ISO INTERNATIONAL STANDARD 7120 First edition 1987-04-01 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXKAYHAPOAHAA OPrAHM3ALWAOCTAHAAPTM3AUMM Petroleum products and lubricants - Petroleum oils and other fluids -- Determination of rust-preventing characteristics in the presence of water Produits petroliers et lubrifiants - Huiles de pétrole et autres fluides -- Détermination des caracteristiques anti-rouille en présence d'eau Reference number ISO 7120 : 1987 (E) itted without license from IHS Not for Resale 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 ISoO technical committees. Each member 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the iso Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard iSO 7120 was prepared by Technical Committee ISO/TC 28 Petroleum products and lubricants. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. International Organization for Standardization, 1987 Printed in Switzerland ted without license from IHS Not for Resale ISO 7120 : 1987 (E) INTERNATIONAL STANDARD Petroleum products and lubricants - Petroleum oils and other fluids - Determination of rust-preventing characteristics in the presence of water 1 Scope and field of application CAUTION -- Iso-octane is flammable. Do not use in an areanear sparks oran openflame.Provideadequateven- 1.1 This International Standard specifies a method for tilation. evaluating petroleum oils and other fluids to indicate their effectiveness in preventing the rusting of ferrous parts should 4.2 Chromic acid cleaning solution or other equally water become mixed with the oil/fluid. The method is for effective glassware cleaning fluid. application to inhibited mineral oils including steam turbine oils, circulating oils and hydraulic oils and non-hydrocarbon fluids CAUTION -- Chromic acid is a highly corrosive and toxic including fluids denser than water. substance. For environmental and/or toxicological reasons, its use is forbidden in many laboratories. In this 1.2 In many cases, such as in the gears of a steam-turbine, case, use an alternative cleaning fluid which has been water can become mixed with the lubricant, and rusting of shownto producechemically cleanglassware ferrous parts may occur. This test indicates the effectiveness of Prepare chromic acid cleaning solution by dissolving 400 g of inhibited mineral oils aid in preventing this type of rusting. sodium dichromate (Na2CrOz) in 100 ml of hot water.Allow the solution to cool and store in a glass-stoppered bottle. Place 2 References 35 ml of this saturated sodium dichromate solution in a 1 500 mi beaker. In a fume hood, while stirring, carefully add Iso 3170, Petroleum products - Liquid hydrocarbons 1 litre of sulfuric acid (H2SO4). Stir for 5 min. Store in a glass- Manual sampling. stoppered bottle. ISo 3171, Petroleum products - Liquid hydrocarbons Distilled water. 4.3 Automatic pipeline sampling. ISO 3448, Industrial liquid lubricants -- iSO viscosity classi- 4.4 Synthetic sea water, for testing in accordance with fication. procedure B, and conforming to the requirements given in 9.1 and 9.2. 3 Principle 4.5 Steel test specimen, as described in 7.1. A mixture of 300 ml of the oil or fluid under test is stirred with 30 ml of distilled water or synthetic se