ISO INTERNATIONAL STANDARD 7662 First edition 1988-04-15 INTERNATIONALORGANIZATIONFORSTANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION ME>KAYHAPOAHAOPTAHM3ALMROCTAHAAPTW3ALMM Rubber and plastics hoses - Determinationof abrasion of lining Tuyaux en caoutchouc et en plastique-- Determination de I'abrasion du tube du tuyau Reference number ISO 7662:1988 (E) ISO7662:1988(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 bodyinterested in a subjectfor which atechnical 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 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 7662 was prepared by Technical Committee ISo/TC 45, Rubberandrubberproducts. lnternationalOrganizationforStandardization,1988 Printed in Switzerland Coovriaht International Oraanization for Standardization INTERNATIONAL STANDARD ISO7662:1988(E) Rubber and plastics hoses - Determination of abrasion of lining 1 Scope 5 Procedure This International Standard specifies a method for determining 5.1 Weigh the test piece (clause 4) to the nearest 0,1 g. the abrasion of a hose lining when a certain amount of specified grit is passed through the hose. The method is applicable to rubber and plastics hoses with an internal bore of 20 to 50 mm 5.2 Check the flow rate of the grit (clause 3), which shall be used for grit blasting, shot blasting and similar operations. 42 g/s ± 2 g/s at an air pressure of 250 kPa, by collecting and weighing the amount of grit passing in a given period. The method may be used for comparison of the abrasion resistanceofdifferenttypesofhose,butnotforspecificationof 5.3 Mount the test piece in the vertical position in the cabinet maximum abrasion in a hose standard. Comparison should be (2.1),usingthe fixture(2.5)toobtainthecorrectpositionin made on the same type and size of hose. Results from tests car- accordance with figure 3. The bend radius r shalf be six times ried out with different types of grit should not be compared. the nominal bore size of the hose. 5:4Connect the blasting nozzle to the test piece and check 2 Apparatus that the centreline of the nozzle and that of the test piece do not deviate more than 10. The nozzle shall be inserted in the 2.1 Grit blasting cabinet, constructed according to the test piece for a length of 25 to 50 mm. basic principles shown in figure 1. The cabinet shall contain 25 kg of grit which is continually circulated during the test. The 5.5 Fill the grit container in the cabinet with 25 kg of new, dimensions of the feed hose and air inlet of the grit container not previously used, grit. shall allow a grit flow rate of 42 g/s ± 2 g/s. 5.6Set the air pressure at 250 kPa ± 25 kPa (see 2.4). 2.2 Ejector,witha blasting nozzle manufactured fromhard metal, having an internal diameter of 10 mm ± 1mm, the 5.7 Start the blasting and continue for 400 min ± 1 min. length of the cylindrical part being between50 and 100 mm.A typical arrangement is shown in figure 2. 5.8 Remove the test piece from the cabinet and clear it of residual grit by blowing air through the hose bore and brushing 2.3 Filter, for drying the compressed air. the cover of the hose. 2.4 Pressure e regulator, capable of controlling the air 5.9 Weigh the test piece to the nearest 0,1 g pressure. 6 Expre