1、Pressure equipment and assembliesPart 8: Proof testPD CEN/TS 764-8:2016BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06National forewordThis Published Document is the UK implementation of CEN/TS 764-8:2016.The UK participation in its preparation was entrusted to Tech
2、nicalCommittee PVE/1, Pressure Vessels.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Ins
3、titution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 84743 1ICS 23.020.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published Document was published under the authority of theStandards Policy and Strategy Committee on 30 June 2016.Amendments/c
4、orrigenda issued since publicationDate Text affectedPUBLISHED DOCUMENTPD CEN/TS 764-8:2016TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 764-8 June 2016 ICS 23.020.30 English Version Pressure equipment and assemblies - Part 8: Proof test quipements sous pression et en
5、sembles - Partie 8: preuve Druckgerte und Zusammenbauten- Teil 8: Druckprfung This Technical Specification (CEN/TS) was approved by CEN on 8 March 2016 for provisional application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be r
6、equested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard. CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate f
7、orm. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic,
8、 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 United Kingdom. EUROPEAN COMM
9、ITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TS 764-8:2016 EPD CEN/TS
10、 764-8:2016CEN/TS 764-8:2016 (E) 2 Contents Page European foreword . 3 Introduction 4 1 Scope 5 2 Terms and definitions . 5 3 Symbols and abbreviations . 6 4 General 6 4.1 Purpose of proof testing by pressure test 6 4.2 Form of the pressure test . 6 4.3 Pressure test procedure . 7 5 Pressure equipme
11、nt . 7 5.1 Hydrostatic test 7 5.1.1 Basic rule 7 5.1.2 Specific adjustment 8 5.1.3 Creep consideration . 8 5.2 Pneumatic test 8 6 Assemblies . 9 Annex A (informative) Guidelines from the European Commission . 10 Bibliography . 12 PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 3 European foreword This doc
12、ument (CEN/TS 764-8:2016) has been prepared by Technical Committee CEN/TC 54 “Unfired pressure vessels”, the secretariat of which is held by BSI. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held
13、 responsible for identifying any or all such patent rights. This European Standard consists of eight parts, which are currently: Part 1 Vocabulary; Part 2 Quantities, symbols and units; Part 4 Establishment of technical delivery conditions for metallic materials; Part 5 Inspection documentation of m
14、etallic materials and compliance with the material specification; Part 6 Structure and content of operating instructions technical report; Part 7 Safety systems for unfired pressure equipment; Part 8 Proof test technical specification. According to the CEN-CENELEC Internal Regulations, the national
15、standards organizations of the following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lit
16、huania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 4 Introduction This document is intended to establish a common approach for the proof testing by pressur
17、e test of items of pressure equipment and assemblies, in order to fulfil the essential requirement 3.2.2 of Annex 1 of the pressure equipment directive 97/23/CE. It is intended to be used as a basis in the specific product standards, or directly by a manufacturer. It takes into account the existing
18、guidelines adopted by the European Commission, detailed in Annex A. For the determination of the pressure test value, this document provides two methods in 5.1. Further investigation will take place, in order to better specify the method to be retained in the future. The determination of the nominal
19、 design stress will be part of this analysis. CEN technical committees, which apply this document in their product standard, are encouraged to give feedback to CEN/TC 54, for the future revision of this document. PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 5 1 Scope This document specifies the purpose
20、, form and procedure of proof testing by pressure test of items of pressure equipment and assemblies. It also specifies how to determine the value of the test pressure. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE Other useful definitions
21、 can be found in EN 7641 to -7. 2.1 pressure equipment vessel, piping, safety accessory or pressure accessory with a maximum allowable pressure PS greater than 0,5 bar Note 1 to entry: Where applicable, pressure equipment includes elements attached to pressurized parts, such as flanges, nozzles, cou
22、plings, supports, lifting lugs, etc. SOURCE: Directive 97/23/CE 2.2 assembly several pieces of pressure equipment assembled by a manufacturer to constitute an integrated and functional whole SOURCE: Directive 97/23/CE 2.3 product standard standard that specifies requirements to be fulfilled by a pro
23、duct or a group of products, to establish its fitness for purpose Note 1 to entry: For this document, a product standard is a standard dealing with a pressure equipment or an assembly. SOURCE: EN 45020 2.4 maximum allowable pressure PS psmaximum pressure for which the equipment is designed, as speci
24、fied by the manufacturer Note 1 to entry: The subscript “max” is added to the symbol for maximum values. SOURCE: EN 764-1 PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 6 2.5 test pressure PT ptpressure to which the equipment is subjected for test purposes SOURCE: EN 764-1 3 Symbols and abbreviations For
25、 the purposes of this document, the symbols and abbreviations shall be in accordance with Table 1. Table 1 Symbols, descriptions and units Symbol Description Unit PS, psamaximum allowable pressure MPa bPT, ptatest pressure MPa bk cmaterial strength characteristic MPa aps or pt for calculation purpos
26、es ; PS or PT for marking purposes bMPa for calculation purpose, otherwise the unit may be bar (1 MPa = 10 bar) csubscript 20 or T is used for ambient temperature or maximum allowable temperature, respectively 4 General 4.1 Purpose of proof testing by pressure test Proof testing by pressure test sha
27、ll be a test for the pressure containment aspect, which verifies the adequacy of manufacture. In addition, it can demonstrate tightness of the equipment. NOTE 1 The proof testing by pressure test is not primarily intended to prove the design or to change material behaviour or dimensioning of the equ
28、ipment. NOTE 2 Leak tightness, in the frame of this document, only considers testing under positive hydraulic or pneumatic pressure and aims at ensuring a visually leak tight assembly without a precise quantification. If necessary, additional tightness test are conducted as per the requirements of t
29、he product standard. 4.2 Form of the pressure test For pressure equipment, the hydrostatic pressure test, as described in 5.1, shall be the standard pressure test. If this is not practical then it may be substituted by: a) a pneumatic test as described in 5.2; b) a combined hydrostatic/pneumatic tes
30、t. The manufacturer shall document the form of the pressure test in the documentation, which shall be reviewed before manufacturing commencing. For assemblies, refer to Clause 6. NOTE Local regulations may apply to the performance of pneumatic testing. PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 7 4.3
31、 Pressure test procedure Any item of pressure equipment shall be subjected to a pressure test; however items of category I may be tested on a statistical basis. The test sequence shall consist of the following: filling the equipment and pressurising it gradually; maintaining the required test pressu
32、re for a sufficient length of time; reducing the pressure for inspection where necessary; visually inspecting it to check if there has been any deterioration, deformation and/or leak resulting from the pressure test; deciding if any possible deterioration, deformation and/or leak is acceptable; then
33、, fully draining and cleaning the equipment. Items that have a value of ptless than that determined in accordance with the requirements of Clause 5, and that are not part of the pressure-bearing housing of the equipment, shall be removed or isolated during the pressure test. For assemblies, refer to
34、 Clause 6. 5 Pressure equipment 5.1 Hydrostatic test 5.1.1 Basic rule The test pressure shall be based on psand k, with possible specific adjustment as stated in 5.1.2. NOTE 1 Design takes account of maximum loadings and variation in allowable stresses across the design temperature range. This leads
35、 to selection of material grades, thicknesses and permanent joining processes. To test the adequacy of manufacture, the value of k is considered a practical parameter, which is applicable to determining the temperature related effects. The test pressure shall be determined by the greater of the foll
36、owing values for pt: T20stakkpp = or stb pp = where a and b are coefficients depending on the type of pressure equipment, defined as follows: for vessels, a = 1,25 and b = 1,43; for piping, pressure accessories, safety accessories, or items of pressure equipment constituting boilers, a and b are def
37、ined in the product standard, generally the same values as for vessels. NOTE 2 Boilers as such are considered as assemblies, covered under Clause 6. PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 8 k is defined in accordance with one of the following two methods: k is the nominal design stress of the con
38、sidered material whenever this value is determined for the design; k is a material property defined in the technical specification for the material below the creep range, to be used for the item of pressure equipment. k is either the yield strength or rupture strength as appropriate, to be decided i
39、n the product standard. NOTE 3 The above equations intentionally do not relate to the remaining thickness after corrosion has taken place. For items of pressure equipment that consists of several pressure parts (with several ratios), the smallest of the ratios in the above formula shall be used. Fur
40、ther details can be specified in the product standard. 5.1.2 Specific adjustment In specific cases, it may be necessary to adjust the basic rule to take account of more complex situations (e.g. PSmaxand TSmaxnot coincidental, compensation for water column etc.). The purpose of the adjusted rule shal
41、l still comply with 4.1 without resulting in “over-engineering”. It shall be described in the relevant product standards. For specific applications, when a pressure test at the value according to 5.1.1 is not possible, a lower pressure value may be found in the product standard with additional compe
42、nsatory measures. 5.1.3 Creep consideration Creep, when applicable, shall be taken into account in the equipment design. Due to its short duration, the pressure test can confirm the strength of equipment only with respect to the time-independent failure hazards. It cannot provide any indication on i
43、ts long-term strength, in particular on its strength against the degradation of the material with time when the service temperature lies inside the creep range. Thus, creep (i.e. creep values used for the design) shall not be taken into account for the determination of the test pressure. As a basic
44、requirement, the determination of ptshall use the values corresponding to the highest temperature at which time-independent characteristics are given in the relevant harmonized material standard. 5.2 Pneumatic test The hydrostatic test may be substituted by a pneumatic test when hydrostatic testing
45、would be harmful or impractical, for example (non-exhaustive): unacceptable presence of residual water for the process (e.g. ice) or the equipment (e.g. corrosion that may be detrimental to the stability/usability of the equipment); technical constraints like loads due to the water weight on either
46、pressure equipment, supports or the ground that would possibly cause damage; environmental constraints with respect to large amounts of water of controlled purity. PD CEN/TS 764-8:2016CEN/TS 764-8:2016 (E) 9 For pneumatic test, ptshall be determined as follows: 1) If possible, use ptas calculated in
47、 5.1, and place the equipment in a safe place like a bunker or area with restricted access. 2) If this is not feasible, lower the stored energy (normally by lowering the test pressure) for personnel safety reasons (public and manufacturers employees) and conduct additional tests of recognized value,
48、 e.g. additional NDT or complementary production test specimens. NOTE A typical value for the lowered test pressure is 1,1 x ps. 6 Assemblies As far as possible, the different items of pressure equipment of an assembly shall be pressure tested individually. When the different items of pressure equip
49、ment of an assembly are pressure tested individually, and when the piping is tested when connected to the assembly, no further proof pressure test of the assembly is necessary. For the final joints, if an additional pressure test is not feasible, the final permanent joints shall be subjected to NDT, possibly supplemented by a tightness test. Flange connections not subjected to the proof pressure test shall be tested for leak tightness. If the individual tests cannot be performed because some items cannot be isolated or tes
