ISO/TS 16332:2006

Diesel engines — Fuel filters — Method for evaluating fuel/water separation efficiency

ISO/TS 16332:2006 specifies a fuel/water separation test with continuous water injection, using an offline water concentration measuring method, for evaluating the ability of a fuel filter to separate either finely or coarsely dispersed undissolved water out of fuel. This test is intended for application to filter elements which are installed upstream or downstream of the low pressure pump, having a rated flow between 50 l/h and 900 l/h. By agreement between customer and filter manufacturer, and with some modification, the procedure may be used for fuel filters with higher flow rates.

Moteurs diesels — Filtres à carburant — Méthode d'évaluation de l'efficacité des séparateurs carburant-eau

General Information

• Status: Withdrawn
• Publication Date: 13-Sep-2006
• Withdrawal Date: 13-Sep-2006
• ICS: 43.060.40 - Fuel systems
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 1 - Fuel filters
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 05-Apr-2018

Relations

• Revised: ISO 16332:2018 - Diesel engines — Fuel filters — Method for evaluating fuel/water separation efficiency
• Effective Date: 28-Feb-2009

Standards Content (Sample)

TECHNICAL ISO/TS
SPECIFICATION 16332
First edition
2006-09-15

Diesel engines — Fuel filters — Method
for evaluating fuel/water separation
efficiency
Moteurs diesels — Filtres à carburant — Méthode d'évaluation de
l'efficacité des séparateurs carburant-eau



Reference number
ISO/TS 16332:2006(E)
©
ISO 2006

---------------------- Page: 1 ----------------------
ISO/TS 16332:2006(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 2006
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 [e-mail]
Web www.iso.org
Published in Switzerland

ii © ISO 2006 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/TS 16332:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Symbols . 2
5 Test equipment . 2
5.1 Test fluids . 2
5.1.1 Test fuels . 2
5.1.2 Test water . 3
5.2 Laboratory equipment. 3
5.2.1 High-speed mixer. 3
5.3 Test stand . 3
5.3.1 Filter test circuit (see Figure 1) . 4
6 Test conditions . 6
6.1 Volume of fuel . 6
6.2 Test temperature T.6
6.3 Test flow rate Q . 7
T
6.4 Water concentration (undissolved water) . 7
6.5 Differential pressure ∆p across water emulsifying device (orifice plate) . 7
O
6.6 Total test duration t . 7
total
7 Accuracy of measuring instruments and test conditions . 7
8 Validation procedure . 8
8.1 Test stand . 8
8.2 Sampling procedure . 9
8.2.1 Primary sampling procedure . 9
8.2.2 Secondary sampling procedure . 9
8.2.3 Secondary sampling procedure validation . 9
9 Test procedure . 10
9.1 Pre-test preparation. 10
9.2 Efficiency measurement . 10
10 Calculation and reporting of test results. 11
10.1 Calculation of water separation efficiency. 11
10.2 Test report . 12
Annex A (normative) Water emulsifying device. 13
Annex B (normative) Procedure to determine the water droplet size distribution (DSD) . 16
Annex C (informative) Typical filter test report . 21
Annex D (informative) Selection of the specified average water droplet sizes D . 23
50
Bibliography . 24

© ISO 2006 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/TS 16332:2006(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.
In other circumstances, particularly when there is an urgent market requirement for such documents, a
technical committee may decide to publish other types of normative document:
— an ISO Publicly Available Specification (ISO/PAS) represents an agreement between technical experts in
an ISO working group and is accepted for publication if it is approved by more than 50 % of the members
of the parent committee casting a vote;
— an ISO Technical Specification (ISO/TS) represents an agreement between the members of a technical
committee and is accepted for publication if it is approved by 2/3 of the members of the committee casting
a vote.
An ISO/PAS or ISO/TS is reviewed after three years in order to decide whether it will be confirmed for a
further three years, revised to become an International Standard, or withdrawn. If the ISO/PAS or ISO/TS is
confirmed, it is reviewed again after a further three years, at which time it must either be transformed into an
International Standard or be withdrawn.
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/TS 16332 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 7,
Injection equipment and filters for use on road vehicles.
Annexes A and B form normative parts of this Technical Specification. Annexes C and D are for information
only.
iv © ISO 2006 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/TS 16332:2006(E)
Introduction
Modern fuel injection systems, installed in passenger cars, as well as in heavy duty or off-road vehicle
applications, require high and stable separation efficiencies for all insoluble contaminants in the fuel to ensure
a prolonged life. Beside solid contamination, undissolved water, in finely or coarsely emulsified form, can also
reduce the lifetime of injection systems. Suitable fuel filters, having a high level water separation efficiency,
are an absolute necessity for system longevity.
Factors found to affect the separation efficiency of undissolved water in the field are mainly due to the fuel
quality, which is strongly influenced by the performance of additives in the fuel itself, as well as the actual
characteristics of the fuel/water-emulsion, the specific flow rate of the system, the type of media in the filter
element, as well as the size and design of the filter housing itself. To ensure laboratory test results are
comparable, these various parameters have to be taken into account in the test method, in order to reduce
their influence on the test results.
NOTE A variety of tests were investigated prior and parallel to the preparation of this Technical Specification to
specify the required test conditions. Additional work is underway to validate, confirm and if necessary to modify the
following parameters:
⎯ test fuel (5.1.1);
⎯ water concentration of 1 500 ppm (6.4);
⎯ volume of fuel (6.1);
⎯ total test duration t (6.6).
total
At the time of publication of this Technical Specification, interlaboratory tests are being organized to establish the
repeatability and reproducibility of the results.

© ISO 2006 – All rights reserved v

---------------------- Page: 5 ----------------------
TECHNICAL SPECIFICATION ISO/TS 16332:2006(E)

Diesel engines — Fuel filters — Method for evaluating
fuel/water separation efficiency
1 Scope
This Technical Specification specifies a fuel/water separation test with continuous water injection, using an
offline water concentration measuring method, for evaluating the ability of a fuel filter to separate either finely
or coarsely dispersed undissolved water out of fuel. This test is intended for application to filter elements
which are installed upstream or downstream of the low pressure pump, having a rated flow (in litres per hour)
between 50 l/h and 900 l/h. By agreement between customer and filter manufacturer, and with some
modification, the procedure may be used for fuel filters with higher flow rates.
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 760, Determination of water — Karl Fischer method (General method)
ISO 1219-1, Fluid power systems and components — Graphic symbols and circuit diagrams —
Part 1: Graphic symbols for conventional use and data-processing applications
ISO 6889, Surface active agents — Determination of interfacial tension by drawing up liquid films
ISO 13320-1, Particle size analysis — Laser diffraction methods — Part 1: General principles
ASTM D 1401, Standard Test Method for Water Separability of Petroleum Oils and Synthetic Fluids
1)
CEC RF-06-03:2003 , CEC Legislative fuel RF-06-03 (reference fuel specification)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
interfacial tension
IFT
force required to increase the surface area of the interface between two liquids by a unit amount
NOTE Interfacial tension is expressed in millinewtons per metre (mN/m).

1) The reference fuel specification is provided by CEC secretariat services: Interlynk Administrative Services Ltd.,
PO Box 6475, Earl Shilton, Leicester LE9 9ZB, UK; T [phone]; F [phone].
© ISO 2006 – All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/TS 16332:2006(E)
3.2
droplet size distribution
DSD
curve of the percentage of the droplet population in different size ranges
See Figure B.1.
3.3
base water concentration
concentration of water in water saturated fuel
3.4
undissolved water
difference between total and base water concentration
3.5
test time
t
“point of time” when a test or a measurement is started or running respectively
NOTE In contrast to the total test duration t , see 6.6.
total
4 Symbols
Graphical symbols used in this Technical Specification for fluid power system components are in accordance
with ISO 1219-1.
5 Test equipment
5.1 Test fluids
5.1.1 Test fuels
2)
The test fuel shall be according to CEC RF-06-03 and processed to achieve the following requirements by
adding a multifunctional fuel additive (see Note 1):
a) IFT
15 mN/m ± 3 mN/m measured according to ISO 6889 after 60 s;
b) water separability
270 s ± 30 s, when 75 % of test fuel is separated (sedimentation test according to ASTM D 1401 at
25 °C). Within this document, the water separability is defined through the point of time, when 75 % of the
test fuel is separated.
NOTE 1 Fundamental tests lead to a mass fraction of approximately 0,1 % of the multifunctional fuel additive
2)
HiTEC 4620 to reach the required values.
The test fuel shall be stored protected from humidity, dust and light.
The batch of test fuel shall be changed when the fuel no longer meets the specified requirements.

2) Suitable products are available commercially. Details may be obtained from the Secretariat of Technical Committee
ISO/TC22 or from the ISO Central Secretariat.
2 © ISO 2006 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/TS 16332:2006(E)
Optionally, if agreed between customer and filter manufacturer, the test can be performed with a fuel used in
the application, but the deviations of the relevant fuel parameters shall be recorded in the test report.
NOTE 2 By using other fuel qualities (e.g. fuels used in application), the test results may not be comparable with the
results obtained with the test fuel according to 5.1.1.
5.1.2 Test water
Clean, distilled, or deionized water with a surface tension of at least 70 mN/m, measured at 20 °C ± 1,5 °C.
5.2 Laboratory equipment
5.2.1 General
All laboratory equipment and glassware, required to determine the water concentration, shall be according to
ISO 760.
5.2.2 Sampling bottles and glassware, 100 ml sampling bottles with 45 mm screw caps carefully rinsed
with clean petroleum ether and dried in an oven.
3)
5.2.3 Karl Fischer titration system , as commercially available and validated according to 8.2.3.
Recommended equipment should be composed of a coulometric, diaphragmless titration cell and a
codistillation unit.
Humidity is probably the largest source of error during the titration process. Special precautions should be
taken during setup and testing. The recommended amount of water per sample should be W 50 µg to reach a
good relation between titration time and accuracy.
5.2.4 Analytical balance, with an accuracy of ± 1 mg.
5.2.5 Sampling syringe, with a volume of 1 ml ± 0,1 ml.
5.2.6 High-speed mixer
3)
Mixer of the ULTRA-TURRAX type with
⎯ a stator of 18 mm ± 1 mm,
⎯ a rotor of 12,5 mm ± 1 mm, and
−1 −1
⎯ a rotational speed of 15 000 min ± 500 min .
5.3 Test stand
5.3.1 General
The test stand, shown diagrammatically in Figure 1, shall comprise a filter test circuit as described in 5.3.2.

3) This equipment has been found satisfactory. This information is given for the convenience of users of this Technical
Specification and does not constitute an endorsement by ISO. Details may be obtained from the Secretariat of Technical
Committee ISO/TC22 or from the ISO Central Secretariat.
© ISO 2006 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO/TS 16332:2006(E)
5.3.2 Filter test circuit (see Figure 1)
4)
5.3.2.1 Fuel sump (1) : conical bottom, stainless steel or corrosion resistant container with a fuel outlet
at the bottom of the container.
The container shall be able to contain the volume as specified in 6.1. The fuel sump has to be covered with a
non transparent cover to protect the fuel from light.
5.3.2.2 Water sump (6): stainless steel or corrosion resistant container with approximate capacity of 30 l.
NOTE Instead of the container, continuous water supply may be used.
5.3.2.3 Test pump (2) which does not exhibit pressure pulsation with an amplitude greater than 10 % of
the average pressure at the inlet of the water emulsifying device.
5)
5.3.2.4 Adjustable water injection pump (7) , capable of delivering a water flow between 0,15 % and
2 % of the fuel flow.
5.3.2.5 Fuel flow meter (5a), capable of measuring with an accuracy as specified in Table 1.
5)
5.3.2.6 Water flow meter (5b) , capable of measuring with an accuracy as specified in Table 1.
5.3.2.7 Injection device (8), with a maximum inner diameter of the injection pipe of 1 mm.
5.3.2.8 Water emulsifying device (9): fixture with an exchangeable orifice plate, as described in
Annex A.
5.3.2.9 Upstream (12) and downstream (17) sampling devices, as shown in Figure 3.
5.3.2.10 Temperature indicator (13) with an accuracy as specified in Table 1.
5.3.2.11 Pressure gauge (10) with an accuracy as specified in Table 1.
5.3.2.12 Differential pressure gauges (11) with an accuracy as specified in Table 1.
5.3.2.13 Water drainage system (15): closed collector (e.g. laboratory measuring cylinder), located
directly below the test filter (water separator) (14) and capable to collect the injected amount of water; it is
connected to the water outlet of the test filter with pressure-tight fittings.
The internal diameter of the connecting pipe between the test filter and the closed collector shall be of at least
10 mm.
5.3.2.14 Test stand pipes shall be made of stainless steel; painted or coated pipes are not allowed.
For the adaptation of the test filter (14) to the test stand piping, flexible lines are allowed.
The piping shall be designed with a minimum number of flanges or fittings and grounded upstream near the
test filter (potential difference < 10 V between each point).
The test stand pipes inner diameter d between injection device (8) and downstream sampling point (17) (see
i
Figure 2) should allow a flow velocity W 0,75 m/s.
The pipes, outside of Figure 2, shall be as short as possible.
5.3.2.15 Inline static mixer (16) to provide a representative sample at the downstream sampling
point (17).
NOTE Using a water emulsifying device (see 5.3.2.8 ) has been proven to be suitable as a static mixer.

4) The numbers in brackets refer to the key numbers in Figure 1.
5) Suitable products are available commercially. Details may be obtained from the Secretariat of Technical Committee
ISO/TC22 or from the ISO Central Secretariat.
4 © ISO 2006 – All rights reserved

---------------------- Page: 9 ----------------------
ISO/TS 16332:2006(E)
5.3.2.16 Optional: three-way ball valve (18) and collecting sump (19), if the test stand is used to run as
a single pass system (open test circuit).
5.3.2.17 Final water separator assembly (20),
⎯ with a suitable container in which to drain the water, and
⎯ such that not more than 30 ppm by volume of undissolved water is recycled on an average basis under
test conditions.
5.3.2.18 Back pressure regulating valve (21) to ease test filter venting and optionally to control the test
flow rate Q .
T
5.3.2.19 Heat exchanger (3), capable of maintaining the test temperature T within the tolerances given in
Table 1.

Key
1 fuel sump 7 adjustable water injection pump 14 test filter (water separator)
2 test pump 8 injection device 15 water drainage system
3 heat exchanger 9 water emulsifying device 16 inline static mixer
(orifice plate holder)
4 sampling point 10 pressure gauge 17 downstream sampling point
(sampling valve) (downstream sampling device: see Figure 3)
5a fuel flow meter 11 differential pressure gauges (2) 18 three-way ball valve (optional)
5b water flow meter 12 upstream sampling point 19 collecting sump (optional)
(upstream sampling device: see Figure 3)
6 water sump 20 final water separator assembly
13 temperature indicator 21 back pressure regulating valve
a
See Figure 2.
Figure 1 — Filter test stand (diagrammatically)
© ISO 2006 – All rights reserved 5

---------------------- Page: 10 ----------------------
ISO/TS 16332:2006(E)

Key
Ød inner pipe diameter
i
Figure 2 — Length and inner diameter d of test stand pipes (detail X of Figure 1)
i
Dimension in millimetres

Key
l d /4 < l < d /3
i i
Ød inner pipe diameter
i
a
Flow of test fluid.
b
Sampling flow.
Figure 3 — Upstream and downstream sampling device
6 Test conditions
6.1 Volume of fuel
The volume of the fuel [fuel sump (1)] shall be 15 times the test flow rate Q per minute.
T
6.2 Test temperature T
The test shall be conducted at a test temperature T of 23 °C ± 2 °C, measured at the test filter inlet.
Alternatively, the test may be performed at a test temperature T as agreed between customer and filter
manufacturer. This shall be recorded in the test report.
6 © ISO 2006 – All rights reserved

---------------------- Page: 11 ----------------------
ISO/TS 16332:2006(E)
6.3 Test flow rate Q
T
The test flow rate Q is specified by the customer and is defined as the flow rate of fuel.
T
6.4 Water concentration (undissolved water)
One of the following two conditions for the undissolved water concentration (see 3.4) shall be used for the
test:
⎯ standard condition: 1 500 ppm volume fraction ± 75 ppm volume fraction (approx. 0,15 %);
⎯ optional condition: 2 % volume fraction ± 0,1 % volume fraction.
6.5 Differential pressure ∆p across water emulsifying device (orifice plate)
O
The following differential pressure ∆p measured across the water emulsifying device shall be adjusted in
O
order to achieve the required DSD.
⎯ For coarse water droplets (D of 300 µm), an orifice plate shall be installed with an orifice which creates
50
a differential pressure ∆p of 48 hPa ± 5 hPa;
O
⎯ For fine water droplets (D of 60 µm), an orifice plate shall be installed with an orifice which creates a
50
differential pressure ∆p of 260 hPa ± 10 hPa.
O
⎯ For the definition of D , see Annex B.
50
⎯ For the selection of the specified average water droplet size (D ), see Annex D.
50
The choice of whether to use coarse or fine water droplets depends on the application and has to be specified
by the customer.
NOTE As agreed between customer and filter manufacturer, other D values may be used. These values shall be
50
reported in the test report as a deviation to the standard operating conditions.
6.6 Total test duration t
total
Depending on the concentration of undissolved water (see 6.4) the total test duration shall be
a) t = 90 min for 1 500 ppm (standard condition), and
total
b) t = 60 min for 2 % (optional condition).
total
7 Accuracy of measuring instruments and test conditions
The measuring instruments shall be capable of measuring to the levels of accuracy given in Table 1. In
addition, Table 1 specifies the limits within which the test conditions shall be maintained.
© ISO 2006 – All rights reserved 7

---------------------- Page: 12 ----------------------
ISO/TS 16332:2006(E)
Table 1 — Instrument accuracy and test condition variation
Test condition Units Measurement Allowed test condition variation
accuracy
Fuel flow rate (Q, Q Q ) l/h
± 1 % ± 2 %
C, T
(fuel flow meter)
a
Water flow rate ml/min
± 1 % ± 2 %
(water flow meter)
Pressure (gauge between injection hPa —
± 2 %
device and water emulsifying device)
Differential pressure ∆p hPa ± 0,5 % —
O

(gauge at orifice plate)
Differential pressure ∆p hPa ± 2 % —
F
(gauge at test filter)
Temperature
°C ± 1 °C ± 2 °C
(temperature indicator)
b a
% mass fraction
Water concentration ± 5 ppm ± 5 %
a Undissolved water (see 3.4).

b Upstream [at sample point (12) of Figure 1].
8 Validation procedure
8.1 Test stand
The validation of the test stand shall be performed at the minimum and maximum test stand design flow rates
with a straight pipe in place of the test filter (14).
For each of these two flow rates, perform the following procedure in the order given:
a) commence operation of the final water separator (20);
b) start the test pump (2) and adjust the flow rate to the required value;
c) circulate the test liquid until the temperature reaches the required value;
d) inject water at the required concentration (see 6.4);
e) allow to stabilize for at least 10 min;
f) for a 90 min test, take samples every 10 min according to the sampling procedure described in 8.2,
1) at the sampling point (4),
[validation of final water separator assembly (20) and determination of base water concentration]
2) at the upstream sampling point (12), and
[validation of the injection system (6), (7), (5b) and (8) and the water emulsifying device (9)]
3) at the downstream sampling point (17);
[validation of the inline static mixer (16)]
g) measure the water content of each sample.
8 © ISO 2006 – All rights reserved

---------------------- Page: 13 ----------------------
ISO/TS 16332:2006(E)
The validation shall be accepted only if
⎯ at the sampling point (4), the variation between the total water concentration of each sample is less than
30 ppm by volume, and
⎯ at the sampling points (12) and (17), the actual concentration of water of each sample, reduced by the
base water concentration, is equal to the injected water concentration, within the limits defined in Table 1.
NOTE Many water in oil analytical devices will determine the water concentration in terms of micrograms. To convert
micrograms to parts per million (ppm) by volume, use the following equation:
Titration reading, in ppm volume fraction = titration reading, in ppm mass fraction × fuel/water densities correlation factor
where the fuel/water densities correlation factor is (fuel density, in grams per litre) / (water density, in grams per litre).
8.2 Sampling procedure
8.2.1 Primary sampling procedure
The following procedure shall be executed for the upstream and downstream sampling points:
a) open the sampling valves at sampling points (12) and (17);
b) flush the volume between the sampling points (12) and (17) and discard in an appropriate repository;
c) immediately open the sampling bottles (prepared as described in 5.2.2) and fill approximately 50 ml;
d) close the sampling bottles directly after filling and identify the sample.
If an automatic codistillation unit is used for Karl-Fisher titration, insert the bottles directly in the distillation unit.
If an automatic sampling unit is used, flushing of the sampling pipes and exclusion of humidity inflow into the
sample volume shall be assured, until final analysis in titration cells is completed.
8.2.2 Secondary sampling procedure
If a manually served cell is used, homogenize the sample using the
...