150 6615 93 4851903 0544785 371 INTERNATIONAL ISO STANDARD 6615 Second edition 1993-09-15 Petroleum products Determination of carbon residue Conradson method Produits petroliers - Détermination du résidu de carbone - Méthode Conradson SO Reference number ISO6615:1993(E) Licensed by 150 6615 93 E06TS 90544786208 ISO 6615:1993(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 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 nternational 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 a vote. ISO/TC 28, Petroleum products and lubricants. Thissecond editioncancelsand replaces the first edition (1SO 6615:1983), which has been technically revised. Annex A forms an integral part of this International Standard. Annex B is for information only. CISO1993 All rights reserved. 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 per- mission in writing from the publisher. International OrganizationforStandardization Case Postale 56 · CH-1211 Geneve 20 · Switzerland Printed in Switzerland ii COPYRIGHT, International Organization for Standardization Licensedby 0 E6 ST99 0SI hht INTERNATIONAL STANDARD ISO6615:1993(E) Petroleum products - Determination of carbon residue -- Conradson method WARNING -- The use of this International Standard may involve hazardous materials, operations and equipment. This International Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this International Standard to establish prior to use. 1 Scope 3 The carbon residue of distillate and residual fuel oils gives an approximate ranking of such fuels in terms of their propensity to form deposits in specific applications. 4 The presence of alkyl nitrates in distillate fuels, or ash- This Internationai Standard specifies a method for forming additives ineitherdistillate orresiduefuels,will give determining the amount of carbon residue, in the carbon residue results that are higher than the correspond- range of 0.01 % (m/m) to 30,0 % (m/m). left after ing values on the fuel without additives. These values may evaporationandpyrolysisofanoil,andisintendedto not correlate with the propensity of a fuel to form deposits provide some indication of relative coke-forming 5 The carbon residue of base lubricating oils may give an tendency. The method is generally applicable to rela- tively non-volatile petroleum products which partially indication of the propensity of the oil to lay down deposits incombustionchambersand/oroftherelativechemical decompose ondistillationat atmosphericpressure. constitution of oils of similar viscosity. Most finished lubri- Petroleum products containing ash-forming constitu- cating oils contain ash-forming additives,and thus the car ents as determined by 1sO 6245 will exhibit an erro- bon residue of finished lubricants cannot be used in this neously high carbon residue, depending upon the manner. amountofashformed 6 The carbon residue of a gas oil is a useful guide in the NOTES manufacture of gas. The term "carbon residue" is used throughout this In- ternational Standard todesignate the carbonaceous residue 2 Normative references formed after evaporation and pyrolysis of a petroleum product. The residue is not entirely composed of carbon, but The following standards contain provisions which, is a coke which can be further changed by pyrolysis. The throughreferenceinthistext,constitut