DIN 50934-3-2000 Corrosion of metals - Methods for evaluation of efficiency of water treatment apparatus for corrosion protection - Part 3 Field corrosion test for removal of corro.pdf

1、ICS 77.060Korrosion der Metalle Verfahren zur Beurteilung der Wirksamkeit von Wasserbehandlungsanlagen zumKorrosionsschutz Teil 3: Feldversuche zum Abbau von Korrosionsprodukten aus inkrustierten Rohr-leitungenForewordThis standard has been prepared by Technical Committee Korrosion und Korrosionssch

2、utz of the Normen-ausschuss Materialprfung (Materials Testing Standards Committee).Ref. No. DIN 50934-3 : 2000-04English price group 05 Sales No. 010503.01DEUTSCHE NORM April 200050934-3Continued on page 2. No part of this translation may be reproduced without the prior permission ofDIN Deutsches In

3、stitut fr Normung e.V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).Methods of evaluating the effectiveness of watertreatment equipment for corrosion controlPart 3: Field testing of equipment for removing scaleTranslation by DIN-

4、Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.1 ScopeThis standard specifies a field method of testing the effectiveness of water treatment equipment used toremove corrosion products (scale) from steel pipes.2 Normative referencesThis sta

5、ndard incorporates, by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the titles of the publications arelisted below. For dated references, subsequent amendments to or revisions of any of these publicatio

6、nsapply to this standard only when incorporated in it by amendment or revision. For undated references, thelatest edition of the publication referred to applies.DIN 50905-1 Corrosion testing PrinciplesDIN 50905-2 Corrosion testing Corrosion characteristics of metals subjected to uniform corrosionatt

7、ackDIN 50930-1 Corrosion behaviour of metallic materials in contact with water GeneralDIN 50934-2 Methods of evaluating the effectiveness of water treatment equipment for corrosioncontrol Equipment for reducing the release of corrosion products into drinking waterDIN EN ISO 8044 Corrosion of metals

8、and alloys Basic terms and definitions (ISO 8044 : 1999)3 ConceptsFor the purposes of this standard, the concepts defined in DIN EN ISO 8044, DIN 50930-1 and DIN 50934-2apply.4 Principle of methodPressure loss/flow curves are plotted based on measurements taken at the ends of encrusted (i.e. corrode

9、d)pipe sections in an existing system before and after water treatment.Page 2DIN 50934-3 : 2000-045 Testing5.1 Test arrangementRemove an encrusted pipe section that is at least 1 m long from an existing pipeline, and separate it into twoequally long sections, A and B. Fit them back into the place fr

10、om which the original section was taken so thetwo halves form two parallel test sections. Install the treatment equipment to be tested in one of the testsections. Store the pipe sections under water until they are replaced into the system.5.2 Reagent waterThe drinking water being distributed through

11、 the system shall be used as reagent water. Its quality shall becharacterized as specified in DIN 50930-1.5.3 ProcedureTo characterize the extent of corrosion before and after water treatment, remove a 5 cm section from both endsof each test section before and after testing and determine the mass pe

12、r unit area of the surface covered withscale as specified in DIN 50905-1 and DIN 50905-2.The test sections are to be operated as in practice using the reagent water over a period of six months.6 Evaluation of resultsThe effectiveness of the equipment, expressed in mg/l, is given by the increase in f

13、low at a differential pressureof 0,01 bar, expressed in terms of the difference between the measured flow before and after exposure, Q, asshown in equation (1).Effectiveness = (Qafter Qbefore)m(Qafter Qbefore)o(1)The effectiveness factor, fw, is given by equation (2).()()obeforembeforewQQf+=nesseffe

14、ctive2(2)wheresubscript m means with the water treatment equipment;subscript o means without the water treatment equipment.7 Test reportThe test report shall refer to this standard and contain the following information:a) place of test;b) duration of test;c) type of pipes tested (cold water, hot water);d) pipe diameters and lengths;e) mass per unit area of the surface covered with scale measured at pipe ends before and after testing;f) analysis of reagent water as in DIN 50930-1;g) pressure loss/flow curves for each pipe before and after testing;h) effectiveness;i) effectiveness factor.