Petroleum liquids - Manual sampling (ISO 3170:2004)

ISO 3170:2004 specifies the manual methods to be used for obtaining samples of liquid or semi-liquid hydrocarbons, tank residues and deposits from fixed tanks, railcars, road vehicles, ships and barges, drums and cans, or from liquids being pumped in pipelines.
ISO 3170:2004 applies to the sampling of petroleum products, crude oils and intermediate products, which are stored in tanks at or near atmospheric pressure, or transferred by pipelines, and are handled as liquids at temperatures from near ambient up to 200 degrees Celsius.
The sampling procedures specified are not intended for the sampling of special petroleum products which are the subject of other International Standards, such as electrical insulating oils (IEC 60475), liquefied petroleum gases (ISO 4257), liquefied natural gases (ISO 8943) and gaseous natural gases (ISO 10715).

Flüssige Mineralölerzeugnisse - Manuelle Probenahme (ISO 3170:2004)

Diese Internationale Norm legt die manuellen Verfahren fest, die anzuwenden sind, um Proben von flüssigen oder halb-flüssigen Kohlenwasserstoffen, Tankrückständen und Ablagerungen aus feststehenden Tanks, Eisenbahnkesselwagen, Straßentankwagen, Schiffen und Lastkähnen, Fässern und Kanistern oder aus Flüssigkeiten, die durch Rohrleitungen gepumpt werden, zu gewinnen.
Die Norm bezieht sich auf die Probenahme von Mineralölerzeugnissen, Rohölen und Zwischenprodukten, welche in Tanks bei oder nahe bei Atmosphärendruck gelagert oder die durch Rohrleitungen gefördert werden und welche bei Temperaturen von etwa Umgebungstemperatur bis zu 200 °C als Flüssigkeiten vorliegen.
Die hier beschriebenen Verfahren zur Probenahme gelten nicht für die Probenahme von speziellen Mineralölerzeugnissen, die anderen Normen unterliegen, wie beispielsweise Isolieröle (IEC 60475), Flüssiggase (ISO 4257), verflüssigtes Erdgas (ISO 8943), und gasförmige Erdgase (ISO 10715).
Diese Internationale Norm bezieht sich auf existierende Probenahmeverfahren und gebräuchliche Ausrüstungen. Es ist jedoch nicht beabsichtigt, den Gebrauch von neuerer Ausrüstung, die noch nicht für die allgemeine Anwendung entwickelt wurde, auszuschließen, vorausgesetzt, dass solche Ausrüstungen eine Probenahme in Übereinstimmung mit den Anforderungen und Verfahren dieser Internationalen Norm ermöglichen.
ANMERKUNG   Für den Zweck dieser Internationalen Norm darf das Symbol % (m/m) verwendet werden, um Massenanteile in Prozent auszudrücken.

Produits pétroliers liquides - Echantillonnage manuel (ISO 3170:2004)

L'ISO 3170:2004 spécifie les méthodes manuelles de prélèvement à employer en vue d'obtenir des échantillons d'hydrocarbures liquides ou semi-liquides, de résidus et de dépôts contenus dans des réservoirs fixes, des wagons-citernes, des camions-citernes, des navires-citernes, des chalands, des fûts et des bidons, ou de liquides en cours de pompage dans des oléoducs.
L'ISO 3170:2004 s'applique à l'échantillonnage de produits pétroliers, de pétroles bruts et de produits intermédiaires, stockés dans des réservoirs à la pression atmosphérique ou approchante, ou acheminés par oléoduc, et qui sont manutentionnés à l'état liquide à des températures allant d'une température voisine de celle ambiante à 200 °C.
Les méthodes d'échantillonnage spécifiées ne concernent pas certains produits pétroliers qui font l'objet d'autres Normes internationales, tels que les huiles diélectriques (CEI 60475), les gaz de pétrole liquéfiés (ISO 4257), les gaz naturels liquéfiés (ISO 8943) et à l'état gazeux (ISO 10715).

Naftne tekočine - Ročno vzorčenje (ISO 3170:2004)

General Information

Status
Published
Publication Date
30-Jun-2004
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jul-2004
Due Date
01-Jul-2004
Completion Date
01-Jul-2004

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SLOVENSKI STANDARD
SIST EN ISO 3170:2004
01-julij-2004
1DGRPHãþD
SIST EN ISO 3170:1999
1DIWQHWHNRþLQH5RþQRY]RUþHQMH ,62
Petroleum liquids - Manual sampling (ISO 3170:2004)
Flüssige Mineralölerzeugnisse - Manuelle Probenahme (ISO 3170:2004)
Produits pétroliers liquides - Echantillonnage manuel (ISO 3170:2004)
Ta slovenski standard je istoveten z: EN ISO 3170:2004
ICS:
75.080 Naftni proizvodi na splošno Petroleum products in
general
SIST EN ISO 3170:2004 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 3170:2004
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SIST EN ISO 3170:2004
EUROPEAN STANDARD
EN ISO 3170
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2004
ICS 75.080 Supersedes EN ISO 3170:1998
English version
Petroleum liquids - Manual sampling (ISO 3170:2004)

Produits pétroliers liquides - Echantillonnage manuel (ISO Flüssige Mineralölerzeugnisse - Manuelle Probenahme

3170:2004) (ISO 3170:2004)
This European Standard was approved by CEN on 16 January 2004.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the Central Secretariat or to any CEN member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official

versions.

CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,

Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,

Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3170:2004: E

worldwide for CEN national Members.
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SIST EN ISO 3170:2004
EN ISO 3170:2004 (E)
CORRECTED 2004-03-17
Foreword

This document (EN ISO 3170:2004) has been prepared by Technical Committee ISO/TC 28

"Petroleum products and lubricants" in collaboration with Technical Committee CEN/TC 19

"Petroleum products, lubricants and related products", the secretariat of which is held by NEN.

This European Standard shall be given the status of a national standard, either by publication of

an identical text or by endorsement, at the latest by August 2004, and conflicting national

standards shall be withdrawn at the latest by August 2004.
This document supersedes EN ISO 3170:1998.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of

the following countries are bound to implement this European Standard: Austria, Belgium,

Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,

Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,

Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice

The text of ISO 3170:2004 has been approved by CEN as EN ISO 3170:2004 without any

modifications.
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SIST EN ISO 3170:2004
INTERNATIONAL ISO
STANDARD 3170
Third edition
2004-02-01
Petroleum liquids — Manual sampling
Produits pétroliers liquides — Échantillonnage manuel
Reference number
ISO 3170:2004(E)
ISO 2004
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
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© ISO 2004

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electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

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ii © ISO 2004 – All rights reserved
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
Contents Page

Foreword............................................................................................................................................................ iv

Introduction ........................................................................................................................................................ v

1 Scope...................................................................................................................................................... 1

2 Normative references ........................................................................................................................... 1

3 Terms and definitions........................................................................................................................... 1

4 Principles ............................................................................................................................................... 6

5 Apparatus............................................................................................................................................... 7

5.1 General................................................................................................................................................... 7

5.2 Tank samplers ....................................................................................................................................... 8

5.3 Drum and can samplers ..................................................................................................................... 22

5.4 Pipeline samplers................................................................................................................................ 24

5.5 Sample receivers, vessels and containers....................................................................................... 25

5.6 Container closures.............................................................................................................................. 27

5.7 Sample coolers.................................................................................................................................... 27

6 Safety precautions .............................................................................................................................. 27

7 Procedures for homogeneous petroleum liquids............................................................................ 27

7.1 Introduction ......................................................................................................................................... 27

7.2 Precautions.......................................................................................................................................... 28

7.3 Tank sampling ..................................................................................................................................... 30

7.4 Pipeline sampling................................................................................................................................ 36

7.5 Dispenser (nozzle) sampling.............................................................................................................. 40

8 Procedures for crude oils and other non-homogeneous petroleum liquids ................................ 41

8.1 General................................................................................................................................................. 41

8.2 Procedures .......................................................................................................................................... 41

9 Sample handling ................................................................................................................................. 43

9.1 General................................................................................................................................................. 43

9.2 Homogenization of samples .............................................................................................................. 43

9.3 Verification of mixing efficiency........................................................................................................ 45

9.4 Transfer of samples ............................................................................................................................ 47

10 Sampling of tank residues/deposits ................................................................................................. 47

11 Package sampling............................................................................................................................... 47

11.1 Statistical aspects of sampling packages........................................................................................47

11.2 Procedures for sampling packages .................................................................................................. 49

Annex A (informative) Guidance on safety precautions............................................................................... 52

Bibliography ..................................................................................................................................................... 55

© ISO 2004 – All rights reserved iii
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SIST EN ISO 3170:2004
ISO 3170:2004(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.

ISO 3170 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants,

Subcommittee SC 3, Static petroleum measurement.

This third edition cancels and replaces the second edition (ISO 3170:1988), which has been technically

revised.
The principal technical changes include the addition of

 procedures for tank sampling under restricted and closed system conditions, and

 procedures for the taking of manual spot samples from pipelines containing high vapour pressure liquids.

iv © ISO 2004 – All rights reserved
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
Introduction
This International Standard may be applied in combination with ISO 3171.

The purpose of this International Standard is to standardize conditions for obtaining a sample of liquid/semi-

liquid hydrocarbons from a tank, drum or pipeline by manual means. If the hydrocarbon to be sampled is of

non-homogeneous character showing significant variations in composition or containing sediments and water,

samples taken manually should not be expected to be representative, but may enable the degree of non-

homogeneity to be assessed and estimates of quality and quantity to be made.

Procedures are specified which minimize or eliminate losses of light ends from samples. Such losses can

occur during handling or transfer of samples, thereby making them non-representative of the bulk.

The procedures specified are intended to provide samples for the following purposes:

a) the determination of the liquid/hydrocarbon quality;
b) the determination of the water content;

c) the determination of other contaminants that are not considered to be part of the liquid transferred.

If the sampling conditions for purposes a), b) and c) are in conflict, separate samples are required.

Sampling procedures for tank contents that are not homogeneous are specified that enable the degree of non-

homogeneity to be assessed and estimates of quality and quantity to be made.

Procedures for the tank sampling of liquid hydrocarbons under inert gas pressure are included, together with

techniques for sampling from tanks which are equipped with vapour emission control systems.

It is recognized that, in many countries, some or all of the items covered by this International Standard are the

subject of mandatory regulations imposed by the laws of those countries. In cases of conflict between such

mandatory regulations and this International Standard, the former prevail.
© ISO 2004 – All rights reserved v
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SIST EN ISO 3170:2004
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SIST EN ISO 3170:2004
INTERNATIONAL STANDARD ISO 3170:2004(E)
Petroleum liquids — Manual sampling
1 Scope

This International Standard specifies the manual methods to be used for obtaining samples of liquid or semi-

liquid hydrocarbons, tank residues and deposits from fixed tanks, railcars, road vehicles, ships and barges,

drums and cans, or from liquids being pumped in pipelines.

It applies to the sampling of petroleum products, crude oils and intermediate products, which are stored in

tanks at or near atmospheric pressure, or transferred by pipelines, and are handled as liquids at temperatures

from near ambient up to 200 °C.

The sampling procedures specified are not intended for the sampling of special petroleum products which are

the subject of other International Standards, such as electrical insulating oils (IEC 60475), liquefied petroleum

gases (ISO 4257), liquefied natural gases (ISO 8943) and gaseous natural gases (ISO 10715).

This International Standard refers to existing methods of sampling and the type of equipment presently in use.

It is, however, not intended that it should exclude the use of new equipment not yet developed for commercial

use, provided that such equipment enables samples to be obtained in accordance with the requirements and

procedures of this International Standard.

NOTE For the purposes of this International Standard, the term “% (m/m)” is used to represent the mass fraction.

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 1998 (all parts), Petroleum industry — Terminology

ISO 2859-1:1999, Sampling procedures for inspection by attributes — Part 1: Sampling plans indexed by

acceptable quality limit (AQL) for lot-by-lot inspection
ISO 3171:1988, Petroleum liquids — Automatic pipeline sampling
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 1998 and the following apply.

3.1
acceptable quality level
AQL

maximum per cent defective (or the maximum number of defects per hundred units) that, for purposes of

sampling inspection, can be considered satisfactory as a process average
© ISO 2004 – All rights reserved 1
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
3.2
all-level sample

sample obtained with an apparatus which accumulates the sample while passing in one direction only through

the total liquid height, excluding any free water
3.3
automatic sampler
device used to extract a representative sample from the liquid flowing in a pipe

NOTE The automatic sampler generally consists of a probe, a sample extractor, an associated controller, a flow

measuring device, and a sample receiver.
3.4
batch

collection of packages containing a product of a single type and composition and of a single manufactured lot,

or of a single delivery
3.5
bottom sample

spot sample taken from the product at or close to the bottom of a tank or container

See Figure 1.
3.6
bottom water sample
spot sample of free water taken from beneath the petroleum in a tank
3.7
closed sampling

process of taking samples within a tank under closed conditions, which does not permit the release of any

tank contents or vapour to the atmosphere
3.8
composite sample

sample obtained by combining a number of spot samples in defined proportions so as to obtain a sample

representative of the bulk of the product
3.9
dipper sample

sample obtained by placing a dipper or other collecting vessel in the path of a free-flowing stream to collect a

definite volume from the full cross-section of the stream at regular time intervals for a constant time rate of

flow, or at time intervals varied in proportion to the flow rate

NOTE This method is normally restricted to sampling petroleum coke from conveyor belts.

3.10
drain sample
sample obtained from the water draw-off valve on a storage tank

NOTE Occasionally, a drain sample may be the same as a bottom sample, for example, in the case of a tank car.

3.11
floating roof sample

spot sample taken just below the surface to determine the density of the liquid on which the roof is floating

3.12
grease sample

spot sample obtained by scooping or dipping a quantity of soft or semi-liquid material from a container

2 © ISO 2004 – All rights reserved
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
3.13
integrity of the sample

condition of being complete and unaltered, i.e. the sample being preserved with the same composition as

when it was taken from the bulk of the liquid
3.14
lower sample

spot sample taken at a level of five-sixths of the depth of liquid below the top surface

See Figure 1.
3.15
middle sample

spot sample taken at a level of one-half of the depth of liquid below the top surface

See Figure 1.
3.16
mixer

device which provides a homogeneous mixture of the liquid within a pipeline or container in order to obtain a

representative sample
3.17
open sampling

process of taking traditional samples within a tank via an open gauge hatch or gauging access point

NOTE If the tank ullage space is pressurized, it will normally be necessary to use other (closed or restricted)

procedures to avoid de-pressurizing the tank and the consequent loss of volatile organic compounds (VOCs).

3.18
per cent defective

one hundred times the number of defective units of product contained in any given quantity of units of product

divided by the total number of units of product inspected, i.e.:
number of defectives
per cent defective = × 100
number of units inspected
3.19
portable sampling device
PSD

housing designed to provide a gas-tight connection to a vapour-lock valve, which contains a restricted or

closed system sampler and is fitted with a tape or cable winding mechanism for lowering and retrieving the

sampler
3.20
representative sample

sample having its physical or chemical characteristics identical to the volumetric average characteristics of the

total volume being sampled
3.21
residues and deposits

organic and inorganic matter, together with any water dispersed within it, which has separated from the liquid

and either fallen to the bottom of the tank containing the liquid, or been left in the tank after the liquid has been

pumped out
© ISO 2004 – All rights reserved 3
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
3.22
restricted sampling

process of taking samples within a tank using equipment which is designed to substantially reduce or

minimize the vapour losses that would occur during open sampling, but where the equipment is not completely

gas-tight
3.23
running sample

sample obtained with an apparatus which accumulates the sample while passing in both directions through

the total liquid height, excluding any free water
3.24
sample conditioning

mixing necessary to homogenize the sample during sample handling in preparation for subsampling and/or

analysis
3.25
sample handling
any conditioning, transferring, dividing and transporting of the sample

NOTE Sample handling includes transferring the sample from the primary sampling device to any secondary

container, and the transferring of subsamples to the laboratory apparatus in which it is to be analyzed.

3.26
sample size

number of samples to be drawn from a batch to determine its acceptability as given in sampling plans

3.27
skim sample
surface sample
spot sample taken from the surface of the liquid
See Figure 1.
3.28
spot sample

sample taken at a specific location in a tank or from a flowing stream in a pipe at a specific time

3.29
static mixer
mixing device having no moving parts and located within a pipe or tube

NOTE The effectiveness of the static mixer depends on the kinetic energy of the moving liquid for the energy

required to mix the liquid.
3.30
still-well
guide pole
still-pipe
sounding-pipe
stand pipe

vertical cylindrical pipe built into a tank to permit gauging operations while reducing errors arising from

turbulence or agitation of the liquid

NOTE 1 Samples taken from unperforated or unslotted still-wells should not be used for custody transfer applications,

see 7.2.1.3.
NOTE 2 Still-wells may also be found on ships and barges.
4 © ISO 2004 – All rights reserved
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
3.31
suction-level sample
outlet sample

sample taken at the lowest level from which liquid hydrocarbon is pumped from the tank

See Figure 1.

NOTE In determining this level, appropriate allowance is made for any fittings within the tank such as swing-arm,

suction baffle or internal bend.
3.32
sump sample
spot sample taken from within a sump
3.33
suspended water
water within the oil that is finely dispersed as small droplets

NOTE It may, over a period of time, either collect as free water or become dissolved water, depending on the

conditions of temperature and pressure prevailing.
3.34
tap sample
tank-side sample
spot sample taken from a sample tap on the side of a tank
3.35
test portion

portion of a sample or subsample that is introduced into the analytical test apparatus

3.36
top sample
spot sample obtained 150 mm below the top surface of the liquid
See Figure 1.
3.37
total water
sum of all the dissolved, suspended and free water in a cargo or parcel of oil
3.38
ullage

empty capacity left in a fixed volume sample receiver/container above the liquid surface

3.39
upper sample

spot sample taken at a level of one-sixth of the depth of liquid below the top surface

See Figure 1.
3.40
vapour-lock valve
vapour control valve

device fitted to the top of vapour-tight or pressure tanks to permit manual measurement and/or sampling

operations to be carried out without loss of pressure
© ISO 2004 – All rights reserved 5
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SIST EN ISO 3170:2004
ISO 3170:2004(E)
3.41
zone sample
core sample
flow-through sample

sample taken as that part of the liquid column which is trapped within the whole height of a sampler when it is

sealed at a single spot location within a tank, after having been fully flushed as it was lowered to that position

Key
1 top sample 6 suction level or outlet sample
2 surface of oil 7 lower sample
3 skim sample 8 bottom sample
4 upper sample 9 sump sample
5 middle sample
Figure 1 — Examples of spot sample positions
4 Principles

4.1 To ensure that samples submitted for examination are as representative as possible of the liquid being

sampled, the necessary precautions are given. These depend on the characteristics of the liquid, the tank,

container or pipeline from which the sample is being obtained, and the nature of the tests to be carried out on

the sample.
Two basic manual sampling methods are available:
 tank sampling (static sampling);
 pipeline sampling (dynamic sampling).
6 © ISO 2004 – All rights reserved
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SIST EN ISO 3170:2004
ISO 3170:2004(E)

When a batch is received or consigned, either tank or pipeline sampling, or both, may be possible. However, if

both methods are used, the two sets of samples shall not be mixed.

4.2 Tank sampling is commenced when the contents of the tank are at rest. The following types of samples

are normally taken for analysis:
a) upper, middle and lower samples, or
b) upper, middle and suction-level (outlet) samples.

If tests on these samples show that the contents of the tank are homogeneous, they may be combined, in

proportion to the volume that each sample represents, for further tests.

If the tests on these samples show that the contents of the tank are non-homogeneous, it may be necessary

to draw spot samples from more than three levels and either a composite sample is prepared for analysis or, if

blending would impair the integrity of the sample, each sample is analysed separately and the composition

corresponding to the composite sample is calculated. In this calculation, allowance is made for the proportion

of the oil represented by each sample. Examples of spot sample positions are shown in Figure 1.

Other methods are a running sample or an all-level sample.

As both these methods only result in a single sample, they cannot be used to assess the homogeneity (or

otherwise) of a tank’s contents. Running and all-level samples are commonly taken and used to determine the

average quality of a tank's contents.

NOTE 1 Safety and environmental regulations may restrict tank sampling operations which can result in the release of

hydrocarbons or other volatile organic compounds (VOCs) into the atmosphere. In these circumstances, it will not normally

be feasible to use traditional open sampling procedures via an open gauge hatch or gauging access point. If the tank

ullage space is pressurized, and/or the tank forms part of a vapour balancing/recovery system, it will normally be

necessary to use closed or restricted sampling procedures to avoid de-pressurizing the tank and minimize the consequent

loss of VOCs. If the vapour from the tank contents is hazardous, it will also normally be necessary to use closed or

restricted sampling procedures to minimize the risk of environmental impact.

NOTE 2 Closed sampling is the process of taking samples within a tank using closed sampling devices under closed

system conditions. A closed system exists when the operations do not permit the direct exposure and/or release of any

tank contents to atmosphere. Manual closed sampling is therefore normally carried out via a vapour-lock valve, using a

closed sampling device that provides a gas-tight seal when in use. In order to ensure that no residual vapour is released

from a closed system, special facilities may be provided to displace any vapour held up within the device prior to

disconnecting the sampling device from the vapour-lock valve.

NOTE 3 Restricted sampling is the process of taking samples within a tank using a restricted sampling device that is

operated via a vapour-lock valve. Restricted equipment is designed to substantially reduce or minimize the vapour losses

that would occur during open sampling, but may still allow a small quantity of vapour to escape because the equipment is

not completely gas-tight.

4.3 To obtain a representative sample of a batch/parcel transfer quantity being pumped in a pipeline, the

sample is drawn using an automatic sampling device in accordance with ISO 3171. On occasions, it may be

necessary to take dynamic pipeline samples manually. These are spot samples and may not be

representative of the bulk (see 7.4).
5 Appara
...

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