SIST EN 16321-1:2013

Petrol vapour recovery during refuelling of motor vehicles at service stations - Part 1: Test methods for the type approval efficiency assessment of petrol vapour recovery systems

This European Standard specifies the measurement and test methods for the efficiency assessment of petrol vapour recovery systems for service stations (Stage II).

Benzindampf-Rückrückführung während der Betankung von Kraftfahrzeugen an Tankstellen - Teil 1: Prüfverfahren für die Typzulassung der Effizienzbewertung von Gasrückführsystemen

Die vorliegende Europäische Norm legt die Mess- und Prüfverfahren für die Effizienzbewertung von Gasrückführsystemen für Tankstellen fest (Phase II).

Récupération des vapeurs d'essence lors du ravitaillement en carburant des véhicules à moteur dans les stations-service - Partie 1: Méthodes d'essai pour l'homologation et l'évaluation de l'efficacité des systèmes de récupération des vapeurs

La présente Norme européenne spécifie les méthodes de mesurage et d’essai pour l’évaluation de l’efficacité des systèmes de récupération des vapeurs d’essence dans les stations-service (phase II).

Rekuperiranje bencinskih hlapov med polnjenjem motornih vozil na bencinskih servisih - 1. del: Preskusne metode za odobritev tipa, ocena učinkovitosti sistema za rekuperiranje bencinskih hlapov

Ta evropski standard določa merilne in preskusne metode za oceno učinkovitosti sistemov za rekuperiranje bencinskih hlapov za bencinske servise (II. stopnja).

General Information

• Status: Published
• Public Enquiry End Date: 31-Jan-2012
• Publication Date: 17-Nov-2013
• ICS: 75.200 - Petroleum products and natural gas handling equipment
• Technical Committee: TLP - Pressure vessels
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Oct-2013
• Due Date: 23-Dec-2013
• Completion Date: 18-Nov-2013
• Directive: 2009/126/EC - Stage II petrol vapour recovery during refuelling of motor vehicles at service stations
• Mandate: M/456 - Mandate to CEN for the development of European standards to establish the petrol vapour recovery efficiency of new Stage II petrol vapour recovery equipment and the in-use performance of such equipment once installed at service stations.
• Ref Project: EN 16321-1:2013 - Petrol vapour recovery during refuelling of motor vehicles at service stations - Part 1: Test methods for the type approval efficiency assessment of petrol vapour recovery systems

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 16321-1:2013
01-december-2013
5HNXSHULUDQMHEHQFLQVNLKKODSRYPHGSROQMHQMHPPRWRUQLKYR]LOQDEHQFLQVNLK
VHUYLVLKGHO3UHVNXVQHPHWRGH]DRGREULWHYWLSDRFHQDXþLQNRYLWRVWLVLVWHPD
]DUHNXSHULUDQMHEHQFLQVNLKKODSRY
Petrol vapour recovery during refuelling of motor vehicles at service stations - Part 1:
Test methods for the type approval efficiency assessment of petrol vapour recovery
systems
Benzindampf-Rückrückführung während der Betankung von Kraftfahrzeugen an
Tankstellen - Teil 1: Prüfverfahren für die Typzulassung der Effizienzbewertung von
Gasrückführsystemen
Récupération des vapeurs d'essence lors du ravitaillement en carburant des véhicules à
moteur dans les stations-service - Partie 1: Méthodes d'essai pour l'homologation et
l'évaluation de l'efficacité des systèmes de récupération des vapeurs
Ta slovenski standard je istoveten z: EN 16321-1:2013
ICS:
75.200 2SUHPD]DVNODGLãþHQMH Petroleum products and
QDIWHQDIWQLKSURL]YRGRYLQ natural gas handling
]HPHOMVNHJDSOLQD equipment
SIST EN 16321-1:2013 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 16321-1:2013

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SIST EN 16321-1:2013


EUROPEAN STANDARD
EN 16321-1

NORME EUROPÉENNE

EUROPÄISCHE NORM
September 2013
ICS 75.200
English Version
Petrol vapour recovery during refuelling of motor vehicles at
service stations - Part 1: Test methods for the type approval
efficiency assessment of petrol vapour recovery systems
Récupération des vapeurs d'essence lors du ravitaillement Benzindampf-Rückführung während der Betankung von
en carburant des véhicules à moteur dans les stations- Kraftfahrzeugen an Tankstellen - Teil 1: Prüfverfahren für
service - Partie 1: Méthodes d'essai pour l'homologation et die Typzulassung der Effinzienzbewertung von
l'évaluation de l'efficacité des systèmes de récupération Gasrückführungssystemen
des vapeurs
This European Standard was approved by CEN on 26 July 2013.

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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same
status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2013 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 16321-1:2013: E
worldwide for CEN national Members.

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
Contents Page
Foreword .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Requirements .8
4.1 General .8
4.2 Efficiency .8
4.3 Petrol vapour /petrol ratio .8
4.4 Proportionality .9
4.5 Correction factor . 10
4.6 Vapour processing unit . 10
5 Measurement and test methods for the assessment of petrol vapour recovery systems at
service stations . 11
5.1 General test conditions . 11
5.2 Efficiency test . 11
5.2.1 General . 11
5.2.2 Test tanks . 12
5.2.3 Test procedure . 13
5.2.4 Test refuelling . 14
5.2.5 Adsorber . 14
5.2.6 Calculation of the efficiency . 14
5.3 Petrol vapour/petrol ratio . 14
5.3.1 General . 14
5.3.2 Test procedure . 15
5.4 Proportionality test . 16
5.4.1 General . 16
5.4.2 Test procedure . 16
5.5 Correction factor determination . 17
5.5.1 General . 17
5.5.2 Test with petrol vapour . 17
5.5.3 Test with air . 17
5.6 Retesting criteria for modifications . 19
6 Automatic monitoring systems . 19
7 Environmental aspects . 19
8 Certificate for vapour recovery systems . 19
9 Marking . 19
Annex A (normative) List of representative tanks . 20
Annex B (normative) Retesting criteria for modifications . 21
Annex C (normative) Certificate format . 22
Annex D (normative) Monitoring system . 23
D.1 General . 23
D.2 Requirements . 23
2

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
D.3 Measurement and test methods . 24
D.3.1 Test for pressure loss . 24
D.3.2 Test for detection of a vapour recovery efficiency error . 24
D.3.3 Test for an alarm when the monitor detects an error during a self-test . 24
D.3.4 Test for de-activation of a delivery point . 25
D.4 Example monitoring system certificate . 25
Annex E (informative) Identification of petrol vapour recovery systems . 26
Annex F (informative) Environmental aspects . 27
Bibliography . 28

3

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
Foreword
This document (EN 16321-1:2013) has been prepared by Technical Committee CEN/TC 393 “Equipment for
storage tanks and for filling stations”, the secretariat of which is held by DIN.
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 March 2014, and conflicting national standards shall be withdrawn at
the latest by March 2014.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
EN 16321, Petrol vapour recovery during refuelling of motor vehicles at service stations, is divided into the
following parts:
— Part 1:Test methods for the type approval efficiency assessment of petrol vapour recovery systems;
— Part 2: Test methods for verification of vapour recovery systems at service stations.
WARNING — Persons using this European Standard should be familiar with normal laboratory
practice. This standard does not purport to address all of the safety problems, if any, associated with
its use. It is the responsibility of the user to establish appropriate safety and health practices and to
ensure compliance with any national regulatory conditions.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
4

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)

1 Scope
This European Standard specifies the measurement and test methods for the efficiency assessment of petrol
vapour recovery systems for service stations (Stage II).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 228:2012, Automotive fuels — Unleaded petrol — Requirements and test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
back pressure
differential pressure relative to atmosphere caused by the flow resistance of the petrol vapour recovery return
line from the system to the petrol vapour receiving area
3.2
maximum back pressure
differential pressure relative to atmosphere at the outlet of the vapour pump up to which the system operates
properly
3.3
basic emission
hydrocarbons (petrol vapour) that are emitted into the environment during refuelling of test tanks without an
operating petrol vapour recovery system
3.4
gas volume meter
device for continuous measurement of air or vapour volume
Note 1 to entry: Bellows type gas volume meters are recommended.
3.5
boot measurement method
measurement method whereby the hydrocarbon emissions from the filler neck area of the test tanks that are
not retrieved by the petrol vapour recovery system are collected in a collecting device (boot)
3.6
calibration factor of the gas volume meter
specific factor of the gas volume meter used for the data processing when using an external display
3.7
certificate
qualification document confirming that the petrol vapour recovery system meets the requirements of this
standard
5

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
3.8
correction factor
system dependent factor used to allow calibration and periodic checking of the vapour recovery system under
simulated flow conditions using air
3.9
simulated petrol flow method
dry test method
method for determining the petrol vapour/petrol ratio without any fuel flow
3.10
efficiency
ratio between the average values of the hydrocarbon mass recovered to the petrol vapour receiving area and
the basic emission
3.11
petrol dispenser
metering pump or dispenser according to EN 13617-1
3.12
petrol meter
measuring instrument to measure the petrol volume flow
3.13
hose assembly
fuel hose complete with an internal vapour tubing or vapour hose and fitted with couplings
[SOURCE: EN 13483:2013, Clause 3]
3.14
nozzle
automatic delivery nozzle which is a manually operated device that controls the flow of fuel during a
dispensing operation and includes a spout and an automatic shut-off mechanism
[SOURCE: EN 13012:2012, 3.1]
3.15
pulsing rate
number of pulses generated from 1 l of petrol flow
3.16
proportionality
linearity of the petrol vapour/petrol ratio at different petrol volume flow rates
3.17
residual emission
hydrocarbons (petrol vapour) that are emitted to the environment during refuelling of test tanks with the petrol
vapour recovery system operating
3.18
SHED chamber
measuring facility for verification of the test equipment used in determining the basic and residual emission
Note 1 to entry: SHED stands for Sealed Housing for Evaporative Determination.
6

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
3.19
test tank
petrol tank and filler neck of a motor vehicle of the representative fleet of motor vehicles, fitted with a plate
allowing the interface of the test equipment to be positioned in a similar way as would be achieved with the
motor vehicle body
3.20
petrol vapour/petrol ratio
ratio of the recovered volume of petrol vapour/air mixture to the volume of petrol dispensed at the same time
Note 1 to entry: Petrol vapour/petrol ratio expressed in percentage.
3.21
post processing unit
PPU
device for setting and control of the vapour recovery system to simulate petrol flow, to read data, to change
settings, to calculate and to indicate results
Note 1 to entry: A hand-held control unit is a post-processing unit.
3.22
collecting device
boot
device to capture the hydrocarbon emissions from the filler neck of the motor vehicle or test tank
3.23
vapour processing unit
unit to process petrol vapour captured during refuelling
Note 1 to entry: The vapour processing unit may exhaust petrol vapour to atmosphere.
3.24
delivery point
dispensing nozzle with associated vapour collection components
3.25
de-activation time
time between the detection of a petrol vapour/petrol ratio error, self-diagnostic error or self-test error, and the
delivery point being de-activated
3.26
wet test method
method for determining the petrol vapour/petrol ratio with fuel flow
3.27
air/petrol ratio
ratio of the recovered volume of air to the volume of petrol dispensed at the same time
Note 1 to entry: Air/petrol ratio expressed in percentage.
3.28
gas flow meter
device for measurement of air or vapour flow rate
7

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
3.29
maximum petrol volume flow rate
maximum petrol volume flow rate stated by the applicant of the petrol vapour recovery system
Note 1 to entry: Maximum petrol volume flow rate expressed in litre per minute.
4 Requirements
4.1 General
The maximum back pressure stated by the applicant of the petrol vapour recovery system shall be ≥ 1 kPa.
The test equipment placed in the return-line shall not add more back pressure than 1 kPa.
An overview of the performance characteristics and the appropriate tests is given in Table 1.
Table 1 — Performance characteristics
Performance Requirement Subclause Criterion Test according
characteristic to:
efficiency η ≥ 85 % 4.2 — 5.2
petrol individual 4.3 — 5.3
vapour/petrol ratio measurement:
95 % ≤ x ≤ 105 %
average value:
98 % ≤ y ≤ 102 %
proportionality 95 % ≤ z ≤ 105 % 4.4.2 maximum petrol flow rate 5.4
stated by the applicant
4.4.3
petrol volume flow rate
−1
(38,0 ± 1,0) l·min
−1
z ± 5 % 4.4.4 (28,5 ± 1,0) l·min 5.4
−1
z ± 10 % 4.4.5 (19,0 ± 1,0) l·min 5.4
−1
95 % ≤ z ≤ 105 % 4.4.6 (38,0 ± 1,0) l·min 5.4
−1
z ± 10 % 4.4.7 (19,0 ± 1,0) l·min 5.4
Ik – k I ≤ 0,03 4.5.7 petrol volume flow rate 5.5.2, 5.5.3
b a
−1
(38,0 ± 1,0) l min ,
maximum back pressure
and back
pressure < 1 kPa
4.2 Efficiency
When tested in accordance with 5.2 the efficiency of each petrol vapour recovery system shall reach at
least 85 %.
4.3 Petrol vapour /petrol ratio
Systems intended to return petrol vapour directly to a storage tank, shall be tested in accordance with 5.3 at a
-1
petrol volume flow rate of (38,0 ± 1,0) l·min .
8

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
Where a petrol vapour recovery pump serves more than one delivery point, the test shall initially be performed
on one delivery point with no other delivery points dispensing. The test shall be repeated on the same delivery
point with the maximum number of simultaneous delivery points, as stated by the applicant of the vapour
recovery system, also delivering fuel. During this test all delivery points shall deliver fuel at a petrol volume
-1
flow rate of (38,0 ± 1,0) l·min .
The individual petrol vapour/petrol ratios shall be ≥ 95 % and ≤ 105 %. The average petrol vapour/petrol ratios
of all tests according to 5.3 shall be ≥ 98 % and ≤ 102 %.
For systems which process the petrol vapour, the requirements of 4.6 apply.
4.4 Proportionality
4.4.1 The sequence 4.4.2 to 4.4.12 shall be carried out at a defined back pressure. The defined back
pressure shall be the maximum back pressure stated by the applicant of the petrol vapour recovery system
-1
measured at a petrol volume flow rate of (38,0 ± 1,0) l·min .
4.4.2 Where the maximum petrol volume flow rate stated by the applicant of the petrol vapour recovery
−1
system is greater than 38,0 l·min , the petrol vapour recovery system shall be tested at the maximum petrol
flow rate according to 5.4 and the result shall be recorded. The petrol vapour/petrol ratio shall be ≥ 95 %
and ≤ 105 %.
4.4.3 The petrol vapour recovery system shall be tested according to 5.4 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l·min and the result shall be recorded. The petrol vapour/petrol ratio shall be ≥ 95 %
and ≤ 105 %.
4.4.4 The petrol vapour recovery system shall be tested according to 5.4 at a petrol volume flow rate of
-1
(28,5 ± 1,0) l·min and the result shall be recorded.
4.4.5 The petrol vapour recovery system shall be tested according to 5.4 at a petrol volume flow rate of
-1
(19,0 ± 1,0) l·min and the result shall be recorded.
4.4.6 The petrol vapour recovery system shall be tested according to 5.4 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l·min and the result shall be recorded.
4.4.7 The petrol vapour recovery system shall be tested according to 5.4 at a petrol volume flow rate of
-1
(19,0 ± 1,0) l·min and the result shall be recorded.
4.4.8 Where the maximum petrol volume flow rate stated by the applicant of the petrol vapour recovery
-1
system is greater than 38,0 l·min , the petrol vapour recovery system shall be tested at the maximum petrol
flow rate according to 5.4 and the result shall be recorded. The petrol vapour/petrol ratio shall be ≥ 95 %
and ≤ 105 %.
4.4.9 The result of 4.4.4 shall be within ± 5 % of 4.4.3.
4.4.10 The result of 4.4.5 shall be within ± 10 % of 4.4.3.
4.4.11 The result of 4.4.6 shall be within the tolerance of 4.4.3.
4.4.12 The result of 4.4.7 shall be within ± 10 % of 4.4.6.
4.4.13 The sequence 4.4.2 through 4.4.12 shall be repeated at a back pressure < 1 kPa.
4.4.14 The maximum petrol volume flow rate stated by the applicant shall be tested and given in the test
certificate.
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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
4.4.15 Where a petrol vapour recovery pump serves more than one delivery point the sequence 4.4.2
through 4.4.13 shall initially be performed with only one delivery point operational. The sequence shall be
repeated at the maximum vacuum pressure stated by the applicant of the vapour recovery system. The
sequence shall then be repeated at the minimum vacuum pressure stated by the applicant of the vapour
recovery system. The maximum number of delivery points stated on the certificate shall not require a vacuum
pressure greater than the maximum vacuum pressure used for the tests.
4.5 Correction factor
4.5.1 The petrol vapour recovery system shall be tested according to 5.5.2 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l·min and maximum back pressure stated by the applicant of the vapour recovery system, the
) and shall be recorded.
ratio calculated in 5.5.2 is (r
1
4.5.2 The petrol vapour recovery system shall be tested according to 5.5.3 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l·min and maximum back pressure stated by the applicant of the vapour recovery system, the
ratio calculated in 5.5.3 is (r ) and shall be recorded.
2
4.5.3 The petrol vapour recovery system shall be tested according to 5.5.2 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l min and at a back pressure < 1 kPa, the ratio calculated in 5.5.2 is (r ) and shall be recorded.
3
4.5.4 The petrol vapour recovery system shall be tested according to 5.5.3 at a petrol volume flow rate of
-1
(38,0 ± 1,0) l·min and at a back pressure < 1 kPa, the ratio calculated in 5.5.3 is (r ) and shall be recorded.
4
4.5.5 The correction factor k shall be calculated according to Formula (1) with maximum back pressure and
a
record the result:
r
2
k = (1)
a
r
1

4.5.6 The correction factor k shall be calculated according to Formula (2) with a back pressure < 1 kPa and
b
record the result:
r
4
k = (2)
b
r
3
4.5.7 k − k shall be ≤ 0,03.
b a
The correction factor k shall be calculated according to Formula (3) and shall be rounded to two decimal
places.
k + k
a b
k= (3)
2
4.6 Vapour processing unit
Vapour processing units are not mandatory. Vapour processing units may be used in systems which do not
return petrol vapour to a storage tank. When vapour processing units are incorporated the exhaust emission
hydrocarbon content shall be ≤ 3 % of the input hydrocarbon mass when tested with a state of the art
measurement method, e.g. with FID (Flame Ionisation Detector).
10

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
5 Measurement and test methods for the assessment of petrol vapour
recovery systems at service stations
5.1 General test conditions
It shall be verified that the test equipment and the vapour recovery system under test are free from leaks.
During the measurements, the following parameters and boundary conditions shall be maintained:
a) petrol according to Table 1 of EN 228:2012;
b) petrol temperature (15 ± 5) °C measured at the nozzle outlet;
c) petrol vapour pressure shall be measured before the first test and after the last test. The vapour pressure
shall not change by more than ± 10 % from the first measurement;
d) maximum back pressure ± 10 %;
e) ambient air temperature (20 ± 5) °C;
f) test tanks according to Annex A;
-1 -1
g) gas volume meter capable of operating at flow rates of between 10 l min and 50 l min , having an
accuracy of ± 2 %.
5.2 Efficiency test
5.2.1 General
The basis for the calculation of the efficiency shall be the determination of the basic emission and the residual
emission. The basic emission shall be measured with the petrol vapour recovery system switched off and the
residual emission with the petrol vapour recovery system switched on. The residual emission shall be
determined for each test tank in two orientations of the nozzle on the filler neck.
a) Normal position (nozzle trigger guard in the vertical position); and
b) position of the nozzle rotated 45° with respect to the normal position with bottom of the handle pointing to
the rear of the car.
The test shall be performed with the maximum back pressure of the vapour recovery system stated by the
applicant.
-1
The measurement shall be carried out with a petrol volume flow rate of (38,0 ± 1,0) l·min . It shall be carried
out twice on each test tank.
If, on an individual test tank, the two test results for the efficiency in % differ by no more than 1,5 %, the
average of these results shall be recorded.
If, on an individual test tank, the two test results for the efficiency in % differ by more than 1,5 % a third
measurement shall be carried out. If the third result differs by no more than 1,5 % from the second
measurement, then the average of the second and third measurement shall be recorded.
If, on an individual test tank, the third result differs by more than 1,5 % from the second measurement, but
differs by less than 1,5 % from the first measurement, then the average of the first and third measurement
shall be recorded.
11

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SIST EN 16321-1:2013
EN 16321-1:2013 (E)
If the third result differs by more than 1,5 % from both the second measurement and the first measurement,
then the test has failed.
The efficiency of the vapour recovery system shall be calculated using the average result for each test tank
according to 5.2.6.
The basic emission and the residual emission shall be determined by absorption of the emitted hydrocarbons
on activated carbon and gravimetric analysis. The hydrocarbons shall be captured at the filler neck, where the
emissions occur, using a collecting device (boot), see Figure 1. Before new test equipment is used for testing
petrol vapour recovery systems, the performance of the test equipment including a test tank shall be verified
by comparative measurements in a SHED chamber.

Key
part of the dispenser
1 underground storage tank 5 petrol volume display
2 petrol pump 6 hose assembly
3 petrol volume meter 7 nozzle
4 splitter valve 8 vapour recover
...