ISO 19438:2023

INTERNATIONAL ISO
STANDARD 19438
Second edition
2023-02
Diesel fuel and petrol filters for
internal combustion engines —
Filtration efficiency using particle
counting and contaminant retention
capacity
Filtres à carburant, essence ou diesel, pour moteurs à combustion
interne — Efficacité de filtration par comptage des particules et
capacité de rétention
Reference number
© ISO 2023
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Test apparatus and materials . 2
5.1 Test apparatus. 2
5.1.1 Test rig . 2
5.1.2 On line dilution and particle counting system . . 4
5.2 Test materials . 5
5.2.1 Test contaminant . 5
5.2.2 Test fluid . 5
6 Accuracy of measuring instruments and test conditions . 5
7 Test rig validation . .6
7.1 General . 6
7.2 Validation of the on line dilution and particle counting system . 6
7.3 Validation of filter test circuit . 6
7.4 Validation of contaminant injection circuit . 7
8 Preliminary preparation . 7
8.1 Test filter assembly . 7
8.2 Contaminant injection circuit . 7
8.3 Filter test circuit . 9
9 Test procedure .9
9.1 Initial procedure . 9
9.2 Filter test . . 11
10 Calculation and reporting of test results .12
10.1 Test report .12
10.2 Calculation .12
10.2.1 General .12
10.2.2 Gravimetric levels . 13
10.2.3 Filtration efficiencies . 13
10.2.4 Filter ratings. 14
10.2.5 Injected mass of contaminant . 14
10.2.6 Non-retained mass of contaminant . 14
10.2.7 Retained filter capacity . 15
Annex A (normative) Specification of test fluid for filter test .16
Annex B (informative) Typical filter test report, presentation of test results .17
Annex C (normative) Example filter efficiency calculations .22
Annex D (informative) Effect of dust cake filtration on filter capacity .26
Bibliography .28
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
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electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain and powertrain fluids.
This second edition cancels and replaces the first edition (ISO 19438:2003), which has been technically
revised.
The main changes are as follows:
— revised validation procedure;
— added requirement to measure final test system conductivity;
— revised test report to include initial and final test system conductivity;
— Replaced Annex D “Summary of the International interlaboratory trial (round robin) to validate
ISO 19438 protocol” with “Effect of dust cake filtration on filter capacity”.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document establishes a standard test procedure for measuring the filtration efficiency, retention
capacities and resistance to flow of fuel filters. This test is intended to differentiate filters according to
their functional performance but is not intended to represent performance under actual field operating
conditions. Test conditions are steady-state and the dynamic characteristics of the fuel systems are not
represented. Other test protocols are in development to evaluate performance under cyclic flow and
vibration.
v
INTERNATIONAL STANDARD ISO 19438:2023(E)
Diesel fuel and petrol filters for internal combustion
engines — Filtration efficiency using particle counting and
contaminant retention capacity
1 Scope
This document specifies a multi-pass filtration test, with continuous contaminant injection and using
the on line particle counting method, to evaluate the performance of diesel fuel and petrol filters
for internal combustion engines submitted to a constant flow rate of test liquid. The test procedure
determines the contaminant capacity of a filter, its particulate removal characteristics and differential
pressure. This document is applicable to filter elements having a rated flow between 50 l/h and 800 l/h;
however, by agreement between the filter manufacturer and customer, and with some modifications,
the procedure is permitted for application to fuel filters with higher flow rates.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 2942, Hydraulic fluid power — Filter elements — Verification of fabrication integrity and determination
of the first bubble point
ISO 3968, Hydraulic fluid power — Filters — Evaluation of differential pressure versus flow
ISO 4021, Hydraulic fluid power — Particulate contamination analysis — Extraction of fluid samples from
lines of an operating system
ISO 4405, Hydraulic fluid power — Fluid contamination — Determination of particulate contamination by
the gravimetric method
ISO 11171, Hydraulic fluid power — Calibration of automatic particle counters for liquids
ISO 11841-1, Road vehicles and internal combustion engines — Filter vocabulary — Part 1: Definitions of
filters and filter components
ISO 11841-2, Road vehicles and internal combustion engines — Filter vocabulary — Part 2: Definitions of
characteristics of filters and their components
ISO 11943:2021, Hydraulic fluid power — Online automatic particle-counting systems for liquids —
Methods of calibration and validation
ISO 12103-1, Road vehicles — Test contaminants for fi
...