ISO 7507-1:2003

SLOVENSKI STANDARD
SIST ISO 7507-1:2006
01-februar-2006
Nafta in tekoči naftni proizvodi – Umerjanje navpičnih valjastih rezervoarjev – 1.
del: »Strapping« metoda
Petroleum and liquid petroleum products -- Calibration of vertical cylindrical tanks -- Part
1: Strapping method
Pétrole et produits pétroliers liquides -- Jaugeage des réservoirs cylindriques verticaux --
Partie 1: Méthode par ceinturage
Ta slovenski standard je istoveten z: ISO 7507-1:2003
ICS:
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
SIST ISO 7507-1:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 7507-1:2006

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SIST ISO 7507-1:2006


INTERNATIONAL ISO
STANDARD 7507-1
Second edition
2003-12-15

Petroleum and liquid petroleum
products — Calibration of vertical
cylindrical tanks —
Part 1:
Strapping method
Pétrole et produits pétroliers liquides — Jaugeage des réservoirs
cylindriques verticaux —
Partie 1: Méthode par ceinturage




Reference number
ISO 7507-1:2003(E)
©
ISO 2003

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2003 — All rights reserved

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 Precautions. 5
5 Equipment. 6
6 General requirements. 7
7 Circumference measurements. 7
8 Other measurements on tank shell plates. 10
9 Deadwood. 10
10 Tank bottoms. 11
11 Measurement of tilt . 11
12 Floating-roof tanks. 11
13 Recalibration. 12
14 Computation of tank capacity tables — General rules . 12
15 Form of tank capacity tables . 13
16 Computation of open capacity . 13
17 Construction of final tables. 17
Annex A (normative) Specification for equipment used in strapping . 23
Annex B (informative) Recommendations for monitoring, checking and verification of tank
calibration and capacity table. 26
Annex C (informative) Tank calibration data and calculation sheet. 32
Annex D (informative) Tank calibration uncertainties . 36
Annex E (informative) Tank shell temperature determination . 47
Annex F (normative) Gauge tape temperature correction . 48
Annex G (informative) Expansion due to liquid head . 50
Annex H (normative) Expansion due to temperature . 58
Annex I (normative) Certificate of calibration. 61
Bibliography . 62


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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 7507-1 was prepared by Technical Committee ISO/TC 28, Petroleum products and
lubricants, Subcommittee SC 3, Static petroleum measurement.
This second edition cancels and replaces the first edition (ISO 7507-1:1993). It also cancels and replaces
ISO 7507-6:1997, the subject of which is now included in this part of ISO 7507.
ISO 7507 consists of the following parts, under the general title Petroleum and liquid petroleum products —
Calibration of vertical cylindrical tanks:
 Part 1: Strapping method
 Part 2: Optical-reference-line method
 Part 3: Optical-triangulation method
 Part 4: Internal electro-optical distance-ranging method
 Part 5: External electro-optical distance-ranging method
 Part 6: Recommendations for monitoring, checking and verification of tank calibration and capacity table
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Introduction
This part of ISO 7507 forms part of a series on tank calibration including the following:
ISO 7507-2:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 2: Optical-reference-line method
ISO 7507-3:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 3: Optical-triangulation method
ISO 7507-4:1995, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 4: Internal electro-optical distance-ranging method
ISO 7507-5:2000, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 5: External electro-optical distance-ranging method
ISO 7507-6:1997, Recommendations for monitoring, checking and verification of tank calibration and capacity
table
ISO 8311:1989, Refrigerated light hydrocarbon fluids — Calibration of membrane tanks and independent
prismatic tanks in ships — Physical measurement
ISO 9091-1:1991, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 1:
Stereo-photogrammetry
ISO 9091-2:1992, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 2:
Triangulation measurement
The strapping method for the calibration of vertical cylindrical tanks has been used for many years and is a
recognized method of determining the capacity of storage tanks from measurements of the circumference of a
tank at various heights. The strapping method is also often used to establish a reference circumference at a
selected height to use as a datum in other methods of tank calibration.

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SIST ISO 7507-1:2006

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SIST ISO 7507-1:2006
INTERNATIONAL STANDARD ISO 7507-1:2003(E)

Petroleum and liquid petroleum products — Calibration of
vertical cylindrical tanks —
Part 1:
Strapping method
1 Scope
1.1 This part of ISO 7507 specifies a method for the calibration of substantially vertical cylindrical tanks by
measuring the tank using a strapping tape.
1.2 This method is known as the “strapping method” and is suitable for use as a working method, a
reference method or a referee method.
NOTE For the reference method, the number of strappings required will be specified in the standard which refers to
this part of ISO 7507.
1.3 The operation of strapping, the corrections to be made and the calculations leading to the compilation of
the tank capacity table are described.
1.4 This method does not apply to abnormally deformed, e.g. dented or non-circular, tanks.
1.5 This method is suitable for tilted tanks with a deviation of up to 3 % from the vertical, provided that a
correction for the measured tilt is applied in the calculations.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 91-1:1992, Petroleum measurement tables — Part 1: Tables based on reference temperatures of 15 °C
and 60 °F
ISO 3675:1998, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Hydrometer method
ISO 4269:2001, Petroleum and liquid petroleum products — Tank calibration by liquid measurement —
Incremental method using volumetric meters
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3 Terms and definitions
For the purposes of this document and subsequent parts of ISO 7507, the following terms and definitions
apply.
3.1
argument
independent variable of a function
NOTE A table is entered with value(s) of the independent variable(s), the value(s) extracted from the table being
known as the dependent value(s).
3.2
bottom calibration
procedure to determine the quantity of liquid contained in a tank below the calibration datum-point
3.3
calibration
process of determining the capacity of a tank, or the partial capacities corresponding to different levels
3.4
capacity
total volume of a tank
3.5
capacity table
tank table
tank capacity table
table showing the capacities of, or volumes in, a tank corresponding to various liquid levels measured from a
stable reference point
3.6
course
one circumferential ring of plates in a tank
3.7
calibration datum-point
point used as the datum in the preparation of a calibration table
NOTE Course heights and the effective levels of deadwood are measured from this point, to which the bottom
calibration is also related.
3.8
deadwood
any tank fitting that affects the capacity of the tank
NOTE Deadwood is referred to as “positive deadwood” when the capacity of the fitting increases the effective
capacity of the tank, or “negative deadwood” when the volume of the fitting displaces liquid and reduces the effective
capacity.
3.9
dip
innage
depth of a liquid in a tank above the dipping datum-point
3.10
dip-hatch
gauge-hatch
opening in the top of a tank through which dipping and sampling operations are carried out
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.11
dip-point
point on the dip-plate which the dip-weight touches during gauging and from which the measurements of the
oil and water depths are taken
NOTE The dip-point usually corresponds to the datum-point, but when this is not so, the difference in level between
the datum-point and the dip-point has to be allowed for in the calibration table.
3.12
dip-plate
striking-plate positioned below the dip-hatch
NOTE The position of the dip-plate should not be affected by bottom or wall movements.
3.13
dip-tape
graduated steel tape used for measuring the depth of the oil or water in a tank, either directly by dipping or
indirectly by ullage
3.14
dip-weight
weight attached to a steel dip-tape, of sufficient mass to keep the tape taut and of such shape as to facilitate
the penetration of any sludge that might be present on the dip-point or the dip-plate
3.15
floating cover
screen
lightweight cover of either metal or plastics material designed to float on the surface of a liquid in a tank
NOTE The cover rests upon the liquid surface and is used to retard evaporation of volatile products in a tank.
3.16
floating-roof tank
tank in which the roof floats freely on the surface of the liquid contents, except at low levels when the weight of
the roof is taken through its supports by the tank bottom
3.17
function
when two variable quantities are interrelated, one quantity is said to be a function of the other
NOTE In the context of tank calibration, the volume of liquid contained in a tank is said to be a function of the dip or
of the ullage.
3.18
gauging
process of taking all the necessary measurements in a tank in order to determine the quantity of liquid that it
contains
3.19
interpolation
process of obtaining the value of a function corresponding to a value of the argument intermediate between
those given
3.20
Littlejohn grip
quick-release clamp that may be fitted around a strapping tape at any convenient position throughout its
length
NOTE A handle is attached to the Littlejohn grip so that the strapping tape can be pulled to the correct tension.
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.21
open capacity
calculated capacity of a tank or part of a tank before any allowance has been made for deadwood
3.22
reference height
vertical distance between the dip-point and the upper reference point
3.23
overall height
total external height from the top of the shell to the base of the tank (plate)
3.24
referee method
application of the strapping method of tank calibration to give a calibration of a tank for custody transfer
purposes or to provide a basis for assessing the accuracy of other methods of tank calibration
3.25
reference method
application of the strapping method of tank calibration to the measurement of a reference circumference for
use in other methods of tank calibration
NOTE An example of such a method is the optical-reference-line method (see ISO 7507-2).
3.26
reference point
a point to which measurements in either calibration or gauging are related
3.27
step-over
device used in strapping for measuring the distance apart, along the arc, of two points on a tank shell where it
is not possible to use a strapping tape directly because of an intervening obstruction, e.g. a protruding fitting
3.28
step-over constant
distance between the measuring points of a step-over as measured along the arc of the particular course of
the tank concerned
3.29
step-over correction
difference between the apparent distance between two points on a tank shell as measured by a strapping tape
passing over an obstruction and the true arc distance as measured by a step-over, i.e. the step-over constant
3.30
strapping tape
specially designed and calibrated steel measuring tape graduated in units of length and used for taking
circumferential measurements in tank calibration
3.31
strapping method
method of tank calibration in which the capacities are calculated from the measurement of the external
circumferences, due allowance being made for the thickness of the shell of the tank
3.32
tape positioner
guide sliding freely on the strapping tape, used to pull and hold it in the correct position for taking
measurements
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.33
tensioning handles
handles fastened to the strapping tape, used for pulling it into the correct position and applying tension
3.34
ullage
outage
capacity of a tank not occupied by the liquid
3.35
upper reference point
point clearly defined on the dip-hatch directly above the dip-point to indicate the position at which dipping or
ullaging shall be carried out
3.36
working method
application of the strapping method of tank calibration by a simplified procedure that may result in some loss
of accuracy and is unsuitable for assessing other methods
4 Precautions
4.1 Introduction
This clause outlines the precautions that are applicable when tanks are being calibrated. The precautions
necessary to ensure the safety of the operator are dealt with separately from those precautions which have to
be taken to ensure the necessary precision required in the calibration of tanks.
4.2 General precautions
4.2.1 The utmost care and attention to detail shall be exercised when calibrating storage tanks.
4.2.2 All measurements shall be carefully observed and recorded as read, and any corrections which are
required shall be recorded separately. If any unusual occurrences are noted during the operations, these
occurrences shall be documented and the calibration shall be repeated, if necessary.
4.2.3 If the tank is only slightly distorted, sufficient additional measurements shall be taken to allow
satisfactory calculation of its capacity table. If such additional measurements are required, the calibrator’s
notes shall include the reasons for the extra measurements.
It is also recommended that dimensioned sketches should be provided by the calibrator to show any
abnormality of the tank or the fittings that affect calibration.
NOTE Seriously distorted tanks are best calibrated using liquid calibration methods similar to the method described
in ISO 4269.
4.2.4 To ensure accuracy and repeatability of readings, lumps of paint, scale, etc., likely to interfere with
measurement, shall be removed or the position of the measuring equipment adjusted accordingly.
4.2.5 If drawings for the tank are available, all relevant measurements shall be compared with the
corresponding dimensions shown on the drawings. Any measurement which shows a significant discrepancy
as a result of this comparison shall be reported and, if necessary, repeated.
4.2.6 If the calibration of a tank is interrupted, it may be resumed at a later date provided that:
a) if there is a change of equipment or personnel, sufficient check measurements shall be made to ensure
that the results obtained prior to the change correspond within the tolerances given in this method;
b) all records of work done are complete and legible;
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
c) the liquid contents remain unchanged at substantially the same level;
d) the average liquid and atmospheric temperatures are within 10 °C of the average liquid and atmospheric
temperatures recorded during the earlier working period.
4.3 Safety precautions
4.3.1 The safety precautions given in 4.3.2 to 4.3.6 constitute good practice, but the list is not necessarily
comprehensive. It is recommended that the list should be read in conjunction with the appropriate sections of
any applicable safety code. The precautions shall be taken whenever they do not conflict with legislative
requirements, which shall always be followed.
4.3.2 All regulations covering entry into hazardous areas shall be rigorously observed.
4.3.3 If a tank being strapped contains a petroleum product, attention shall be paid to the normal safety
precautions which apply to such tanks.
4.3.4 Before a tank which has been in use is entered, a safe-entry certificate issued in accordance with
local or national regulations shall be obtained. All lines entering the tank shall be disconnected and blanked.
The national or local regulations regarding the entry into tanks which have contained leaded fuels shall be
meticulously observed.
4.3.5 Hand lamps shall be of a type approved for use in explosive atmospheres.
4.3.6 The safety of operating personnel shall be safeguarded by strict attention to the following.
a) Ladders shall be inspected before use, and extendable ladders used only within their safe operating
range. The footing for each ladder shall be level and firm, and all ladders shall be securely lashed in
position before being used.
b) When painters’ cradles or bo’suns’ chairs are used, blocks, falls, ropes, etc., shall be tested before
erection, and any item of questionable strength or condition shall be replaced. Every care shall be paid to
the securing of the equipment and its operational use.
c) If calibration cannot be carried out without the use of staging, properly constructed steel tube or timber
scaffolding shall be erected. Loose bricks, drums, boxes, etc., shall not be used to form staging.
d) Where appropriate, safety harnesses shall be worn by personnel working above ground level.
5 Equipment
5.1 Strapping tape, conforming to A.1. The tape shall be well greased before use.
5.2 Spring balance, conforming to A.2, for measuring the tension applied to the tape.
5.3 Step-over, conforming to A.3.
5.4 Tape positioners and cords, conforming to A.4, fitted to the strapping tape, and supplied with plaited
cords. Both upper and lower cords shall be long enough to cover the height of the tank.
5.5 Littlejohn grip, conforming to A.5, to hold the tape, without kinking, in order to facilitate application of
the necessary tension.
5.6 Apparatus for thickness measurement, either a steel rule of convenient length graduated throughout
its length in millimetres, with at least the first 10 mm subdivided into half-millimetres, and/or another device,
such as an electronic thickness gauge.
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
5.7 Dip-tape conforming to A.6, long enough to reach from the dipping reference point at the tank roof to
the dip-point on the tank bottom.
5.8 Dip-weight, conforming to A.7.
5.9 End-to-end rule, 1 m in length, with graduations in centimetres and millimetres, for measuring
deadwood, etc. If a wooden rule is used, it shall be fitted with a brass ferrule at each end and shall be free
from warp.
5.10 Ladders and staging: see 4.3.6 for safety precautions.
5.11 Density- and temperature-measuring apparatus, conforming to ISO 3675.
6 General requirements
NOTE If possible, measurements should be compared with the corresponding dimensions on the tank construction
drawings and the roundness of the tank should be ascertained.
6.1 Fill the tank to its normal working capacity at least once and allow to stand for at least 24 h prior to
calibration.
If the tank is calibrated with liquid in it, record the depth, temperature and density of the liquid at the time of
calibration. However, if the temperature of the wall surface can differ by more than 10 °C between the empty
part and the full part of the tank, the tank shall be either completely full or empty. Do not make transfers of
liquid during the calibration.
The ambient temperature before and after calibration should be recorded.
Obtain the required number of external circumference measurements, together with the subsidiary
measurements, where necessary, to correct for deviation of the strap due to obstructions, as described in 7.2.
NOTE Additional measurements required to enable a table of capacities to be prepared and the procedures to be
used in obtaining them are described in Clauses 8 to 12.
6.2 It is necessary to refer all tank dips to the dip-point, which may be in a different position from the
calibration datum-point, e.g. a point on the bottom angle, used for the purpose of tank calibration. Check that
the dip-plate has been securely mounted in a stable position so that it is not affected by movement of the tank
bottom or walls. Determine any difference in level between the dip-point and calibration datum-point, either by
normal surveying methods or by other suitable means, and record it.
6.3 Measure the height of the upper reference point above the dip-point using the dip-tape and dip-weight.
Record this reference height, to the nearest subdivision on the dip-tape, in the empty and the full conditions,
as appropriate.
7 Circumference measurements
7.1 Levels strapped
7.1.1 If the calibration is for referee purposes, measure the circumference by three or more strappings per
course, at approximately the following levels:
a) for riveted tanks:
1) 100 mm to 150 mm above the level of the top of the bottom angle of the tank, and 100 mm to
150 mm above the upper edge of each horizontal overlap between courses;
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
2) at the middle position of each course;
3) 100 mm to 150 mm below the lower edge of each horizontal overlap between courses and 100 mm
to 150 mm below the level of the lowest part of the top angle.
b) for welded tanks:
three or more levels as indicated in a), but the upper and lower levels shall be 270 mm to 330 mm from the
bottom angle, top angle or horizontal seams.
7.1.2 If the calibration is for the working method, the circumference may be measured, if preferred, by only
two strappings per course, taking one at each of the following levels:
 at about 1/5 to 1/4 of the course height or the ring height above the lower horizontal seam;
 at about 1/5 to 1/4 of the course height or the ring height below the upper horizontal seam.
7.1.3 If for any reason it is impracticable to take a strapping at the normal level, take a strapping as close to
this level as practicable, but not nearer the bottom or top angle or any seam than is specified in 7.1.1 a) or b).
Record in the strapper’s notes the level at which this circumference has been measured, with the reason for
abandoning the normal level.
If the tape is not in close contact with the surface of the tank throughout its whole path, apply a step-over as
in 7.5, so that a correction may be calculated to adjust the gross circumference for this effect.
7.2 Strapping procedure
7.2.1 Strap the tank by either of the methods described in 7.2.2 and 7.2.3
...

INTERNATIONAL ISO
STANDARD 7507-1
Second edition
2003-12-15

Petroleum and liquid petroleum
products — Calibration of vertical
cylindrical tanks —
Part 1:
Strapping method
Pétrole et produits pétroliers liquides — Jaugeage des réservoirs
cylindriques verticaux —
Partie 1: Méthode par ceinturage




Reference number
ISO 7507-1:2003(E)
©
ISO 2003

---------------------- Page: 1 ----------------------
ISO 7507-1:2003(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2003 — All rights reserved

---------------------- Page: 2 ----------------------
ISO 7507-1:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 Precautions. 5
5 Equipment. 6
6 General requirements. 7
7 Circumference measurements. 7
8 Other measurements on tank shell plates. 10
9 Deadwood. 10
10 Tank bottoms. 11
11 Measurement of tilt . 11
12 Floating-roof tanks. 11
13 Recalibration. 12
14 Computation of tank capacity tables — General rules . 12
15 Form of tank capacity tables . 13
16 Computation of open capacity . 13
17 Construction of final tables. 17
Annex A (normative) Specification for equipment used in strapping . 23
Annex B (informative) Recommendations for monitoring, checking and verification of tank
calibration and capacity table. 26
Annex C (informative) Tank calibration data and calculation sheet. 32
Annex D (informative) Tank calibration uncertainties . 36
Annex E (informative) Tank shell temperature determination . 47
Annex F (normative) Gauge tape temperature correction . 48
Annex G (informative) Expansion due to liquid head . 50
Annex H (normative) Expansion due to temperature . 58
Annex I (normative) Certificate of calibration. 61
Bibliography . 62


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ISO 7507-1:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 7507-1 was prepared by Technical Committee ISO/TC 28, Petroleum products and
lubricants, Subcommittee SC 3, Static petroleum measurement.
This second edition cancels and replaces the first edition (ISO 7507-1:1993). It also cancels and replaces
ISO 7507-6:1997, the subject of which is now included in this part of ISO 7507.
ISO 7507 consists of the following parts, under the general title Petroleum and liquid petroleum products —
Calibration of vertical cylindrical tanks:
 Part 1: Strapping method
 Part 2: Optical-reference-line method
 Part 3: Optical-triangulation method
 Part 4: Internal electro-optical distance-ranging method
 Part 5: External electro-optical distance-ranging method
 Part 6: Recommendations for monitoring, checking and verification of tank calibration and capacity table
iv © ISO 2003 — All rights reserved

---------------------- Page: 4 ----------------------
ISO 7507-1:2003(E)
Introduction
This part of ISO 7507 forms part of a series on tank calibration including the following:
ISO 7507-2:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 2: Optical-reference-line method
ISO 7507-3:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 3: Optical-triangulation method
ISO 7507-4:1995, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 4: Internal electro-optical distance-ranging method
ISO 7507-5:2000, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 5: External electro-optical distance-ranging method
ISO 7507-6:1997, Recommendations for monitoring, checking and verification of tank calibration and capacity
table
ISO 8311:1989, Refrigerated light hydrocarbon fluids — Calibration of membrane tanks and independent
prismatic tanks in ships — Physical measurement
ISO 9091-1:1991, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 1:
Stereo-photogrammetry
ISO 9091-2:1992, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 2:
Triangulation measurement
The strapping method for the calibration of vertical cylindrical tanks has been used for many years and is a
recognized method of determining the capacity of storage tanks from measurements of the circumference of a
tank at various heights. The strapping method is also often used to establish a reference circumference at a
selected height to use as a datum in other methods of tank calibration.

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INTERNATIONAL STANDARD ISO 7507-1:2003(E)

Petroleum and liquid petroleum products — Calibration of
vertical cylindrical tanks —
Part 1:
Strapping method
1 Scope
1.1 This part of ISO 7507 specifies a method for the calibration of substantially vertical cylindrical tanks by
measuring the tank using a strapping tape.
1.2 This method is known as the “strapping method” and is suitable for use as a working method, a
reference method or a referee method.
NOTE For the reference method, the number of strappings required will be specified in the standard which refers to
this part of ISO 7507.
1.3 The operation of strapping, the corrections to be made and the calculations leading to the compilation of
the tank capacity table are described.
1.4 This method does not apply to abnormally deformed, e.g. dented or non-circular, tanks.
1.5 This method is suitable for tilted tanks with a deviation of up to 3 % from the vertical, provided that a
correction for the measured tilt is applied in the calculations.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 91-1:1992, Petroleum measurement tables — Part 1: Tables based on reference temperatures of 15 °C
and 60 °F
ISO 3675:1998, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Hydrometer method
ISO 4269:2001, Petroleum and liquid petroleum products — Tank calibration by liquid measurement —
Incremental method using volumetric meters
© ISO 2003 — All rights reserved 1

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ISO 7507-1:2003(E)
3 Terms and definitions
For the purposes of this document and subsequent parts of ISO 7507, the following terms and definitions
apply.
3.1
argument
independent variable of a function
NOTE A table is entered with value(s) of the independent variable(s), the value(s) extracted from the table being
known as the dependent value(s).
3.2
bottom calibration
procedure to determine the quantity of liquid contained in a tank below the calibration datum-point
3.3
calibration
process of determining the capacity of a tank, or the partial capacities corresponding to different levels
3.4
capacity
total volume of a tank
3.5
capacity table
tank table
tank capacity table
table showing the capacities of, or volumes in, a tank corresponding to various liquid levels measured from a
stable reference point
3.6
course
one circumferential ring of plates in a tank
3.7
calibration datum-point
point used as the datum in the preparation of a calibration table
NOTE Course heights and the effective levels of deadwood are measured from this point, to which the bottom
calibration is also related.
3.8
deadwood
any tank fitting that affects the capacity of the tank
NOTE Deadwood is referred to as “positive deadwood” when the capacity of the fitting increases the effective
capacity of the tank, or “negative deadwood” when the volume of the fitting displaces liquid and reduces the effective
capacity.
3.9
dip
innage
depth of a liquid in a tank above the dipping datum-point
3.10
dip-hatch
gauge-hatch
opening in the top of a tank through which dipping and sampling operations are carried out
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ISO 7507-1:2003(E)
3.11
dip-point
point on the dip-plate which the dip-weight touches during gauging and from which the measurements of the
oil and water depths are taken
NOTE The dip-point usually corresponds to the datum-point, but when this is not so, the difference in level between
the datum-point and the dip-point has to be allowed for in the calibration table.
3.12
dip-plate
striking-plate positioned below the dip-hatch
NOTE The position of the dip-plate should not be affected by bottom or wall movements.
3.13
dip-tape
graduated steel tape used for measuring the depth of the oil or water in a tank, either directly by dipping or
indirectly by ullage
3.14
dip-weight
weight attached to a steel dip-tape, of sufficient mass to keep the tape taut and of such shape as to facilitate
the penetration of any sludge that might be present on the dip-point or the dip-plate
3.15
floating cover
screen
lightweight cover of either metal or plastics material designed to float on the surface of a liquid in a tank
NOTE The cover rests upon the liquid surface and is used to retard evaporation of volatile products in a tank.
3.16
floating-roof tank
tank in which the roof floats freely on the surface of the liquid contents, except at low levels when the weight of
the roof is taken through its supports by the tank bottom
3.17
function
when two variable quantities are interrelated, one quantity is said to be a function of the other
NOTE In the context of tank calibration, the volume of liquid contained in a tank is said to be a function of the dip or
of the ullage.
3.18
gauging
process of taking all the necessary measurements in a tank in order to determine the quantity of liquid that it
contains
3.19
interpolation
process of obtaining the value of a function corresponding to a value of the argument intermediate between
those given
3.20
Littlejohn grip
quick-release clamp that may be fitted around a strapping tape at any convenient position throughout its
length
NOTE A handle is attached to the Littlejohn grip so that the strapping tape can be pulled to the correct tension.
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ISO 7507-1:2003(E)
3.21
open capacity
calculated capacity of a tank or part of a tank before any allowance has been made for deadwood
3.22
reference height
vertical distance between the dip-point and the upper reference point
3.23
overall height
total external height from the top of the shell to the base of the tank (plate)
3.24
referee method
application of the strapping method of tank calibration to give a calibration of a tank for custody transfer
purposes or to provide a basis for assessing the accuracy of other methods of tank calibration
3.25
reference method
application of the strapping method of tank calibration to the measurement of a reference circumference for
use in other methods of tank calibration
NOTE An example of such a method is the optical-reference-line method (see ISO 7507-2).
3.26
reference point
a point to which measurements in either calibration or gauging are related
3.27
step-over
device used in strapping for measuring the distance apart, along the arc, of two points on a tank shell where it
is not possible to use a strapping tape directly because of an intervening obstruction, e.g. a protruding fitting
3.28
step-over constant
distance between the measuring points of a step-over as measured along the arc of the particular course of
the tank concerned
3.29
step-over correction
difference between the apparent distance between two points on a tank shell as measured by a strapping tape
passing over an obstruction and the true arc distance as measured by a step-over, i.e. the step-over constant
3.30
strapping tape
specially designed and calibrated steel measuring tape graduated in units of length and used for taking
circumferential measurements in tank calibration
3.31
strapping method
method of tank calibration in which the capacities are calculated from the measurement of the external
circumferences, due allowance being made for the thickness of the shell of the tank
3.32
tape positioner
guide sliding freely on the strapping tape, used to pull and hold it in the correct position for taking
measurements
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ISO 7507-1:2003(E)
3.33
tensioning handles
handles fastened to the strapping tape, used for pulling it into the correct position and applying tension
3.34
ullage
outage
capacity of a tank not occupied by the liquid
3.35
upper reference point
point clearly defined on the dip-hatch directly above the dip-point to indicate the position at which dipping or
ullaging shall be carried out
3.36
working method
application of the strapping method of tank calibration by a simplified procedure that may result in some loss
of accuracy and is unsuitable for assessing other methods
4 Precautions
4.1 Introduction
This clause outlines the precautions that are applicable when tanks are being calibrated. The precautions
necessary to ensure the safety of the operator are dealt with separately from those precautions which have to
be taken to ensure the necessary precision required in the calibration of tanks.
4.2 General precautions
4.2.1 The utmost care and attention to detail shall be exercised when calibrating storage tanks.
4.2.2 All measurements shall be carefully observed and recorded as read, and any corrections which are
required shall be recorded separately. If any unusual occurrences are noted during the operations, these
occurrences shall be documented and the calibration shall be repeated, if necessary.
4.2.3 If the tank is only slightly distorted, sufficient additional measurements shall be taken to allow
satisfactory calculation of its capacity table. If such additional measurements are required, the calibrator’s
notes shall include the reasons for the extra measurements.
It is also recommended that dimensioned sketches should be provided by the calibrator to show any
abnormality of the tank or the fittings that affect calibration.
NOTE Seriously distorted tanks are best calibrated using liquid calibration methods similar to the method described
in ISO 4269.
4.2.4 To ensure accuracy and repeatability of readings, lumps of paint, scale, etc., likely to interfere with
measurement, shall be removed or the position of the measuring equipment adjusted accordingly.
4.2.5 If drawings for the tank are available, all relevant measurements shall be compared with the
corresponding dimensions shown on the drawings. Any measurement which shows a significant discrepancy
as a result of this comparison shall be reported and, if necessary, repeated.
4.2.6 If the calibration of a tank is interrupted, it may be resumed at a later date provided that:
a) if there is a change of equipment or personnel, sufficient check measurements shall be made to ensure
that the results obtained prior to the change correspond within the tolerances given in this method;
b) all records of work done are complete and legible;
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ISO 7507-1:2003(E)
c) the liquid contents remain unchanged at substantially the same level;
d) the average liquid and atmospheric temperatures are within 10 °C of the average liquid and atmospheric
temperatures recorded during the earlier working period.
4.3 Safety precautions
4.3.1 The safety precautions given in 4.3.2 to 4.3.6 constitute good practice, but the list is not necessarily
comprehensive. It is recommended that the list should be read in conjunction with the appropriate sections of
any applicable safety code. The precautions shall be taken whenever they do not conflict with legislative
requirements, which shall always be followed.
4.3.2 All regulations covering entry into hazardous areas shall be rigorously observed.
4.3.3 If a tank being strapped contains a petroleum product, attention shall be paid to the normal safety
precautions which apply to such tanks.
4.3.4 Before a tank which has been in use is entered, a safe-entry certificate issued in accordance with
local or national regulations shall be obtained. All lines entering the tank shall be disconnected and blanked.
The national or local regulations regarding the entry into tanks which have contained leaded fuels shall be
meticulously observed.
4.3.5 Hand lamps shall be of a type approved for use in explosive atmospheres.
4.3.6 The safety of operating personnel shall be safeguarded by strict attention to the following.
a) Ladders shall be inspected before use, and extendable ladders used only within their safe operating
range. The footing for each ladder shall be level and firm, and all ladders shall be securely lashed in
position before being used.
b) When painters’ cradles or bo’suns’ chairs are used, blocks, falls, ropes, etc., shall be tested before
erection, and any item of questionable strength or condition shall be replaced. Every care shall be paid to
the securing of the equipment and its operational use.
c) If calibration cannot be carried out without the use of staging, properly constructed steel tube or timber
scaffolding shall be erected. Loose bricks, drums, boxes, etc., shall not be used to form staging.
d) Where appropriate, safety harnesses shall be worn by personnel working above ground level.
5 Equipment
5.1 Strapping tape, conforming to A.1. The tape shall be well greased before use.
5.2 Spring balance, conforming to A.2, for measuring the tension applied to the tape.
5.3 Step-over, conforming to A.3.
5.4 Tape positioners and cords, conforming to A.4, fitted to the strapping tape, and supplied with plaited
cords. Both upper and lower cords shall be long enough to cover the height of the tank.
5.5 Littlejohn grip, conforming to A.5, to hold the tape, without kinking, in order to facilitate application of
the necessary tension.
5.6 Apparatus for thickness measurement, either a steel rule of convenient length graduated throughout
its length in millimetres, with at least the first 10 mm subdivided into half-millimetres, and/or another device,
such as an electronic thickness gauge.
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ISO 7507-1:2003(E)
5.7 Dip-tape conforming to A.6, long enough to reach from the dipping reference point at the tank roof to
the dip-point on the tank bottom.
5.8 Dip-weight, conforming to A.7.
5.9 End-to-end rule, 1 m in length, with graduations in centimetres and millimetres, for measuring
deadwood, etc. If a wooden rule is used, it shall be fitted with a brass ferrule at each end and shall be free
from warp.
5.10 Ladders and staging: see 4.3.6 for safety precautions.
5.11 Density- and temperature-measuring apparatus, conforming to ISO 3675.
6 General requirements
NOTE If possible, measurements should be compared with the corresponding dimensions on the tank construction
drawings and the roundness of the tank should be ascertained.
6.1 Fill the tank to its normal working capacity at least once and allow to stand for at least 24 h prior to
calibration.
If the tank is calibrated with liquid in it, record the depth, temperature and density of the liquid at the time of
calibration. However, if the temperature of the wall surface can differ by more than 10 °C between the empty
part and the full part of the tank, the tank shall be either completely full or empty. Do not make transfers of
liquid during the calibration.
The ambient temperature before and after calibration should be recorded.
Obtain the required number of external circumference measurements, together with the subsidiary
measurements, where necessary, to correct for deviation of the strap due to obstructions, as described in 7.2.
NOTE Additional measurements required to enable a table of capacities to be prepared and the procedures to be
used in obtaining them are described in Clauses 8 to 12.
6.2 It is necessary to refer all tank dips to the dip-point, which may be in a different position from the
calibration datum-point, e.g. a point on the bottom angle, used for the purpose of tank calibration. Check that
the dip-plate has been securely mounted in a stable position so that it is not affected by movement of the tank
bottom or walls. Determine any difference in level between the dip-point and calibration datum-point, either by
normal surveying methods or by other suitable means, and record it.
6.3 Measure the height of the upper reference point above the dip-point using the dip-tape and dip-weight.
Record this reference height, to the nearest subdivision on the dip-tape, in the empty and the full conditions,
as appropriate.
7 Circumference measurements
7.1 Levels strapped
7.1.1 If the calibration is for referee purposes, measure the circumference by three or more strappings per
course, at approximately the following levels:
a) for riveted tanks:
1) 100 mm to 150 mm above the level of the top of the bottom angle of the tank, and 100 mm to
150 mm above the upper edge of each horizontal overlap between courses;
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ISO 7507-1:2003(E)
2) at the middle position of each course;
3) 100 mm to 150 mm below the lower edge of each horizontal overlap between courses and 100 mm
to 150 mm below the level of the lowest part of the top angle.
b) for welded tanks:
three or more levels as indicated in a), but the upper and lower levels shall be 270 mm to 330 mm from the
bottom angle, top angle or horizontal seams.
7.1.2 If the calibration is for the working method, the circumference may be measured, if preferred, by only
two strappings per course, taking one at each of the following levels:
 at about 1/5 to 1/4 of the course height or the ring height above the lower horizontal seam;
 at about 1/5 to 1/4 of the course height or the ring height below the upper horizontal seam.
7.1.3 If for any reason it is impracticable to take a strapping at the normal level, take a strapping as close to
this level as practicable, but not nearer the bottom or top angle or any seam than is specified in 7.1.1 a) or b).
Record in the strapper’s notes the level at which this circumference has been measured, with the reason for
abandoning the normal level.
If the tape is not in close contact with the surface of the tank throughout its whole path, apply a step-over as
in 7.5, so that a correction may be calculated to adjust the gross circumference for this effect.
7.2 Strapping procedure
7.2.1 Strap the tank by either of the methods described in 7.2.2 and 7.2.3. The calibration tension specified
on the strapping tape shall be applied to the tape using the tensioning handles and spring balance, and
transmitted throughout the length of the tape.
NOTE A slight sawing motion imparted to the strapping tape will achieve this, or the strapping tape can be eased
round the tank by pulling it away from the shell by the cords attached to the tape positioners, sliding these along the
strapping tape as required.
Place the strapping tape on its correct path which shall be parallel to the horizontal seams of the tank.
7.2.2 If the strapping tape used is not long enough to encircle the tank completely, choose the level of the
strapping tape path and then measure the circumference in sections. Draw scribed lines not nearer than about
one-third of a plate length from a vertical seam at such distances apart as will enable measurements to be
made conveniently. When the tension on the spring balance at the end of the strapping tape is as specified in
7.2.1 for each separate section, record the individual readings. The external circumference of the tank shall
then be the sum of the separate measurements.
7.2.3 If the strapping tape
...

SLOVENSKI STANDARD
SIST ISO 7507-1:2006
01-februar-2006
1DIWDLQWHNRþLQDIWQLSURL]YRGL±8PHUMDQMHQDYSLþQLKYDOMDVWLKUH]HUYRDUMHY±
GHOª6WUDSSLQJ©PHWRGD
Petroleum and liquid petroleum products -- Calibration of vertical cylindrical tanks -- Part
1: Strapping method
Pétrole et produits pétroliers liquides -- Jaugeage des réservoirs cylindriques verticaux --
Partie 1: Méthode par ceinturage
Ta slovenski standard je istoveten z: ISO 7507-1:2003
ICS:
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
SIST ISO 7507-1:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 7507-1:2006

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SIST ISO 7507-1:2006


INTERNATIONAL ISO
STANDARD 7507-1
Second edition
2003-12-15

Petroleum and liquid petroleum
products — Calibration of vertical
cylindrical tanks —
Part 1:
Strapping method
Pétrole et produits pétroliers liquides — Jaugeage des réservoirs
cylindriques verticaux —
Partie 1: Méthode par ceinturage




Reference number
ISO 7507-1:2003(E)
©
ISO 2003

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
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©  ISO 2003
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
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Published in Switzerland

ii © ISO 2003 — All rights reserved

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references. 1
3 Terms and definitions. 2
4 Precautions. 5
5 Equipment. 6
6 General requirements. 7
7 Circumference measurements. 7
8 Other measurements on tank shell plates. 10
9 Deadwood. 10
10 Tank bottoms. 11
11 Measurement of tilt . 11
12 Floating-roof tanks. 11
13 Recalibration. 12
14 Computation of tank capacity tables — General rules . 12
15 Form of tank capacity tables . 13
16 Computation of open capacity . 13
17 Construction of final tables. 17
Annex A (normative) Specification for equipment used in strapping . 23
Annex B (informative) Recommendations for monitoring, checking and verification of tank
calibration and capacity table. 26
Annex C (informative) Tank calibration data and calculation sheet. 32
Annex D (informative) Tank calibration uncertainties . 36
Annex E (informative) Tank shell temperature determination . 47
Annex F (normative) Gauge tape temperature correction . 48
Annex G (informative) Expansion due to liquid head . 50
Annex H (normative) Expansion due to temperature . 58
Annex I (normative) Certificate of calibration. 61
Bibliography . 62


© ISO 2003 — All rights reserved iii

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 7507-1 was prepared by Technical Committee ISO/TC 28, Petroleum products and
lubricants, Subcommittee SC 3, Static petroleum measurement.
This second edition cancels and replaces the first edition (ISO 7507-1:1993). It also cancels and replaces
ISO 7507-6:1997, the subject of which is now included in this part of ISO 7507.
ISO 7507 consists of the following parts, under the general title Petroleum and liquid petroleum products —
Calibration of vertical cylindrical tanks:
 Part 1: Strapping method
 Part 2: Optical-reference-line method
 Part 3: Optical-triangulation method
 Part 4: Internal electro-optical distance-ranging method
 Part 5: External electro-optical distance-ranging method
 Part 6: Recommendations for monitoring, checking and verification of tank calibration and capacity table
iv © ISO 2003 — All rights reserved

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
Introduction
This part of ISO 7507 forms part of a series on tank calibration including the following:
ISO 7507-2:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 2: Optical-reference-line method
ISO 7507-3:1993, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 3: Optical-triangulation method
ISO 7507-4:1995, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 4: Internal electro-optical distance-ranging method
ISO 7507-5:2000, Petroleum and liquid petroleum products — Calibration of vertical cylindrical tanks —
Part 5: External electro-optical distance-ranging method
ISO 7507-6:1997, Recommendations for monitoring, checking and verification of tank calibration and capacity
table
ISO 8311:1989, Refrigerated light hydrocarbon fluids — Calibration of membrane tanks and independent
prismatic tanks in ships — Physical measurement
ISO 9091-1:1991, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 1:
Stereo-photogrammetry
ISO 9091-2:1992, Refrigerated light hydrocarbon fluids — Calibration of spherical tanks in ships — Part 2:
Triangulation measurement
The strapping method for the calibration of vertical cylindrical tanks has been used for many years and is a
recognized method of determining the capacity of storage tanks from measurements of the circumference of a
tank at various heights. The strapping method is also often used to establish a reference circumference at a
selected height to use as a datum in other methods of tank calibration.

© ISO 2003 — All rights reserved v

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SIST ISO 7507-1:2006

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SIST ISO 7507-1:2006
INTERNATIONAL STANDARD ISO 7507-1:2003(E)

Petroleum and liquid petroleum products — Calibration of
vertical cylindrical tanks —
Part 1:
Strapping method
1 Scope
1.1 This part of ISO 7507 specifies a method for the calibration of substantially vertical cylindrical tanks by
measuring the tank using a strapping tape.
1.2 This method is known as the “strapping method” and is suitable for use as a working method, a
reference method or a referee method.
NOTE For the reference method, the number of strappings required will be specified in the standard which refers to
this part of ISO 7507.
1.3 The operation of strapping, the corrections to be made and the calculations leading to the compilation of
the tank capacity table are described.
1.4 This method does not apply to abnormally deformed, e.g. dented or non-circular, tanks.
1.5 This method is suitable for tilted tanks with a deviation of up to 3 % from the vertical, provided that a
correction for the measured tilt is applied in the calculations.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 91-1:1992, Petroleum measurement tables — Part 1: Tables based on reference temperatures of 15 °C
and 60 °F
ISO 3675:1998, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Hydrometer method
ISO 4269:2001, Petroleum and liquid petroleum products — Tank calibration by liquid measurement —
Incremental method using volumetric meters
© ISO 2003 — All rights reserved 1

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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3 Terms and definitions
For the purposes of this document and subsequent parts of ISO 7507, the following terms and definitions
apply.
3.1
argument
independent variable of a function
NOTE A table is entered with value(s) of the independent variable(s), the value(s) extracted from the table being
known as the dependent value(s).
3.2
bottom calibration
procedure to determine the quantity of liquid contained in a tank below the calibration datum-point
3.3
calibration
process of determining the capacity of a tank, or the partial capacities corresponding to different levels
3.4
capacity
total volume of a tank
3.5
capacity table
tank table
tank capacity table
table showing the capacities of, or volumes in, a tank corresponding to various liquid levels measured from a
stable reference point
3.6
course
one circumferential ring of plates in a tank
3.7
calibration datum-point
point used as the datum in the preparation of a calibration table
NOTE Course heights and the effective levels of deadwood are measured from this point, to which the bottom
calibration is also related.
3.8
deadwood
any tank fitting that affects the capacity of the tank
NOTE Deadwood is referred to as “positive deadwood” when the capacity of the fitting increases the effective
capacity of the tank, or “negative deadwood” when the volume of the fitting displaces liquid and reduces the effective
capacity.
3.9
dip
innage
depth of a liquid in a tank above the dipping datum-point
3.10
dip-hatch
gauge-hatch
opening in the top of a tank through which dipping and sampling operations are carried out
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.11
dip-point
point on the dip-plate which the dip-weight touches during gauging and from which the measurements of the
oil and water depths are taken
NOTE The dip-point usually corresponds to the datum-point, but when this is not so, the difference in level between
the datum-point and the dip-point has to be allowed for in the calibration table.
3.12
dip-plate
striking-plate positioned below the dip-hatch
NOTE The position of the dip-plate should not be affected by bottom or wall movements.
3.13
dip-tape
graduated steel tape used for measuring the depth of the oil or water in a tank, either directly by dipping or
indirectly by ullage
3.14
dip-weight
weight attached to a steel dip-tape, of sufficient mass to keep the tape taut and of such shape as to facilitate
the penetration of any sludge that might be present on the dip-point or the dip-plate
3.15
floating cover
screen
lightweight cover of either metal or plastics material designed to float on the surface of a liquid in a tank
NOTE The cover rests upon the liquid surface and is used to retard evaporation of volatile products in a tank.
3.16
floating-roof tank
tank in which the roof floats freely on the surface of the liquid contents, except at low levels when the weight of
the roof is taken through its supports by the tank bottom
3.17
function
when two variable quantities are interrelated, one quantity is said to be a function of the other
NOTE In the context of tank calibration, the volume of liquid contained in a tank is said to be a function of the dip or
of the ullage.
3.18
gauging
process of taking all the necessary measurements in a tank in order to determine the quantity of liquid that it
contains
3.19
interpolation
process of obtaining the value of a function corresponding to a value of the argument intermediate between
those given
3.20
Littlejohn grip
quick-release clamp that may be fitted around a strapping tape at any convenient position throughout its
length
NOTE A handle is attached to the Littlejohn grip so that the strapping tape can be pulled to the correct tension.
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.21
open capacity
calculated capacity of a tank or part of a tank before any allowance has been made for deadwood
3.22
reference height
vertical distance between the dip-point and the upper reference point
3.23
overall height
total external height from the top of the shell to the base of the tank (plate)
3.24
referee method
application of the strapping method of tank calibration to give a calibration of a tank for custody transfer
purposes or to provide a basis for assessing the accuracy of other methods of tank calibration
3.25
reference method
application of the strapping method of tank calibration to the measurement of a reference circumference for
use in other methods of tank calibration
NOTE An example of such a method is the optical-reference-line method (see ISO 7507-2).
3.26
reference point
a point to which measurements in either calibration or gauging are related
3.27
step-over
device used in strapping for measuring the distance apart, along the arc, of two points on a tank shell where it
is not possible to use a strapping tape directly because of an intervening obstruction, e.g. a protruding fitting
3.28
step-over constant
distance between the measuring points of a step-over as measured along the arc of the particular course of
the tank concerned
3.29
step-over correction
difference between the apparent distance between two points on a tank shell as measured by a strapping tape
passing over an obstruction and the true arc distance as measured by a step-over, i.e. the step-over constant
3.30
strapping tape
specially designed and calibrated steel measuring tape graduated in units of length and used for taking
circumferential measurements in tank calibration
3.31
strapping method
method of tank calibration in which the capacities are calculated from the measurement of the external
circumferences, due allowance being made for the thickness of the shell of the tank
3.32
tape positioner
guide sliding freely on the strapping tape, used to pull and hold it in the correct position for taking
measurements
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
3.33
tensioning handles
handles fastened to the strapping tape, used for pulling it into the correct position and applying tension
3.34
ullage
outage
capacity of a tank not occupied by the liquid
3.35
upper reference point
point clearly defined on the dip-hatch directly above the dip-point to indicate the position at which dipping or
ullaging shall be carried out
3.36
working method
application of the strapping method of tank calibration by a simplified procedure that may result in some loss
of accuracy and is unsuitable for assessing other methods
4 Precautions
4.1 Introduction
This clause outlines the precautions that are applicable when tanks are being calibrated. The precautions
necessary to ensure the safety of the operator are dealt with separately from those precautions which have to
be taken to ensure the necessary precision required in the calibration of tanks.
4.2 General precautions
4.2.1 The utmost care and attention to detail shall be exercised when calibrating storage tanks.
4.2.2 All measurements shall be carefully observed and recorded as read, and any corrections which are
required shall be recorded separately. If any unusual occurrences are noted during the operations, these
occurrences shall be documented and the calibration shall be repeated, if necessary.
4.2.3 If the tank is only slightly distorted, sufficient additional measurements shall be taken to allow
satisfactory calculation of its capacity table. If such additional measurements are required, the calibrator’s
notes shall include the reasons for the extra measurements.
It is also recommended that dimensioned sketches should be provided by the calibrator to show any
abnormality of the tank or the fittings that affect calibration.
NOTE Seriously distorted tanks are best calibrated using liquid calibration methods similar to the method described
in ISO 4269.
4.2.4 To ensure accuracy and repeatability of readings, lumps of paint, scale, etc., likely to interfere with
measurement, shall be removed or the position of the measuring equipment adjusted accordingly.
4.2.5 If drawings for the tank are available, all relevant measurements shall be compared with the
corresponding dimensions shown on the drawings. Any measurement which shows a significant discrepancy
as a result of this comparison shall be reported and, if necessary, repeated.
4.2.6 If the calibration of a tank is interrupted, it may be resumed at a later date provided that:
a) if there is a change of equipment or personnel, sufficient check measurements shall be made to ensure
that the results obtained prior to the change correspond within the tolerances given in this method;
b) all records of work done are complete and legible;
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
c) the liquid contents remain unchanged at substantially the same level;
d) the average liquid and atmospheric temperatures are within 10 °C of the average liquid and atmospheric
temperatures recorded during the earlier working period.
4.3 Safety precautions
4.3.1 The safety precautions given in 4.3.2 to 4.3.6 constitute good practice, but the list is not necessarily
comprehensive. It is recommended that the list should be read in conjunction with the appropriate sections of
any applicable safety code. The precautions shall be taken whenever they do not conflict with legislative
requirements, which shall always be followed.
4.3.2 All regulations covering entry into hazardous areas shall be rigorously observed.
4.3.3 If a tank being strapped contains a petroleum product, attention shall be paid to the normal safety
precautions which apply to such tanks.
4.3.4 Before a tank which has been in use is entered, a safe-entry certificate issued in accordance with
local or national regulations shall be obtained. All lines entering the tank shall be disconnected and blanked.
The national or local regulations regarding the entry into tanks which have contained leaded fuels shall be
meticulously observed.
4.3.5 Hand lamps shall be of a type approved for use in explosive atmospheres.
4.3.6 The safety of operating personnel shall be safeguarded by strict attention to the following.
a) Ladders shall be inspected before use, and extendable ladders used only within their safe operating
range. The footing for each ladder shall be level and firm, and all ladders shall be securely lashed in
position before being used.
b) When painters’ cradles or bo’suns’ chairs are used, blocks, falls, ropes, etc., shall be tested before
erection, and any item of questionable strength or condition shall be replaced. Every care shall be paid to
the securing of the equipment and its operational use.
c) If calibration cannot be carried out without the use of staging, properly constructed steel tube or timber
scaffolding shall be erected. Loose bricks, drums, boxes, etc., shall not be used to form staging.
d) Where appropriate, safety harnesses shall be worn by personnel working above ground level.
5 Equipment
5.1 Strapping tape, conforming to A.1. The tape shall be well greased before use.
5.2 Spring balance, conforming to A.2, for measuring the tension applied to the tape.
5.3 Step-over, conforming to A.3.
5.4 Tape positioners and cords, conforming to A.4, fitted to the strapping tape, and supplied with plaited
cords. Both upper and lower cords shall be long enough to cover the height of the tank.
5.5 Littlejohn grip, conforming to A.5, to hold the tape, without kinking, in order to facilitate application of
the necessary tension.
5.6 Apparatus for thickness measurement, either a steel rule of convenient length graduated throughout
its length in millimetres, with at least the first 10 mm subdivided into half-millimetres, and/or another device,
such as an electronic thickness gauge.
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
5.7 Dip-tape conforming to A.6, long enough to reach from the dipping reference point at the tank roof to
the dip-point on the tank bottom.
5.8 Dip-weight, conforming to A.7.
5.9 End-to-end rule, 1 m in length, with graduations in centimetres and millimetres, for measuring
deadwood, etc. If a wooden rule is used, it shall be fitted with a brass ferrule at each end and shall be free
from warp.
5.10 Ladders and staging: see 4.3.6 for safety precautions.
5.11 Density- and temperature-measuring apparatus, conforming to ISO 3675.
6 General requirements
NOTE If possible, measurements should be compared with the corresponding dimensions on the tank construction
drawings and the roundness of the tank should be ascertained.
6.1 Fill the tank to its normal working capacity at least once and allow to stand for at least 24 h prior to
calibration.
If the tank is calibrated with liquid in it, record the depth, temperature and density of the liquid at the time of
calibration. However, if the temperature of the wall surface can differ by more than 10 °C between the empty
part and the full part of the tank, the tank shall be either completely full or empty. Do not make transfers of
liquid during the calibration.
The ambient temperature before and after calibration should be recorded.
Obtain the required number of external circumference measurements, together with the subsidiary
measurements, where necessary, to correct for deviation of the strap due to obstructions, as described in 7.2.
NOTE Additional measurements required to enable a table of capacities to be prepared and the procedures to be
used in obtaining them are described in Clauses 8 to 12.
6.2 It is necessary to refer all tank dips to the dip-point, which may be in a different position from the
calibration datum-point, e.g. a point on the bottom angle, used for the purpose of tank calibration. Check that
the dip-plate has been securely mounted in a stable position so that it is not affected by movement of the tank
bottom or walls. Determine any difference in level between the dip-point and calibration datum-point, either by
normal surveying methods or by other suitable means, and record it.
6.3 Measure the height of the upper reference point above the dip-point using the dip-tape and dip-weight.
Record this reference height, to the nearest subdivision on the dip-tape, in the empty and the full conditions,
as appropriate.
7 Circumference measurements
7.1 Levels strapped
7.1.1 If the calibration is for referee purposes, measure the circumference by three or more strappings per
course, at approximately the following levels:
a) for riveted tanks:
1) 100 mm to 150 mm above the level of the top of the bottom angle of the tank, and 100 mm to
150 mm above the upper edge of each horizontal overlap between courses;
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SIST ISO 7507-1:2006
ISO 7507-1:2003(E)
2) at the middle position of each course;
3) 100 mm to 150 mm below the lower edge of each horizontal overlap between courses and 100 mm
to 150 mm below the level of the lowest part of the top angle.
b) for welded tanks:
three or more levels as indicated in a), but the upper and lower levels shall be 270 mm to 330 mm from the
bottom angle, top angle or horizontal seams.
7.1.2 If the calibration is for the working method, the circumference may be measured, if preferred, by only
two strappings per course, taking one at each of the following levels:
 at about 1/5 to 1/4 of the course height or the ring height above the lower horizontal seam;
 at about 1/5 to 1/4 of the course height or the ring height below the upper horizontal seam.
7.1.3 If for any reason it is impracticable to take a strapping at the normal level, take a strapping as close to
this level as practicable, but not nearer the bottom or top angle or any seam than is specified in 7.1.1 a) or b).
Record in the strapper’s notes the level at which this circumference has been measured, with the reason for
abandoning the normal level.
If the tape is not in close contact with the surface of the tank throughout its whole path, apply a step-over as
in 7.5, so that a correction may be calculated to adjust the gross circumference for this effect.
7.2 Strapping procedure
7.2.1 Strap the tank by either of the methods
...

NORME ISO
INTERNATIONALE 7507-1
Deuxième édition
2003-12-15

Pétrole et produits pétroliers liquides —
Jaugeage des réservoirs cylindriques
verticaux —
Partie 1:
Méthode par ceinturage
Petroleum and liquid petroleum products — Calibration of vertical
cylindrical tanks —
Part 1: Strapping method




Numéro de référence
ISO 7507-1:2003(F)
©
ISO 2003

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ISO 7507-1:2003(F)
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ii © ISO 2003 — Tous droits réservés

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ISO 7507-1:2003(F)
Sommaire Page
Avant-propos. iv
Introduction . v
1 Domaine d'application. 1
2 Références normatives. 1
3 Termes et définitions . 2
4 Précautions. 5
5 Équipement. 7
6 Exigences générales. 7
7 Mesurages de la circonférence . 8
8 Autres mesurages effectués sur les tôles de robe du réservoir. 11
9 Corps intérieurs et extérieurs. 11
10 Fonds des réservoirs. 11
11 Mesurage de l'inclinaison . 12
12 Réservoirs à toit flottant. 12
13 Rejaugeage. 13
14 Calcul des barèmes de jaugeage de réservoirs — Règles générales . 13
15 Forme des barèmes de jaugeage de réservoir. 14
16 Calcul du volume brut . 14
17 Élaboration des barèmes définitifs . 18
Annexe A (normative) Spécifications pour le matériel de ceinturage . 24
Annexe B (informative) Recommandations relatives au suivi, au contrôle et à la vérification du
jaugeage et des barèmes de jaugeage .27
Annexe C (informative) Feuille de données de jaugeage et de calcul . 33
Annexe D (informative) Incertitudes de jaugeage des réservoirs . 37
Annexe E (informative) Détermination de la température de la robe d'un réservoir . 48
Annexe F (normative) Correction de la température pour le ruban de pige . 49
Annexe G (informative) Dilatation due à la charge hydrostatique du liquide . 52
Annexe H (normative) Dilatation due à la température . 60
Annexe I (normative) Certificat de jaugeage . 63
Bibliographie . 64


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ISO 7507-1:2003(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 7507-1 a été élaborée par le comité technique ISO/TC 28, Produits pétroliers et lubrifiants, sous-comité
SC 3, Mesurage statique du pétrole.
Cette deuxième édition annule et remplace la première édition (ISO 7507-1:1993). Elle annule et remplace
également l’ISO 7507-6:1997, qui est maintenant incluse dans la présente partie de l’ISO 7507.
L'ISO 7507 comprend les parties suivantes, présentées sous le titre général Pétrole et produits pétroliers
liquides — Jaugeage des réservoirs cylindriques verticaux:
 Partie 1: Méthode par ceinturage
 Partie 2: Méthode par ligne de référence optique
 Partie 3: Méthode par triangulation optique
 Partie 4: Méthode par mesurage électro-optique interne de la distance
 Partie 5: Méthode par mesurage électro-optique externe de la distance
 Partie 6: Recommandations relatives à la surveillance, au contrôle et à la vérification du jaugeage des
réservoirs et des tables de jaugeage
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ISO 7507-1:2003(F)
Introduction
La présente partie de l’ISO 7507 fait partie d’une série de normes sur l’étalonnage des réservoirs incluant les
normes suivantes:
ISO 7507-2:1993, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs cylindriques verticaux —
Partie 2: Méthode par ligne de référence optique
ISO 7507-3:1993, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs cylindriques verticaux —
Partie 3: Méthode par triangulation optique
ISO 7507-4:1995, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs cylindriques verticaux —
Partie 4: Méthode par mesurage électro-optique interne de la distance
ISO 7507-5:2000, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs cylindriques verticaux —
Partie 5: Méthode par mesurage électro-optique externe de la distance
ISO 7507-6:1997, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs cylindriques verticaux —
Recommandations relatives à la surveillance, au contrôle et à la vérification du jaugeage des réservoirs et des
tables de jaugeage
ISO 8311:1989, Hydrocarbures légers réfrigérés — Étalonnage des réservoirs à membrane et réservoirs
pyramidaux — Mesurage Physique
ISO 9091-1:1991, Hydrocarbures légers réfrigérés — Jaugeage des réservoirs sphériques à bord des
navires — Partie 1: Stéréo-photogrammétrie
ISO 9091-2:1992, Hydrocarbures légers réfrigérés — Jaugeage des réservoirs sphériques à bord des
navires — Partie 2: Méthode par triangulation
La méthode par ceinturage pour le jaugeage des réservoirs verticaux est utilisée depuis de nombreuses
années et est reconnue pour déterminer la capacité des réservoirs de stockage à partir des mesures de la
circonférence d’un réservoir à différentes hauteurs. La méthode par ceinturage est également souvent utilisée
pour établir une circonférence de référence à une hauteur définie qui est ensuite utilisée comme donnée dans
les autres méthodes de jaugeage.

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NORME INTERNATIONALE ISO 7507-1:2003(F)

Pétrole et produits pétroliers liquides — Jaugeage des
réservoirs cylindriques verticaux —
Partie 1:
Méthode par ceinturage
1 Domaine d'application
1.1 La présente partie de l'ISO 7507 spécifie une méthode permettant de jauger les réservoirs cylindriques
pratiquement verticaux par mesurage avec un ruban de ceinturage.
1.2 Cette méthode connue sous le nom de «méthode par ceinturage» convient tant comme méthode de
travail que comme méthode de référence ou encore comme méthode d'arbitrage.
NOTE Pour la méthode de référence, le nombre de ceinturages requis sera spécifié dans la norme faisant appel à la
présente partie de l'ISO 7507.
1.3 Les opérations de ceinturage à mettre en œuvre ainsi que les corrections et les calculs à effectuer pour
élaborer un barème de jaugeage de réservoir sont décrits.
1.4 La présente méthode ne s'applique pas aux réservoirs anormalement déformés, par exemple les
réservoirs bosselés ou non circulaires.
1.5 Cette méthode convient pour les réservoirs dont l'inclinaison par rapport à la verticale n'excède pas 3 %,
à condition qu'une correction soit apportée aux calculs pour tenir compte de l'inclinaison mesurée.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO 91-1:1992, Tables de mesure du pétrole — Partie 1: Tables basées sur les températures de référence de
15 °C et 60 °F
ISO 3675:1998, Pétrole brut et produits pétroliers liquides — Détermination en laboratoire de la masse
volumique — Méthode à l'aréomètre
ISO 4269:2001, Pétrole et produits pétroliers liquides — Jaugeage des réservoirs par épalement — Méthode
par empotement utilisant des compteurs volumétriques
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ISO 7507-1:2003(F)
3 Termes et définitions
Dans le cadre de la présente partie l'ISO 7507 et de ses parties suivantes, les termes et définitions suivants
s'appliquent.
3.1
argument
variable indépendante d'une fonction
NOTE On entre dans une table numérique avec la (les) valeur(s) de la (des) variable(s) indépendante(s), la (les)
valeur(s) extraite(s) de la table étant connue(s) comme valeur(s) dépendante(s).
3.2
jaugeage du fond
procédé permettant de déterminer la quantité de liquide contenue dans un réservoir sous le point de référence
inférieur
3.3
jaugeage
processus permettant de déterminer la capacité d'un réservoir ou les capacités partielles correspondant à
différents niveaux
3.4
capacité
volume total d'un réservoir
3.5
barème de jaugeage
table de jaugeage
table des volumes
table indiquant la capacité d'un réservoir et les volumes qu'il contient à divers niveaux de liquide repérés à
partir d'un point de référence stable
3.6
virole
anneau de tôles sur la circonférence d'un réservoir
3.7
point de repère
point utilisé comme repère dans l'élaboration d'un barème de jaugeage
NOTE Les hauteurs des viroles et les niveaux réels des corps intérieurs et extérieurs sont repérés à partir de ce
point qui sert également de référence pour le jaugeage du fond.
3.8
corps intérieurs et extérieurs
tout accessoire qui influe sur la capacité d'un réservoir
NOTE Les accessoires extérieurs dont la capacité s'ajoute à celle du réservoir sont désignés «corps positifs» et les
accessoires intérieurs dont le volume déplace du liquide et réduit la capacité réelle du réservoir sont désignés «corps
négatifs».
3.9
hauteur de plein
hauteur de liquide dans un réservoir au-dessus du point de référence inférieur
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ISO 7507-1:2003(F)
3.10
orifice de pige
orifice de repérage des niveaux
ouverture pratiquée à la partie supérieure d'un réservoir par laquelle s'effectuent les opérations de repérage
des niveaux et d'échantillonnage
3.11
point de référence inférieur
point placé sur la plaque de touche qu'atteint le lest gradué au cours d'un repérage de niveau et à partir
duquel sont effectués les mesurages des hauteurs de plein de produit et d'eau
NOTE Le point de référence inférieur correspond généralement au point de repère, mais si tel n'est pas le cas, il
convient de tenir compte de la différence de niveau entre le point de repère et le point de référence inférieur dans le
barème de jaugeage.
3.12
plaque de touche
plaque d'arrêt placée à la verticale de l'orifice de pige
NOTE Il est recommandé que la position de la plaque de touche ne subisse pas les effets dus aux mouvements du
fond ou des parois.
3.13
ruban de pige
ruban en acier gradué utilisé pour le mesurage de la hauteur d'hydrocarbures ou d'eau contenue dans un
réservoir, ce mesurage pouvant être effectué soit directement par la hauteur de plein, soit indirectement par la
hauteur de creux
3.14
lest
lest fixé au ruban de pige en acier, d'une masse suffisante pour que le ruban soit bien tendu et d'une forme
telle qu'il puisse traverser facilement des boues éventuelles au niveau du point de référence inférieur ou de la
plaque de touche
3.15
écran flottant
écran léger en métal ou en plastique conçu pour flotter à la surface d'un liquide contenu dans un réservoir
NOTE L'écran repose sur la surface du liquide et sert à retarder l'évaporation des produits volatils présents dans un
réservoir.
3.16
réservoir à toit flottant
réservoir dont le toit flotte librement sur la surface du liquide, sauf lorsque le niveau est bas, la masse du toit
étant alors supportée par le fond du réservoir par l'intermédiaire de supports
3.17
fonction
lorsque deux quantités variables sont en relation mutuelle, une quantité est dite fonction de l'autre
NOTE Dans le cadre du jaugeage des réservoirs, on dit que le volume de liquide contenu dans un réservoir est une
fonction de la hauteur de plein ou de la hauteur de creux.
3.18
jaugeage
processus consistant à effectuer tous les mesurages nécessaires dans un réservoir afin de déterminer la
quantité de liquide qu'il contient
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3.19
interpolation
processus permettant d'obtenir la valeur d'une fonction correspondant à une valeur de l'argument
intermédiaire entre les valeurs données
3.20
Étau Littlejohn
étau à desserrage rapide pouvant être fixé sur un ruban de ceinturage en tout point voulu de sa longueur
NOTE Une poignée est fixée sur l'étau Littlejohn de façon à pouvoir tendre le ruban jusqu'à la tension correcte.
3.21
capacité brute
capacité d'un réservoir, ou d'une partie d'un réservoir, calculée avant de tenir compte des corps intérieurs et
extérieurs
3.22
hauteur totale témoin
distance verticale entre le point de référence inférieur et le point de référence supérieur
3.23
hauteur totale
hauteur de robe
hauteur extérieure totale mesurée de la base du réservoir (tôle du fond) au sommet de la robe
3.24
méthode d'arbitrage
application de la méthode par ceinturage pour le jaugeage d'un réservoir à des fins de transaction
commerciale ou afin de servir de base pour apprécier l'exactitude d'autres méthodes de jaugeage de
réservoirs
3.25
méthode de référence
application de la méthode de jaugeage des réservoirs par ceinturage au mesurage d'une circonférence de
référence qui sera utilisée dans d'autres méthodes de jaugeage de réservoirs
NOTE La méthode par lignes de référence optique (voir l'ISO 7507-2) est un exemple d'une telle méthode.
3.26
point de référence
point auquel se rapportent tous les mesurages de jaugeage et de repérage de niveau d'un réservoir
3.27
cadre pour mesurage des recouvrements
dispositif utilisé dans le ceinturage pour mesurer la distance séparant, sur un arc, deux points de la robe du
réservoir entre lesquels il n'est pas possible d'utiliser un ruban de ceinturage en raison d'un obstacle, par
exemple un accessoire saillant
3.28
constante de recouvrement
distance comprise entre les pointes d'un cadre pour mesurage des recouvrements, mesurée le long de l'arc
d'une virole donnée du réservoir concerné
3.29
correction de recouvrement
différence entre la distance apparente entre deux points sur la robe d'un réservoir, mesurée à l'aide d'un
ruban de ceinturage passant au-dessus d'un obstacle et la longueur réelle de l'arc mesurée avec un cadre
pour mesure des recouvrements, c'est-à-dire la constante de recouvrement
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3.30
ruban de ceinturage
ruban de mesure en acier spécialement conçu et étalonné, gradué en unités de longueur et utilisé pour
effectuer des mesurages de circonférence lors d'un jaugeage de réservoir
3.31
méthode de jaugeage par ceinturage
méthode de jaugeage de réservoirs dans laquelle on calcule les capacités à partir de mesurages de
circonférences extérieures, en tenant compte de l'épaisseur de la robe du réservoir
3.32
positionneur de ruban
guide coulissant librement sur le ruban de ceinturage, utilisé pour tirer le ruban et le maintenir dans la position
convenable pour les mesurages
3.33
poignées de serrage
poignées fixées au ruban de ceinturage, utilisées pour le tendre en position correcte et pour appliquer une
tension
3.34
creux d'un réservoir
volume d'un réservoir non occupé par le liquide
3.35
point de référence supérieur
point clairement défini sur l'orifice de pige, situé directement au-dessus et à la verticale du point de référence
inférieur, pour indiquer l'emplacement auquel doit être pratiqué le mesurage par le creux ou par le plein
3.36
méthode de travail
application de la méthode de jaugeage de réservoirs par ceinturage selon un procédé simplifié qui peut
entraîner une certaine perte d'exactitude et ne convient donc pas pour évaluer d'autres méthodes
4 Précautions
4.1 Introduction
Le présent article trace les grandes lignes des précautions à suivre lors du jaugeage des réservoirs. Les
précautions requises pour assurer la sécurité de l'opérateur sont traitées séparément des précautions à
observer pour obtenir la précision nécessaire au jaugeage des réservoirs.
4.2 Précautions générales
4.2.1 Il faut faire preuve d'un soin extrême et porter une grande attention aux détails lors du jaugeage d'un
réservoir de stockage.
4.2.2 Tous les résultats des mesurages doivent être soigneusement lus et consignés sitôt relevés, et toutes
les corrections nécessaires doivent être notées séparément. Si des événements inhabituels sont observés au
cours des opérations, ils doivent être consignés et le jaugeage doit être recommencé si nécessaire.
4.2.3 Si le réservoir est seulement légèrement déformé, un nombre suffisant de mesurages
supplémentaires doit être effectué afin de permettre un calcul satisfaisant de son barème de jaugeage. Si de
tels mesurages supplémentaires sont nécessaires, les notes de l'opérateur doivent faire mention des raisons
pour lesquelles ils ont été effectués.
Il est également recommandé que l'opérateur produise des schémas cotés montrant toute anomalie du
réservoir et les accessoires influant sur le jaugeage.
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NOTE Pour les réservoirs fortement déformés, il est préférable d'utiliser une méthode de jaugeage par transfert de
liquide, telle que celle décrite dans l'ISO 4269.
4.2.4 Pour assurer l'exactitude et la répétabilité des lectures, les coulures de peinture, la calamine, etc.
susceptibles de gêner le mesurage doivent être retirées ou le dispositif de mesurage doit être placé en
conséquence.
4.2.5 S'il existe des plans du réservoir, tous les résultats des mesurages utiles doivent être comparés aux
dimensions correspondantes figurant sur ces plans. Tout résultat présentant une différence significative à la
suite de cette comparaison doit être signalé et, si nécessaire, le jaugeage doit être réitéré.
4.2.6 Si l'opération de jaugeage d'un réservoir est interrompue, elle peut être poursuivie ultérieurement à
condition que
a) s'il y a eu changement d'équipement ou de personnel, des mesurages de vérification seront effectués en
nombre suffisant pour s'assurer que les résultats obtenus avant le changement concordent dans les
limites des tolérances fixées dans la présente méthode;
b) toutes les notes portant sur le travail effectué sont complètes et lisibles;
c) le contenu liquide reste inchangé, sensiblement au même niveau;
d) les températures moyennes du liquide et de l'atmosphère ne différent pas de plus de 10 °C des
températures moyennes du liquide et de l'atmosphère observées au cours de la période de travail
précédente.
4.3 Précautions de sécurité
4.3.1 Les mesures de sécurité indiquées en 4.3.2 à 4.3.6 constituent une pratique courante, mais la liste
n'est pas nécessairement exhaustive. Il est recommandé d'utiliser cette liste conjointement avec les
paragraphes appropriés de tout code de sécurité applicable. Ces précautions doivent être observées chaque
fois qu'elles n'interfèrent pas avec les exigences légales, qui doivent être suivies dans tous les cas.
4.3.2 Toutes les réglementations relatives à l'accès dans des zones dangereuses doivent être strictement
observées.
4.3.3 Si le réservoir ceinturé contient un produit pétrolier, il faut observer les précautions normales de
sécurité qui s'appliquent à de tels réservoirs.
4.3.4 Avant de pénétrer à l'intérieur d'un réservoir préalablement utilisé, il faut obtenir une autorisation
d'entrée, conformément aux règlements locaux ou nationaux. Toutes les canalisations pénétrant dans le
réservoir doivent être déconnectées et obturées. Les règlements locaux ou nationaux relatifs à l'accès à
l'intérieur des réservoirs ayant contenu des carburants plombés doivent être scrupuleusement respectés.
4.3.5 Les lampes portatives doivent être d'un type agréé pour l'emploi dans des atmosphères explosives.
4.3.6 La sécurité du personnel opérationnel doit être garantie en observant strictement les points suivants.
a) Les échelles doivent être inspectées avant utilisation et les échelles à coulisse doivent être utilisées
uniquement sur leur longueur utile de sécurité. Toutes les échelles doivent être solidement attachées en
place avant utilisation et leurs pieds doivent être de niveau et stables.
b) Lorsqu'on utilise des échafaudages volants de peintre ou des «chaises suspendues» de gabier, les
chapes de palans, les câbles de mécanisme élévateur, les cordes, etc. doivent être testés avant le levage
et tout élément dont la résistance ou l'état s'avère douteux doit être remplacé. Il faut veiller tout
particulièrement à la fixation du matériel et à sa bonne utilisation.
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c) Si le jaugeage ne peut pas être effectué sans un échafaudage, un échafaudage correctement construit
en tubes d'acier ou en bois doit être monté. On ne doit pas utiliser de briques, de fûts, de caisses, etc.
pour former l'échafaudage.
d) Là où cela est nécessaire, le personnel travaillant au-dessus du niveau du sol doit porter un harnais de
sécurité.
5 Équipement
5.1 Ruban de ceinturage, conforme aux prescriptions données en A.1. Le ruban doit être bien graissé
avant emploi.
5.2 Dynamomètre, conforme aux prescriptions données en A.2, pour mesurer la tension appliquée au
ruban.
5.3 Cadre pour mesurage des recouvrements, conforme à la description donnée en A.3.
5.4 Câbles et positionneurs de ruban, conformes aux prescriptions données en A.4. Les positionneurs
doivent être montés sur le ruban de ceinturage et dotés de câbles tressés. Les câbles supérieur et inférieur
doivent être suffisamment longs pour couvrir la hauteur du réservoir.
5.5 Étau Littlejohn, conforme à la description donnée en A.5, pour maintenir le ruban sans qu'il ne vrille, et
faciliter l'application de la tension nécessaire.
5.6 Dispositif de mesurage d'épaisseur de tôle, soit une règle d'acier graduée en millimètres sur toute sa
longueur, dont au moins les premiers dix millimètres sont subdivisés en demi-millimètres, soit un autre
dispositif tel qu'une jauge d'épaisseur électronique.
5.7 Ruban de pige, conforme aux prescriptions données en A.6, suffisamment long pour atteindre, du
point de référence supérieur situé sur le toit du réservoir, le point de référence inférieur au fond du réservoir.
5.8 Lest, conforme aux prescriptions données en A.7.
5.9 Règle à bouts, d'un mètre de long, avec des graduations en centimètres et en millimètres pour
mesurer les corps extérieurs et intérieurs, etc. Si on utilise une règle en bois, elle doit être munie d'un
manchon en laiton à chaque extrémité et ne pas présenter de gauchissement.
5.10 Échelles et échafaudages: voir 4.3.6 pour les précautions de sécurité.
5.11 Appareils de mesure de la masse volumique et de la température, conformes aux prescriptions de
l'ISO 3675.
6 Exigences générales
NOTE Il convient de comparer, si possible, les mesures obtenues aux dimensions correspondantes figurant sur les
plans de construction du réservoir et de s'assurer de la rotondité de celui-ci.
6.1 Remplir au moins une fois le réservoir à sa capacité de service normale et laisser reposer au moins
24 h avant le jaugeage.
Si l'on jauge le réservoir alors qu'il contient du liquide, noter la hauteur de plein, la température et la masse
volumique du liquide lors du jaugeage. Toutefois, si la température de surface de sa paroi diffère de plus de
10 °C entre la partie vide et la partie pleine du réservoir, il devra être soit complètement rempli, soit vidé. Ne
pas transvaser de liquide pendant le jaugeage.
Il convient d'enregistrer la température ambiante avant et après le jaugeage.
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Effectuer le nombre requis de mesurages de circonférence extérieure, et le cas échéant les mesurages
supplémentaires permettant de corriger la déviation du ruban provoquée par des obstacles comme décrit
en 7.2.
NOTE Les mesurages supplémentaires nécessaires à la préparation d'un barème de jaugeage et les méthodes à
suivre pour les effectuer sont décrits dans les Articles 8 à 12.
6.2 Il est nécessaire de rapporter toutes les mesures de niveau au point de référence inférieur qui peut être
situé à une position différente du point de repère, par exemple, un point de l'angle du fond utilisé dans le but
de jauger le réservoir. Vérifier que la plaque de touche est sol
...