ISO 4020:2001

Road vehicles — Fuel filters for diesel engines — Test methods

ISO 4020 specifies the types of test for fuel filters in accordance with their application. It applies to fuel filters provided for road vehicles with diesel engines and for test installations for fuel injection equipment and is intended for filters having a rated flow of up to 200 l .h-1. By agreement, the tests, with some modifications, may be used for filters with higher rates of flow. The test described may be used for fuel filters located either on the pressure side or on the suction side of the fuel supply pump.

Véhicules routiers — Filtres à combustible pour moteurs diesels — Méthodes d'essai

General Information

• Status: Published
• Publication Date: 19-Dec-2001
• 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: 9093 - International Standard confirmed

Relations

• Revises: ISO 4020-1:1979 - Road vehicles — Fuel filters for automotive compression ignition engines — Part 1: Test methods
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 4020
First edition
2001-12-15


Road vehicles — Fuel filters for diesel
engines — Test methods
Véhicules routiers — Filtres à combustible pour moteurs diesels —
Méthodes d'essai




Reference number
ISO 4020:2001(E)
©
ISO 2001

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ISO 4020:2001(E)
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©  ISO 2001
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ISO 4020:2001(E)
Contents Page
Foreword.iv
1 Scope .1
2 Normative references.1
3 Terms and definitions .2
4 Flow rates .4
5 Test materials.4
5.1 Test liquid.4
5.2 Test contaminants for tests to determine instantaneous filtration efficiency and filter life.4
5.3 Test installation, general.5
6 Tests.5
6.1 Test for cleanliness of new filters.5
6.2 Fabrication integrity test.6
6.3 Test for differential pressure of new filters.6
6.4 Test for instantaneous filtration efficiency and filter life .7
6.5 Test for water separation efficiency .14
6.6 Collapse/burst test of the filter element.16
6.7 Burst test of complete filters.17
6.8 Pulsating pressure fatigue test .18
6.9 Vibration resistance fatigue test .20
Annex A (normative) Test liquid for fuel filter test .21
Annex B (normative) Test installations .22
Annex C (normative) Organic contaminant.37
Annex D (normative) Specification for carbon black powder used for the organic contaminant
concentrate .40
Annex E (normative) Supplementary details for water separation test .42
Annex F (normative) Determination of the insoluble content .44
Annex G (normative) Diagram for showing instantaneous filtration efficiency and differential pressure
versus choking time.47
Bibliography.48


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ISO 4020:2001(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 3.
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 International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 4020 was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee
SC 7, Injection equipment and filters for use on road vehicles.
This first edition cancels and replaces ISO 4020-1:1979, which has been technically revised. The former Part 2 has
been withdrawn.
Annexes A to G form a normative part of this International Standard.
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INTERNATIONAL STANDARD ISO 4020:2001(E)

Road vehicles — Fuel filters for diesel engines — Test methods
1 Scope
This International Standard specifies the types of test for fuel filters in accordance with their application.
This International Standard applies to fuel filters provided for road vehicles with diesel engines and for test
installations for fuel injection equipment.
The test described may be used for fuel filters located either on the pressure side or on the suction side of the fuel
supply pump.
−1
This International Standard is intended for filters having a rated flow of up to 200 l⋅h .
By agreement, the tests, with some modifications, may be used for filters with higher rates of flow.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 565:1990, Test sieves — Metal wire cloth, perforated metal plate and electroformed sheet — Nominal sizes of
openings
ISO 760:1978, Determination of water — Karl Fischer method (General method)
1)
ISO 2719:— , Determination of flash point — Pensky-Martens closed cup method
ISO 2942:1994, Hydraulic fluid power — Filter elements — Verification of fabrication integrity and determination of
the first bubble point
ISO 3016:1994, Petroleum products — Determination of pour point
ISO 3104:1994, Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity and
calculation of dynamic viscosity
ISO 3405:2000, Petroleum products — Determination of distillation characteristics at atmospheric pressure
ISO 3675:1998, Crude petroleum and liquid petroleum products — Laboratory determination of density —
Hydrometer method

1) To be published. (Revision of ISO 2719:1988)
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ISO 4020:2001(E)
ISO 4548-7:1990, Methods of test for full-flow lubricating oil filters for internal combustion engines — Part 7:
Vibration fatigue test
ISO 8213:1986, Chemical products for industrial use — Sampling techniques — Solid chemical products in the
form of particles varying from powders to coarse lumps
ISO 11841-1:2000, Road vehicles and internal combustion engines — Filter vocabulary — Part 1: Definitions of
filters and filter components
ISO 11841-2:2000, Road vehicles and internal combustion engines — Filter vocabulary — Part 2: Definitions of
characteristics of filters and their components
ISO 12103-2:1997, Road vehicles — Test dust for filter evaluation — Part 2: Aluminium oxide test dust
ASTM-D 971-99a, Standard Test Method for Interfacial Tension of Oil Against Water by the Ring Method
ASTM-D 2784-98, Standard Test Method for Sulfur in Liquefied Petroleum Gases (Oxy-Hydrogen Burner or Lamp)
3 Terms and definitions
For the purposes of this International Standard the terms and definitions given in ISO 11841-1, ISO 11841-2 and
the following apply.
NOTE Pressures are indicated in kPa (instead of bar) or in Pa (instead of mbar); to obtain them in bar or mbar, divide them
2
by 10 ⋅(100 kPa = 1 bar; 100 Pa = 1 mbar)
3.1
sedimentor
separator in which contaminant is removed by density difference
3.2
instantaneous filtration efficiency
h
ratio between the test contaminant retained versus that added, expressed as a percentage
dd-
12
h = 100
d
1
where
d is the concentration of test contaminant at filter inlet;
1
d is the concentration of test contaminant at filter outlet.
2
3.3
filter life
t or V
service interval of a filter or filter element until maintenance or replacement, expressed in minutes or until final
differential pressure is reached, expressed in litres
3.4
pressure difference
p
stat
difference in static pressure between upstream and downstream of a filter, expressed in pascals
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ISO 4020:2001(E)
3.5
rated flow
q

v
normal operating flow at which liquid is passed through a filter, expressed in litres per hour or litres per minute
NOTE The flow can be that specified by the manufacturer or as agreed between manufacturer and user.
3.6
contaminant, organic
suspension of finely divided carbon black in test liquid, formulated to provide similar filter choking characteristics to
those of normal diesel fuel
3.7
contaminant, inorganic
fused aluminium oxide dust of closely controlled particle size
NOTE It is the incombustible constituent that is added to the organic contaminant for the purpose of revealing the
instantaneous filtration efficiency property of a filter.
3.8
collapse/burst pressure of filter element
p
diff
differential pressure at which a choked filter element suffers structural failure, expressed in kilopascals
3.9
burst pressure of complete filter
p
internal pressure at which the filter housing suffers structural failure, expressed in kilopascals
3.10
fabrication integrity test
test to indicate quality standard of filter element by measurement of volume of air escaping through filter medium or
joints in unit time, when immersed in liquid at specified depth and internal pressure
NOTE The volume is measured in millilitres per minute and is given the symbol V .
B
3.11
test of cleanliness
test to enables the degree of cleanliness of new filters to be determined and reveal the amount of impurities flushed
from the clean side of the filter under specified test conditions
NOTE The amount is measured in milligrams and is given the symbol W.
3.12
test flow rate
q

t
rate at which test liquid flows through the filter during a specific test, expressed in litres per hour or litres per minute
NOTE It may be different from the rated flow q .
v
3.13
undissolved water
water dispersed in test liquid
NOTE This means diesel fuel containing water which can be separated by physical means, e. g. by centrifuging.
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ISO 4020:2001(E)
4 Flow rates
The test flow rate shall reflect service conditions and shall be one of the following values:
−1 −1 −1 −1 −1 −1 −1 −1 −1
10 l⋅h , 25 l⋅h , 50 l⋅h , 75 l⋅h , 100 l⋅h , 125 l⋅h , 150 l⋅h , 175 l⋅h , 200 l⋅h
or as agreed between filter manufacturer and user.
5 Test materials
5.1 Test liquid
The test liquid used for all tests, except the water separation test (see 6.5) and collapse/burst test of the filter
2)
element (see 6.6), shall be a straight mineral oil with properties as shown in annex A.
Except in tests 6.1 and 6.2, this liquid shall be used at such a temperature that the kinematic viscosity of the liquid
2 2
lies between 4 mm /s and 6 mm /s. Alternatively, the liquid shall be blended with refined spindle oil or premium
grade kerosene to give a viscosity that is between these limits at the test temperature. All test liquids shall be free
from additives apart from colouring dyes. Provision shall be made to ensure that the test liquid is free from
undissolved water. The liquid for each test shall be drawn from its storage container at a point above the zone of
sedimentation.
Before use, and if needed, all liquids shall be passed through a highly efficient filter medium, the latter being
adequately supported and suitably clamped at the edges; see the following items from B.3 (2nd, 3rd and 4th items
under Other equipment), e.g.:
 vacuum pump: 85 kPa below atmospheric pressure;
 filtration apparatus: filter paper disc holder;
 filter paper disc or membrane: diameter 140 mm, mean pore size between 0,4 µm and 1,1 µm.
The differential pressure across the filter paper shall not exceed 85 kPa.
Providing the test liquid is suitably cleaned, it may be reused up to a maximum of 20 times.
5.2 Test contaminants for tests to determine instantaneous filtration efficiency and filter life
5.2.1 Organic contaminant concentrate
The concentrate (see note) shall consist of a dispersion in a ratio of 1 g of carbon black to a mixture of 90 ml of test
liquid and 10 ml of dispersant additive.
For the method of preparation, see annex C.
The specification of the carbon black can be found in annex D.
NOTE This concentrate is difficult to prepare and when prepared requires to be tested for suitability as described in
annex C.

2) Suitable products are available commercially. Details (product list) may be obtained from the Secretariat of Technical
Committee ISO/TC 22 or from the ISO Central Secretariat.
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ISO 4020:2001(E)
5.2.2 Inorganic contaminant
The contaminant shall be fused aluminium oxide dust. The particle size distribution shall conform to grades M1 and
M2 of ISO 12103-2. Normally, grade M2 dust shall be used, however, for filters manufactured from fine paper the
finer M1 grade dust shall be used as an alternative contaminant.
5.3 Test installation, general
There shall be no sudden changes in tube or hose bore throughout the test rigs.
6 Tests
6.1 Test for cleanliness of new filters
6.1.1 Purpose of the test
This test shall be carried out first to ascertain whether the clean side of the filter to be tested is free from dirt and of
other loose particles which may result from production, storage and transport.
6.1.2 Test installation
See B.1.
The test liquid temperature shall be 23 °C ± 5 °C.
6.1.3 Other equipment
See B.1.
6.1.4 Procedure
a) Clean and dry the test sieve for 30 min in a drying cabinet at approximately 20 °C above the final boiling point
of the petroleum ether employed in accordance with 6.1.4 d) and allow to cool for 30 min to ambient
temperature.
b) Weigh the test sieve to the nearest 0,1 mg on a laboratory balance and insert the test sieve in a horizontal
position in the measuring device (B.1.7).
c) Pump the test liquid through the circuit for 1 h at twice the rated flow of the filter under test.
d) Spray approximately 10 ml of petroleum ether through the cleaning hole on to the inner walls of the measuring
device in order to wash down particles from the wall and to gather them on the sieve.
e) Remove the test sieve with tweezers, place it on filter paper and allow to dry.
f) Place the test sieve in a clean, dry Petri dish, cover it with a lid, dry and allow to cool as before the first
weighing.
g) Weigh the test sieve to the nearest 0,1 mg. The mass of dirt released by the filter is equal to the difference
between the results of the two weighings of the sieve.
6.1.5 Test report
The test report shall indicate at least the following:
a) the filter make and model;
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ISO 4020:2001(E)
b) a description of the filter tested and internal diameter of connections;
c) the rated flow, in litres per hour;
d) the type or blend of test liquid.
Indicate the mass, in milligrams, of dirt released.
6.2 Fabrication integrity test
This test shows whether the filter element is “tight”; i.e. whether it does not contain pores larger than the unused
filter medium. The test shall be conducted in accordance with ISO 2942. However, test liquid in accordance with
annex E shall be used instead of isopropanol, as specified in ISO 2942. If this test is made, it should be carried out
prior to the other tests specified, but it may be carried out after the cleanliness test.
6.3 Test for differential pressure of new filters
6.3.1 Purpose and application of the test
The purpose of this test is to measure the differential pressure across the filter at the filter manufacturer’s rated
flow. This test shall be carried out prior to the tests for instantaneous filtration efficiency and filter life and for water
separation efficiency, but may be carried out after the cleanliness and fabrication integrity tests.
NOTE This method is equally applicable for the measurement of the pressure drop in a filter which has been in use for a
determined period, or at a flow rate different from the nominal rate.
6.3.2 Test installation
See B.2.
The test liquid temperature shall be 23 °C ± 5 °C.
6.3.3 Other equipment
See B.2.
6.3.4 Procedure
a) Connect the filter to be tested to the test rig, start up the system and prime and vent the filter to ensure
removal of air from the filter and pressure gauges, inverting the filter if necessary.
b) Close the control valve (B.2.10) and adjust the pressure by means of the by-pass valve (B.2.12) to that used in
practice. Adjust the zero of the differential manometer (B.2.14).
c) Open the control valve to re-establish the pressure reading on the upstream pressure gauge (B.2.8) to that
used in practice, and partially close the by-pass valve. Thus adjust the flow rate, indicated by the flowmeter
(B.2.6), to the desired value.
d) Record the value shown on the differential manometer.
6.3.5 Test report
The test report shall indicate at least the following:
a) the filter make and model;
b) a description of the filter; whether it is new or used; in the latter case, the approximate period of service;
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ISO 4020:2001(E)
c) the rated flow and the test flow rate, in litres per hour;
d) the type of blend of test liquid;
e) its viscosity at the test temperature, in square millimetres per second;
f) the test temperature, in degrees Celsius;
g) the internal diameter, d, actually used for the pipes itemized in B.2.
Indicate the differential pressure in Pa.
6.4 Test for instantaneous filtration efficiency and filter life
6.4.1 Purpose and application of the test
The purpose of this test is to measure the percentage retention of specific particles by a filter under defined test
conditions and at the filter manufacturer’s rated flow.
It is useful to conduct the test with filters which have already been tested by the cleanliness test, the fabrication
integrity test or the differential pressure test.
6.4.2 Test installation
See B.3.
The test liquid temperature shall be 23 °C ± 5 °C.
6.4.3 Other equipment
See B.3.
6.4.4 Procedure
6.4.4.1 Description
The filter test shall be carried out as a continuous process during which the contamination concentration of the test
liquid being fed to the filter is constant. The effectiveness of the filter under test (B.3.8) is determined by measuring
the amount of inorganic test dust remaining in the effluent samples initially and during the process of choking.
Clean test liquid is pumped from the tank (B.3.1b) by means of the main delivery pump (B.3.6) through the filter
under test into the collection tank (B.3.12). This enables the filter to be primed and vented. The organic and
inorganic contaminants are added as follows:
a) either as shown in diagram B.3: manually into the tanks (B.3.1a and B.1.3b) with the contaminants held in
suspension with stirrers (B.3.2);
b) or as shown in Figure B.4: with the injection pump (B.3.21) the organic contaminant is fed into the tank (B.3.1a
or B.3.1b) and with the injection pump (B.3.24) the inorganic contaminant is fed via the injection nozzle
(B.3.25) before the main delivery pump. The contaminants are held in suspension in the injection tanks by
recirculating pumps (B.3.19 and B.3.23).
The main delivery pump transfers this suspension to the filter under test, from which the filtered liquid flows via the
flow-measuring device [head tube (B.3.10)] and the orifice (B.3.11) into the collection tank. Samples of the effluent
are taken 2 min after the addition of the contaminants and at 4 min intervals thereafter for the determination of the
inorganic concentration. The continuity of the process is ensured by having a second tank (B.3.1b) prepared and
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ISO 4020:2001(E)
ready for use in the event that the whole of the contaminated test liquid contained in the first tank (B.3.1a) has
been used up.
The test for instantaneous filtration efficiency and filter life ends when the end pressure or any other agreed value is
attained.
To determine the instantaneous filtration efficiency of felt filters, terminate the instantaneous filtration efficiency test
after 20 min and analyse the samples taken during that time period.
6.4.4.2 Preparation of contaminants
6.4.4.2.1 Organic contaminant
See 5.2.1 and annexes C and D.
Before use ensure that the organic contaminant is thoroughly mixed; an example of the mixing procedure is as
follows.
a) The contaminant shall be supplied in a container which is not more than 75 % full. It shall be agitated by hand
shaking for approximately 5 min. To do this, the container shall be turned upside down and back again a
number of times.
b) Immediately following this, the container shall be placed on its side on a laboratory shaker and agitated at a
frequency of approximately 250 cycles per minute (approx. 4,2 Hz) at approximately 25 mm amplitude for 2 h.
c) The container shall then be taken from the shaker and the cap removed. A laboratory stirrer shall be lowered
into the container to a position as near as possible to the bottom and stirring shall be maintained for 3 h at a
-1
rotational frequency of approximately 1 000 min .
d) Immediately after stirring, a sample shall be removed and the solid content determined (see annex F) to
ensure that it is within (1 ± 0,1) % mass/volume.
6.4.4.2.2 Inorganic contaminant
See 5.2.2.
a) To obtain the test dust samples from the bulk supply, the appropriate standard sampling method, e.g. as
specified in ISO 8213, shall be used.
b) Immediately before use, each small quantity of inorganic contaminant shall be dried at a temperature between
110 °C and 150 °C (see B.3, Other equipment) for not less than 1 h.
c) The inorganic contaminant shall be allowed to cool in a desiccator and shall be stored in same.
6.4.4.3 Test rig and contaminents
6.4.4.3.1 Preparation of test rig
a) Prepare the test liquid as described in 5.1.
b) Flush the test rig by pouring 5 l of clean test liquid into the main tanks and and recirculating for 15 min. This is
achieved by attaching a separate flexible hose to the flexible transparent hose and suspending the other end
in either of the tanks.
c) After this flushing operation, pump out and discard the test liquid; refill the rig with 10 l.
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ISO 4020:2001(E)
d) Clean the test rig with an arrangement in accordance with Figure B.3 or Figure B.4.
This test shall be carried out prior to the tests for instantaneous filtration efficiency and filter life and for water
separation efficiency, but may be carried out after the cleanliness and fabrication integrity tests.
e) After approximately 30 min and before discarding the test liquid, take a sample at the orifice and determine the
level of contamination using the method specified in 6.4.4.5.
f) If the level of contamination exceeds 0,004 g/l (i.e. 1 % of the inorganic contaminant concentration), the
cleaning shall be repeated until this or a lower level is reached.
g) Prime the system by partially filling the tank (B.3.1a) with clean test liquid, and starting the pump to transfer
test liquid through the filter under test into the collection tank. During this process, vent air from the filter by
opening bleed orifices normally located on the filter head.
h) When priming is complete, close the bleed orifices and continue pumping test liquid through the filter until the
collection tank is almost full but before the level of the test liquid reaches the outlet opening of the main tank
(B.3.1a).
6.4.4.3.2 Preparation of contaminants
a) For manual feeding, a mixture of organic contaminant concentrate and clean test liquid shall be produced with
a volume ratio of 1:99 in the tanks. The concentrate shall be thoroughly mixed, as described in 6.4.4.2.1. A
quantity of inorganic test dust shall be weighed out that will give a concentration of 0,4 g/l in the test liquid
contained in the tanks. The inorganic contaminant shall be added to a volume of 500 ml from the contents of
-1
the tank, and then stirred for 15 min at about 1 000 min . The suspension of the inorganic contaminant shall
then be added to the whole amount of test liquid which contains the organic contaminant in the tanks. The
prepared test liquid, to which the organic and the inorganic contaminants have now been added, shallt be
stirred for at least 30 min with the stirrer before the start of the test.
b) For separate contaminant injection, the organic contaminant concentrate – prepared as described in
6.4.4.2.1 – is added to the injection tank (B.3.22). The solids are held in suspension with the recirculating
pump. The contaminant is injected in the as-delivered state.
A quantity of 80 g of the inorganic contaminant – prepared as described in 6.4.4.2.2 – is weighed out and manually
wetted with a rubber scraper in 950 ml of clean test liquid. Then 5 ml of an anti-static agent are added. This is
made up to 1 000 ml with clean test liquid and placed in an ultrasonic bath for 3 min to 5 min. The contaminant
prepar
...