ISO 5781:2000

Hydraulic fluid power — Pressure-reducing valves, sequence valves, unloading valves, throttle valves and check valves — Mounting surfaces

Transmissions hydrauliques — Réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes d'étranglement et clapets de non-retour — Plan de pose

La présente Norme internationale spécifie, à des fins d'interchangeabilité, les dimensions et autres caractéristiques des plans de pose sur lesquels sont montés des réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes d'étranglement et clapets de non-retour pour transmissions hydrauliques. Elle est applicable aux plans de pose des réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes d'étranglement et clapets de non-retour, qui représentent la pratique courante. Ils sont généralement utilisés dans les équipements industriels.

Fluidna tehnika - Hidravlika - Tlačno-reducirni ventili, sekvenčni ventili, razbremenilni ventili, dušilni ventili in protipovratni ventili - Priključne površine

General Information

• Status: Withdrawn
• Publication Date: 16-Aug-2000
• Withdrawal Date: 16-Aug-2000
• ICS: 23.100.50 - Control components
• Technical Committee: ISO/TC 131/SC 5 - Control products and components
• Drafting Committee: ISO/TC 131/SC 5/WG 2 - Hydraulic control products
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 04-Aug-2016
• Ref Project: SIST ISO 5781:2001 - Hydraulic fluid power -- Pressure-reducing valves, sequence valves, unloading valves, throttle valves and check valves -- Mounting surfaces

Relations

• Revised: ISO 5781:2016 - Hydraulic fluid power — Pressure-reducing valves, sequence valves, unloading valves, throttle valves and check valves — Mounting surfaces
• Effective Date: 22-Sep-2012
• Revises: ISO 5781:1987 - Hydraulic fluid power — Pressure-control valves (excluding pressure-relief valves), sequence valves, unloading valves, throttle valves and check valves — Mounting surfaces
• Effective Date: 15-Apr-2008

Standards Content (Sample)

SLOVENSKI STANDARD
SIST ISO 5781:2001
01-december-2001
)OXLGQDWHKQLND+LGUDYOLND7ODþQRUHGXFLUQLYHQWLOLVHNYHQþQLYHQWLOL
UD]EUHPHQLOQLYHQWLOLGXãLOQLYHQWLOLLQSURWLSRYUDWQLYHQWLOL3ULNOMXþQHSRYUãLQH
Hydraulic fluid power -- Pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves -- Mounting surfaces
Transmissions hydrauliques -- Réducteurs de pression, soupapes de séquence,
soupapes de décharge, soupapes d'étranglement et clapets de non-retour -- Plan de
pose
Ta slovenski standard je istoveten z: ISO 5781:2000
ICS:
23.100.50 Krmilni sestavni deli Control components
SIST ISO 5781:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ISO 5781:2001

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SIST ISO 5781:2001
INTERNATIONAL ISO
STANDARD 5781
Second edition
2000-08-15
Hydraulic fluid power — Pressure-reducing
valves, sequence valves, unloading valves,
throttle valves and check valves —
Mounting surfaces
Transmissions hydrauliques — Réducteurs de pression, soupapes de
séquence, soupapes de décharge, soupapes d'étranglement et clapets de
non-retour — Plan de pose
Reference number
ISO 5781:2000(E)
©
ISO 2000

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

SIST ISO 5781:2001
ISO 5781:2000(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 2000
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 [e-mail]
Web www.iso.ch
Printed in Switzerland
ii © ISO 2000 – All rights reserved

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

SIST ISO 5781:2001
ISO 5781:2000(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 5781 was prepared by Technical Committee ISO/TC 131, Fluid power systems,
Subcommittee SC 5, Control products and components.
This second edition cancels and replaces the first edition (ISO 5781), which has been technically revised.
© ISO 2000 – All rights reserved iii

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

SIST ISO 5781:2001
ISO 5781:2000(E)
Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure circulating
within an enclosed circuit. The most typical components found in such systems are hydraulic valves. They control
flow direction, pressure or the flow rate of liquids in the enclosed circuit.
iv © ISO 2000 – All rights reserved

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

SIST ISO 5781:2001
INTERNATIONAL STANDARD ISO 5781:2000(E)
Hydraulic fluid power — Pressure-reducing valves, sequence
valves, unloading valves, throttle valves and check valves —
Mounting surfaces
1 Scope
This International Standard specifies, in order to ensure interchangeability, the dimensions and other
characteristics of surfaces on which hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves are mounted.
It is applicable to mounting surfaces for hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves, which represent current practice. They are generally used in industrial equipment.
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.
1)
ISO 1101:— , Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out.
ISO 1219-1:1991, Fluid power systems and components — Graphic symbols and circuit diagrams — Part 1:
Graphic symbols.
2)
ISO 1302:— , Geometrical Product Specification (GPS) — Indication of surface texture in technical product
documentation.
ISO 4401:1994, Hydraulic fluid power — Four-port directional control valves — Mounting surfaces.
ISO 5598:1985, Fluid power systems and components — Vocabulary.
ISO 5783:1995, Hydraulic fluid power — Code for identification of valve mounting surfaces and cartridge valve
cavities.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 5598 apply.
1) To be published. (Revision of ISO 1101:1983)
2) To be published. (Revision of ISO 1302:1992)
© ISO 2000 – All rights reserved 1

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SIST ISO 5781:2001
ISO 5781:2000(E)
4 Symbols
4.1 For the purposes of this International Standard, the following symbols apply:
a) A, B, P, T, X and Y identify ports;
b) F ,F ,F ,F ,F and F identify threaded holes for fixing screws;
1 2 3 4 5 6
c) G identifies the location of pin holes;
d) D identifies the fixing screw diameter;
e) r identifies the mounting surface edge radius.
max
4.2 The graphic symbols used in Figures 2, 3, 5, 6, 8, 9, 11, 12, 14 and 15 are in conformance with the graphical
symbols in ISO 1219-1.
4.3 The code system used in this International Standard is defined in ISO 5783.
5 Tolerances
5.1 The following values shall be applied to the mounting surface, i.e. the area within the chain thick lines:
� surface roughness: Rau 0,8�m (see ISO 1302);
� surface flatness: 0,01 mm over a distance of 100 mm (see ISO 1101);
� tolerance on diameters of locating pin holes: H12
5.2 With respect to the point of origin, along the x and y axes, the following tolerances shall be complied with:
� pin holes:� 0,1 mm
� screw holes:� 0,1 mm
� main ports:� 0,2 mm
For the other dimensions, refer to the figures.
6 Dimensions
6.1 Mounting surface dimensions for hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves shall be selected from the figures and tables specified in 6.2 to 6.6.
6.2 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in
Figure 1.
6.3 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in
Figure 4.
6.4 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in
Figure 7.
2 © ISO 2000 – All rights reserved

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SIST ISO 5781:2001
ISO 5781:2000(E)
6.5 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in
Figure 10.
6.6 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in
Figure 13.
7 Port marking
7.1 The port symbols to be used for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves shall be selected from the figures specified in 7.2 to 7.11.
7.2 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in
Figure 2.
7.3 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in Figure 3.
7.4 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in
Figure 5.
7.5 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in Figure 6.
7.6 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in
Figure 8.
7.7 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in Figure 9.
7.8 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in
Figure 11.
7.9 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in Figure 12.
7.10 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in
Figure 14.
7.11 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in Figure 15.
7.12 The direction A to B should not be used in new designs.
8 Modular stack valves
For modular stack valves, the mounting surfaces and port markings defined in ISO 4401 shall be used.
© ISO 2000 – All rights reserved 3

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SIST ISO 5781:2001
ISO 5781:2000(E)
9 Rated pressure
For an indication of the maximum limit of the rated pressure, see paragraph 1 of Figures 1, 4, 7, 10 and 13.
10 Identification statement (Reference to this International Standard)
It is strongly recommended to manufacturers who have chosen to conform to this International Standard that the
following statement be used in test reports, catalogues and sales literature:
“Mounting surface dimensions of pressure-reducing valves, sequence valves, unloading valves, throttle valves and
check valves conform to ISO 5781:2000, Hydraulic fluid power — Pressure-reducing valves, sequence valves,
unloading valves, throttle valves and check valves — Mounting surfaces.”
4 © ISO 2000 – All rights reserved

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SIST ISO 5781:2001
ISO 5781:2000(E)
Code: 5781-02-01-0-00
Dimensions in millimetres
The supplier shall establish the maximum rated pressure for subplates and manifold blocks.
a
The minimum thread depth is 1,5 times the screw diameter, D. The full thread depth recommended is 2D� 6 mm, to
facilitate interchangeability of valves and reduce the number of fixing screw lengths. The recommended engagement of fixing
screw thread for ferrous mountings is 1,25D.
b The dimensions specifying the area within the chain thick lines are the minimum dimensions for the mounting surface. The
corners of the rectangle may be radiused to a maximum radius, r , equal to the thread diameter of the fixing screws.
max
c This dimension gives the minimum space required for a valve with this mounting surface. The dimension is also the
minimum distance from centreline to centreline of two identical mounting surfaces placed on a manifold block.
d Blind hole in the mounting surface to accommodate the locating pin on the valves; the minimum depth is 4 mm.
NOTE See Figures
...

INTERNATIONAL ISO
STANDARD 5781
Second edition
2000-08-15
Hydraulic fluid power — Pressure-reducing
valves, sequence valves, unloading valves,
throttle valves and check valves —
Mounting surfaces
Transmissions hydrauliques — Réducteurs de pression, soupapes de
séquence, soupapes de décharge, soupapes d'étranglement et clapets de
non-retour — Plan de pose
Reference number
ISO 5781:2000(E)
©
ISO 2000

---------------------- Page: 1 ----------------------
ISO 5781:2000(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 2000
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 [e-mail]
Web www.iso.ch
Printed in Switzerland
ii © ISO 2000 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 5781:2000(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 5781 was prepared by Technical Committee ISO/TC 131, Fluid power systems,
Subcommittee SC 5, Control products and components.
This second edition cancels and replaces the first edition (ISO 5781), which has been technically revised.
© ISO 2000 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 5781:2000(E)
Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure circulating
within an enclosed circuit. The most typical components found in such systems are hydraulic valves. They control
flow direction, pressure or the flow rate of liquids in the enclosed circuit.
iv © ISO 2000 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 5781:2000(E)
Hydraulic fluid power — Pressure-reducing valves, sequence
valves, unloading valves, throttle valves and check valves —
Mounting surfaces
1 Scope
This International Standard specifies, in order to ensure interchangeability, the dimensions and other
characteristics of surfaces on which hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves are mounted.
It is applicable to mounting surfaces for hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves, which represent current practice. They are generally used in industrial equipment.
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.
1)
ISO 1101:— , Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out.
ISO 1219-1:1991, Fluid power systems and components — Graphic symbols and circuit diagrams — Part 1:
Graphic symbols.
2)
ISO 1302:— , Geometrical Product Specification (GPS) — Indication of surface texture in technical product
documentation.
ISO 4401:1994, Hydraulic fluid power — Four-port directional control valves — Mounting surfaces.
ISO 5598:1985, Fluid power systems and components — Vocabulary.
ISO 5783:1995, Hydraulic fluid power — Code for identification of valve mounting surfaces and cartridge valve
cavities.
3 Terms and definitions
For the purposes of this International Standard, the terms and definitions given in ISO 5598 apply.
1) To be published. (Revision of ISO 1101:1983)
2) To be published. (Revision of ISO 1302:1992)
© ISO 2000 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 5781:2000(E)
4 Symbols
4.1 For the purposes of this International Standard, the following symbols apply:
a) A, B, P, T, X and Y identify ports;
b) F ,F ,F ,F ,F and F identify threaded holes for fixing screws;
1 2 3 4 5 6
c) G identifies the location of pin holes;
d) D identifies the fixing screw diameter;
e) r identifies the mounting surface edge radius.
max
4.2 The graphic symbols used in Figures 2, 3, 5, 6, 8, 9, 11, 12, 14 and 15 are in conformance with the graphical
symbols in ISO 1219-1.
4.3 The code system used in this International Standard is defined in ISO 5783.
5 Tolerances
5.1 The following values shall be applied to the mounting surface, i.e. the area within the chain thick lines:
� surface roughness: Rau 0,8�m (see ISO 1302);
� surface flatness: 0,01 mm over a distance of 100 mm (see ISO 1101);
� tolerance on diameters of locating pin holes: H12
5.2 With respect to the point of origin, along the x and y axes, the following tolerances shall be complied with:
� pin holes:� 0,1 mm
� screw holes:� 0,1 mm
� main ports:� 0,2 mm
For the other dimensions, refer to the figures.
6 Dimensions
6.1 Mounting surface dimensions for hydraulic pressure-reducing valves, sequence valves, unloading valves,
throttle valves and check valves shall be selected from the figures and tables specified in 6.2 to 6.6.
6.2 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in
Figure 1.
6.3 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in
Figure 4.
6.4 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in
Figure 7.
2 © ISO 2000 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 5781:2000(E)
6.5 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in
Figure 10.
6.6 Mounting surface dimensions for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in
Figure 13.
7 Port marking
7.1 The port symbols to be used for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves shall be selected from the figures specified in 7.2 to 7.11.
7.2 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in
Figure 2.
7.3 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 4,5 mm maximum diameter (code: 5781-02-01-0-00) are given in Figure 3.
7.4 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in
Figure 5.
7.5 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 7,5 mm maximum diameter (code: 5781-03-04-0-00) are given in Figure 6.
7.6 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in
Figure 8.
7.7 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 14,7 mm maximum diameter (code: 5781-06-07-0-00) are given in Figure 9.
7.8 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in
Figure 11.
7.9 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 23,4 mm maximum diameter (code: 5781-08-10-0-00) are given in Figure 12.
7.10 The symbols for directly-operated pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with main ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in
Figure 14.
7.11 The symbols for pilot-operated pressure-reducing valves, sequence valves and unloading valves with main
ports of 32 mm maximum diameter (code: 5781-10-13-0-00) are given in Figure 15.
7.12 The direction A to B should not be used in new designs.
8 Modular stack valves
For modular stack valves, the mounting surfaces and port markings defined in ISO 4401 shall be used.
© ISO 2000 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 5781:2000(E)
9 Rated pressure
For an indication of the maximum limit of the rated pressure, see paragraph 1 of Figures 1, 4, 7, 10 and 13.
10 Identification statement (Reference to this International Standard)
It is strongly recommended to manufacturers who have chosen to conform to this International Standard that the
following statement be used in test reports, catalogues and sales literature:
“Mounting surface dimensions of pressure-reducing valves, sequence valves, unloading valves, throttle valves and
check valves conform to ISO 5781:2000, Hydraulic fluid power — Pressure-reducing valves, sequence valves,
unloading valves, throttle valves and check valves — Mounting surfaces.”
4 © ISO 2000 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 5781:2000(E)
Code: 5781-02-01-0-00
Dimensions in millimetres
The supplier shall establish the maximum rated pressure for subplates and manifold blocks.
a
The minimum thread depth is 1,5 times the screw diameter, D. The full thread depth recommended is 2D� 6 mm, to
facilitate interchangeability of valves and reduce the number of fixing screw lengths. The recommended engagement of fixing
screw thread for ferrous mountings is 1,25D.
b The dimensions specifying the area within the chain thick lines are the minimum dimensions for the mounting surface. The
corners of the rectangle may be radiused to a maximum radius, r , equal to the thread diameter of the fixing screws.
max
c This dimension gives the minimum space required for a valve with this mounting surface. The dimension is also the
minimum distance from centreline to centreline of two identical mounting surfaces placed on a manifold block.
d Blind hole in the mounting surface to accommodate the locating pin on the valves; the minimum depth is 4 mm.
NOTE See Figures 2 and 3 for graphic symbols.
Axis PA T B F F F F G
1 2 3 4
M5 M5 M5 M5
� 4,5 max. � 4,5 max. � 4,5 max. � 4,5 max. � 3,4
x 12 4,3 12 19,7 0 24 24 0 26,5
y 20,25 11,25 2,25 11,25 0 23,25 22,5 17,75
�0,75
Figure 1 — Mounting surface for pressure-reducing valves, sequence valves, unloading valves, throttle
valves and check valves with
...

NORME ISO
INTERNATIONALE 5781
Deuxième édition
2000-08-15
Transmissions hydrauliques — Réducteurs
de pression, soupapes de séquence,
soupapes de décharge, soupapes
d'étranglement et clapets de non-retour —
Plan de pose
Hydraulic fluid power — Pressure-reducing valves, sequence valves,
unloading valves, throttle valves and check valves — Mounting surfaces
Numéro de référence
ISO 5781:2000(F)
©
ISO 2000

---------------------- Page: 1 ----------------------
ISO 5781:2000(F)
PDF – Exonération de responsabilité
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ii © ISO 2000 – Tous droits réservés

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ISO 5781:2000(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiéeaux
comités techniques de l'ISO. Chaque comité membre intéressé par une étude ale droit de fairepartie ducomité
technique créé à cet effet. Les organisations internationales, gouvernementales et non gouvernementales, en
liaison avec l'ISO, participent également aux travaux. L'ISO collabore étroitement avec la Commission
électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI, Partie 3.
Les projets de Normes internationales adoptés par les comités techniques sont soumis aux comités membres pour
vote. Leur publication comme Normes internationales requiert l'approbation de 75 % au moins des comités
membres votants.
L’attention est appelée sur le fait que certains des éléments delaprésente Norme internationale peuvent faire
l’objet de droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable de
ne pas avoir identifié de tels droits de propriété et averti de leur existence.
La Norme internationale ISO 5781 a étéélaborée par le comité technique ISO/TC 131, Transmissions hydrauliques
et pneumatiques, sous-comité SC 5, Appareils de régulation et de distribution et leurs composants.
Cette deuxième édition annule et remplace la première édition (ISO 5781:1987), dont elle constitue une révision
technique.
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ISO 5781:2000(F)
Introduction
Dans les systèmes de transmissions hydrauliques, l'énergie est transmise et commandée par l'intermédiaire d'un
liquide sous pression circulant en circuit fermé. Les organes les plus courants dans ce genre de système sont les
distributeurs hydrauliques. Ils règlent le sens de l'écoulement, la pression ou le débit des liquides dans le circuit
fermé.
iv © ISO 2000 – Tous droits réservés

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NORME INTERNATIONALE ISO 5781:2000(F)
Transmissions hydrauliques — Réducteurs de pression, soupapes
de séquence, soupapes de décharge, soupapes d'étranglement et
clapets de non-retour — Plan de pose
1 Domaine d'application
La présente Norme internationale spécifie, à des fins d'interchangeabilité, les dimensions et autres caractéristiques
des plans de pose sur lesquels sont montés des réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour pour transmissions hydrauliques.
Elle est applicable aux plans de pose des réducteurs de pression, soupapes de séquence, soupapes de décharge,
soupapes d'étranglement et clapets de non-retour, qui représentent la pratique courante. Ils sont généralement
utilisés dans les équipements industriels.
2Références normatives
Les documents normatifs suivants contiennent des dispositions qui, par suite de la référence qui y est faite,
constituent des dispositions valables pour la présente Norme internationale. Pour les références datées, les
amendements ultérieurs ou les révisions de ces publications ne s’appliquent pas. Toutefois, les parties prenantes
aux accords fondés sur la présente Norme internationale sont invitées à rechercher la possibilité d'appliquer les
éditions les plus récentes des documents normatifs indiqués ci-après. Pour les références non datées, la dernière
édition du document normatif en référence s’applique. Les membres de l'ISO et de la CEI possèdent le registre des
Normes internationales en vigueur.
1)
ISO 1101:— , Spécification géométrique des produits (GPS) — Tolérancement géométrique — Tolérancement de
forme, orientation, position et battement.
ISO 1219-1:1991, Transmissions hydrauliques et pneumatiques — Symboles graphiques et schémas de circuits —
Partie 1: Symboles graphiques.
2)
ISO 1302:— , Spécification géométrique des produits (GPS) — Indication des états de surface dans la
documentation technique de produits.
ISO 4401:1994, Transmissions hydrauliques — Distributeurs à quatre orifices — Plan de pose.
ISO 5598:1985, Transmissions hydrauliques et pneumatiques — Vocabulaire.
ISO 5783:1995, Transmissions hydrauliques — Code pour l'identification des plans de pose et des logements de
cartouche.
1) À publier. (Révision de l’ ISO 1101:1983)
2) À publier. (Révision de l’ ISO 1302:1992)
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ISO 5781:2000(F)
3 Termes et définitions
Pour les besoins de la présente Norme , les termes et définitions donnésdansl'ISO5598
internationale
s'appliquent.
4 Symboles
4.1 Pour les besoins de la présente Norme internationale, les symboles suivants s'appliquent:
a) A, B, P, T, X et Y désignent les orifices;
b) F ,F ,F ,F ,F et F désignent les trous taraudés pour les vis de fixation;
1 2 3 4 5 6
c) G désigne les trous de détrompeur;
d) D désigne le diamètre des vis de fixation;
e) r désigne le rayon de raccordement des bords du plan de pose.
max
4.2 Les symboles graphiques utilisés aux Figures 2, 3, 5, 6, 8, 9, 11, 12, 14 et 15 sont conformes aux symboles
graphiques de l'ISO 1219-1.
4.3 La codification utiliséedanslaprésente Norme internationale est définie dans l'ISO 5783.
5 Tolérances
5.1 Les valeurs suivantes doivent s'appliquer au plan de pose, c'est-à-dire à la surface délimitée par des traits
mixtes forts:
� rugosité de surface: Rau 0,8�m (voir ISO 1302);
� planéité de surface: 0,01 mm sur une distance de 100 mm (voir ISO 1101);
� tolérance sur les diamètres des trous de détrompeur: H12.
5.2 Par rapport au point origine, suivant les axes x et y,lestolérances suivantes doivent être respectées:
� trous de détrompeur:� 0,1 mm;
� trous taraudés:� 0,1 mm;
� orifices principaux:� 0,2 mm.
En ce qui concerne les autres dimensions, se reporter aux figures.
6 Dimensions
6.1 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour pour transmissions hydrauliques doivent être choisies
parmi les figures spécifiées de 6.2 à 6.6.
6.2 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour avec orifices principaux de diamètre maximal 4,5 mm
(code: 5781-02-01-0-00) sont données à la Figure 1.
2 © ISO 2000 – Tous droits réservés

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ISO 5781:2000(F)
6.3 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour avec orifices principaux de diamètre maximal 7,5 mm
(code: 5781-03-04-0-00) sont données à la Figure 4.
6.4 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour avec orifices principaux de diamètre maximal
14,7 mm (code: 5781-06-07-0-00) sont données à la Figure 7.
6.5 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour avec orifices principaux de diamètre maximal
23,4 mm (code: 5781-08-10-0-00) sont données à la Figure 10.
6.6 Les dimensions des plans de pose pour réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour avec orifices principaux de diamètre maximal 32 mm
(code: 5781-10-13-0-00) sont données à la Figure 13.
7 Marquage des orifices
7.1 Les symboles des orifices à utiliser pour les réducteurs de pression, soupapes de séquence, soupapes de
décharge, soupapes d'étranglement et clapets de non-retour doivent être choisis parmi les figures spécifiées de 7.2
à 7.11.
7.2 Les symboles pour réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour à action directe avec orifices principaux de diamètre maximal 4,5 mm
(code: 5781-02-01-0-00) sont donnés à la Figure 2.
7.3 Les symboles pour réducteurs de pression, soupapes de séquence et soupapes de décharge à action
pilotée avec orifices principaux de diamètre maximal 4,5 mm (code: 5781-02-01-0-00) sont donnés à la Figure 3.
7.4 Les symboles pour réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour à action directe avec orifices principaux de diamètre maximal 7,5 mm
(code: 5781-03-04-0-00) sont donnés à la Figure 5.
7.5 Les symboles pour réducteurs de pression, soupapes de séquence et soupapes de décharge à action
pilotée avec orifices principaux de diamètre maximal 7,5 mm (code: 5781-03-04-0-00) sont donnés à la Figure 6.
7.6 Les symboles pour réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour à action directe avec orifices principaux de diamètre maximal 14,7 mm
(code: 5781-06-07-0-00) sont donnés à la Figure 8.
7.7 Les symboles pour réducteurs de pression, soupapes de séquence et soupapes de décharge à action
pilotée avec orifices principaux de diamètre maximal 14,7 mm (code: 5781-06-07-0-00) sont donnés à la Figure 9.
7.8 Les symboles pour réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour à action directe avec orifices principaux de diamètre maximal 23,4 mm
(code: 5781-08-10-0-00) sont donnés à la Figure 11.
7.9 Les symboles pour réducteurs de pression, soupapes de séquence et soupapes de décharge à action
pilotée avec orifices principaux de diamètre maximal 23,4 mm (code: 5781-08-10-0-00) sont donnés à la Figure 12.
7.10 Les symboles pour réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour à action directe avec orifices principaux de diamètre maximal 32 mm
(code: 5781-10-13-0-00) sont donnés à la Figure 14.
7.11 Les symboles pour réducteurs de pression, soupapes de séquence et soupapes de décharge à action
pilotée avec orifices principaux de diamètre maximal 32 mm (code: 5781-10-13-0-00) sont donnés à la Figure 15.
7.12 Il convient de ne pas utiliser le sens A vers B pour de nouvelles conceptions.
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ISO 5781:2000(F)
8 Appareils empilables
Pour les appareils empilables, les plans de pose et le marquage des orifices définis dans l'ISO 4401 doivent être
utilisés.
9 Pression de travail
Pour l'indication de la limite maximale de la pression de fonctionnement, voir l'alinéa 1 des Figures 1, 4, 7, 10 et 13.
10 Phrase d'identification (Référence à la présente Norme internationale)
Il est vivement recommandé aux fabricants qui ont choisi de se conformer à la présente Norme internationale
d'utiliser dans leurs rapports d'essai, catalogues et documentation commerciale, la phrase d'identification suivante
:
«Les dimensions des plans de pose des réducteurs de pression, soupapes de séquence, soupapes de décharge,
soupapes d'étranglement et clapets de non-retour sont conformes à l'ISO 5781:2000, Transmissions
hydrauliques — Réducteurs de pression, soupapes de séquence, soupapes de décharge, soupapes
d'étranglement et clapets de non-retour — Plan de pose.»
4 © ISO 2000 – Tous droits réservés

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ISO 5781:2000(F)
Code: 5781-02-01-0-00
Dimensions en millimètres
La pression de fonctionnement maximale des embases et des blocs multiples doit être stipulée par le constructeur.
a
La profondeur minimale du taraudage est de 1,5 fois le diamètredela vis, D. La profondeur de filetage recommandéeest
2D � 6 mm pour faciliter l’interchangeabilité des distributeurs et réduire le nombre de longueurs de vis de fixation. La longueur
en prise recommandée des vis de fixation sur les embases en métaux ferreux est 1,25D.
b
Les dimensions caractérisant la surface délimitée par les traits mixtes forts sont les dimensions minimales du plan de pose.
Les angles du rectangle peuvent être arrondis avec un rayon maximal, r , égal au diamètre de filetage des vis de fixation.
max
c
Cette dimension donne l’intervalle minimal requis pour le montage d’un distributeur. Cette dimension est aussi la distance
minimale entre axes centraux de deux plans de pose identiques placés sur un bloc multiple.
d
Trou borgne pratiqué dans le plan de pose pour recevoir le détrompeur monté sur l’appareil; sa profondeur minimale est de
4 mm.
NOTE Voir les Figures 2 et 3 pour les symboles graphiques.
Axe PA T B F F F F G
1 2 3 4
� 4,5 max. � 4,5 max. � 4,5 max. � 4,5 max. M5 M5 M5 M5 � 3,4
x
...