. All manual samples, shore tank and vessel tank, will be taken in accordance with methods
prescribed in API MPMS, Chapter 8.1;
2. Laboratory analysis of all samples will be performed using standard industry test procedures,
usually as specified by the American Society for Testing and Materials (ASTM);
3. If analysis results indicate a possible problem with a cargo, blending, sampling and testing procedures will be carefully reviewed and findings promptly reported to the customer(s);
4. Test method precision limits (repeatability and reproducibility) will not be used to adjust the analysis results of any sample except as specifically authorized in ASTM method D3244.

CARGO RETENTION CLAUSES.

Cargo retention clauses provide a means for interested parties to account for the quantity of cargo
remaining in a vessel’s tank/s when discharge is concluded. This quantity is reported as ROB


[Remaining on Board] on completion of discharge.
Such clauses may require the inspector conducting the ROB inspection to offer, in addition to a record
of volume, a description to be applied to the ROB material.
In accordance with internationally accepted petroleum measurement documents produced by
API/ISO/EI (previously IP), the only standard terms which IFIA member companies are prepared to
use when describing ROB are “liquid”, “non-liquid” or “free water”. The use of any other terms for the characterization of ROB material, would be subject to a written definition agreed to in writing prior to the transaction, by all interested parties.
The requirement to operate under closed or restricted conditions is becoming more common and
under these conditions it is not possible to carry out direct visual examination of retained volumes in cargo tanks. This impairs the ability of the Inspector to describe the nature of any ROB, as the assessment is limited to small amounts of material which may be retrieved via vapour lock valves.
Where a description is made, particularly under these conditions, it may not necessarily be
representative of the total volume of ROB.
Irrespective of the operating conditions, when the terms, liquid, non-liquid and free water are used by Inspectors to describe ROB, it should be noted that they apply only:

1. To the material observed by the inspector
2. At the time of measurement
3. To the material at the point of measurement


ROB - Quantity remaining on board
Sum of liquid volume, including free water and non-liquid volume in cargo tanks just after discharge has been completed, excluding clingage, hydrocarbon vapours and the contents of associated lines and pump

US shore Tank Gauging Procedures and Customs Requirements

It has come to our attention that some Terminal procedures may still require that all measurement
activities are performed by Terminal personnel, and that third party inspectors are only allowed to
witness the measurements being performed.
While this may be acceptable on the part of those transacting product within the Terminal it is in direct
violation of US Customs Service requirements for licensing of commercial gaugers when involved in
importation of foreign cargoes, or in the movement of product within a ‘Foreign Trade Zone’ (FTZ).
With the proliferation of FTZ locations it is often difficult to establish whether a particular movement is
actually, or potentially, governed under US Customs regulations at the time an inspection is
conducted. In this respect, IFIA Members have adopted a protocol of treating all movements in an FTZ
as being US Customs related.
The US Customs requirements for ‘Commercial Gaugers’ (US Customs approved and bonded
Inspection Companies) are set forth in the Code of Federal Regulations at 19 CFR 151 and require
that all instruments used by Commercial Gaugers on behalf of US Customs are owned and calibrated
by the Commercial Gauger. It is also implicit in these regulations that Commercial Gauger personnel
physically perform the measurements. The obligations of a Customs-approved gauger as specified in
19CFR 151.13 are reproduced below.
(b) What are the obligations of a Customs-approved gauger? A commercial gauger approved
by Customs agrees to the following conditions and requirements:
(1) To comply with the requirements of part 151, Customs Regulations (19 CFR part 151),
and to conduct professional services in conformance with approved standards and
procedures, including procedures which may be required by the Commissioner of Customs
or the Executive Director;
(2) To have no interest in or other connection with any business or other activity which might
affect the unbiased performance of duties as a Customs-approved gauger. It is understood that
this does not prohibit acceptance of the usual fees for professional services;
(3) To maintain the ability, i.e., the instrumentation, equipment, qualified staff, facilities,
etc., to perform the services for which the gauger is approved, and allow the Executive
Director to evaluate that ability on a periodic basis by such means as on-site inspections,
demonstrations of gauging procedures, and reviews of submitted records;
(4) To retain those gauger records beyond the five-year record-retention period specified by
Customs as necessary to address matters concerned in pending litigation, and, if gauger
operations or approval cease, to contact Customs immediately regarding the disposition of
records retained;
US shore Tank Gauging Procedures and
Customs Requirements
Bulletin 03-01
Rev. 0

(5) To promptly investigate any circumstance which might affect the accuracy of work
performed as an approved gauger, to correct the situation immediately, and to notify both the
port director and the Executive Director of such matters, their consequences, and any
corrective action taken or that needs to be taken; and
(6) To immediately notify both the port director and the Executive Director of any attempt to
impede, influence, or coerce gauger personnel in the performance of their duties, or of any
decision to terminate gauger operations or approval status. Further, within 5 days of any
changes involving legal name, address, ownership, parent-subsidiary relationships, bond,
other offices or sites, or approved signatories to notify the Executive Director by certified
mail.
(c) What are the approved measurement procedures? Customs-approved gaugers must comply
with appropriate procedures published by such professional organizations as the American
Society for Testing and Materials (ASTM) and the American Petroleum Institute (API),
unless the Executive Director gives written permission to use an alternate method. Alternative
methods will be considered and approved on a case-by case basis.
It is the purpose of this Technical Bulletin to alert all parties to these transactions to the above
mentioned, and to the fact that IFIA Members must insist on their staff being allowed to perform the
physical measurements on any product movement with an actual or potential reporting requirement to
the US Customs Service. IFIA Members feel that once this issue is raised and understood there will be
full cooperation from those involved.

API MPMS Chapter 12, Section 1, Part 1 - Calculation of Static Petroleum Quantities Application From The Independent Inspector’s Perspective

Introduction:
The purpose of this technical bulletin is to provide information and commentary to IFIA Member Companies
and their clients.
In August, 1996 the American Petroleum Institute published Chapter 12,
Section 1, Part 1 of its Manual of
Petroleum Measurement Standards.
This document is titled, “Calculation
of Static Petroleum Quantities - Upright Cylindrical Tanks and Marine
Vessels”. While static calculations
have been sited in other prior API
MPMS documents, this is the first
time that they have been compiled
into one stand-alone document.
It might be assumed that as there has
been little significant change in static
petroleum measurement for many
years, this document would not have
much impact on the industry in general. However, this is not the case.
By the introduction of a new correction for the effect of temperature on
the steel shell of a tank [CTSh], this
standard has introduced a significant
change in how shore tank quantities
are calculated. While not the only
change required by this new standard,
it is the only one that involves a significant departure from previous
methods of calculation.
The New Correction
Upright cylindrical tanks have capacity tables based upon a specific tank
shell temperature. In the U.S.A. this
is usually 60°F. If the actual tank shell
temperature differs from the capacity table tank shell temperature, the
volumes extracted from that table will
need to be corrected, accordingly.
There are three items to be considered in making this correction; calculate the temperature of the tank
shell, determine the correction and
apply the correction.
Note: The new correction is only
applicable to upright cylindrical tanks. It does not apply to spherical, horizontal
cylindrical, square or rectangular tanks.
Calculate the Temperature of
the Tank Shell:
On a non-insulated tank this is done
by adding 7/8 [0.875] of the product
temperature to 1/8 [0.125] of the ambient air temperature.
For example, what is the tank shell
temperature if the temperature of the
product in the tank is 135°F and the
ambient air temperature is 88°F?
135 x 0.875 = 118.13
88 x 0.125 = 11.00
Tk Shell Temp = 129.13
Rounding to the nearest degree, the
tank shell temperature is recorded as
129°F.
The new standard does not provide
any instruction or advice on how or
where to take the ambient air temperature. IFIA Member Companies
recommend if the terminal has a
weather station, it should be used. Alternatively, leave a cup-case thermometer in a shady area for at least
fifteen minutes or use a portable electronic thermometer that has stabilized
to the surrounding air. Ambient air
temperatures should not be taken in
direct sunlight or enclosed areas.
On insulated tanks, the temperature
of the tank shell is considered to be
the same temperature as the product
in the tank.
Determine the Correction:
For mild steel tanks that were calculated using a tank shell temperature
of 60°F, this can be easily achieved
by entering the table in Appendix
“B1” of the new standard with the
temperature of the tank shell. The
factor can be read directly from the
table. In our example, the correction
for a tank shell temperature of 129°F
is 1.00086.
The “Appendix B” table of correction factors will apply in most situations; however, tanks that contain
heated products often have capacity
tables that were calculated using a
tank shell temperature other than
60°F. Alternately, tanks containing
specialty products such as corrosive
chemicals may be constructed from
something other than mild steel, such
as stainless steel. In this case it will
be necessary to use the formula found
in section 9.1.3 of the new standard,to calculate the correction factor. This
formula is:
CTSh = 1 + 2α∆T + α
2
∆T2
Where:
α = Linear coefficient of expansion
of the tank shell material [see
note 4]
∆T = Tank Shell Temperature (TSh)
minus Base Temperature (T
B
(
The Base Temperature (T
B
) is the
tank shell temperature for which the
capacity table volumes were calculated to. In the US, this is usually
60°F. The base temperature is usually stated on the capacity table. If
this is not the case, contact the company that generated the table. Some
capacity tables make reference to an
operating product temperature; this
should not be confused with the base
temperature, which is a tank shell
temperature. If the tank capacity
tables only reference a product operating temperature, it will be necessary to obtain the actual base tank
shell temperature that was used to
compute the capacity table volumes.
If the tank is insulated, it can be assumed that the base tank shell temperature is the same as the product
operating temperature. If the tank is
not insulated, the user should contact
the company that generated the capacity table to determine what base
tank shell temperature was used.
Some capacity tables state both the
operating product temperature and
the ambient air temperature. In this
case it is possible to calculate the tank
shell temperature; however, caution
must be exercised. Prior to the publication of API MPMS Chapter 2.2A,
in February 1995, the 7/8ths product
and 1/8th ambient temperature rule
for calculating tank shell temperatures did not apply. In earlier documents, tank shell temperature was
calculated by averaging (50/50) the
product temperature and the ambient
air temperature. If this sounds confusing, it is because it is confusing;
and, for this reason we recommend
contacting the company that produced the capacity table, just to be
on the safe side.
When calculating ∆T it is important
to maintain the arithmetic sign as this
value can be positive or negative and
must be applied as such in the CTSh
formula. Table B2 in Appendix B
lists linear expansion coefficients of
various metals.
How to apply the factor
The correction must be applied to the
table volume after it has been corrected for free
water; and, before any correction is made
for the floating
roof, if applicable. The
floating roof
correction is a
function of the
weight of the
roof and the
observed density [API Gravity] of the liquid it floats in;
therefore, it is
essential that
the CTSh is applied before
the floating
roof correction. This gives
the gross observed volume
[GOV] which
is corrected to
gross standard
volume [GSV] in the usual manner,
by applying the VCF.
TABLE VOLUME
GROSS
OBSERVED
VOLUME
GROSS
STANDARD
VOLUME
Volume Correct ion
Factor
[Multiply]
Minus Free
Water
Multiply by CTSh
Plus or Minus
Floating Roof Adjustment
History
As previously mentioned, API
MPMS Chapter 12, Section 1, Part 1
was published in August 1996 and
became effective when it was published. The introduction of the new
correction factor caused both confusion and consternation within the industry and its implementation by oil
companies and terminals has been
extremely varied. Some facilities
implemented it as soon as they could
reprogram their computers while others have yet to implement it.
The position of IFIA Member Companies to this new API standard was
the same as that of any API standard,
which is to implement it fully, unless
another procedure is agreed to by all
parties. It must be borne in mind,
however, that the U.S. Customs may
be one of those parties. When conducting an inspection that falls under the jurisdiction of the U.S. Customs [this includes all imports and
both foreign and domestic merchandise entering and exiting foreign trade
zones, bonded warehouses and
bonded tank farms] independent inspection companies are required to
carry out their inspection activities
according to the latest API standards,
as specified in 19CFR151.13(g)(2).
According to “Houston Service Port
Trade Bulletin 97-15” issued by the
U.S. Customs Service on April 8th,
1997, the Customs will begin man dating the requirements of API
MPMS Chapter 12.1.1 on June 1st,
1997.
No sooner had the industry gotten
used to the idea of a new calculation
standard, than it was discovered that
there were a number of errors in it.
Most of these were typographical in
nature or situations where a formula
had been modified but the associated
IFIA NAC - Technical Bulletin 97-1Page 3
text had not. However, the equation
that was used to calculate the tank
shell correction was taken from API
MPMS Chapter 2.2A and this was
subsequently found to be incorrect.
This also impacted most of the data
in “Appendix B” including Table B1.
On April 24th, 1997 an errata to API
MPMS Chapter 12.1.1 was issued.
Any references made herein to the
standard include any changes incorporated in the errata.
When working cargoes that are not
subject to Customs jurisdiction, the
application of this standard is a commercial issue and may be used or not,
subject to the agreement of the parties concerned.
Other Requirements
There are additional changes that this
standard imposes, which while not as
significant as the tank shell temperature correction, are nevertheless important.
One of the aims of API MPMS Chapter 12.1.1 was to produce a strict performance standard whereby different
individuals with the same base data
would arrive at exactly the same
number. While coming most of the
way to achieving this aim, it falls a
little short in the area of Volume Correction Factors [VCF], also referred
to as the Correction for the Temperature of the Liquid [CTL].
Table 1of API MPMS Chapter
12.1.1, which details the number of
significant digits (i.e. decimal places)
to use with various measurement
units, shows four decimal places for
the volume correction factor or CTL.
There is also a notation attached
which states that the standard for producing volume correction factors is
the computer subroutine implemenIFIA NAC - Technical Bulletin 97-1
tation procedures of API MPMS
Chapter 11.1, Volume X; which,
when fully implemented generates a
factor of five significant places. The
use of the printed table is acknowledged as a matter of practical necessity but the notation goes on to staate
that this only produces volume correction factors with four decimal
places, in addition to limiting table
entry discrimination levels. It further
states that in the event of a dispute,
the computer generated volume correction factor should take preference.
The procedure for calculating Net
Standard Volume [NSV] from Gross
Standard Volume [GSV] requires the
sediment and water percentage
[S&W] to be converted into a correction factor which is applied to the
GSV. If the volumetric value of the
S&W is required, the NSV is subtracted from the GSV.
There are many other requirements
of API MPMS Chapter 12.1.1 which
are not referenced in this technical
bulletin and it is in no way intended
for this to be a substitute for the standard. The Manual of Petroleum Measurement Standards, of which Chapter 12.1.1 is a part, is published by
the American Petroleum Institute,
1220 L Street Northwest, Washington D.C. 20005-4070. Copies of the
standard are available from API Publications and Distribution (202) 682-
8000, Order No. H12011.