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1、INTERNATIONAL STANDARD IS0 6803 Second edition 1994-l o-01 Rubber or plastics hoses and hose assemblies - Hydraulic-pressure impulse test without flexing Tuyaux et flexibles en caoutchouc ou en plastique - Essai dimpulsions de pression hydraulique sans flexions Reference number IS0 6803: 1994(E) Cop
2、yright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,- Foreword IS0 (the International Organization for S
3、tandardization) 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 ri
4、ght to be represented on that committee. International organizations, governmental 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 Intern
5、ational Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 6803 was prepared by Technical Committee ISO/TC 45, Rubber
6、 and rubber products, Subcommittee SC 1, Hoses (rubber and p/as tics). This second edition cancels and replaces the first edition (IS0 6803:1984), which has been technically revised. 0 IS0 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
7、 in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56 . CH-1211 Geneve 20 l Switzerland Printed in Switzerland ii Copyright International Organizat
8、ion for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD 0 IS0 IS0 6803:1994(E) Rubber or plastics hoses and hose
9、assemblies - Hydraulic-pressure impulse test without flexing 1 Scope This International Standard describes a pressure im- pulse test without flexing for rubber or plastics hy- draulic hoses and hose assemblies. The test is applicable to high-pressure hydraulic hoses and hose assemblies which are sub
10、ject to pulsating pressures in service. NOTE 1 If it is required to carry out the test with flexing, the method described in IS0 6802:1991, Rubber and plas- tics hose and hose assemblies with wire reinforcements - Hydraulic impulse test with flexing, should be used. 2 Normative references The follow
11、ing standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are enc
12、ouraged to investigate the possibility of applying the most re- cent editions of the standards indicated below. Members of IEC and IS0 maintain registers of cur- rently valid International Standards. IS0 34461992, Industrial liquid lubricants - IS0 vis- cosity classification. lSO/TR 11340:1994, Rubb
13、er and rubber products - Hydraulic hose assemblies - External leakage classi- fica tion for hydraulic systems. 3 Apparatus 3.1 Pressure-application apparatus, capable of applying an internal pulsating pressure to the test piece at a rate of 1 Hz + 0,25 Hz using a hydraulic fluid which circulates thr
14、ough the test piece, the fluid being maintained at the required test temperature. Each pressure cycle shall be within the tolerances shown in figure 1. The nominal rate of pressure rise R shall be calculated from the equation R =f(lOp - 5) where f is the frequency, in hertz; P is the nominal pulse p
15、ressure, in mega- pascals. The actual rate of pressure rise shall be determined as shown in figure1 and shall be within a tolerance of -t 10 % of the calculated nominal value. 3.2 Suitable graphical recorder, digital-storage facility or oscilloscope, to enable the pressure cycle to be checked agains
16、t figure 1. The recorder shall have a natural frequency of more than 250 Hz, critically damped to give a response flat to within 5 % up to 0,6 times the natural frequency. 4 Test fluid Unless otherwise specified, the test fluid shatl comply with the requirements of IS0 VG 46 at 40 “C, in ac- cordanc
17、e with IS0 3448. 5 Test temperature The following temperatures are preferred for the test: 85 “C, 100 “C, 125 “C, 135 “C or 150 “C The test fluid shall be circulated through the test pieces at the chosen temperature with a tolerance of f 3 “C. The test fluid temperature shall be measured 1 Copyright
18、 International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6803:1994(E) 6 IS0 at the inlet and the outlet of th
19、e test pieces and the test temperature is defined as the mean value of the two measured temperatures. No one of the measured values may deviate from the test temperature by more than 3 “C. 6 Test pieces 6.1 Test pieces shall consist of complete hose as- semblies or lengths of hose with suitable end
20、fittings attached. Unless otherwise specified, four test pieces shall be tested. 6.2 Calculate the free (exposed) length of hose un- der test, shown in figure2, as follows: a) for hose sizes up to and including 22 mm nominal inside diameter: 180”-bend free length = 7: + 2d b) for hose sizes larger t
21、han 22 mm nominal inside diameter: 90”-bend free length = -$ where + 2d r is the minimum bend radius; d is the hose outside diameter. A tolerance of + 1 %/ - 0 or + 15 mm/ - 0, which- ever is greater, applies to the calculated free hose length. 7 Procedure 7.1 Connect the test pieces to the apparatu
22、s. The test pieces shall be installed in accordance with figure2, where test pieces of nominal bore size up to and including 22 mm shall be bent through 180” and test pieces of nominal bore size above 22 mm shall be bent through 90”. 7.2 Bring the test fluid to the test temperature and then apply th
23、e pulse pressure in accordance with fig- ure 1. Continue the test for the specified number of cycles or until the assembly fails. If a pulse test is stopped before completion of the minimum number of cycles, slight leakage of the test fluid may occur at the hose/fitting junction upon re- starting th
24、e test until the test temperature is reached. Any leakage shall be reported in accordance with the classification in lSO/TR 11340. 8 Expression of results 8.1 Record the number of cycles to failure or, if failure did not occur, the number of cycles completed. 8.2 Leakage at the end fitting, blow-off
25、 or rupture of the hose within 25 mm of the fitting or within a distance equal to the external diameter of the hose, whichever is greater, shall be considered as failures in the performance of the assembly. Such failures do not necessarily demonstrate an inability of the hose to meet the specified r
26、equirements with an alternative fitting. 9 Test report The test report shall include the following information: a) a reference to this International Standard; b) a full description of the hose or hose assembly tested, including fitting identification and attach- ment details, such as skive length, c
27、rimp diam- eter, etc.; c) the test temperature; d) the test pressure; e) the test fluid; f) the rate of pressure rise; g) the pulse cycle rate; h) whether the test pieces were bent through 90” or through 180”; i) the number of cycles to failure, or the number of cycles completed, for each test piece
28、; j) the position and mode of failure of each test piece, or the condition of each test piece on completion of the test. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:4
29、2 MDTNo reproduction or networking permitted without license from IHS -,-,- Q IS0 IS0 6803:1994(E) Test pressure- 45 % to 55 56 of the cycle One puke cycle NOTES 1 The secant pressure rise is the straight line drawn through two points on the pressure rise curve, one point at 15 % of the test pressur
30、e and the other at 85 % of the test pressure. 2 Point 0 is the intersection of the secant pressure rise with 0 pressure. 3 The pressure rise rate is the slope of the secant pressure rise, expressed in megapascals per second. 4 The cycle rate shall be uniform at 1 Hz 4 0,25 Hz. 5 The nominal rate of
31、pressure rise R shall be given by R =f(lOp - 5) where f is the frequency, in hertz; P is the nominal pulse pressure, in megapascals. The actual rate of pressure rise shall be within a tolerance of f IO % of the calculated nominal value. Figure 1 - Pressure pulse cycle 3 Copyright International Organ
32、ization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6903:1994(E) Q IS0 Hose free length End fitting Hose sizes up to and inc
33、luding 22 mm nominal inside diameter NOTES I- = Minimum bend radius d = Hose outside diameter Hose free length = n + 2d (2r + dl -0 I Hose sizes larger than 22 mm nominal inside diameter 2d NOTES r = Minimum bend radius d = Hose outside diameter Hose free length = 5 + 2d I I Figure 2 - Test pieces f
34、or pressure pulse test Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 6803:1994(E) Q IS0 I
35、CS 23.040.70 Descriptors: rubber products, plastics products, hoses, rubber hoses, plastics hoses, tests, pressure tests, hydraulic tests, pulsating flow. Price based on 4 oases Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 03:35:42 MDTNo reproduction or networking permitted without license from IHS -,-,-