1、BSI Standards PublicationBS EN 14718:2014Influence of organic materialson water intended for humanconsumption Determinationof the chlorine demand TestmethodBS EN 14718:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 14718:2014. It supersedes BS EN 14718:200
2、6 which is withdrawn. At the time of publication, this standard is not currently included in the (UK) product testing to be used for materials in contact with drinking water as all the methodology in BS 6920, together with the pass/fail criteria, has not been replaced by EN standards. To ensure the
3、correct methodology is being used, refer to the National Approval schemes for the UK before undertaking any testing. Further information can be obtained for UK approvals from the Drinking Water Inspectorate and the Water Regulations Advisory Scheme.The UK participation in its preparation was entrust
4、ed to Technical Committee EH/6, Effects of materials on water quality.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct appli
5、cation. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 85701 0ICS 13.060.20; 23.040.20; 67.250Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of theStandards Policy
6、and Strategy Committee on 31 January 2015.Amendments/corrigenda issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14718 December 2014 ICS 13.060.20; 67.250 Supersedes EN 14718:2006English Version Influence of organic materials on water intended for human
7、consumption - Determination of the chlorine demand - Test method Influence des matriaux organiques sur leau destine la consommation humaine - Dtermination de la demande en chlore - Mthode dessai Einfluss organischer Materialien auf Wasser fr den menschlichen Gebrauch - Bestimmung der Chlorzehrung -
8、Prfverfahren This European Standard was approved by CEN on 18 October 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and biblio
9、graphical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsi
10、bility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republ
11、ic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALI
12、SATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14718:2014 EBS EN 14718:2014EN 14718:2014 (E) 2 Contents Page Foreword 4 1
13、Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Principle 6 5 Reagents .6 5.1 Sodium hypochlorite solution 6 5.2 Test water .6 5.3 Rinsing water .6 5.4 Cleaning liquids for apparatus .6 6 Apparatus for chlorine demand assessment 7 6.1 Materials .7 6.2 Test vessels 7 6.3 Equipment 7 7 P
14、rocedural constraints 7 8 Samples of products and test pieces 7 8.1 Factory made products .7 8.1.1 General 7 8.1.2 Samples and test pieces of factory made products .8 8.2 Site applied products 8 8.2.1 General 8 8.2.2 Samples and test pieces of site applied products .9 8.3 Surface-area-to-volume rati
15、o (S/V) .9 9 Preparation of test water and apparatus 10 9.1 Test water 10 9.2 Preparation of apparatus . 10 9.3 Cleaning of the glassware . 10 9.4 Cleaning of stainless steel . 10 10 Test procedure 10 10.1 General . 10 10.2 Flushing . 10 10.3 Stagnation . 11 10.4 Pre-washing . 11 10.4.1 General . 11
16、 10.4.2 Flushing . 11 10.4.3 Rinsing . 11 10.5 Determination of chlorine demand . 11 10.5.1 General . 11 10.5.2 Contact water 11 10.5.3 Blank waters 11 10.6 Determination of free chlorine . 11 11 Expression of results . 12 11.1 Description of the calculation . 12 11.2 Validation of the test results
17、12 11.2.1 General . 12 11.2.2 Validation of duplicate samples 12 11.2.3 Validation of blank tests 12 BS EN 14718:2014EN 14718:2014 (E) 3 11.2.4 Validation of test samples 13 12 Test report 13 Annex A (normative) Procedure for establishing the suitability of apparatus and test water 14 Annex B (infor
18、mative) Arrangement for flushing large diameters pipes . 15 BS EN 14718:2014EN 14718:2014 (E) 4 Foreword This document (EN 14718:2014) has been prepared by Technical Committee CEN/TC 164 “Water supply”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a
19、national standard, either by publication of an identical text or by endorsement, at the latest by June 2015, and conflicting national standards shall be withdrawn at the latest by June 2015. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
20、 rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. This document supersedes EN 14718:2006 In this second edition, alo
21、ng with editorial corrections, an error in Formula (2) in 11.2.3 has been corrected. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Re
22、public, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS
23、 EN 14718:2014EN 14718:2014 (E) 5 1 Scope This European Standard specifies a method for determining the chlorine demand of organic materials intended for use in contact with drinking water. This European Standard is applicable to factory made and site applied products used for the distribution, tran
24、sport and storage of drinking water. This European Standard does not cover the use of high levels of chlorine to disinfect products when they are put into service. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable f
25、or its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 7393-2:2000, Water quality - Determination of free chlorine and total chlorine - Part 2: Colorimetric method usin
26、g N, N-diethyl-1, 4-phenylenediamine, for routine control purposes (ISO 7393-2:1985) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 chlorine demand ability of a material in contact with chlorinated water to remove/reduce the concentration of
27、 free chlorine in the water compared with a reference sample SOURCE: EN ISO 7393-2:2000, 2.1 3.2 test water water used for testing purposes prepared with a free-chlorine content as described in 5.2 3.3 rinsing water test water without added chlorine 3.4 contact water test water (see 3.2) which has b
28、een in contact with a test piece under specified conditions 3.5 blank water test water (see 3.2) which has been kept at the same specified conditions (e.g. temperature, contact time, contact with any sealing material) as contact water but without contact with the test piece 3.6 flushing water tap wa
29、ter 3.7 product manufactured item, in its finished form BS EN 14718:2014EN 14718:2014 (E) 6 3.8 sample one or more units, or a specified quantity of a product, selected from a batch or lot 3.9 test piece sample or portion of it which is tested to obtain a single test result 3.10 factory made product
30、 product made in a factory under controlled conditions as part of the manufacturing process 3.11 site applied product manufactured item for application on-site and subsequent contact with water Note 1 to entry: In this context, the product is the final prepared surface that comes into contact with w
31、ater. 4 Principle Initially test pieces are pre-conditioned by washing and rinsing procedures. Test pieces are then completely filled with or immersed in test water. This filling or immersion procedure is carried out three times on the same test pieces under specified conditions. After each contact
32、period the contact water is immediately analysed to determine the residual content of free chlorine. Blank tests without test pieces are undertaken with the same test water to obtain blank water results. NOTE If the reduction in the free-chlorine concentration of the test water in contact with the t
33、est material is particularly high, the test will have to be repeated using fresh test samples and a reduced S/V test ratio (see 8.3). The chlorine demand of the material is based on the difference between the free chlorine content of the contact water (see 3.4) and of the blank water (see 3.5). 5 Re
34、agents 5.1 Sodium hypochlorite solution Sodium hypochlorite solution, with a concentration of about 0,1 % by mass of free chlorine determined in accordance with EN ISO 7393-2, to be prepared from a commercial solution of sodium hypochlorite (NaOCl). As this sodium hypochlorite solution is unstable,
35、it shall be prepared on the day of use. 5.2 Test water Test water shall have a conductivity of 0,2 mg/l corrective measures should be taken.; reference to this standard and to the referring standard or national regulation, if applicable; number of test pieces used together in a test, if applicable;
36、volume of the test liquid (V) in litres; surface area of the test piece exposed to the test liquid (S) in square decimetres calculated from the actual dimensions of the test pieces; actual S/V ratio; any deviation from the test procedure specified in this standard; any factors which may have affecte
37、d the results, such as any incidents or any operating details not specified in this standard; dates of start and completion of the test. c) Test results The test results shall include the calculated chlorine demand data for the three periods (CD1, CD2and CD3- see 11.1). BS EN 14718:2014EN 14718:2014
38、 (E) 14 Annex A (normative) Procedure for establishing the suitability of apparatus and test water The apparatus used for testing shall conform with the requirement that free-chlorine depletion shall not exceed 0,1 mg/l for each contact period. If new glassware or related items are introduced then t
39、his requirement shall be satisfied by pre-testing (blank test procedure). After the test procedure has been undertaken for the first time it is recommended that the test vessels are kept permanently filled with test water between tests to avoid deterioration of the surface with regard to the chlorin
40、e depletion. After the third test exposure, the vessel shall be refilled completely with test water and stored under test conditions (room temperature, not exposed to light) until the next test starts in the following week (typically Thursday through Tuesday). During these five days, chlorine deplet
41、ion shall not exceed 0,15 mg Cl2/l, otherwise the results show the need to clean the vessel. To obtain the depletion rates of the blanks (see 5.2) and the figures mentioned above for between tests, test water shall conform with 5.2. This shall be verified each time the tests are undertaken. If the t
42、ests are not carried out continuously, or if the test vessels are not kept continuously filled with chlorinated water, each test shall be preceded by a controlled filling and evaluation of the actual chlorine depletion of the test vessels as described above. BS EN 14718:2014EN 14718:2014 (E) 15 Anne
43、x B (informative) Arrangement for flushing large diameters pipes An alternative arrangement for flushing large diameter pipes is shown in Figures B.1 and B.2. This arrangement is designed to produce the required flow rate over the surface of the test piece while using the minimum quantity of water.
44、The device is a cylinder made of inert material (see 6.1) with a diameter less than that of the internal diameter of the test piece. It is essential for the diameter of the cylinder be at least 10 mm less than that of the internal diameter of the test piece. This will leave a gap of at least 5 mm be
45、tween the wall of the cylinder and the test piece. If the gap is any smaller than this, there will possibly be too much resistance to the waterflow. The wash water is delivered from a mains tap via a valve and flow meter through a pipe to a space at the bottom of the cylinder. The cylinder is suppor
46、ted on the base plate by three or four short legs. The space into which the pipe delivers the water should allow for equal flow of wash water over the whole inside of the test piece. The space has an air vent which is opened at the start of the washing period in order to let out the air which would
47、otherwise be trapped in the distribution space. Most of the volume of the cylinder is empty space which can be filled with e.g. water or sand in order to stabilize the setup. Towards the top of the cylinder there is an adjustable ring with three or four screws to adjust the height of the ring for di
48、fferent lengths of test pieces. There are also three or four screws which can be tightened into the outside of the test pieces in order to ensure that the cylinder is centred within the test piece, thus ensuring equal flows of wash water over the whole inside surface of the test piece. The position
49、of the ring is adjusted to allow a free flow of water over the top edge of the test piece. A vertical gap of about 10 mm should be sufficient. BS EN 14718:2014EN 14718:2014 (E) 16 Key 1 air vent 5 flow meter 9 test piece 2 gap 5 mm 6 plug 10 seal 3 valve 7 height adjusting screw 11 base plate 4 wash water 8 centering screw Figure B.1 - Example of an arrangement for flushing large diameter pipes, side view BS EN 14718:2014EN 14718:2014 (E) 17 Key 1 air vent 5 wash water 2 main cylinder 6 test piece 3 centering screw 7 water inlet 4 adjustable rin
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