1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 10275:1999 The Euro
2、pean Standard EN 10275:1999 has the status of a British Standard ICS 77.040.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Metallic materials Tube ring hydraulic pressure testThis British Standard, having been prepared under the direction of the Engineering Sector Committe
3、e, was published under the authority of the Standards Committee and comes into effect on 15 September 1999 BSI 09-1999 ISBN 0 580 32637 3 BS EN 10275:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard is the English language version of EN 10275:19
4、99. The UK participation in its preparation was entrusted by Technical Committee ISE/NFE/4, Mechanical testing of metals, to Subcommittee ISE/NFE/4/2, Ductility tests, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries o
5、n the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British
6、 Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British S
7、tandard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cov
8、er, an inside front cover, the EN title page, pages 2 to 7 and a back cover. The BSI copyright notice displayed throughout this document indicates when the document was last issued.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central
9、 Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 10275:1999 E EUROPEAN STANDARD EN 10275 NORME EUROPE ENNE EUROPA ISCHE NORM May 1999 ICS 77.040.10 English version Metallic mate
10、rials Tube ring hydraulic pressure test Mate riaux me talliques Essai dexpansion hydraulique sur anneau tubulaire Metallische Werkstoffe Hydraulischer Ringaufweitversuch This European Standard was approved by CEN on 16 April 1999. CEN members are bound to comply with the CEN/CENELEC Internal Regulat
11、ions which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This Euro
12、pean Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the nati
13、onal standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 10275:1999 BSI 09-1999 Foreword This European Standard has been prepared b
14、y Technical Committee ECISS/TC 29, Steel tubes and fittings for steel tubes, the Secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 1999, and conflicting
15、 national standards shall be withdrawn at the latest by November 1999. This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. This European Standard is considered to be a supporting standard to those application and p
16、roduct standards which in themselves support an essential safety requirement of a New Approach Directive and which make reference to this European Standard. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this
17、European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword 2 1 Scope 3 2 Symbols 3 3 Principle 3 4 Apparatus 3 5 Test rin
18、g 3 6 Test procedure 5 7 Hoop strength evaluation 6 8 Test report 6 Annex A (informative) Proof and reduced section testing 7Page 3 EN 10275:1999 BSI 09-1999 1 Scope This European Standard specifies the ring hydraulic pressure test for metallic tubes. It is generally applied to tubes with an outside
19、 diameter generally greater than 120 mm and outside diameter to thickness ratio not less than 20. The objective of this test is to ascertain the value of the hoop stress required to produce a specified total circumferential (hoop) strain. 2 Symbols Symbols and corresponding designations are given in
20、 Table 1. Table 1 Symbols and designations Symbol Unit Designation T mm Measured tube test ring thickness D mm Measured outside diameter of the tube test ring L mm Length of tube test ring p N/mm 2 Hydrostatic pressure to produce the specified total strain x Specified total strain R tx N/mm 2 Hoop s
21、trength at the specified total strain 3 Principle The test involves the unrestrained expansion of the test ring between two platens, under internal hydraulic pressure; the outer circumference of the tube is the effective test piece gauge length. The test is carried out on a test piece (see Figure 1)
22、 removed from a welded or seamless tube of thickness up to a limit dependent upon the capacity of the machine and the strength of the tube. Where the hydraulic pressure required to produce the specified circumferential strain exceeds the capacity of the test machine modified tests may be carried out
23、 as described in annex A. The test is specified when a measure of the hoop strength is required which is not influenced by cold forming and residual stress introduced when flattening a standard tensile test piece. The standard tensile test is necessary, however, when tensile strength and elongation
24、measurements are required. 4 Apparatus 4.1 The testing machine shall be capable of allowing the test ring to expand freely without imposing any end restraint. This shall be achieved by leaving a small gap between the test piece and the top platen. Pressure loss during testing shall be prevented by t
25、he use of a flexible seal. NOTE A typical testing machine is shown schematically in Figure 2. 4.2 To reduce friction between the test piece, platens and inner die to a minimum, the platens shall be parallel and have a fine turned or ground finish. Prior to each test, friction at the contact surfaces
26、 shall be further minimized either by the use of a lubricant e.g. graphited grease or by the use of PTFE (polytetrafluorethylene) sheet. The platens shall be inspected regularly and any ridges that develop shall be removed. 4.3 Stress shall be applied to the test ring by means of a pressurized fluid
27、. Provision shall be made to remove any air in the system through a bleed line. 5 Test ring 5.1 Shape and position 5.1.1 Prior to separation from the main body of the tube the test ring shall be marked with a unique identification. 5.1.2 The test ring may be prepared from an oversize flame cut sampl
28、e. Final preparation shall be by a cold machining process to ensure removal of any heat affected zones. The machined edges shall have a fine turned or ground finish and be free from burrs. 5.1.3 The dimensions and tolerances for the test piece are given in Figure 1. The machined edges shall be paral
29、lel and normal to the axis of the tube to within 0,15 mm measured across the diameter. 5.2 Determination of dimensions 5.2.1 The outside diameter of the test ring shall be calculated from measurement of the tube circumference, e.g. using a flexible steel tape. The maximum tolerance on the accuracy o
30、f this measurement shall be 1 mm. 5.2.2 The wall thickness shall be determined by calculating the mean of eight measurements taken at approximately 458 intervals around the test piece, excluding the weld region of welded tubes (see Figure 3). The measuring device shall be capable of measuring thickn
31、ess with an accuracy of better than 0,025 mm. 5.2.3 All tube diameter and thickness measurements of the test ring shall be fully documented.Page 4 EN 10275:1999 BSI 09-1999 1) Tolerance on L 0,25 mm. L is commonly taken as 76 mm. NOTE Remove all sharp edges and protect machined surfaces. Figure 1 Te
32、st ring dimensions and tolerances Figure 2 Schematic diagram of testing machine (with insalled test ring)Page 5 EN 10275:1999 BSI 09-1999 Figure 3 Wall thickness measurement positions 6 Test procedure 6.1 The test procedure consists of applying pressure and measuring circumferential extension. 6.2 C
33、ircumferential extension of the test ring shall be measured during pressurization as follows. The equipment for measuring the change of circumference, e.g. steel tape or roller chain extensometer shall be wrapped around the test ring perimeter at the mid-point and crossing at the weld. NOTE An examp
34、le of the use of a steel tape is shown in Figure 4. When a steel tape is used friction shall be minimized by coating both the tape and test ring circumference with a suitable lubricant. Change in circumference shall be measured by a suitable mechanical or electrical device having an accuracy of 0,25
35、 mm. 6.3 The equipment for measuring the increase in circumference shall be wrapped around the test ring before application of the internal pressure. 6.4 The tolerance for the measurement of internal pressure shall be within 1 %. Accuracy of the pressure measurement device shall be verified, e.g. by
36、 comparison with dead weight test equipment, at the commencement of a sequence of testing and then once every 200 tests, and not less than once per year during the testing period. 6.5 The rate of strain shall not exceed 0,2 % per minute. 6.6 The pressure and circumferential extension output signals
37、shall be recorded, for example on a XY plotter, and related to the test piece identity.Page 6 EN 10275:1999 BSI 09-1999 NOTE The separation between the two parallel portions of the measuring device shall be between 1,5 mm and 3,0 mm. Figure 4 Measuring device position for extension measurement 7 Hoo
38、p strength evaluation 7.1 A typical test pressurecircumferential extension record is shown in Figure 5. 7.2 The pressure p corresponding to the specified total strain shall be determined from the test record. 7.3 For tubes where D/T$ 20 the hoop strength at the specified total strain shall be calcul
39、ated from the formula: R tx = pD 2T NOTE 1 For tubes with D/T 20 the hoop strength calculated from this formula becomes increasingly inaccurate and quantitative results should be used with caution. Factors such as strain hardening could have a significant effect on the validity of the calculated str
40、ength. NOTE 2 The specified total strain is calculated from the circumferential extension divided by the original test ring circumference. 8 Test report The test report shall contain at least the following information: a) reference to this European Standard i.e. EN 10275; b) identification of test r
41、ing, e.g. cast No./tube No. /identification No.; c) material specification, if known; d) diameter and wall thickness of the tube; e) length of the tube test ring; f) calculated hoop strength at specified total strain; g) reference to an alternative test method used, when appropriate (see annex A).Pa
42、ge 7 EN 10275:1999 BSI 09-1999 Figure 5 Typical pressure/extension test record Annex A (informative) Proof and reduced section testing A.1 Proof testing This method may be used where the stress necessary to produce the specified circumferential extension has not been achieved but where the stress in
43、 the test ring exceeds the specified minimum hoop strength requirement. In this case the percentage circumferential expansion achieved shall be quoted in the report. A.2 Reduced section testing This method enables the stress corresponding to the specified circumferential extension to be achieved by
44、a reduction in the test ring thickness. This reduction can be effected by machining the inside and/or outside diameter. To ensure that the full thickness is represented two or possibly three tests should be carried out after machining i) inside, ii) outside and iii) both diameters. Details of all te
45、st piece locations and dimensions relative to the full thickness ring section will be included in the report.BS EN 10275:1999 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
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