© ISO 2016 Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum Tuyaux et flexibles en caoutchouc et en plastique — Détermination de la résistance à l’aspiration INTER[.]
INTERNATIONAL STANDARD ISO 7233 Fourth edition 2016-10-15 Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum Tuyaux et flexibles en caoutchouc et en plastique — Détermination de la résistance l’aspiration Reference number ISO 7233:2016(E) © ISO 2016 ISO 7233:2016(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2016, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2016 – All rights reserved ISO 7233:2016(E) Contents Page Foreword iv Introduction v Scope Normative references Terms and definitions Principle Apparatus Test pieces Conditioning of test pieces Test pressure Procedure (method A) 10 Procedure (method B) 11 Procedure (method C) 12 Test report Bibliography © ISO 2016 – All rights reserved iii ISO 7233:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f 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, governmental 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 o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso.org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html The committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 1, Rubber and plastics hoses and hose assemblies This fourth edition cancels and replaces the third edition (ISO 7233:2006), which has been technically revised with the following changes: — Clause 11 has been re-written to clari fy further on the minor axis measurement (D2 and D3 ) as shown in the new Figure 2; as well as addition of a paragraph for examining interior and exterior of the hose; — Clause 12 f) has been re-written to include the observation that needs to be made for method C iv © ISO 2016 – All rights reserved ISO 7233:2016(E) Introduction Vac uu m te s ti ng i s appl ie d to ho s e s to de term i ne whe ther they wi l l with s ta nd the d i fferentia l pre s s u re encountered in service resulting from reduced pressure within the hose © ISO 2016 – All rights reserved v INTERNATIONAL STANDARD ISO 7233:2016(E) Rubber and plastics hoses and hose assemblies — Determination of resistance to vacuum Scope T h i s c u ment s p e c i fie s th re e me tho d s for de term i n i ng the re s i s tance to vac uu m o f ho s e s and ho s e assemblies manufactured from plastic or rubber Applicable dimensions of hoses for each method are as follows: — method A for hoses of nominal bore up to and including 80 mm; — method B for hoses of nominal bore greater than 80 mm; — method C for hoses of all dimensions Methods A and B can also be used to check the adhesion of the lining to the reinforcement (delamination) i n a leng th o f hard-wa l l ho s e or ho s e a s s embly Normative references T he fol lowi ng c u ments are re ferre d to i n the tex t i n s uch a way th at s ome or a l l o f thei r content s titute s re qu i rements o f th i s c u ment For date d re ference s , on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c ument (i nclud i ng a ny amend ments) appl ie s ISO 4671:2007, Rubber and plastics hoses and hose assemblies — Methods o f measurement o f the dimensions o f hoses and the lengths o f hose assemblies ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods Terms and definitions For the pu r p o s e s o f th i s c u ment, the term s and defi nition s given i n I S O 3 apply ISO and IEC maintain terminological databases for use in standardization at the following addresses: — IEC Electropedia: available at http://www.electropedia.org/ — ISO Online browsing platform: available at http://www.iso.org/obp Principle T he tes t me tho dolog y for determi ning the res i s tance to vacuum o f plas tic and rubb er ho s es and ho s e as s embl ies cons i s ts o f reduci ng the i nternal pres s ure i n a leng th o f ho s e by me ans o f a vacuum pump and gauge, whi le exami ni ng the ho s e for any s igns o f de formation or delami nation o f rei n forcement or l ini ng Apparatus 5.1 Vacuum pump , provided with a gauge and capable of reducing the internal pressure in the hose within s to the p res s ure s p ecified in the p ro duct s tandard that pressure for a minimum of 10 © ISO 2016 – All rights reserved fo r the ho s e under tes t and maintaining it at ISO 7233:2016(E) Smooth, solid ball (for method A) , with a diameter equal to 0,9 times the bore of the hose under test, rounded down to the nearest whole millimetre 5.2 Two transparent airtight plates (for method B) , for sealing each end of the hose One of the plates shall permit attachment of the vacuum pump to the hose, while allowing internal visual inspection of the hose during the test 5.3 Test pieces I f the comple te ho s e or ho s e a s s embly i s more th an m long , e ach te s t pie ce sh a l l s i s t o f a m i n i mu m leng th o f ho s e, cle ar o f the end fitti ngs , o f m I f the comple te ho s e or ho s e as s embly i s le s s than m long, the complete length shall be used Conditioning of test pieces No tests shall be carried out within 24 h of manufacture Test pieces shall be conditioned at the appropriate temperature in accordance with ISO 23529 for at least h before testing T h i s h p erio d may form p ar t o f the m i n i mu m p erio d o f h b e twe en ma nu fac ture and te s ti ng Test pressure T he i nterna l pre s s u re to wh ich the ho s e i s s ubj e c te d to for the du ration o f the te s t s l l b e that s tate d i n the product standard for the hose under test as being the minimum internal pressure which the hose is required to withstand Procedure (method A) L ay out the ho s e a s s traight as p o s s ible on a flat s ur face and bla n k o ff one end to form a n r tight s e a l Insert into the hose a smooth, solid ball (5.2) and then connect the open end of the hose to a vacuum pump and gauge Reduce the pressure in the hose within 60 s to the required test pressure and maintain this pressure for the required period, which shall not be less than 10 Wh i le the te s t pre s s u re i s b ei ng ma i ntai ne d, exam i ne the ho s e ex terna l ly for any s ign s o f i ndentation or collapse and then tilt the hose to permit the solid ball to traverse the full length of the hose to check for any ob s truc tion s c au s e d b y i nterna l de formation or dela m i nation 10 Procedure (method B) 5.3) to both ends of the hose, one of which shall then be connected to a vacuum pump and gauge Reduce the pressure in the hose within 60 s to the required test pressure and maintain this pressure for the required period, which shall not be less than 10 While the test pressure is being maintained, examine the interior of the hose through one of the f f the hose for signs of delamination or blistering of the lining Also examine the exterior of the hose for signs of indentation or collapse L ay out the ho s e as s traight a s p o s s ible on a flat s u r face a nd fit tra n s p a rent a i r tight plate s ( tra n s p arent plate s b y me an s o i l lu m i nation s uppl ie d th rough the tran s p arent plate at the o ther end o 11 Procedure (method C) L ay out the ho s e as s tra ight a s p o s s ible on a flat s ur face, bla n k o ff one end to connect the other end to a vacuum pump and gauge form an r tight s e a l , and © ISO 2016 – All rights reserved ISO 7233:2016(E) Before reducing the pressure in the hose, mark two lines (lines A and B), equidistant from the centre and 500 mm apart, round the hose (see Figure 1) Then, mark a third line (line C) round the hose at a point between lines A and B Measure the average outside diameter of the hose round line C in accordance with the me tho d s p e ci fie d i n I S O 671 : 0 7, Dimensions in millimetres Key A, B lines marked on test piece for measurement of change in length C line marked on test piece for measurement of change in outside diameter Figure — Marking measurement lines on test piece Key minor axis (D2 , D3 ) Figure — Minor axis of a deformed test piece Reduce the pressure in the hose to the required test pressure and maintain this pressure for the required period, which shall not be less than 10 After 10 or the required test period (whichever is greater) and before releasing the pressure, measure the distance between lines A and B, as well as the minor axis, D2 , (see Figure 2) round line C, as before Release the pressure and, after 10 min, measure, for a third time, the distance between lines A and B and the minor axis, D3 , round line C After releasing the pressure, examine the interior of the hose for signs of delamination or blistering of the lining Also examine the exterior of the hose for signs of indentation or collapse © ISO 2016 – All rights reserved ISO 7233:2016(E) T he p ercentage ch ange i n the leng th o f the ho s e, Δ Formula (1) and Formula (2): L , b e fore a nd a fter rele a s i ng the pre s s u re i s given b y L − L ∆L t = × 100 L L − L ∆L p = × 100 L1 (1) (2) where Δ Lt Δ Lp i s the temp orar y leng th change ( b e fore rele a s i ng the pre s s u re) ; is the permanent length change (after releasing the pressure); is the distance between lines A and B before reducing the pressure, in millimetres; is the distance between lines A and B before releasing the pressure, in millimetres; is the distance between lines A and B after releasing the pressure, in millimetres f D, before and after releasing the pressure Formula (3) and Formula (4): L1 L2 L3 T he p ercentage cha nge i n the outs ide d i ame ter o the ho s e , Δ i s given b y D − D1 ∆D t = × 00 D D − D1 ∆D p = × 00 D1 (3) (4) where Δ Dt Δ Dp D1 D2 D3 i s the temp orar y outs ide d i ame ter ch ange ( b e fore rele as i ng the pre s s u re) ; is the permanent outside diameter change (after releasing the pressure); is the average outside diameter of the hose before reducing the pressure, in millimetres; is the minor axis of the hose before releasing the pressure, in millimetres; is the minor axis of the hose after releasing the pressure, in millimetres 12 Test report The test report shall contain the following information: a) the nu mb er and ye ar o f publ ic ation o f th i s c u ment, i e I S O 3 : 016; b) a full description of the hose tested; c) the method of test used; d) the internal test pressure applied, expressed in bars below atmospheric pressure; NOTE bar = 0,1 MPa e) the period for which the test pressure was applied; © ISO 2016 – All rights reserved ISO 72 3 : 01 6(E) f) g) h) ob s er vation s on the b ehaviou r of the ho s e duri ng the te s t, i nclud i ng any e xterna l s ign s of indentation or collapse and, if method A was used, whether or not the ball traversed the full length of the test piece or, if method B or C was used, whether or not lining delamination or blistering was observed; i f me tho d C wa s u s e d, the p ercentage cha nge i n the leng th (temp orar y and p ermanent) o f the ho s e when the pressure was reduced and after the pressure was released; i f me tho d C was u s e d, the p ercentage ch ange i n the outs ide d iame ter (temp ora r y and p erma nent) of the hose when the pressure was reduced and after the pressure was released; i) the date of the test © ISO 2016 – All rights reserved ISO 7233:2016(E) Bibliography [1] ISO 8330, Rubber and plastics hoses and hose assemblies — Vocabulary © ISO 2016 – All rights reserved ISO 72 3 : 01 6(E) ICS 23.040.70 Price based on pages © ISO 2016 – All rights reserved