ISO INTERNATIONAL STANDARD 7440-2 Second edition 1991-12-01 Road vehicles -- Fuel injection equipment testing - Part 2: Orifice plate ffow-measurement Vehicules routiers - Essai des équipements d'injection de combustible Partie 2: Mesurage du debit des pastilles a trou 'eference number 3O 7440-2:1991(E) Not for Resale ISO 7440-2:1991(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, govern- mental 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 bodies casting a vote. International Standard iso 7440-2 was prepared by Technical Committee IsO/Tc 22, Road.vehicles, Sub-Committee sc 7, Injection equipment and fiters for use on road vehicles. This second edition cancels and replaces the first edition (lso 7440-2:1985), of which it constitutes a complete revision. Iso 7440 consists of the following parts, under the general title Road vehicles - Fuel injection equipment testing: Part 1: Calibrating nozzle and holder assemblies Part 2: Orifice plate flow-measurement Annexes A and B of this part of Iso 7440 are for information only. @ISO1991 or by any means, electronic or mechanical, including photocopying and mlcrofilm, without permission in writing from the publtsher. International Organization for Standardization CasePostale56CH-1211Geneve20+Switzerland Printed in Switzeriand ii pyright International Organization for Standardization Notfor Resale INTERNATIONAL STANDARD ISO 7440-2:1991(E) Road vehicles -- Fuel injection equipment testing Part 2: Orifice plate flow-measurement Scope 3 Orifice plate flow-measuring system 1 This part of is0 7440 specifies the flow-measuring system, including the fixture, to be used for flow- testing the single hole orifice plates used in an orifice plate type nozzle and holder assembly (de- 3.1 General description scribed in Iso 7440-1) which are intended for testing and setting diesel fuel injection pumps on test Figure 1 shows an orifice plate flow-measuring sys- benches. tem comprising: The flow-measuring system and fixture described in a) fluid supply circuit and flow-measuring device this part of Iso 7440 ensure accurate flow-testing of (an example is shown in annex A): the entire range of orifices from 0,4 mm to 0,8 mm diameter as specified in IsO 7440-1. It is intended b) orifice plate holding fixture; primarily for use by the manufacturers of single hole orifice plates. c) flow overcheck device (optional) [This device is for periodic overchecking of the accuracy of the primary flow-measuring device in a) and is specified in annex B.J The system shall be designed and constructed with particular attention being given to the problems as- 2 Normative references sociated with fluid evaporation, contamination, aer- ation and instability of pressure and temperature. The following standards contain provisions which, Flow values obtained by alternative systems shall through reference in this text, constitute provisions of this part of 1sO 7440. At the time of publication, require correlation with values determined using the the editions indicated were valid.Alf standards are system shown in figure 1. subject to revision, and parties to agreements based on this part of iso 7440 are encouraged to investi- gate the possibility of applying the most recent edi- tions of the standards indicated below.Members of IEC and Iso maintain registers of currently valid In- 3.2 Orifice plate holding fixture ternational Standards. I