1、November 2014 English price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 23.040.80!%C%c“2320264www.din.de
2、DIN 28090-2Static gaskets for flange connections Gaskets made from sheets Part 2: Special test procedures for quality assurance,English translation of DIN 28090-2:2014-11Statische Dichtungen fr Flanschverbindungen Dichtungen aus Dichtungsplatten Teil 2: Spezielle Prfverfahren zur Qualittssicherung,E
3、nglische bersetzung von DIN 28090-2:2014-11Joints statiques dtanchit pour assemblages brides Joints dtanchit en plaques isolantes Partie 2: Mthodes dessai spcifiques pour lassurance de la qualit,Traduction anglaise de DIN 28090-2:2014-11SupersedesDIN 280902:199509www.beuth.deDocument comprises 13 pa
4、gesD02.16Translation by DIN-Sprachendienst. In case of doubt, the German-language original shall be considered authoritative. DIN 28090-2:2014-11 2 A comma is used as the decimal marker. Contents Page Foreword . 3 1 Scope 4 2 Normative references 4 3 Quantities, symbols and units . 5 4 General 7 5 S
5、ampling, forms and conditioning of specimens . 7 6 Checking the appearance of the gasket material . 7 7 Checking the dimensions and mass 7 8 Determination of density 7 9 Testing deformation behaviour . 8 9.1 Apparatus . 8 9.2 Test procedure (long-term) . 8 9.2.1 General 8 9.2.2 Deformation behaviour
6、 at ambient temperature 9 9.2.3 Deformation behaviour at elevated temperatures . 9 9.3 Test procedure (short-term) . 9 9.3.1 General 9 9.3.2 Deformation behaviour at ambient temperature 10 9.3.3 Deformation behaviour at elevated temperatures . 11 10 Determination of leakage behaviour . 11 11 Determi
7、nation of chloride content in graphite-based gasket materials . 11 11.1 Principle 11 11.2 Sampling . 11 11.3 Procedure . 11 11.4 Evaluation . 12 12 Determination of the oxidation resistance of graphite . 12 12.1 Apparatus . 12 12.2 Sampling . 12 12.3 Conditioning 12 12.4 Procedure . 12 12.5 Evaluati
8、on . 12 13 Test report . 13 DIN 28090-2:2014-11 3 Foreword This document has been prepared by Working Committee NA 082-00-16 AA Flansche und ihre Verbindungen of the DIN-Normenausschuss Rohrleitungen und Dampfkesselanlagen (NARD) (DIN Standards Committee Piping and Boiler Plant). Attention is drawn
9、to the possibility that some of the elements of this document may be the subject of patent rights. DIN shall not be held responsible for identifying any or all such patent rights. Amendments This standard differs from DIN 28090-2:1995-09 as follows: a) normative references have been updated; b) symb
10、ols in Table 1 have been supplemented; c) in Clause 5 requirements regarding sampling, specimen forms and specimen conditioning have been revised; d) in 9.1 the recommendations regarding test equipment have been revised; e) in 9.3 a short-term test to determine deformation behaviour has been added;
11、f) in Clause 10 requirements regarding leakage testing have been brought in line with current national and European standardization; g) a new Clause 12 on the determination of the oxidation stability of graphite has been added; h) the standard has been editorially revised. Previous editions DIN V 28
12、090: 1989-01 DIN 28090-2: 1995-09 DIN 28090-2:2014-11 4 1 Scope This standard applies to the testing of gasket sheet materials as specified in DIN 28091-1 to DIN 28091-4 and the gaskets produced from such materials. 2 Normative references The following documents, in whole or in part, are normatively
13、 referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. DIN 862, Geometrical product specifications (GPS) Callipers Maximum
14、permissible errors DIN 863-1, Verification of geometrical parameters Micrometers Part 1: Standard design micrometer callipers for external measurement; concepts, requirements, testing DIN 3535-6, Gaskets for gas supply Part 6: Gasket materials based on fibres, graphite or polytetrafluoroethylene (PT
15、FE) for gas valves, gas appliances and gas mains DIN 28091-1, Technical delivery conditions for gasket sheets Part 1: General requirements for gasket materials DIN 28091-2, Technical delivery conditions for gasket sheets Part 2: Requirements and testing for fibre-based gasket materials (FA) DIN 2809
16、1-3, Technical delivery conditions for gasket sheets Part 3: Requirements and testing for PTFE-based gasket materials (TF) DIN 28091-4, Technical delivery conditions for gasket sheets Part 4: Requirements and testing for expanded graphite-based gasket materials (GR) DIN EN 1514-1, Flanges and their
17、joints Dimensions of gaskets for PN-designated flanges Part 1: Non-metallic flat gaskets with or without inserts DIN EN 13555:2005-02, Flanges and their joints Gasket parameters and test procedures relevant to the design rules for gasketed circular flange connections DIN 28090-2:2014-11 5 3 Quantiti
18、es, symbols and units Table 1 Symbols Symbol Quantity Unit a Cross-sectional area of U-tube cm2dDMean effective diameter of gasket mm FVPreload, see DIN 28091-2, DIN 28091-3 and DIN 28091-4 N FHKMain load applied to determine the cold compression set, see DIN 28091-2, DIN 28091-3 and DIN 28091-4 N F
19、HWMain load applied to determine the compression set at elevated temperature, see DIN 28091-2, DIN 28091-3 and DIN 28091-4 N hD1Initial specimen thickness mm hD2Specimen thickness at FVafter 1 min mm hD3Specimen thickness at FHKafter 5 min mm hD4Specimen thickness measured after 1 min, once load has
20、 been reduced to FVmm hD5Specimen thickness at FHWafter 5 min mm hD6Specimen thickness at FHWafter 16 hmm hD7Specimen thickness after 1 min, once load has been reduced to FV(test at elevated temperature) mm hD1kInitial specimen thickness, short-term test mm hD2kSpecimen thickness at FVafter 1 min, s
21、hort-term test mm hD3kSpecimen thickness at FHKafter 5 min, short-term test mm hD4kSpecimen thickness at FHKafter 1 min at elevated temperature, short-term test mm PBAir pressure bar PNStandard pressure (1,013 bar) bar Pt0Initial test pressure bar Pt1Final test pressure (high leak rate) bar Pt2Final
22、 test pressure (low leak rate) bar R Recovered thickness mm RzMaximum height of profile (roughness parameter) m t Stress duration h, min, s taHeating time s LConditioning temperature C DIN 28090-2:2014-11 6 Table 1 (continued) Symbol Quantity Unit TNStandard temperature (273,15 K) K TpTest temperatu
23、re, see DIN 28091-2, DIN 28091-3 and DIN 28091-4 K Tt0Initial test temperature K Tt1Final test temperature (high leak rate) K Tt2Final test temperature (low leak rate) K VgesTotal volume cm3VLVolume of measuring system cm3VMVolume of pressure vessel cm3VZExtra gas volume added cm3hUDifference in lev
24、el of water column of U-tube/inclined manometer cm p Pressure drop bar pZPressure increase in U-tube/inclined manometer bar t Measuring time s VNLeakage volume during measuring time cm3VZVolume increase in U-tube manometer cm3KRWRecovery at ambient temperature % KSWCold compression set (long-term te
25、st)%KSWkCold compression set (short-term test) % WRW/TRecovery at elevated temperature, at Tp%WSW/TCompression set at elevated temperature, at Tp (long-term test)%WSWk/TCompression set at elevated temperature, at Tp (short-term test) % Density of test gas under standard conditionsmg/cm3 2,0Specific
26、leakage rate for a 2 mm thick gasketmg/(sm)QSmax/RTMaximum surface pressure to which the gasket may be exposed at operating temperature without damage MPaDIN 28090-2:2014-11 7 4 General The purpose of this standard is to specify test methods specifically intended for quality assurance. 5 Sampling, f
27、orms and conditioning of specimens Specimens shall be taken from areas near the edge and centre of the sheet, as seen from the direction of manufacture. The manufacturer, designation, batch number, and the date of manufacture shall be documented. Prior to the test, the specimens shall be conditioned
28、 for 48 h at (23 null 2) C in a desiccator containing calcium chloride. The gaskets shall comply with the dimensions specified in DIN EN 1514-1, DN 40, PN 40. 6 Checking the appearance of the gasket material The surface and edges of gasket sheets shall be visually checked. 7 Checking the dimensions
29、and mass During testing the limits of error in Table 2 shall be complied with. A specimen measuring 100 mm 100 mm thickness shall be selected to determine the mass. Table 2 Limits of error Parameter Measuring device Limits of error for sheet specimen Thickness, as the mean of 4 measurements each, ta
30、ken along the long and the short side of the sheet at 40 mm from the edge Micrometer calliper (e.g. as in DIN 863-1) 0,01 mm 0,01 mm Compression sensor (apply 1 N per 10 mm diameter) Width and length Straight edge or measuring tape 1 mm Vernier calliper (e.g. as in DIN 862) 0,1 mm Mass Scale 0,01 g
31、8 Determination of density The density of gasket materials shall be calculated on the basis of the values established in accordance with Clause 7. DIN 28090-2:2014-11 8 9 Testing deformation behaviour 9.1 Apparatus Test apparatus, flange facings, loading procedure and test rig shall be as in DIN EN
32、13555:2005-02, Annex B, for example. The raised face on the test gasket (usually only on one side) shall have an inside diameter of 55 mm and an outside diameter of 75 mm (null 0,05 mm, Rz 6,3 m). 9.2 Test procedure (long-term) 9.2.1 General Carefully clean the platens. Centre the specimen - if nece
33、ssary, covered with stainless steel foil - between the platens. Apply a preload, FV, increasing it at a uniform rate until it has reached 1 MPa within 1 min. Maintain the preload at a constant level for 1 min, and then measure the specimen thickness, hD2(see Figure 1). Key Y Temperature in C Figure
34、1 Determination of compression set values at ambient and elevated temperatures (upper diagram) and typical change in thickness during testing (lower diagram) DIN 28090-2:2014-11 9 9.2.2 Deformation behaviour at ambient temperature Next, within 1 min steadily increase the main load, FHK, until the ma
35、in load, FHK, specified in DIN 28091-2, DIN 28091-3 and DIN 28091-4 has been reached. Five minutes later, measure the specimen thickness, hD3. Then, reduce the test load to the preload, FV, maintain it for 1 min, and measure the specimen thickness, hD4. Calculate recovery at ambient temperature, KSW
36、, and the cold compression set, KRW, as percentages using the following equations: KSW= D2 D3D1 100 (1) KRW= D4 D3D1 100 (2) 9.2.3 Deformation behaviour at elevated temperatures After determining deformation behaviour at ambient temperature as specified above, apply the main load, FHW, specified in
37、DIN 28091-2, DIN 28091-3 or DIN 28091-4 within one min. After 5 min, measure the specimen thickness, hD5. Then, heat the platens at a rate of 5 K/min until the test temperature, Tp, specified in DIN 28091-2, DIN 28091-3 and DIN 28091-4 is attained. Maintain the constant main load and temperature (to
38、 within null 5 K) for 16 hours. Then, measure the specimen thickness, hD5. Next, reduce the load to preload, FV, maintain it for 1 min, and then measure the specimen thickness, hD7. The compression set, WSW/T, and recovery, WRW/T, at the test temperature are to be calculated as follows: WSW/T= D5 D6
39、D1 100 (3) WRW/T= D7 D6D1 100 (4) The recovery, R, is to be calculated as follows: R = hD7 hD6(5) 9.3 Test procedure (short-term) 9.3.1 General Carefully clean the platens. Centre the specimen - if necessary, covered with stainless steel foil - between the platens. Apply a preload, FV, increasing it
40、 at a uniform rate until, after 1 min, it has reached 1 MPa. Maintain the preload at a constant level for 1 min and measure the specimen thickness, hD2k(see Figure 2). DIN 28090-2:2014-11 10 Key Y Temperature in C Figure 2 Determination of the compression set at ambient and elevated temperatures (up
41、per diagram) and typical change in thickness during short-term testing (lower diagram) 9.3.2 Deformation behaviour at ambient temperature Next, within 1 min increase the load steadily at a rate of 10 MPa/min until the main load, FHK, specified in DIN 28091-2, DIN 28091-3 or DIN 28091-4 has been reac
42、hed. 5 min after this load has been reached, measure the specimen thickness, hD3k. The cold compression set, KSWk, shall be calculated using the following equation: KSWk=D2kD3kD1k 100 (6) DIN 28090-2:2014-11 11 9.3.3 Deformation behaviour at elevated temperatures Heat the platens at a rate of 10 K/m
43、in until the test temperature, Tp, specified in DIN 28091-2, DIN 28091-3 and DIN 28091-4 is attained. Maintain the constant main load and temperature (to within null 5 K) for 1 min. Then, measure the specimen thickness, hD4k. The compression set at the test temperature, WSWk/T, is to be calculated u
44、sing the following equation: WSWk/T= D3k D4kD3k 100 (7) 10 Determination of leakage behaviour Determine leakage behaviour in accordance with DIN 3535-6. In deviation from that standard, a PE film shall not be used. 11 Determination of chloride content in graphite-based gasket materials 11.1 Principl
45、e Subclauses 11.2 to 11.4 describe an example of a method for determining the chloride content of various graphite materials (e.g. natural graphite, film) for concentrations down to 1 104 % (the previous notation for 1 104 % was 1 ppm) chloride. Burn the carbon or graphite sample in a stream of oxyg
46、en at 800 C. Introduce the combustion gases into a sodium hydroxide solution. The chloride precipitates as silver chloride. To precipitate the solubility product of silver chloride, titrate using a solution made up of dioxane (with a volume fraction of 75 %), solubility (AgCI/dioxane, 20 C) = 1016mo
47、l/l, solubility (AgCI/H2O, 20 C) = 1010mol/l. Carry out titration using a silver rod electrode and a mercury sulfate reference electrode. 11.2 Sampling When taking samples, care shall be taken that the material under test is not contaminated by inappropriate handling (e.g. touching with bare hands).
48、 11.3 Procedure Weigh 6 g to 8 g of sample material into a porcelain crucible to an accuracy of 0,1 g and burn the sample in a stream of oxygen at 800 C. Introduce the combustion gases produced into a 25,0 ml 0,1 mol/l NaOH solution. Then, wash this solution into a 150 ml beaker and, after adding 30
49、0 l of nitric acid, make it up to 100 ml with dioxane. Now determine the chloride content by means of potentiometric titration using a solution of 0,005 mol/l AgNO3. To determine the blank value, add 75 ml of dioxane to 25 ml 0,1 mol/l NaOH and proceed as described above by analogy. If chloride-free reagents are used, it is not necessary to determine the blank value. Establish the factor of the silver nitrate solution by means of titr
