ISO 7169:2007

INTERNATIONAL ISO
STANDARD 7169
Fourth edition
2007-02-01

Aerospace — Separable tube fittings for
fluid systems, for 24° cones, for
pressures up to 3 000 psi or
21 000 kPa — Procurement specification,
inch/metric
Aéronautique et espace — Raccordements séparables de tubes à cône
de 24° pour circuits de fluides jusqu'à 3 000 psi ou 21 000 kPa —
Spécification d'approvisionnement, inch/métrique



Reference number
ISO 7169:2007(E)
©
ISO 2007

---------------------- Page: 1 ----------------------
ISO 7169:2007(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 2007
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 copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2007 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 7169:2007(E)
Contents Page
Foreword. v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Classification. 1
4 Requirements . 2
4.1 Qualification . 2
4.1.1 Manufacturer qualification. 2
4.1.2 Product qualification . 2
4.2 Materials . 2
4.2.1 Fittings . 2
4.2.2 Tubing . 2
4.3 Design and manufacture. 5
4.3.1 Threads . 5
4.3.2 Fluid passages . 5
4.4 Surface protection and colour identification . 5
4.4.1 Surface protection . 5
4.4.2 Colour identification. 6
4.5 Marking . 6
4.6 Performance . 6
4.6.1 Proof pressure . 6
4.6.2 Gaseous pressure. 7
4.6.3 Hydraulic impulse resistance . 7
4.6.4 Minimum burst pressure. 7
4.6.5 Flexure fatigue resistance . 7
4.6.6 Re-use capability . 8
4.6.7 Tensile load capability. 8
4.7 Workmanship . 8
5 Quality assurance provisions. 9
5.1 Responsibility for inspection . 9
5.2 Inspection lot. 9
5.2.1 Material certification. 10
5.2.2 Heat-treating certification . 10
5.3 Classification of inspections and tests . 10
5.3.1 Qualification inspection . 10
5.3.2 Quality conformance inspection . 10
5.4 Quality control records . 11
5.5 Quality conformance inspection procedures . 11
5.5.1 Examination of product. 11
5.5.2 Material certification. 11
5.5.3 Rolled threads . 11
5.5.4 Fluid passages . 11
5.5.5 Sampling instructions . 12
5.6 Test conditions . 12
5.6.1 Test fluids . 12
5.6.2 Specimen preparation . 12
5.6.3 Lubricants. 15
5.6.4 Qualification test procedures . 15
5.6.5 Sampling instructions . 15
© ISO 2007 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 7169:2007(E)
6 Preparation for delivery. 15
6.1 Cleaning . 15
6.2 Preservative material . 16
6.3 Packaging . 16
6.4 Package identification . 16
6.5 Packing for shipment. 16
6.6 Inspection . 16
Annex A (informative) Equivalent materials and processes . 17
Bibliography . 20

iv © ISO 2007 – All rights reserved

---------------------- Page: 4 ----------------------
ISO 7169:2007(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 7169 was prepared by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee
SC 10, Aerospace fluid systems and components.
This fourth edition cancels and replaces the third edition (ISO 7169:1998), which has been technically revised.
Criteria for imperial dimension (inch-based) tube fittings, as used for commercial aviation, have been
introduced.
© ISO 2007 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO 7169:2007(E)
Introduction
This International Standard establishes the basic performance and quality criteria for screw-together tube
fitting assemblies and port connectors used in aerospace fluid systems.
The test requirements are intended to satisfy the most strenuous demands encountered in a high-
performance aircraft hydraulic system. The procurement requirements are intended to ensure that fittings,
which are procured in accordance with this specification, are of the same quality as the fittings used during the
original qualification testing. Compliance with these test and procurement requirements is necessary for
fittings that are used in control systems where a malfunction would affect the safety of flight.

vi © ISO 2007 – All rights reserved

---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 7169:2007(E)

Aerospace — Separable tube fittings for fluid systems, for
24° cones, for pressures up to 3 000 psi or 21 000 kPa —
Procurement specification, inch/metric
1 Scope
This International Standard specifies performance and quality requirements for the qualification and
manufacture of standard 24° cone fittings and manufacture of 24° cone fittings to ensure reliable performance
or equivalent inch-dimensioned fitting ends to ensure reliable performance in aircraft hydraulic systems.
This International Standard specifies baseline criteria for the design and manufacture of system fittings that
are qualification-tested on engines.
This International Standard covers fittings of the temperature types and pressure classes specified in
ISO 6771.
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 2859-1, Sampling procedures for inspection by attributes — Part 1: Sampling schemes indexed by
acceptance quality limit (AQL) for lot-by-lot inspection
ISO 3161, Aerospace — UNJ threads — General requirements and limit dimensions
ISO 5855-3, Aerospace — MJ threads — Part 3: Limit dimensions for fittings for fluid systems
ISO 6771, Aerospace — Fluid systems and components — Pressure and temperature classifications
ISO 6772, Aerospace — Fluid systems — Impulse testing of hydraulic hose, tubing, and fitting assemblies
ISO 7257, Aircraft — Hydraulic tubing joints and fittings — Rotary flexure test
ISO 8574:1990, Aerospace — Hydraulic system tubing — Qualification tests
ISO 9538, Aerospace — Hydraulic tubing joints and fittings — Planar flexure test
ISO 10583:1993, Aerospace fluid systems — Test methods for tube/fitting assemblies
3 Classification
Fittings furnished under this International Standard shall be classified as follows:
Type A — 3 000 psi (20 684 kPa) Pressure System
Type B — 21 000 kPa (3046 psi) Pressure System
When no classification is specified Type B shall apply.
© ISO 2007 – All rights reserved 1

---------------------- Page: 7 ----------------------
ISO 7169:2007(E)
4 Requirements
4.1 Qualification
Fittings claiming conformity with this International Standard shall be representative of products which have
successfully met the requirements and have passed the tests in this International Standard.
4.1.1 Manufacturer qualification
Manufacturer approval shall be granted by an outside agency procedure (see Annex A, Table A.2, procedure
No. 1).
4.1.2 Product qualification
Product approval shall be granted by an outside agency procedure (see Annex A, Table A.2, procedure No. 2).
4.2 Materials
4.2.1 Fittings
The fitting parts shall be manufactured from materials as given in Table 1 or equivalents passing the specified
tests. The various materials shall be used according to the pressure and temperature requirements of the
system, as shown in Tables 2 to 5.
4.2.2 Tubing
The tubing used with the fittings shall be in accordance with the relevant specification or equivalent tubing
passing the specified qualification tests.
Table 1 — Materials for fittings
Material
a b
Part Material Type Material code Starting stock

c
No.
d
D 1
Straight fittings and nuts Aluminium alloy I Bar, rod
W 2
d
D 3
Shape fittings Aluminium alloy I Bar and forgings
W 2
f
Carbon steel II F Bar, rod, forgings 4
I, II, III J 5
I, II, III K 7
Straight and shape fittings Corrosion-resistant steel Bar and forgings
I, II, III, IV R 6
I, II, III P 11
I, II, II, IV V 11
Titanium alloy I, II, III T Bar and forgings 8
e
Sleeves (bite type) Carbon steel II F Bar 9
I, II, II P 11
Sleeves (swaged, brazed) Corrosion-resistant steel Bar
I, II, II, IV V 11
Corrosion-resistant steel I, II, III, IV V 11
Sleeves (welded) Bar
Titanium alloy I, II, III, IV T  8
a
Temperature types and system pressure classes are defined in ISO 6771.
b
See Table 7.
c
See also Annex A, Table A.1.
d
Inactive for new design, superseded by W.
e
Inactive for new design, no replacement.
f
Inactive for new design, superseded by V.
2 © ISO 2007 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 7169:2007(E)
Table 2 — Test requirements, 3 000 psi steel or titanium fittings on steel or titanium tubing
Fitting and tube
Flexure test, bending
Nominal pressure Proof pressure Burst pressure
stress 0 % to 10 %
Metric Inch
a a
Size Size kPa (psi) kPa (psi) kPa (psi) kPa (psi)
— −02
DN05 −03
DN06 −04
DN08 −05
135 000 (20 000)
DN10 −06
DN12 −08
DN14 — 20 684 (3 000) 41 368 (6 000) 82 740 (12 000)
DN16 −10
DN20 −12
DN25 −16 108 000 (16 000)
DN32 −20
DN40 −24
b b
108 000 (16 000 )
— −32
a
Dash size in 1/16 in, example: −05 = 5/16 in diameter; DN size in millimetres, example: DN05: 5 mm.
b
No data available to support this value.
Table 3 — Test requirements, 21 000 kPa steel or titanium fittings on steel or titanium tubing
Fitting and tube
Flexure test, bending
Nominal pressure Proof pressure Burst pressure
stress 0 % to 10 %
Metric Inch
a a
Size Size kPa (psi) kPa (psi) kPa (psi) kPa (psi)
— −02
DN05 −03
DN06 −04
DN08 −05
135 000 (20 000)
DN10 −06
DN12 −08
21 000 (3 046) 42 000 (6 091) 84 000 (12 183)
DN14 —
DN16 −10
DN20 −12
108 000 (16 000)
DN25 −16
DN32 −20
DN40 −24
b b)
108 000 (16 000
— −32
a
Dash size in 1/16 in, example: −05 = 5/16 in diameter; DN size in millimetres, example: DN05: 5 mm.
b
No data available to support this value.

© ISO 2007 – All rights reserved 3

---------------------- Page: 9 ----------------------
ISO 7169:2007(E)
Table 4 — Test requirements, return line aluminium fittings, up to 1 500 psi, on aluminium
Fitting and tube
Flexure test, bending
Nominal pressure Proof pressure Burst pressure
stress 0 % to 10 %
Metric Inch
a a
kPa (psi) kPa (psi) kPa (psi) kPa (psi)
Size Size
— −02
DN05 −03
41 368 (6 000)
DN06 −04
10 342 (1 500) 20 684 (3 000) 41 368 (6 000)
DN08 −05
DN10 −06
DN12 −08
DN14 — 37 922 (5 500)
DN16 −10 6 845 (1 000) 13 790 (2 000) 27 579 (4 000)
DN20 −12 34 474 (5 000)
6 206 (900) 12 411 (1 800) 24 824 (3 600)
DN25 −16
27 579 (4 000)
DN32 −20
4 137 (600) 8 274 (1 200) 16 548 (2 400)
DN40 −24
b b)
27 579 (4 000
— −32
a
Dash size in 1/16 in, example: −05 = 5/16 in diameter; DN size in millimetres, example: DN05: 5 mm.
b
No data available to support this value.

Table 5 — Test requirements, return line aluminium fittings, 10 500 kPa, on aluminium tubing
Fitting and tube
Flexure test, bending
Nominal pressure Proof pressure Burst pressure
stress 0 % to 10 %
Metric Inch
a a
Size Size kPa (psi) kPa (psi) kPa (psi) kPa (psi)
— −02
DN05 −03
41 368 (6 000)
DN06 −04
DN08 −05
DN10 −06
DN12 −08
10 500 (1 522) 21 000 (3 046) 42 000 (6 091) 37 922 (5 500)
DN14 —
DN16 −10
DN20 −12 34 474 (5 000)
DN25 −16
27 579 (4 000)
DN32 −20
DN40 −24
b b)
27 579 (4 000
— −32
a
Dash size in 1/16 in, example: −05 = 5/16 in diameter; DN size in millimetres, example: DN05: 5 mm.
b
No data available to support this value.
4 © ISO 2007 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 7169:2007(E)
4.3 Design and manufacture
4.3.1 Threads
All threads shall be in accordance with ISO 3161 for inch-size tube fittings, and with ISO 5855-3 for SI-metric
tube fittings.
Threads may be cut, rolled or, except for titanium, ground. The external threads of fittings should be rolled and,
if machined, shall have an arithmetical mean deviation, R , of the profile of 3,2 µm (0,125 µin) or smoother.
a
Rolled threads shall be free of laps, cracks, surface irregularities and seams on any part of the pressure
thread flank, in the thread-root, or on the non-pressure thread flank. Laps and seams whose depths are within
the limits of Table 6 are acceptable on the crest and the non-pressure thread flank above the pitch diameter.
Table 6 — Maximum depth of laps, seams and surface irregularities in rolled threads
Fitting size
Depth
Metric Inch
a
Size Size mm (in)
— −02 0,15 (0,006)
DN05 −03 0,15 (0,006)
DN06 −04 0,18 (0,007)
DN08 −05 0,18 (0,007)
DN10 −06 0,20 (0,008)
DN12 −08 0,22 (0,009)
DN14 — 0,25 (0,01)
DN16 −10 0,25 (0,01)
DN20 −12 0,25 (0,01)
DN25 −20 0,25 (0,01)
DN32 −16 0,25 (0,01)
DN40 −24 0,25 (0,01)
— −32 0,25 (0,01)
a
Dash size in 1/16 in, example: −05 = 5/16 in diameter; DN size in millimetres, example:
DN05 = 5 mm.

4.3.2 Fluid passages
On fittings where the fluid passage is drilled from each end, the offset between the drilled holes at the meeting
point shall not exceed 0,4 mm (0,015 in). It shall be possible to pass through the fitting passage a ball whose
diameter is 0,5 mm (0,020 in) less than the minimum diameter specified for the passage.
4.4 Surface protection and colour identification
4.4.1 Surface protection
The surfaces of fitting parts shall be protected in the following manner.
a) Aluminium alloy fittings: by sulfuric acid anodizing, then dyeing and dichromate or nickel acetate sealing
(process No. 18 in Table A.1).
b) Carbon steel fittings and sleeves: by cadmium plating 0,007 mm to 0,012 mm (0,000 30 in to 0,000 50 in)
thick, followed by a chromate post-plate treatment (process No. 19 in Table A.1).
Note Cadmium plating is not to be used in new designs.
© ISO 2007 – All rights reserved 5

---------------------- Page: 11 ----------------------
ISO 7169:2007(E)
c) Corrosion-resistant steel fittings: by passivation treatment (process No. 12 in Table A.1). Sleeves may be
cadmium plated (process No. 19 in Table A.1).
d) Titanium fittings: by a fluoride conversion coating or anodizing (process No. 20 or No. 21 in Table A.1).
4.4.2 Colour identification
As a reference, the material of the finished fitting may be distinguished by the colours as shown in Table 7.
Table 7 — Material codes and colours
Material Code Colour
a
Aluminium D Green
Aluminium W Brown
a
Carbon steel Gold brown
F
Corrosion-resistant steel J Bright metallic
Corrosion- and acid-resistant steel Bright metallic
K
Corrosion-resistant stabilized steel R Bright metallic
a, b
Heat-treatable corrosion-resistant steel Gold brown
P
Heat-treatable corrosion-resistant steel Metallic
V
Titanium Dull gray
T
a
Inactive for new design.
b
P designatives V material, cadmium plated.

4.5 Marking
Unless otherwise specified, parts shall be permanently identified with the complete part number and the
manufacturer's trademark. The method of marking shall be laser marking, impression stamping or electro-
etching, in that order of preference. When the complete part number cannot be used in the DN10 (−06) size
and under because of the size of the part, the marking may be limited to the basic part number, without a size
designation. The marking shall not be in a location detrimental to the part of its surface protection, and should
preferably be visible when the part is assembled. When material code letters are used, the code letter (see
Table 7) shall also be laser marked, electro-etched or impression stamped on the part.
Laser marking shall not be used on weld-ends of titanium weld fittings.
4.6 Performance
The tubing/fitting assembly shall be capable of meeting the performance requirements specified in 4.6.1 to
4.6.7.
4.6.1 Proof pressure
When testing in accordance with ISO 10583:1993, 5.1, the test assembly shall withstand pressure equal to
twice the nominal pressure in conformity with ISO 8574 without leakage, evidence of permanent deformation
or other malfunction that might affect the ability to disconnect or connect using the specified range of torque
values. All specimens, except tensile specimens, shall be proof tested.
6 © ISO 2007 – All rights reserved

---------------------- Page: 12 ----------------------
ISO 7169:2007(E)
4.6.2 Gaseous pressure
When tested in accordance with ISO 10583:1993, 5.2, assemblies shall pass the gaseous pressure test to the
specified nominal pressure without leakage or other failure. Six specimens shall be tested.
4.6.3 Hydraulic impulse resistance
When tested in accordance with ISO 6772 and ISO 10583:1993, 5.3, the test assembly shall withstand
200 000 impulse pressure cycles without leakage. Six specimens shall be tested.
4.6.4 Minimum burst pressure
When tested in accordance with ISO 10583:1993, 5.4, there shall be no leakage or burst at less than the
specified minimum burst pressure. Tubing expansion is permissible. Six specimens shall be tested to failure.
4.6.5 Flexure fatigue resistance
4.6.5.1 Standard rotary flexure text, temperature type II, pressure class D
When tested in accordance with ISO 7257 and ISO 10583:1993, 5.5, the test assemblies shall not fail. Six
specimens with straight unions shall be tested. Bulkhead-tee fitting connections shall match the flexure fatigue
life of straight unions. Two specimens with bulkhead tees shall be tested.
7
4.6.5.1.1 Basic qualification requirement for flexure testing to 10 cycles
a) Steel 24° cone fittings shall be used with ISO 6771 type II, class D, 304 1/8 hard cold-worked corrosion-
resistant steel tubing (material No. 14 in Table A.1). Inch sizes shall be flexure fatigue tested to 135 MPa
(20 000 psi) bending stress in sizes −10 and under, and 108 MPa (16 000 psi) in sizes −12 and over to a
0
relative tolerance of %.
− 10
Metric sizes shall be flexure fatigue tested to 135 MPa (20 000 psi) bending stress in sizes DN16 and
0
under, and 108 MPa (16 000 psi) in sizes DN20 and over, to a relative tolerance of %.
− 10
b) For use with type II, class D, 21-6-9 cold-worked tubing (Material No. 15 in Table A.1), inch size steel 24°
cone fittings shall be flexure fatigue tested to 135 MPa (20 000 psi) bending stress in sizes −10 and under,
0
and 108 MPa (16 000 psi) in sizes −12 and over, to a relative tolerance of %.
− 10
Metric sizes shall be flexure fatigue tested to 135 MPa (20 000 psi) bending stress in sizes DN16 and
0
under, and 108 MPa (16 000 psi) in sizes DN20 and over, to a relative tolerance of %.
− 10
c) Titanium 24° cone fittings shall be flexure fatigue tested with type II, class D, 3Al-2,5V cold-worked and
stress-relieved tubing (material No. 17 in Table A.1). Inch sizes shall be flexure fatigue tested to 135 MPa
(20 000 psi) bending stress in sizes −10 and under, and 108 MPa (16 000 psi) in sizes −12 and over, to a
0
relative tolerance of %.
− 10
Metric sizes shall be flexure fatigue tested to 135 MPa (20 000 psi) bending stress in sizes DN16 and
0
under, and 108 MPa (16 000 psi) in sizes DN20 and over, to a relative tolerance of %.
− 10
4.6.5.1.2 Alternative qualification test requirements
Modifications of 24° cone fittings, other fitting designs, new tubing materials or other attachment methods are
7
to be qualified by comparing their fatigue life against that of the basic 24° cone fitting by testing to 10 cycles,
to the same fatigue life measured in deflection as the basic fitting. The performance of such other designs,
materials or joining methods shall meet or exceed that of the standard 24° cone type II, class D fitting and
cold-worked corrosion-resistant steel tubing (material No. 14 in Table A.1); that is, all six specimens shall
7
withstand 10 flexure cycles without failure.
© ISO 2007 – All rights reserved 7

---------------------- Page: 13 ----------------------
ISO 7169:2007(E)
4.6.5.1.3 Alternative qualification test requirement using S-N curve
The S-N method of testing eight specimens given in ISO 7257 may be used as an alternative to the method of
7
testing six specimens to 10 cycles at a specified bending or stress level (4.6.5.1.1).
NOTE This alternative method requires testing of at least eight specimens, two each at four stress levels, to produce
an S-N curve. Such a curve shows cycles to failure for three sets of two specimens tested to different high stress levels,
7
and one
...