ISO 8434-4:1995

Metallic tube connections for fluid power and general use — Part 4: 24 degree cone connectors with O-ring weld-on nipples

Lays down general and dimensional requirements for the design and performance of 24° cone connectors with O-ring weld-on nipples that are suitable for use with steel and stainless steel tubes with outside diameters from 6 mm to 42 mm, inclusive. These fittings are for use in fluid power and general applications where elastomeric seals can be used.

Raccords de tubes métalliques pour transmissions hydrauliques et pneumatiques et applications générales — Partie 4: Raccords à cône à 24 degrés, à embout à souder à joint torique

La présente partie de l'ISO 8434 fixe les exigences générales et dimensionnelles pour la conception et la performance des raccords à cônes à 24° à embout à souder à joint torique, utilisables avec des tubes en acier et en acier inoxydable de diamètre extérieur de 6 mm à 42 mm inclus. Ces raccords sont utilisés dans les transmissions hydrauliques et pneumatiques et les applications générales lorsque les joints d'étanchéité élastomères peuvent être utilisés dans les limites de pression et de température spécifiées dans la présente partie de l'ISO 8434. Les raccords de la série S conformément à la présente partie de l'ISO 8434 peuvent être utilisés à des pressions de travail allant jusqu'à 63 MPa (630 bar). Les raccords de la série L conformément à la présente partie de l'ISO 8434 peuvent être utilisés à des pressions de travail allant jusqu'à 25 MPa (250 bar) (voir tableau 1).Ils permettent le raccordement de tubes et de tuyaux à des orifices conformes à l'ISO 6149-1, l'ISO 1179-1 et l'ISO 9974-1.NOTES1 Pour les nouveaux types de raccordement utilisés dans les transmissions hydrauliques, voir les exigences données en 9.6.2 Pour une utilisation en dehors des limites de pression et/ou de température spécifiées, voir 5.4.

Kovinski cevni priključki za fluidno tehniko in splošno uporabo - 4. del: 24°, s stožčastim privarjenim vtičem in tesnilko O

General Information

• Status: Withdrawn
• Publication Date: 22-Mar-1995
• Withdrawal Date: 22-Mar-1995
• ICS: 23.100.40 - Piping and couplings
• Technical Committee: ISO/TC 131/SC 4 - Connectors and similar products and components
• Drafting Committee: ISO/TC 131/SC 4/WG 6 - Methods for connecting hose fittings and tubes to connectors
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 23-Aug-2007
• Ref Project: SIST ISO 8434-4:1997 - Metallic tube connections for fluid power and general use -- Part 4: 24 degree cone connectors with O-ring weld-on nipples

Relations

• Revised: ISO 8434-1:2007 - Metallic tube connections for fluid power and general use — Part 1: 24 degree cone connectors
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 8434-4
First edition
1995-04-01
Metallic tube connections for fluid power
and general use -
Part 4:
24” cone connectors with O-ring weld-on
nipples
Ratcords de tubes m&alliques pour transmissions hydr-auliques et
Pneuma tiques et applica tions g&&ales -
Partie 4: Ratcords 6 cone 8 24 ”, 5 embout 5 souder 5 joint torique
Reference number
ISO 8434-4:1995(E)

---------------------- Page: 1 ----------------------
ISO 8434-4: 1995(E)
Contents
Page
1
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................... 1
..................................
2 Normative references
2
3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
........ ...............................................
4 Requirements for materials
. . . .” 3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Pressure/temperature requirements
4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Designation of fittings
7
....... .............................. .......................
7 Requirements for tubes
7
. . . . . . . . . . . . . . . . . . . . . . . . . . .*.
8 Across-flats dimensions . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
9 Design .,.
8
.........................................................................
IO Screw threads
8
............................................................................
11 Manufacture
8
12 Assembly instruction .
........................................................ 9
13 Procurement information
9
14 Marking of components . . . . . . . . . . . . . . . . . . . . .*.
9
15 Identification Statement (Reference to this part of ISO 8434)
Annex
A Port and stud end working pressures and combinations of tube
outside diameters and port and stud end thread sizes . . . . . . . . . 24
0 ISO 1995
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland

---------------------- Page: 2 ----------------------
0 ISO ISO 8434-4: 1995(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. Esch 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.
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.
International Standard ISO 8434-4 was prepared by Technical Committee
ISO/TC 131, Fluid power Systems, Subcommittee SC 4, Connectors and
similar products and components.
ISO 8434 consists of the following Parts, under the general title Metallic
tube connections for fluid power and general use:
- Part 1: 24 degree compression fittings
- Part 2: 37 degree flared fittings
- Part 3: O-ring face seal fittings
- Part 4: 24 degree cone connectors with O-ring weld-on nipples
- Part 5: Test methods for threaded hydraulic fluid power connections
Annex A forms an integral part of this part of ISO 8434.

---------------------- Page: 3 ----------------------
Q ISO
ISO 8434-4: 1995(E)
Introduction
In fluid power Systems, power is transmitted and controlled through a fluid
(liquid or gas) under pressure within an enclosed circuit. In general appli-
cations, a fluid may be conveyed under pressure. Components may be
connected through their ports by connections (fittings) and conductors.
Tubes are rigid conductors; hoses are flexible conductors.

---------------------- Page: 4 ----------------------
ISO 8434-4: 1995(E)
INTERNATIONAL STANDARD 0 ISO
Metallic tube connections for fluid power and general
use -
Part 4:
24” cone connectors with O-ring weld-on nipples
2 Normative references
1 Scope
The following Standards contain provisions which,
through reference in this text, constitute provisions
This part of ISO 8434 specifies general and dimen-
of this part of ISO 8434. At the time of publication, the
sional requirements for the design and Performance
editions indicated were valid. All Standards are subject
of 24” cone connectors with O-ring weld-on nipples
to revision, and Parties to agreements based on this
that are suitable for use with steel and stainless steel
part of ISO 8434 are encouraged to investigate the
tubes with outside diameters from 6 mm to 42 mm,
possibility of applying the most recent editions of the
inclusive. These fittings are for use in fluid power and
Standards indicated below. Members of IEC and ISO
general applications where elastomeric Seals tan be
maintain registers of currently valid International
used, within the limits of pressure and temperature
Standards.
specified in this part of ISO 8434. S series fittings in
accordance with this part of ISO 8434 may be used
ISO 48: 1994, Rubber, vulcanized or thermoplastic -
at working pressures up to 63 MPa (630 bar-l)). L-
Determination o f hardness (hardness be tween ? 0
series fittings in accordance with this part of ISO 8434
IRHD and 100 IRHD).
may be used at working pressures up to 25 MPa
(250 bar) (see table 1).
ISO 228-1: 1994, Pipe threads where pressure-tight
jein ts are not made on the threads - Part 7: Dimen-
They are intended for the connection of tubes and
sions, tolerantes and designation.
hose fittings to ports in accordance with ISO 6149-1,
ISO 1179-1 and ISO 9974-1. ISO 261:-*),
ISO general-purpose metric screw
threads - General plan.
NOTES
ISO 1127:1992, Stainless steel tubes - Dimensions,
1 For new designs in hydraulic fluid power applications,
tolerantes and conventional masses per unit length.
see the requirements given in 9.6.
ISO 1179-1: -3) Connections for general use and fluid
2 For use under conditions outside the pressure and/or
power - Ports ’and stud ends with ISO 228- 1 threads
temperature Iimits specified, see 5.4.
1) 1 bar= 0,l MPa=105Pa; 1 MPa = 1 N/mm*
2) To be published. (Revision of ISO 261:1973)
3) To be published.
1'

---------------------- Page: 5 ----------------------
/ 43 ISO
ISO 8434-4: 1995(E)
with elastomeric or metal-to-metal sealing - Part 1: ISO 9974-1: -3) Connections for general use and fluid
l-f
I nreaded ports. power - Parts and stud ends with ISO 261 threads
with elastomeric or metal-to-metal sealing - Part 7:
ISO 1179-2: -3) Connections for general use and fluid
Threaded ports.
power - Ports ’and stud ends with ISO 228-1 threads
with elastomeric or metal-to-me tal sealing - Part 2: ISO 9974-2: -3) Connections for general use and fluid
Heavy-duty (S series) and ligh t-duty (L series) s tud power - Parts and stud ends with ISO 261 threads
with elastomeric or metal-to-metal sealing - Part 2:
ends with elastomeric sealing (type E).
Stud ends with elastomeric sealing (type E).
ISO 3304: 1985, Plain end seamless precision steel
tubes - Technical conditions for delivery.
3 Definitions
ISO 3305:1985, Plain end welded precision steel
tubes - Technical conditions for delivery.
For the purposes of this part of ISO 8434, the defi-
nitions given in ISO 5598 and the following definitions
ISO 3601-3: 1987, Fluid Systems - Sealing devices
aPPlY*
- O-rings - Part 3: Quality acceptance criteria.
3.1 fluid power: Means whereby energy is trans-
ISO 4397:1993, Fluid power Systems and com-
mitted, controlled and distributed using a pressurized
ponen ts - Connectors and associated componen ts
fluid as the medium.
- Nominal outside diameters of tubes and nominal
inside diameters of hoses.
[ISO 55981
ISO 4759-1: 1978, Tolerantes for fasteners - Part 7:
3.2 connection; fitting: Leakproof device to con-
Bolts, screws and nuts with thread diameters be-
nett pipelines (conductors) to one another, or to
tween 1,6 (inclusive) and 150 mm (inclusive) and
equipment.
product grades A, B and C.
[ISO 55981
ISO 5598:1985, Fluid power Systems and com-
ponents - Vocabulary.
3.3 fastening thread: Terminal thread of a complete
fitting.
ISO 6149-1 :1993, Connections for fluid power and
general use - Ports and stud ends with ISO 267
3.4 run: Two principal, axially aligned outlets of a tee
threads and O-ring sealing - Part 7: Ports with O-ring
or Cross.
seal in truncated housing.
ISO 6149-2:1993, Connections for fluid power and 3.5 branch: Side outlet(s) of a tee or Cross.
Ports and stud ends with ISO 261
general use -
threads and O-ring sealing - Part 2: Heavy-duty (S 3.6 chamfer: Removal of a conical Portion at the
- Dimensions, design, tes t meth-
series) stud ends entrance of a thread to assist assembly and prevent
ods and requiremen ts. darnage to the statt of the thread.
ISO 6149-3:1993, Connections for fluid power and
3.7 assembly torque: The torque to be applied in
general use - Ports and stud ends with ISO 261
Order to achieve a satisfactory final assembly.
threads and O-ring sealing - Part 3: Light-duty (L
series) stud ends - Dimensions, design, tes t me th-
3.8 working pressure: Pressure at which the ap-
ods and requiremen ts.
paratus is being operated in a given application.
ISO 8434-1: 1994, Metallic tube connections for fluid
[ISO 55981
power and general use - Part 7: 24 degree com-
Pression fittings.
4 Requirements for materials
ISO 9227:1990, Corrosion tests in artificial atmos-
Salt Spray tests.
pheres -
Figure 1 Shows the Cross-section and component
Parts of a typical 24” cone connector with O-ring
weld-on nipple.

---------------------- Page: 6 ----------------------
ISO 8434-4: 1995(E)
5 Pressureltemperature requirements
5.1 Fittings complying with this part of ISO 8434
made of carbon steel and stainless steel shall meet
or exceed without leakage the requirements of a
vacuum of 6,5 kPa (0,065 bar) absolute pressure up
to the working pressures given in table 1 when used
at temperatures between - 35 “C and + 100 “C.
5.2 Weld-on nipples in carbon and stainless steel
with different wall thicknesses shall be suitable for
Figure 1 - Cross-section of typical 24" cone
use up to the working pressures given in table 2 when
connector with O-ring weld-on nipple
between - 35 “C and
used at temperatures
+ 100 “C.
5.3 Fittings in stainless steel shall be suitable for
use at the working pressures given in tables 1 and 2.
For pressure derating for fittings made of stainless
4.1 Fitting bodies
steel that are to be used at temperatures outside the
ranges given in 5.1 and 5.2, see table3.
Bodies shall be manufactured from carbon steel or
stainiess steel that will provide the minimum
pressure/temperature requirements specified in
5.4 For applications under conditions outside the
clause 5. They shall have characteristics that make
pressure and/or temperature limits given in table 1
them suitable for use with the fluid to be conveyed
and in 5.1 to 5.3, the manufacturer shall be consulted.
and that will provide an effective joint. Weld-on
nipples shall be made of materials classified as suit-
able for welding.
5.5 According to different applications and different
pressure ratings, there are two series of fittings. The
series are referred to as
L: light duty
4.2 Nuts
S: heavy duty
Nuts to be used with carbon steel bodies shall be
made of carbon steel and those for use with stainless
Ranges of the tube outside diameters and pressure
steel bodies shall be made of stainless steel unless
requirements are shown in table 1.
otherwise specified.
5.6 The fitting assembly shall not leak or fail when
hydrostatically tested at four times the applicable
recommended working pressure specified in table 1.
4.3 O-rings
Testing shall be conducted at room temperature.
Unless otherwise specified, for use at the pressure
and temperature requirements given in clause 5 and
. The pressure/temperature requirements given
57
table 1, O-rings for use with fittings in accordance
in tables 1 to 3 and in 5.1 to 5.6 are for weld-on
with this part of ISO 8434 shall be made of NBR
nipples and fitting bodies only. For port and stud end
(nitrile) with a hardness of (90 + 5) IRHD, measured
pressure/temperature requirements, the values
in accordance with ISO 48, and shall conform to the
specified in the respective port and stud end stan-
dimensions given in table 5 and shall meet or exceed
dards and in annex A of this part of ISO 8434 shall
the O-ring quality acceptance criteria for grade N 0%
aPPlY*
ISO 3601-3.
3

---------------------- Page: 7 ----------------------
ISO 8434-4: 1995(E) 0 ISO
6.4 Reducing fittings and reducing elbows shall be
Table 1 - Working pressures for carbon and designated by specifying the larger tube end first.
stainless steel 24” cone connectors with O-ring
weld-on nipples
6.5 Stud fittings shall be designated by specifying
the tube end first, then the thread size for the stud
Tube outside
Working pressure
end.
diameterl)
Series
mm MPa
(bar)
6.6 For tee fittings, the Order of designation of the
connection ends shall be from larger to smaller on the
15 25 (250)
run, followed by the branch end.
L 18 to 22 incl. 16 (160)
28 to 42 incl. 10
(100)
6.7 For Cross fittings, the Order of designation of the
connection ends shall be from left to right, followed
6 to 12 incl. 63
(630)
by top to bottom, with the larger ends on the left and
S 16 to 25 incl. 40
(400)
at the top.
30 to 38 incl. 25
(250)
NOTE - For higher pressure ratings and for dynamic 6.8 If the fitting has a tube Union connection, it shall
conditions, the manufacturer shall be consulted.
be designated first, then the designation shall proceed
clockwise.
1) Tube outside diameters per ISO 4397.
6.9 The following letter Symbols shall be used:
6 Designation of fittings
Connection end type Letter
Bulkhead BH
6.1 Fittings shall be designated by an alphanumeric
code to facilitate ordering. They shall be designated
Swivel SW
by ISO 8434-4, followed by a spaced hyphen, then the
Weld-on
WD
fitting style letter Symbols (see 6.2), followed by a
Weld-in
WI
spaced hyphen, then the series letter (see 5.5) im-
mediately followed by the outside diameter of the
Port P
tube with which they are to be connected, followed
Stud SD
by a multiplication sign (x) then the wall thickness. For
Reducing RE
stud ends (connector ends), another spaced hyphen
followed by the thread designation of the stud end
Shape
and the sealing type shall be added. Letter
Straight
S
EXAMPLE
Elbow
E
A straight stud fitting (SDS) for use with tubing of
Tee T
12 mm OD and 2 mm wall thickness, with an
Run tee
RT
M18 x 1,5 stud end in accordance with ISO 6149-2
(S series), is designated as follows:
Branch tee
BT
Cross
K
ISO 8434-4 - SDS - SI2 x 2 - M18
Component type
Letter
6.2 The letter Symbol designation of the fitting style
Nut
shall have two Parts: the connection end type, im- N
mediately followed by the shape of the fitting.
Locknut
LN
Nipple
NP
6.3 Tube ends are assumed to be male and thus do
not need to be included in the Code. However, if an-
Examples of compression fittings and designations
other type of end is involved, it shall be designated.
are given in figures 2 to 7.

---------------------- Page: 8 ----------------------
0 ISO
ISO 8434-4: 1995(E)
- Working pressures for carbon and stainless steel weld-on nipples with various tube wall
Table 2
thicknesses
Dimensions in millimetres
Working pressure
MPa 31,5 MPa 40 MPa 63 MPa
Series Tube ODI) 10 MPa 16 MPa 25
(100 bar) (160 bar) (250 bar) (315 bar) (400 bar) (630 bar)
e 4 e 4 e
4 *’ e 3) 4 e 4 e 4
15 10 2,5 IO 2,5 Io 2l5
18 13 2,5 13 2,5
L 22 17 2,5 l7 2,5
28 23 2,5
3
35 29
3
42 36
2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75
6 25 1,75 2,5 1,75
2 4 2 4 2 4 2
8 4 2 4 2 4
2 6 2 6 2 5 2,5
IO 6 2 6 2 6
8 2 8 2 7 2,5 6 3
12 8 2 8 2
11 2,5 11 2,5 10 3
S 16 11 2,5 11 2,5
3 14 3 14 3 14 3 12 4
20 14
17 4 16 4,5
25 19 3 19 3 19 3
3 24 3 22 4
30 24
3 32 3 28 5
38 32
- For pressure and/or temperature applications outside those given in this part of ISO 8434, the manufacturer shall
NOTE
be consulted.
1) OD = outside diameter
= tube inside diameter
2 d2
3) e = tube wall thickness
Table 3 - Pressure deratings for fittings made from stainless steel and used at temperatures outside the
ranges given in 5.1 and 5.2
Working pressure for temperature range
-35 “Cto + 50 “C + 100 “C +200 “C
MPa
(bat-1 MPa MPa
bar) (bar)
63 630) 56,l (561) 50,4 (504)
(356)
40 (400) 35,6 32 (320)
(280) 25
31,5 (315) 28 (250)
22,3 (223)
25 (250) 20 (200)
14,2 (142)
16 (160) 12,8 (128)
(100) 89 (89)
IO 8 (80)
NOTE
...

SLOVENSKI STANDARD
SIST ISO 8434-4:1997
01-februar-1997
.RYLQVNLFHYQLSULNOMXþNL]DIOXLGQRWHKQLNRLQVSORãQRXSRUDERGHOƒV
VWRåþDVWLPSULYDUMHQLPYWLþHPLQWHVQLONR2
Metallic tube connections for fluid power and general use -- Part 4: 24 degree cone
connectors with O-ring weld-on nipples
Raccords de tubes métalliques pour transmissions hydrauliques et pneumatiques et
applications générales -- Partie 4: Raccords à cône à 24 degrés, à embout à souder à
joint torique
Ta slovenski standard je istoveten z: ISO 8434-4:1995
ICS:
23.100.40 Cevna napeljava in sklopke Piping and couplings
SIST ISO 8434-4:1997 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 8434-4:1997

---------------------- Page: 2 ----------------------

SIST ISO 8434-4:1997
INTERNATIONAL ISO
STANDARD 8434-4
First edition
1995-04-01
Metallic tube connections for fluid power
and general use -
Part 4:
24” cone connectors with O-ring weld-on
nipples
Ratcords de tubes m&alliques pour transmissions hydr-auliques et
Pneuma tiques et applica tions g&&ales -
Partie 4: Ratcords 6 cone 8 24 ”, 5 embout 5 souder 5 joint torique
Reference number
ISO 8434-4:1995(E)

---------------------- Page: 3 ----------------------

SIST ISO 8434-4:1997
ISO 8434-4: 1995(E)
Contents
Page
1
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
................................... 1
..................................
2 Normative references
2
3 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
........ ...............................................
4 Requirements for materials
. . . .” 3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5 Pressure/temperature requirements
4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 Designation of fittings
7
....... .............................. .......................
7 Requirements for tubes
7
. . . . . . . . . . . . . . . . . . . . . . . . . . .*.
8 Across-flats dimensions . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
9 Design .,.
8
.........................................................................
IO Screw threads
8
............................................................................
11 Manufacture
8
12 Assembly instruction .
........................................................ 9
13 Procurement information
9
14 Marking of components . . . . . . . . . . . . . . . . . . . . .*.
9
15 Identification Statement (Reference to this part of ISO 8434)
Annex
A Port and stud end working pressures and combinations of tube
outside diameters and port and stud end thread sizes . . . . . . . . . 24
0 ISO 1995
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-121 1 Geneve 20 l Switzerland
Printed in Switzerland

---------------------- Page: 4 ----------------------

SIST ISO 8434-4:1997
0 ISO ISO 8434-4: 1995(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. Esch 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.
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.
International Standard ISO 8434-4 was prepared by Technical Committee
ISO/TC 131, Fluid power Systems, Subcommittee SC 4, Connectors and
similar products and components.
ISO 8434 consists of the following Parts, under the general title Metallic
tube connections for fluid power and general use:
- Part 1: 24 degree compression fittings
- Part 2: 37 degree flared fittings
- Part 3: O-ring face seal fittings
- Part 4: 24 degree cone connectors with O-ring weld-on nipples
- Part 5: Test methods for threaded hydraulic fluid power connections
Annex A forms an integral part of this part of ISO 8434.

---------------------- Page: 5 ----------------------

SIST ISO 8434-4:1997
Q ISO
ISO 8434-4: 1995(E)
Introduction
In fluid power Systems, power is transmitted and controlled through a fluid
(liquid or gas) under pressure within an enclosed circuit. In general appli-
cations, a fluid may be conveyed under pressure. Components may be
connected through their ports by connections (fittings) and conductors.
Tubes are rigid conductors; hoses are flexible conductors.

---------------------- Page: 6 ----------------------

SIST ISO 8434-4:1997
ISO 8434-4: 1995(E)
INTERNATIONAL STANDARD 0 ISO
Metallic tube connections for fluid power and general
use -
Part 4:
24” cone connectors with O-ring weld-on nipples
2 Normative references
1 Scope
The following Standards contain provisions which,
through reference in this text, constitute provisions
This part of ISO 8434 specifies general and dimen-
of this part of ISO 8434. At the time of publication, the
sional requirements for the design and Performance
editions indicated were valid. All Standards are subject
of 24” cone connectors with O-ring weld-on nipples
to revision, and Parties to agreements based on this
that are suitable for use with steel and stainless steel
part of ISO 8434 are encouraged to investigate the
tubes with outside diameters from 6 mm to 42 mm,
possibility of applying the most recent editions of the
inclusive. These fittings are for use in fluid power and
Standards indicated below. Members of IEC and ISO
general applications where elastomeric Seals tan be
maintain registers of currently valid International
used, within the limits of pressure and temperature
Standards.
specified in this part of ISO 8434. S series fittings in
accordance with this part of ISO 8434 may be used
ISO 48: 1994, Rubber, vulcanized or thermoplastic -
at working pressures up to 63 MPa (630 bar-l)). L-
Determination o f hardness (hardness be tween ? 0
series fittings in accordance with this part of ISO 8434
IRHD and 100 IRHD).
may be used at working pressures up to 25 MPa
(250 bar) (see table 1).
ISO 228-1: 1994, Pipe threads where pressure-tight
jein ts are not made on the threads - Part 7: Dimen-
They are intended for the connection of tubes and
sions, tolerantes and designation.
hose fittings to ports in accordance with ISO 6149-1,
ISO 1179-1 and ISO 9974-1. ISO 261:-*),
ISO general-purpose metric screw
threads - General plan.
NOTES
ISO 1127:1992, Stainless steel tubes - Dimensions,
1 For new designs in hydraulic fluid power applications,
tolerantes and conventional masses per unit length.
see the requirements given in 9.6.
ISO 1179-1: -3) Connections for general use and fluid
2 For use under conditions outside the pressure and/or
power - Ports ’and stud ends with ISO 228- 1 threads
temperature Iimits specified, see 5.4.
1) 1 bar= 0,l MPa=105Pa; 1 MPa = 1 N/mm*
2) To be published. (Revision of ISO 261:1973)
3) To be published.
1'

---------------------- Page: 7 ----------------------

SIST ISO 8434-4:1997
/ 43 ISO
ISO 8434-4: 1995(E)
with elastomeric or metal-to-metal sealing - Part 1: ISO 9974-1: -3) Connections for general use and fluid
l-f
I nreaded ports. power - Parts and stud ends with ISO 261 threads
with elastomeric or metal-to-metal sealing - Part 7:
ISO 1179-2: -3) Connections for general use and fluid
Threaded ports.
power - Ports ’and stud ends with ISO 228-1 threads
with elastomeric or metal-to-me tal sealing - Part 2: ISO 9974-2: -3) Connections for general use and fluid
Heavy-duty (S series) and ligh t-duty (L series) s tud power - Parts and stud ends with ISO 261 threads
with elastomeric or metal-to-metal sealing - Part 2:
ends with elastomeric sealing (type E).
Stud ends with elastomeric sealing (type E).
ISO 3304: 1985, Plain end seamless precision steel
tubes - Technical conditions for delivery.
3 Definitions
ISO 3305:1985, Plain end welded precision steel
tubes - Technical conditions for delivery.
For the purposes of this part of ISO 8434, the defi-
nitions given in ISO 5598 and the following definitions
ISO 3601-3: 1987, Fluid Systems - Sealing devices
aPPlY*
- O-rings - Part 3: Quality acceptance criteria.
3.1 fluid power: Means whereby energy is trans-
ISO 4397:1993, Fluid power Systems and com-
mitted, controlled and distributed using a pressurized
ponen ts - Connectors and associated componen ts
fluid as the medium.
- Nominal outside diameters of tubes and nominal
inside diameters of hoses.
[ISO 55981
ISO 4759-1: 1978, Tolerantes for fasteners - Part 7:
3.2 connection; fitting: Leakproof device to con-
Bolts, screws and nuts with thread diameters be-
nett pipelines (conductors) to one another, or to
tween 1,6 (inclusive) and 150 mm (inclusive) and
equipment.
product grades A, B and C.
[ISO 55981
ISO 5598:1985, Fluid power Systems and com-
ponents - Vocabulary.
3.3 fastening thread: Terminal thread of a complete
fitting.
ISO 6149-1 :1993, Connections for fluid power and
general use - Ports and stud ends with ISO 267
3.4 run: Two principal, axially aligned outlets of a tee
threads and O-ring sealing - Part 7: Ports with O-ring
or Cross.
seal in truncated housing.
ISO 6149-2:1993, Connections for fluid power and 3.5 branch: Side outlet(s) of a tee or Cross.
Ports and stud ends with ISO 261
general use -
threads and O-ring sealing - Part 2: Heavy-duty (S 3.6 chamfer: Removal of a conical Portion at the
- Dimensions, design, tes t meth-
series) stud ends entrance of a thread to assist assembly and prevent
ods and requiremen ts. darnage to the statt of the thread.
ISO 6149-3:1993, Connections for fluid power and
3.7 assembly torque: The torque to be applied in
general use - Ports and stud ends with ISO 261
Order to achieve a satisfactory final assembly.
threads and O-ring sealing - Part 3: Light-duty (L
series) stud ends - Dimensions, design, tes t me th-
3.8 working pressure: Pressure at which the ap-
ods and requiremen ts.
paratus is being operated in a given application.
ISO 8434-1: 1994, Metallic tube connections for fluid
[ISO 55981
power and general use - Part 7: 24 degree com-
Pression fittings.
4 Requirements for materials
ISO 9227:1990, Corrosion tests in artificial atmos-
Salt Spray tests.
pheres -
Figure 1 Shows the Cross-section and component
Parts of a typical 24” cone connector with O-ring
weld-on nipple.

---------------------- Page: 8 ----------------------

SIST ISO 8434-4:1997
ISO 8434-4: 1995(E)
5 Pressureltemperature requirements
5.1 Fittings complying with this part of ISO 8434
made of carbon steel and stainless steel shall meet
or exceed without leakage the requirements of a
vacuum of 6,5 kPa (0,065 bar) absolute pressure up
to the working pressures given in table 1 when used
at temperatures between - 35 “C and + 100 “C.
5.2 Weld-on nipples in carbon and stainless steel
with different wall thicknesses shall be suitable for
Figure 1 - Cross-section of typical 24" cone
use up to the working pressures given in table 2 when
connector with O-ring weld-on nipple
between - 35 “C and
used at temperatures
+ 100 “C.
5.3 Fittings in stainless steel shall be suitable for
use at the working pressures given in tables 1 and 2.
For pressure derating for fittings made of stainless
4.1 Fitting bodies
steel that are to be used at temperatures outside the
ranges given in 5.1 and 5.2, see table3.
Bodies shall be manufactured from carbon steel or
stainiess steel that will provide the minimum
pressure/temperature requirements specified in
5.4 For applications under conditions outside the
clause 5. They shall have characteristics that make
pressure and/or temperature limits given in table 1
them suitable for use with the fluid to be conveyed
and in 5.1 to 5.3, the manufacturer shall be consulted.
and that will provide an effective joint. Weld-on
nipples shall be made of materials classified as suit-
able for welding.
5.5 According to different applications and different
pressure ratings, there are two series of fittings. The
series are referred to as
L: light duty
4.2 Nuts
S: heavy duty
Nuts to be used with carbon steel bodies shall be
made of carbon steel and those for use with stainless
Ranges of the tube outside diameters and pressure
steel bodies shall be made of stainless steel unless
requirements are shown in table 1.
otherwise specified.
5.6 The fitting assembly shall not leak or fail when
hydrostatically tested at four times the applicable
recommended working pressure specified in table 1.
4.3 O-rings
Testing shall be conducted at room temperature.
Unless otherwise specified, for use at the pressure
and temperature requirements given in clause 5 and
. The pressure/temperature requirements given
57
table 1, O-rings for use with fittings in accordance
in tables 1 to 3 and in 5.1 to 5.6 are for weld-on
with this part of ISO 8434 shall be made of NBR
nipples and fitting bodies only. For port and stud end
(nitrile) with a hardness of (90 + 5) IRHD, measured
pressure/temperature requirements, the values
in accordance with ISO 48, and shall conform to the
specified in the respective port and stud end stan-
dimensions given in table 5 and shall meet or exceed
dards and in annex A of this part of ISO 8434 shall
the O-ring quality acceptance criteria for grade N 0%
aPPlY*
ISO 3601-3.
3

---------------------- Page: 9 ----------------------

SIST ISO 8434-4:1997
ISO 8434-4: 1995(E) 0 ISO
6.4 Reducing fittings and reducing elbows shall be
Table 1 - Working pressures for carbon and designated by specifying the larger tube end first.
stainless steel 24” cone connectors with O-ring
weld-on nipples
6.5 Stud fittings shall be designated by specifying
the tube end first, then the thread size for the stud
Tube outside
Working pressure
end.
diameterl)
Series
mm MPa
(bar)
6.6 For tee fittings, the Order of designation of the
connection ends shall be from larger to smaller on the
15 25 (250)
run, followed by the branch end.
L 18 to 22 incl. 16 (160)
28 to 42 incl. 10
(100)
6.7 For Cross fittings, the Order of designation of the
connection ends shall be from left to right, followed
6 to 12 incl. 63
(630)
by top to bottom, with the larger ends on the left and
S 16 to 25 incl. 40
(400)
at the top.
30 to 38 incl. 25
(250)
NOTE - For higher pressure ratings and for dynamic 6.8 If the fitting has a tube Union connection, it shall
conditions, the manufacturer shall be consulted.
be designated first, then the designation shall proceed
clockwise.
1) Tube outside diameters per ISO 4397.
6.9 The following letter Symbols shall be used:
6 Designation of fittings
Connection end type Letter
Bulkhead BH
6.1 Fittings shall be designated by an alphanumeric
code to facilitate ordering. They shall be designated
Swivel SW
by ISO 8434-4, followed by a spaced hyphen, then the
Weld-on
WD
fitting style letter Symbols (see 6.2), followed by a
Weld-in
WI
spaced hyphen, then the series letter (see 5.5) im-
mediately followed by the outside diameter of the
Port P
tube with which they are to be connected, followed
Stud SD
by a multiplication sign (x) then the wall thickness. For
Reducing RE
stud ends (connector ends), another spaced hyphen
followed by the thread designation of the stud end
Shape
and the sealing type shall be added. Letter
Straight
S
EXAMPLE
Elbow
E
A straight stud fitting (SDS) for use with tubing of
Tee T
12 mm OD and 2 mm wall thickness, with an
Run tee
RT
M18 x 1,5 stud end in accordance with ISO 6149-2
(S series), is designated as follows:
Branch tee
BT
Cross
K
ISO 8434-4 - SDS - SI2 x 2 - M18
Component type
Letter
6.2 The letter Symbol designation of the fitting style
Nut
shall have two Parts: the connection end type, im- N
mediately followed by the shape of the fitting.
Locknut
LN
Nipple
NP
6.3 Tube ends are assumed to be male and thus do
not need to be included in the Code. However, if an-
Examples of compression fittings and designations
other type of end is involved, it shall be designated.
are given in figures 2 to 7.

---------------------- Page: 10 ----------------------

SIST ISO 8434-4:1997
0 ISO
ISO 8434-4: 1995(E)
- Working pressures for carbon and stainless steel weld-on nipples with various tube wall
Table 2
thicknesses
Dimensions in millimetres
Working pressure
MPa 31,5 MPa 40 MPa 63 MPa
Series Tube ODI) 10 MPa 16 MPa 25
(100 bar) (160 bar) (250 bar) (315 bar) (400 bar) (630 bar)
e 4 e 4 e
4 *’ e 3) 4 e 4 e 4
15 10 2,5 IO 2,5 Io 2l5
18 13 2,5 13 2,5
L 22 17 2,5 l7 2,5
28 23 2,5
3
35 29
3
42 36
2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75
6 25 1,75 2,5 1,75
2 4 2 4 2 4 2
8 4 2 4 2 4
2 6 2 6 2 5 2,5
IO 6 2 6 2 6
8 2 8 2 7 2,5 6 3
12 8 2 8 2
11 2,5 11 2,5 10 3
S 16 11 2,5 11 2,5
3 14 3 14 3 14 3 12 4
20 14
17 4 16 4,5
25 19 3 19 3 19 3
3 24 3 22 4
30 24
3 32 3 28 5
38 32
- For pressure and/or temperature applications outside those
...