BS ISO BRITISH STANDARD 4401:2005 Hydraulic fluid power Four-port directional control valves Mounting surfaces ICS 23.100.50 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards BSISO4401:2005 National foreword This British Standard reproduces verbatim IS0 4401:2005 and implements it as the UK national standard.It supersedes BS ISO 4401:1994 which is withdrawn. TheUKparticipationinitspreparation wasentrustedbyTechnical Committee MCE/18, Fluid power systems,to Subcommittee MCE/18/-/5, Control components, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BsI Catalogueunder the section entitled "International Standards Correspondence Index", or by using the“Search" facility of the BsI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not ofitselfconfer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages i to v, a blank page, pages 1 to 16, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued sincepublication This British Standard was Amd. No. Date Comments published under the authority of the Standards Policy and Strategy Committee on18November2005 BSI 18 November 2005 ISBN 0 580 46834 8 BS IS0 4401:2005 ISO INTERNATIONAL 4401 STANDARD Third edition 2005-07-15 HydraulicfluidpowerFour-port directional control valves Mounting surfaces Transmissionshydrauliques-Distributeursa quatre orifices-Plan depose Referencenumber ISO 4401:2005(E) ii BSIS04401:2005 Contents Page Foreword. Introductio 1 Scope 2 Normativereference 3 Terms and definitions.. 4 Symbols 5 Tolerances 6 Dimensions.. 2 7 Pressurelimitations. 8 Identification statement (reference to this International Standard) Bibliography ili BSIS04401:2005 Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies InternationalElectrotechnicalCommission(lEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 The main task of technical committees is to prepare International Standards. Draft International Standards 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 4401was prepared by Technical Committee ISO/TC 131,Fluid power systems, Subcommittee SC 5, Controlproductsandcomponents. Thisthirdeditioncancelsandreplacesthesecondedition(lsO4401:1994)whichhasbeentechnicallyrevised iv BSIS04401:2005 Introduction In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit. Typical components found in such systems include hydraulic valves. These devices control flow direction, pressure or flow rate of liquids in the enclosed circuit. V