ISO 18752:2006

INTERNATIONAL ISO
STANDARD 18752
First edition
2006-07-15

Rubber hoses and hose assemblies —
Wire- or textile-reinforced single-pressure
types for hydraulic applications —
Specification
Tuyaux et flexibles en caoutchouc — Types hydrauliques avec
armature de fils métalliques tressés — Spécifications




Reference number
ISO 18752:2006(E)
©
ISO 2006

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ISO 18752:2006(E)
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ii © ISO 2006 – All rights reserved

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ISO 18752:2006(E)
Contents Page
Foreword. iv
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Classification.2
4.1 Classes .2
4.2 Grades and types.3
5 Materials and construction.4
5.1 Hoses .4
5.2 Hose assemblies.4
6 Dimensions and tolerances .4
6.1 Diameters.4
6.2 Cover thickness .6
6.3 Concentricity.6
7 Physical properties.7
7.1 Fluid resistance of rubber compounds .7
7.1.1 Test pieces .7
7.1.2 Oil resistance .7
7.2 Performance requirements .7
7.2.1 Hydrostatic requirements .7
7.2.2 Change in length.7
7.2.3 Minimum bend radius.7
7.2.4 Resistance to impulse.9
7.2.5 Leakage of hose assemblies .9
7.2.6 Cold flexibility .9
7.2.7 Adhesion between components.9
7.2.8 Vacuum resistance .9
7.2.9 Abrasion resistance .10
7.2.10 Ozone resistance .10
8 Frequency of testing .10
9 Marking .10
9.1 Hoses .10
9.2 Hose assemblies.11
10 Recommendations for packaging and storage .11
11 Test report .11
Annex A (normative) Type tests and routine tests .12
Annex B (informative) Production acceptance tests .13
Annex C (informative) Recommendations for lengths of supplied hoses and tolerances on
lengths of hose assemblies.14
Annex D (informative) Information to be provided by hose manufacturer.15
Bibliography .16

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ISO 18752:2006(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.
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 18752 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee
SC 1, Hoses (rubber and plastics).

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INTERNATIONAL STANDARD ISO 18752:2006(E)

Rubber hoses and hose assemblies — Wire- or textile-
reinforced single-pressure types for hydraulic applications —
Specification
1 Scope
This International Standard specifies requirements for nine classes, four grades and seven types of wire- or
textile-reinforced hydraulic hoses and hose assemblies of nominal sizes ranging from 5 to 102. Each class
has a single maximum working pressure for all sizes. Such hoses are suitable for use with hydraulic fluids HH,
HL, HM, HR and HV as defined in ISO 6743-4 at temperatures ranging from – 40 °C to + 100 °C for types AS,
AC, BS and BC and – 40 °C to + 120 °C for types CS, CC and DC.
This International Standard does not include requirements for the connection ends. It is limited to the
performance of hoses and hose assemblies. The hose assembly maximum working pressure is governed by
the lowest maximum working pressure of the components.
NOTE It is the responsibility of the user, in consultation with the hose manufacturer, to establish the compatibility of the
hose with the fluid to be used.
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 1402, Rubber and plastics hoses and hose assemblies — Hydrostatic testing
ISO 1746, Rubber or plastics hoses and tubing — Bending tests
ISO 1817, Rubber, vulcanized — Determination of the effect of liquids
ISO 4671, Rubber and plastics hoses and hose assemblies — Methods of measurement of dimensions
ISO 4672:1997, Rubber and plastics hoses — Sub-ambient temperature flexibility tests
ISO 6803, Rubber or plastics hoses and hose assemblies — Hydraulic-pressure impulse test without flexing
ISO 6945, Rubber hoses — Determination of abrasion resistance of the outer cover
ISO 7233, Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum
ISO 7326:1991, Rubber and plastics hoses — Assessment of ozone resistance under static conditions
ISO 8033:2006, Rubber and plastics hoses — Determination of adhesion between components
ISO 8330, Rubber and plastics hoses and hose assemblies — Vocabulary
ISO 8331, Rubber and plastics hoses and hose assemblies — Guidelines for selection, storage, use and
maintenance
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ISO 18752:2006(E)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8330 apply.
4 Classification
4.1 Classes
Nine classes of hose are specified, distinguished by their maximum working pressure, as shown in Table 1.
Each class may be manufactured in up to 14 nominal sizes.
Table 1 — Classes and nominal sizes
Class 35 70 140 210 250 280 350 420 560

a
MWP (bar) 35 70 140 210 250 280 350 420 560

a
MWP (MPa) 3,5 7 14 21 25 28 35 42 56
Nominal size
5 X X X X X X X X N/A
6,3 X X X X X X X X N/A
8 X X X X X X X X N/A
10 X X X X X X X X N/A
12,5 X X X X X X X X N/A
16 X X X X X X X X X
19 X X X X X X X X X
25 X X X X X X X X X
31,5 X X X X X X X X X
38 X X X X X X X X N/A
51 X X X X X X X X N/A
63 X X X N/A N/A N/A N/A N/A N/A
76 X X X N/A N/A N/A N/A N/A N/A
102 X N/A N/A N/A N/A N/A N/A N/A N/A
NOTE X = Applicable; N/A = Not applicable.
a
Maximum working pressure.

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ISO 18752:2006(E)
4.2 Grades and types
Hoses are classified according to their resistance to impulse into four grades: A, B, C and D. Each grade is
classified by outside diameter into standard types (AS, BS and CS) and compact types (AC, BC, CC and DC),
as shown in Table 2.
Table 2 — Grades and types
Resistance to impulse
a
Grade
Type
Temperature Impulse pressure
Minimum number of cycles
b
°C (% of MWP )
AS
A 100 133 % 200 000
AC
BS
B 100 133 % 500 000
BC
CS
c
C 120 500 000
133 % and 120 %
CC
D DC 120 133 % 1 000 000
a
Standard or compact, e.g. CS is grade C and standard type.
As shown in Table 4 and Table 8, standard types have larger outside diameters and larger bend radii and compact types
have smaller outside diameters and smaller bend radii.
b
Maximum working pressure.
c
120 % of the MWP shall be used for classes 350, 420 and 560 instead of 133 %.

Each class includes one of each type or both as shown in Table 3.
Table 3 — Type and maximum working pressure
Class 35 70 140 210 250 280 350 420 560
a
MWP (bar) 35 70 140 210 250 280 350 420 560
a
MWP (MPa) 3,5 7 14 21 25 28 35 42 56
Grade Type
AS X X X X X X X X N/A
A
AC X X X X X X X X N/A
BS X X X X X X X X N/A
B
BC X X X X X X X X N/A
CS N/A N/A N/A X X X X X N/A
C
CC N/A N/A N/A X X X X N/A X
D DC N/A N/A N/A X X X X N/A N/A
NOTE X = Applicable; N/A = Not applicable.
a
Maximum working pressure.

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ISO 18752:2006(E)
5 Materials and construction
5.1 Hoses
Hoses shall consist of a hydraulic-fluid-resistant rubber lining, one or multiple layers of steel wire or textile and
an oil-, abrasion- and weather-resistant rubber cover. A layer of other materials on the rubber cover is allowed
for improved resistance to abrasion or other.
5.2 Hose assemblies
Hose assemblies shall only be manufactured using hose fittings which conform to the requirements of 7.2.1,
7.2.4 and 7.2.5 of this International Standard.
Follow the manufacturer's instructions for the proper preparation and fabrication of hose assemblies.
6 Dimensions and tolerances
6.1 Diameters
When measured in accordance with ISO 4671, the diameters of hoses shall conform to the values given in
Table 4.

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ISO 18752:2006(E)
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Table 4 — Diameters of hoses
Nom- Inside
Maximum outside diameter of hose
inal diameter
mm
size (all classes)
Class 35 Class 70 Class 140 Class 210 Class 250 Class 280 Class 350 Class 420 Class 560
mm
min. max. Stan- Com- Stan- Com- Stan- Com- Stan- Com- Stan- Com- Stan- Com- Stan- Com- Stan- Com- Stan- Com-
dard pact dard pact dard pact dard pact dard pact dard pact dard pact dard pact dard pact
5
4,6 5,4 14 11 14 11 14 11 14 11 17 15 17 15 17 15 17 15 — —
6,3 6,1 7,0 17 14 17 14 17 14 17 14 19 15 19 15 19 15 19 15 — —
8
7,7 8,5 19 1
...