1、STD-BSI BS EN L2bSO-ENGL 1999 lb24bb9 0778934 510 W BRITISH STANDARD Biotechnology - Performance criteria for shaft seals The European Standasd EN 126901999 has the status of a British Standard ICs 07.080; 21.140 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 12690:1999
2、 STDmBSI BS EN L2b70-ENGL 1777 lb24bb 0778735 457 m been prepared under the direction of the Sector Amd. No. Date Committee for Materiais and Chemicals, was published under the authority of the Standards Committee and cornes into effect on 15 June 1999 O BSI 06-1999 ISBN O 580 32270 X BS EN 126W1999
3、 Comments National foreword This British Standard is the English language version of EN 12690 1999. The UK participation in its preparation was entrusted to Technical Coinniittee CW58, Biotechnology, which has the responsibility to: - aid enquirers to understand the text; - present to the responsibl
4、e European committee any enquiries on the - monitor related international and European developments and promulgate interpretation, or proposals for change, and keep the UK interests informed; them in the UK. A list of organizations represented on this committee can be obtairied on request to its sec
5、retary. Cross-references The British 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 Standar
6、ds Electronic Catalogue. A British Standard does not purport to include aU 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
7、This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. STD.BS1 BS EN 12b90-ENGL L777 m lb2Libb7 077873h 373 m EUROPEAN STANDARD NORME EUR0PEE”E EUROPAISCHE NORIM EN 12690 February 1999 ICs 07.080 07.100.01 Descriptors: biotechnoloa, environmen
8、tal protection, accident prevention, work safes, hazards, contamination, microorganisms, noxious microorganisms, inspection, leaktightness, laboratory equipment, sterilization, marking, technical notices. English version Biotechnology - Perforrnance criteria for shaft se - release of microorganisms
9、after operation due to insufficient inactivation and/or removal of microorganisms when the equipment is opened or dismantled. NOTE Common causes of malfunctioning are age, loss of barrier fluid in double seals, rough shaft, incorrect fitting, incorrect specification, incorrect maintenance. 5 Perform
10、ance classes 5.1 General The shaft seal shall be classified for the following performance criteria with regard to the contained use of microorganisms: - 1eakLightness; - cleanability; - sterilizability. The performance of the shaft seal shali be determined separately for each of these criteria in ac
11、cordance with hbles 1, 2 and 3. NOTE A shaft seal can for example be in class SI-A for sterilizability, but in class LI-C for leaktightness. O BSI 061999 STD-BSI BS EN LZbSO-ENGL 1999 I Lb2LibbS 07789i.10 8/11 m Performance class for sterilizability Sterilizabilitx Index (SI) 6.2 Leaktightness The p
12、erformance classes for leaktightness of the shaft seal are given in Table 1. Table 1 - Leaktightness performance leaktightness class Leaktightness Index (LI) leakage of target microorganism not defined Description of performance class LI-B leakage) of target microorganism detected and quantified und
13、er defined conditions leakage11 of target microorganism tested under defined conditions and leakage below detection limit or Based on leakage assessment by BATNEEC (Best Available Techniques Not Entailing Excessive Costs)“ 2, Prescribed threshold value should be based on the required safety level an
14、d can for example be the detection limit of an approved BATNEEC. 6.3 Cleanability The performance classes for cleanability of the shaft seal are given in Table 2. Table 2 - Cleanabilitv Derformance Performance class for Description of performance cleanability I class Cleanability Indix (CI) I CI-A I
15、 visible soil or cleanliness I not defined I CI-B cleanabilityl) tested and quantified under defined conditions or designed with regard to specified I technical criteria CI-C I cleanabilityl) tested under defined conditions and soil below detection limit or threshold value 2, Based on assessment by
16、BATNEEC (Best Available Techniques Not Entailing Excessive Costs)* 2, Prescribed threshold value should be based on the required safety level and can for example be the detection limit of an approved BATNEEC. NOTE Cleanability applies as a performance criterion for the shaft seal where: - deposits o
17、f soil at or in the shaft seal could jeopardize the sterilization procedure if the sterilization media do not reach all parts of the shaft seal or if the required temperature is not reached; - cleaning procedures are intended to remove and inactivate microorganisms to make the shaft seal safe for ha
18、ndling without using any other sterilization or inactivation procedure. Page 5 EN 12690:1999 6.4 Sterilizability The performance classes for sterilizability of the shaft seal are given in Wle 3. Table 3 - Sterilizability performance SI-A SI-B shaft seal not suiable or not tested for reduction of via
19、ble target microorganisms shaft seal can be treated for a specified reduction of viable target microoramisms SI-C I shaft seal can be sterilized NOTE In this table the result (performance) of an inactivation procedure is described and not the way or means of achieving the result. 6.6 Use of performa
20、nce classes in equipment selection The selection of the appropriate class for performance of a shaft seal in a biotechnological process shall be made in accordance with the risk analysis as described in EN 12460. NOTE In practice the following has been found to be suitable for guidance for the usage
21、 of classes given in Tables 1, 2 and 3. if the release of microorganisms is to be minimized, a shaft seal can be used which is classified SI-B, CI-A and LI-B or better. If the release of microorganisms is to be prevented, a shaft seal can be used which is classified SI-C, CI-B and LI-C or better. if
22、 these performance classes are not used as described or are considered to be inappropriate, alternative andor additional measures are necessary e.g. procedural measures, secondary containment or disposable equipment. 6 Classieation and verincation of performance 6.1 General Shafts seals covered by t
23、his European Standard shd be classified in accordance with Tables 1,2 and 3. The performance of shaft seals is determined and verified by the manufacturer or by the user. NOTE 1 Under certain circumstances the user might reclassify the shaft seal. If for example the shaft seal could comply with ster
24、ilizability class SI-C but is classified SI-B because the manufacturer has done only a simple test, the user can reclassify the shaft seal to SI-C if he executes and documents the appropriate tests. * Use of BATNEEC does not mean that financial issues moderate the degree of safety. Where several met
25、hods are available, the user can choose the most convenient, provided that it gives results of the necessary qualiw. O BSI 06-1999 Page 6 EN 12690:1999 Tests shall be performed under representative process conditions. If shaft seals are manufactured in accordance with an already classified protome t
26、hey are classified in the same class as the prototype, if: - there is no change in design or materials used or - there are only minor changes that do not affect biosafety. If there are only minor changes that do not affect biosafety, the manufacturer shall document the changes and shall provide evid
27、ence to the user that these changes will not result in the need for reclassification. If, for classified existing shaft seal, parts or components are replaced by other parts or components of similar performance class, the overall classification of the shaft seal rem& the me. NOTE 2 Verification of c
28、lassification can for example be done by operating an appropriate quality assurance system (see annex C Guidance on materials, design and manufacture is given in annex A. Guidance on seal classification and applications is given in annex B. 6.2 Leaktightness The shaft seal shall be classified LI-A i
29、f no tests are executed to determine the leaktightness. To be classified U-B or LI-C, the leaktightness of a shaft seal shall be tested in accordance with EN 12298. NOTE 1 Ail shaft seals have a defined leakage rate as a function of the operating conditions. The test methods most suited to leakage m
30、easurement involve liquids with tracer materials which can be measured. Recommended test methods from annex A, Table A.l in EN 12298 for testing leaktightness of shaft seals are: 1, 2, 3, 4, 5, 7 (as a diagnostic test for prediction of vibration in rotational shafts), 8 (oniy in combination with 2),
31、 10 and 11 (only for seals which are visible), 12, 13, 14, 15, 16, 18 and 19. NOTE 2 Test of contamination of barrier fluids (gas, liquid) can be done by direct testing of barrier fluid by measurement of microorganisms or tracers in liquid or aerosols or by indirect testing by pressure loss. The sha
32、ft seal shall be classified in LI-B if the test for LI-C has resulted in a leakage above threshold value. 6.3 Cleanability The shaft seal shall be Classified CI-A if no tesis are executed to determine the cleanability or if there is visible soil after a cleaning procedure. To be classified CI-B or C
33、I-C, the cleanability of a shaft seal shall be tested in accordance with EN 12296. NOTE 1 Recommended test methods from annex B in EN 122% for testing cleanability of shaft seals are: visual inspection (B.2), swabbing the inner surfaces (B.3), sampling of the final rinse (B.4) and testing the follow
34、ing batch for contamination (B.5). Tests should be carried out under conditions anticipated for use. Test results and test conditions should be documented. 41, 51). If the cleanabity test results in a measurable amount of soil equal to or above the threshold value the shaft seal shall be classXied i
35、n CI-B, otherwise in CI-C. Alternatively the shaft seal can be classified CI-B if it is designed according to EN 1672-2 and if sirrface roughness of the metallic material applied in the shaft seal is less than or equal to Ra = 1,6 p, (defined according to EN IS0 4287 and measured according to EN IS0
36、 4288) on internal product contact areas. NOTE 2 An electrochemical surface treatment of melallic materials is preferable to a mechanical polish because it produces a smoother surface even if the Ra values are t,hc same. During this type of surface treatment, sharp peak and valley contours will be r
37、educed preferentially because of high current rates at these particular parts. Applicability of electrochemical trpatiiirnt cati depend on the type of material in use. NOTE 3 To limit the rate of abrasion of the sealing niateiial in contact with the rotational shaft, the surface roughtiess of the ro
38、tational shaft should have an Ra 0,40 p,m. Documentation containing information about surface roughness for different surfaces and drawings showhg how weil the design conforms to EN 1672-2 shall be included. Deviations from the design requirements above shall be pointed out and the reasons for the d
39、eviations shall be explained. NOTE 4 For a shaft seal with barrier fluid a scpurat,e classification can be made for the barrier side. 6.4 Sterilizability The shaft sed shall be classified SI-A if no tests are executed to determine the sterilizability To be classified SI-B or SI-C, the sterilizabilia
40、 of a shaft seal shall be tested in accordance with EN 12297 and EN 285. NOTE Recommended test methods from annex A, Table A.l in EN 12297 for testing sterilizability of shaft seals are: 1.1, 1.3, 1.4, 2.2, 2.3, 4.1, 4.2, 4.3, 4.4, 5, 6, 7.1, 7.2 and 7.3. Tests should be carried out under conditions
41、 anticipated for use. Test. results and test conditions should be documented. The inactivation or sterilization procedure shall be in accordance with the manufacturers recommendations. 7 Marking and packaging Each shaft seal shall be marked in such a way that its performance with regard to cleanabil
42、ity, sterilizability and leaktightness can be verified. If it is not practical to mark a shaft seal or a component of it (e.g. due to its size or nature) the packaging shall be marked. An unmarked shaft seal or package shall be classified LI-A, SI-A and CI-A. NOTE This marking could be for example t
43、rade mark. type number, year of production. 8 Documentation The manufacturer or supplier shall provide a written manual which details the operating procedures which enable the shaft seal to perform in accordance with its specified classification for cleanability, sterilizability and leaktightness. T
44、he user shall keep documentation which demonstrates the current performance of the shaft seal and its verification. O BSI 06-1999 STD.BS1 BS EN L269O-ENGL 1779 H Lb24bb9 0778942 697 Page 7 EN 126m1999 Annex A (informative) Guidance on materials, design and manufacture A.l General A suitable choice o
45、f shaft seal is one that provides the required degree of pressure sealing at acceptable friction and wear levels, and with acceptable leakage rates. A.2 Materiais The materid of the sed (except the sealing material itself) which can come into contact with medium is in many cases sWess steel and shou
46、ld be in accordance with EN 100881 (see annex C 15) or equivalent, appropriate for the intended use, depending upon the corrosive properties of the process fluids, barrier fluids and cleaning fluids. Materials should be chemically inert and resistant, and thermaily stable under sterilization conditi
47、ons, retaining their integrity and principal working properties during the specified lifespan. A.3 Design There should be good access for cleaning and visible inspection. Dead spaces or gaps in which soil could accumulate should be avoided. Gap length to width ratios should be sufficiently large to
48、allow free flow of cleaning fluid. Bolt holes, blind holes and other dead ends should be avoided. Exposed threads should be avoided The orientation of the seal and fittings should be such that they are selfdraining. Annex B (informative) Guidance on seal classification and applications B.1 Leaktight
49、ness Leaktightness is critical in the selection of the shaft seal type. Dynamic seals are subject to wear and, therefore, likely to leak at some point during the life of the shaft seal. The inclusion of steam tracing at positive differential pressure between the seals will prevent egress of microorganisms. A higher rating can be achieved by using a secondary containment facility, local to the seal or to the unit of process equipment which includes the seal. B.2 Cleanability A shaft seal which can not be cleaned-in-place and, therefore, has to be removed for cleaning by hand or m
