EN 20340:1993

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Schwerentflammbare Fördergurte - Anforderungen und Prüfverfahren (ISO 340:1988)Courroies transporteuses - Résistances a la flamme - Spécifications et méthode d'essai (ISO 340:1988)Conveyor belts - Flame retardation - Specifications and test method (ISO 340:1988)53.040.20Deli za transporterjeComponents for conveyorsICS:Ta slovenski standard je istoveten z:EN 20340:1993SIST EN 20340:1999en01-april-1999SIST EN 20340:1999SLOVENSKI
STANDARD



SIST EN 20340:1999



SIST EN 20340:1999



SIST EN 20340:1999



INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEXAYHAPOJJHAfl OPTAHM3A~MR l-l0 CTAHflAPTM3A~MM Conveyor belts - Flame retardation - Specifications and test method Courroies transporteuses - R&stance ;i la flamme - Sp&#ications et m&ode d’essai IS0 340 Second edition 1988-06-15 Reference number 1 IS0 340: 1988 (E) SIST EN 20340:1999



IS0 340 : 1988 (El Foreword IS0 (the international Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 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. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. They are approved in accordance with IS0 procedures requiring at least 75 % approval by the member bodies voting. International Standard IS0 340 was prepared by Technical Committee ISO/TC 41, Pulleys and belts (including veebelts). This second edition cancels and replaces the first edition (IS0 340 : 19421, clauses 0, 1, 4 and 5 of which have been technically revised. 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. 0 International Organization for Standardization, 1988 Printed in Switzerland SIST EN 20340:1999



INTERNATIONAL STANDARD IS0 340 : 1988 (E) Conveyor belts - Flame retardation - Specifications and test method 0 Introduction In many countries, specifications of flame retardation of con- veyor belts and the corresponding methods of test are the sub- ject of legislation. However, it has been thought necessary to prepare an International Standard in order to give a reference if there is no particular legislation. It is stressed that for small-scale laboratory tests of the type covered in this International Standard, the correlation of test results with the flammability under other conditions is not in any case implied. For this reason, the relevant conditions of belt use shall be taken into account in order not to obtain a false sense of security by uncritical application of this International Standard. 1 Scope and field of application This International Standard specifies conditions for a flame retardation test for conveyor belts, and the corresponding re- quirements. NOTE - To increase safety, it is important for tests to take into ac- count, as far as possible, the circumstances which may create hazards. It is for this reason that, in this International Standard, provision is made for performing the test on test pieces without covers, as covers of belts may be ripped off accidentally in service. 2 References IS0 235, Parallel shank twist jobber and stub series drills and Morse taper shank drills. IS0 426-2, Wrought copper-zinc alloys - Chemical composi- tion and forms of wrought products - Part 2 : Leaded copper- zinc alloys. IS0 565, Test sieves - Woven metal wire cloth, perforated plate and electroformed sheet - Nominal sizes of openings. IS0 835, laboratory glassware - Graduated pipettes. IS0 2194, Wire screens and plate screens for industrial pur- poses - Nominal sizes of apertures. IS0 3310-1, lest sieves - Technical requirements and testing - Part I : Test sieves of metal wire cloth. IS0 3310-2, Test sieves - Technical requirements and testing - Part 2 : Test sieves of metal perforated plate. 3 Specifications 3.1 Duration of flame (after removal of the burner) The duration of flame shall be less than 45 s for each group of six tests, and no individual value shall be greater than 15 s (see 4.7.1). 3.2 Non-reappearance of flame (after applying a current of air) The flame shall not reappear (see 4.7.2). 4 Test method 4.1 Principle A test piece is placed in the flame of a burner, the burner is removed and the combustion time of the test piece is noted (duration of flame). A current of air is then applied to the test piece at a specified time after the removal of the burner and the reappearance of the flame is noted. 4.2 Test pieces 4.2.1 Shape and dimensions Rectangular test piece (cut out from the conveyor belt) : - length : 200 mm - width : 25 mm 4.2.2 Number and distribution 4.2.2.1 If the test is made on test pieces with and without covers, prepare 12 test pieces distributed as follows : - with covers : 3 warp way and 3 weft way; - without covers : 3 warp way and 3 weft way. 4.2.2.2 If the test is made on test pieces with covers only, prepare 6 test pieces, 3 warp way and 3 weft way. 1 SIST EN 20340:1999



Is0 340 : 1988 (El 4.2.3 Preparation Cut out the test pieces with a knife. For test pieces without covers, remove the covers by strip- ping or, if this is impossible, with a knife or by buffing. In the latter event, take care that the cover is not abnormally overheated, and cease buffing as soon as the threads of the carcass become visible. 4.3 Burners 4.3.1 Operation On agreement between the parties concerned burners specified in 4.3.2 and 4.3.3 shall be used. one of the 4.3.2 Spirit burner The spirit burner, its characteristics and operating conditions, the fuel, and the tank and flexible supply tube of approximately I,5 m length are specified in figure I and the annex. During the test the fuel consomption of the burner shall be 2,55 k O,I5 ml/min giving a flame length of approximately 150 to 180 mm. Check that the burner is operating properly bY measuring fuel flow according the method described in A. 3.3. 4.3.3 Gas burner the The gas burner (Bunsen burner) with burner tube of diameter between IO and I2 mm shall be operated with town gas or liquid petroleum gas. During the test the burner shall have a flame of a total length of approximately 150 to 180 mm with an inner flame of about 50 mm long. The inner flame temperature shall be 900 + 100 OC. A thermocouple device may be used to measure - the inner flame temperature. The burner shall be inclined at 45O and the vertical plane through its axis shall coincide with the midplane of the test piece parallel to the covers (see figure 2). 4.5.2 Arrange the burner vertically and the test piece inclined at 45O. The relative position between test piece and burner shall be as described in 4.5.1 (see figure 3). 4.6 Procedure Hold the test piece in the flame for 45 s and then remove the burner without extinguishing it. (Keep the burner sheltered from the current
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