1、 Reference number ISO 17455:2005(E) ISO 2005INTERNATIONAL STANDARD ISO 17455 First edition 2005-10-01 Plastics piping systems Multilayer pipes Determination of the oxygen permeability of the barrier pipe Systmes de canalisations en plastiques Tubes multicouches Dtermination de la permabilit loxygne
2、de la couche barrire dun tube ISO 17455:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer pe
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5、l Secretariat at the address given below. ISO 2005 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at
6、the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedISO 17455:2005(E) ISO 2005 All ri
7、ghts reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Principle. 1 3 Terms and definitions. 1 4 Symbols and abbreviated terms . 2 5 Apparatus 3 6 Test piece 4 7 Preconditioning. 4 8 Calibration of the test assembly . 4 9 Preparation for testing . 4 10 Measuring procedure . 5 11 Ca
8、lculation of flux. 7 12 Test report . 8 Annex A (informative) Oxygen solubility as a function of temperature . 9 Bibliography . 10 ISO 17455:2005(E) iv ISO 2005 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
9、 (ISO member bodies). The work of 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,
10、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 of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/
11、IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International 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 me
12、mber bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17455 was prepared by Technical Committee ISO/TC 138, Plastics pipes,
13、 fittings and valves for the transport of fluids, Subcommittee SC 5, General properties of pipes, fittings and valves of plastic materials and their accessories Test methods and basic specifications. ISO 17455:2005(E) ISO 2005 All rights reserved v Introduction In response to the worldwide demand fo
14、r specifications, requirements and test methods for multilayer pipes, WG 16 of ISO/TC 138/SC 5 was created at a meeting held in Kyoto, Japan, in 1998. The working group then started drafting three test standards (including ISO 17455) for multilayer pipes: ISO 17456, Plastics piping systems Multilaye
15、r pipes Determination of long-term strength; ISO 17454, Plastics piping systems Multilayer pipes Test method for the adhesion of the different layers by using a pulling rig. Only multilayer pipes are dealt with in this International Standard and for these purposes cross-linked polyethylene (PE-X) as
16、 well as adhesives are to be considered as a thermoplastics material. INTERNATIONAL STANDARD ISO 17455:2005(E) ISO 2005 All rights reserved 1 Plastics piping systems Multilayer pipes Determination of the oxygen permeability of the barrier pipe 1 Scope This International Standard specifies two test m
17、ethods for determining the oxygen permeability of barrier pipe: the dynamic (Method I) and the static (Method II). In principle, both methods give the same results. The method to be applied is not application-dependent, but can be specified in the referring standard. 2 Principle The principle is mea
18、surement of the oxygen transfer through the wall of the test piece under specified conditions. The oxygen increase is measured in a system of which the test piece forms part. Oxygen can only be transported through the wall of the test piece. Therefore, the increased amount of oxygen in the closed sy
19、stem is the result of the functioning of the barrier layer of the test piece. NOTE A certain continuous oxygen permeation through the barrier layer is allowed. 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 multilayer pipe pipe comprising la
20、yers of different materials 3.2 multilayer M pipe multilayer pipe comprising layers of polymers and one or more metal layers NOTE The wall thickness of the pipe consists of at least 60 % polymer layers. 3.3 multilayer P pipe multilayer pipe comprised of two or more polymer layers 3.4 inner layer lay
21、er in contact with the liquid or gas 3.5 outer layer layer exposed to the outer environment ISO 17455:2005(E) 2 ISO 2005 All rights reserved3.6 embedded layer layer between the outer and inner layer NOTE There can be more than one embedded layer. 3.7 barrier layer layer intended to prevent or greatl
22、y diminish oxygen transport from outside the pipe into the inside water NOTE For multilayer P pipes, the barrier layer is normally not stress-designed. 3.8 closed system system which comprises stainless steel pipes, couplings and a tap, as well as the test piece, allowing only oxygen to permeate fro
23、m the outside to the inside of the test piece 3.9 flux oxygen permeability of the barrier layer of the pipe 4 Symbols and abbreviated terms A barroutside surface of the barrier layer, in square metres (m 2 ) C ox, toxygen concentration after time , in grams per cubic metre (g/m 3 ) F oxflux expresse
24、d in oxygen transfer per unit per area (of the barrier layer),in grams per square metre per hour (g/m 2 h) T test temperature (40C or 80C), expressed in degrees Centigrade V appvolume of the closed system, excluding the volume of the test piece, in cubic metres (m 3 ) V pipevolume of the test piece
25、(pipe sample), in cubic metres (m 3 ) d boutside diameter of the barrier layer, millimetres (mm) d emanufacturers nominal outside diameter, expressed in millimetres (mm) d iinside diameter of the test piece (pipe), in millimetres (mm) l length of the test piece, in metres (m) P astandard atmospheric
26、 pressure (1 000 mbar at 20C), expressed in bar 1)P finatmospheric pressure at the end of the measurement, expressed in bar P initatmospheric pressure at the start of the measurement, expressed in bar t test period, in hours (h) prdimensionless correction factor to atmospheric pressure 1) 1 bar = 0,
27、1 MPa = 10 5Pa; 1 MPa = 1 N/mm 2ISO 17455:2005(E) ISO 2005 All rights reserved 3 6 0 fin 2, O total amount of oxygen after six hours, in grams (g) =0 6 0 init O, H 2 O total amount of oxygen in the water at the start of the test, in grams (g) 5 Apparatus The test assembly shall include the following
28、 main elements: NOTE 1 The test temperature (40C or 80C) is specified in the relevant product- or system standard. NOTE 2 1 ppb = 1 g/m 3 . 5.1 Oven, capable of maintaining a constant temperature of (40 0,5) C and/or (80 0,5) C. 5.2 Test rig, a closed system consisting of stainless steel parts of pi
29、pes, couplings, valves (only for Method II) and taps, including the test piece. 5.3 Water circulation pump, capable of a variable delivery with a capacity range of from 0,15 dm 3 /min to 0,5 dm 3 /min. 5.4 Oxygen sensor, Capable of functioning at (40 0,5) C and/or (80 0,5) C, with a range of from 0,
30、1 ppb to 20 ppm 2) . 5.5 Water pressure meter, with a range of (1 0,1) to (4 0,1) bar. 5.6 Atmospheric pressure meter, with a range of from (965 1) mbar to (1035 1) mbar. 5.7 Water flow meter, with a range of from (0,15 0,05) dm 3 /min to (0,5 0,05) dm 3 /min. 5.8 Water temperature meter, capable of
31、 functioning at (40 0,05) C and/or (80 0,05) C. 5.9 Air temperature meter, capable of functioning at (40 0,05) C and/or (80 0,05) C. 5.10 Airtight vessel, for preparation of water with an oxygen concentration of 10 ppb (nominally oxygen-free) NOTE 3 Normally, sink plates or nitrogen are used to remo
32、ve the oxygen from the water by purging. 5.11 Test medium, deionized water with PH 7 (demi/water). 5.12 Registration device, capable of registering (graphical writer or computer) oxygen concentration as a function of time. 2) “Parts per billion (ppb)” and “parts per million (ppm)” are used exception
33、ally in this International Standard in order to correspond to other, closely related and already published standards. The accepted SI form for the expression of a volume fraction is in units of microlitres per litre (l/l), or, alternatively, as 10 6 , or as a percentage by volume (% by volume); for
34、mass fractions it is expressed in micrograms per gram (g/g). See ISO 31-0:1992, 2.3.3, and ISO 31-8-15:1992. ISO 17455:2005(E) 4 ISO 2005 All rights reserved6 Test piece 6.1 Number of test pieces Unless otherwise specified, the number of pipe test pieces shall be one. 6.2 Preparation The test piece
35、shall have a free length of (20 0,5) m. Prepare the test piece in accordance with the manufacturers instructions, taking into account the minimum free length. The free length between the couplings as well as the inside diameter of the test piece shall be measured and recorded. 7 Preconditioning The
36、test piece shall be preconditioned in accordance with the referring product or system standard. When the relevant product or system standard gives no conditioning time, the conditioning time in relation to the wall thickness according ISO 1167 1is recommended. 8 Calibration of the test assembly 8.1
37、Connect the closed system, without the test piece, to the oxygen sensor and pump. 8.2 Remove all air (bubbles) from the system, which has been filled with water. 8.3 Using the vessel, circulate the water at a maximum of 0,5 dm 3 /min to produce water with an oxygen concentration of 10 ppb. NOTE 1 dm
38、 3 /min = 0,0016 m 3 /s. 8.4 Stop the production of this water after the oxygen sensor shows a steady state concerning the oxygen concentration in the water. 8.5 After at least 15 min stop the calibration procedure. 9 Preparation for testing 9.1 Installation procedure 9.1.1 Connect the test piece in
39、 the closed system using the relevant stainless steel couplings. 9.1.2 Fill the closed system with water and remove all air (bubbles). 9.1.3 Establish the required pressure and temperature. 9.2 Removing the oxygen 9.2.1 Using the vessel, circulate the water through the closed system to produce water
40、 with an oxygen concentration of 10 ppb. ISO 17455:2005(E) ISO 2005 All rights reserved 5 9.2.2 Stop the production and circulation of this water after the oxygen sensor shows a level of u 220 ppb (220 g/l) for a test temperature of 40 C, or 100 ppb (100 g/l) for a test temperature of 80 C. NOTE As
41、long as the final oxygen concentration is much smaller than the solubility values per Annex A, the driving force of the transfer of oxygen can be considered as being constant. 10 Measuring procedure 10.1 General For measuring the oxygen increase, two different methods are allowed: Method I and Metho
42、d II. NOTE With Method I the water is circulated; whereas, in Method II it is stagnant. 10.2 Dynamic test method (Method I) (see Figure 1) 10.2.1 Circulate the water continuously with a volume flow of maximum 0,5 dm 3 /min through the system without refreshment. Maintain the temperature of the water
43、 as well of the surrounding air at the specified values. Maintain the inside water at the specified pressure. 10.2.2 Using the oxygen sensor, continuously measure the total amount of the oxygen in the water. 10.2.3 After one hour, start the measurement of the oxygen concentration in the inside water
44、. NOTE During 5 h, the rate of change in oxygen concentration in the inside water is constant (Stage 2 in Figure 1). 10.2.4 Repeat the procedure according to 9.2 before each measurement. 10.2.5 Only when three measurements in succession have values within 5 % of each other during Stage 2, calculate
45、the value of oxygen concentration in the inside water, F ox . 10.3 Static test method (Method II) (see Figure 2) 10.3.1 After the step according to 9.2.2 (the water circulation has been stopped), close the valves on both sides of the test piece to isolate (make airtight) the test piece from the clos
46、ed system. To prevent a possible vacuum, first close the outlet valve and then the inlet valve. 10.3.2 Maintain the temperature of the water as well of the surrounding air at the specified values. Maintain the pressure of the inside water at the specified pressure. NOTE The water is stagnant inside
47、the test piece without refreshment. 10.3.3 Leave for a period of 6 h to let oxygen diffuse into the stagnant water. 10.3.4 After 6 h, open the valves on both sides of the test piece and force the oxygen-free water (coming from the vessel) out the pipe. 10.3.5 Using the oxygen sensor, measure the tot
48、al amount of oxygen that issues. NOTE 1 The water coming from the vessel forces out the stagnant water. NOTE 2 When the observed concentration of oxygen is displayed as a function of time in Figure 2, the integration of the curve shows the total amount of oxygen flowing past the sensor. 10.3.6 Repea
49、t the procedure according to 9.2 before each measurement. 10.3.7 Only when three measurements in succession have values within 5 % of each other, use the value of the total amount of oxygen in the inside volume of water for calculating F ox . ISO 17455:2005(E) 6 ISO 2005 All rights reservedKey X time t, h Y oxygen concentration, g/m 3 1 stage 1 2 stage 2 3 stage 3 NOTE When the oxygen increase in time is graphically shown, as here, there are three di
