1、DEUTSCHE NORM March 2001 Mechanical seals English version of DIN EN 12756 Principal dimensions, designation and material codes DIN EN 12756 - ICs 21.140 Supersedes DIN 24960, June 1992 edition. Gleitringdichtungen - Hauptmae, Bezeichnung und Werkstoffsch Issel European Standard EN 12756 : 2000 has t
2、he status of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been prepared by CEN/TC 197 Pumps, SC 4 Rotodynamic pumps. The responsible German body involved in its preparation was the Normenausschuss Ma (Mechanical Engineering Standards Committee), Technica
3、l Committee Kreiselpumpen. hinenb I DIN 7724 and DIN 7726 are the standards corresponding to International Standard IS0 1382 referred to in clause 2 of the EN. Amendments DIN 24960, June 1992 edition, has been superseded by the specifications of EN 12756. Previous editions DIN 24960-1 : 1976-1 1 DIN
4、 24960-2: 1976-1 1 DIN 24960: 1980-06, 1992-06. National Annex NA Standards referred to (and not included in Normative references) DIN 7724 Classification of polymer materials on the basis of the effect of temperature on their mechanical behaviour - Principles and concepts DIN 7726 Cellular material
5、s - Concepts and classification EN comprises 1 O pages. No pari of this standard may be reproduced without the prior permission of Ref. No. DIN EN 12756 : 2001 -0 Y Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany, s the exclusive right of sale for German Standar
6、ds (DIN-Normen). English price group O7 Sales No. 1107 07.01 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12756 December 2000 ICs 21.140 English version Mechanical seals Principal dimensions, designation and material codes Garnitures mcaniques dtanchit - Dimensions principales, dsignation et
7、 codes matriaux Gleitringdichtungen - Hauptmae, Bezeichnung und Werkstoffschlssel This European Standard was approved by CEN on 1999-1 1-08. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a natio
8、nal standard without any alteration. Up-to-date lists and bibliographical references concerning such national stand- ards may be obtained on application to the Central Secretariat or to any CEN member. The European Standards exist in three official versions (English, French, German). A version in an
9、y 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 national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, G
10、ermany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussel
11、s O 2000. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN 12756 : 2000 E Page 2 EN 12756 : 2000 Contents Page Foreword 2 1 Scope 3 2 Normative references 3 Dimensions 4 Standard designation 8 Material key 1 O Foreword This Europe
12、an Standard has been prepared by Technical Committee CENTTC 197 “Pumps“, the secretariat of which is held by AFNOR. 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 June 2001, and conflicting natio
13、nal standards shall be withdrawn at the latest by June 2001. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, I
14、celand, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Page 3 EN 12756 : 2000 1 Scope This European Standard defines the principal dimensions for the internal installation of single and multiple mechanical seals with (rotating) spring un
15、its into the pump sealing cavity according to IS0 3069 as minimum cavity dimensions as typical for centrifugal pumps in accordance with EN 22858 and EN 733. It also gives the seal designations and material codes to be used. 2 Normative references This European Standard incorporates by dated or undat
16、ed reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when i
17、ncorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 733, End-suction centrifugal pumps, rating 10 bar with bearing bracket - Nominal duty point, main dimensions, designa tion system EN 22858, End suction centrifugal pumps (
18、rating 16 bar) - Designation, nominal duty point and dimensions (IS0 2858: 1975) IS0 1382, Rubber - Vocabulary Trilingual edition IS0 1629, Rubbers and latices - Classification, symbols IS0 2768-1, General tolerances Part 1: Tolerances for linear and angular dimensions without individual tolerance i
19、ndications IC0 3069, End suction centrifugal pumps - Dimensions of cavities for mechanical seals and for softpacking IC0 51 99, Technical specifications for centrifugal pumps - Class II IS0 9905, Technical specifications for centrifugal pumps - Class I IC0 9908, Technical specifications for centrifu
20、gal pumps Class 111 Page 4 EN 12756 : 2000 3 Dimensions The mechanical seals (abbreviation: GLRD ) ) and cavities need not correspond to the illustrations, however, the dimensions given shall be complied with. The figures show O-rings as the flexible elements but other shapes of seals may also be us
21、ed. General tolerances: IS0 2768-m 3.1 Example for a single mechanical seal2) with rotating spring unit, version N and K3) NOTE Alternative arrangements using the same dimensions can be possible. Type u without shaft step Dimensions in millimeters Il F14 2 3 Type B with shaft step Dimensions in mill
22、imeters 1 *-t 1 rounded 2 spring loaded lead face 3 seat Figure 1 - Examples for single mechanical seals based on the German terminology 2l for abbreviations concerning arrangements of shaft seals refer to IS0 51 99 3, N = Normal, K = Short Page 5 EN 12756 : 2000 3.2 Retention of the seat 3.2.1 Agai
23、nst rotation The design is at the descretion of the manufacturer or as agreed. using a radial pin Dimensions in millimeters 1 Key 1 seat using an axial pin Dimensions in millimeters Figure 2 - Retention of the seat against rotation These options are valid for both types U and B. 3.2.2 Against axial
24、movement using a securing ring and stationary seat housing (only valid for mechanical seals on the product side with multiple arrangements) Example of Type U Example of Type B Key 1 Seat housing 2 Securing ring Figure 3 - Retention of the seat against axial movement The dimension e and d, refer to t
25、he seat housing. The manufacturer of the mechanical seal has to deliver the securing ring on demand. Page 6 EN 12756 : 2000 d, H8 21 23 25 27 33 35 37 39 40 43 45 48 48 50 56 58 61 63 66 70 73 75 78 80 83 85 90 92 97 105 110 115 120 125 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 3
26、.3 Dimensions for versions N and K d, 3 4 Table 1 - Dimensions for versions N and K 4 Nominal diameter h:l Type Type 10 4 HI 1 17 - 1,2 4 Type Type UB H8 H8 26 30 28 32 30 38 32 40 38 42 40 43 42 46 43 48 46 50 48 53 50 60 53 62 Version Version Type U +0,5 - 40 Type U *0,5 - 32,5 35 - 37,5 - 40 rYPe
27、 0 r0,5 - 50 55 rYPe 0 r0,5 - 40 - 42,5 - 45 - 47.5 19 21 23 - - 12 14 16 20 22 36 27 18 20 22 24 29 31 33 - - 45 - 50 - 55 60 25 34 37 39 42 - - 28 30 32 65 42,5 50 54 33 42 53 I 62 44 49 51 54 56 - - - - 35 38 75 - 85 40 43 45 45 - 473 - 52,5 - 60 - 65 - 52.5 23 - 25 50 66 75 72 77 I 48 59 60 50 6
28、2 75 86 77 88 86 91 88 93 65 67 70 - - 57,5 - 62.5 53 55 70 58 60 72 75 77 81 - - - 63 65 95 - 70 68 - 1881 - I 70 75 I 90 I 99 I 83 80 WI 109 114 88 95 1 O0 105 - - - 75 80 85 28 - 105 - 124 129 90 - 90 95 110 75 - 1 O0 115 7 1) In order to provide a safe clearance between the mechanical seal and t
29、he seal housing, the dimensions d3 are recommended as the maximum dimensions. 2) The manufacturer of the mechanical seal may supply a shorter seal than that which corresponds to dimension 1,. In this case, the difference in lenghts should be compensated by use of a spacer, which should be supplied b
30、y the seal manufacturer. For materials sec Position 5 of material key (see clause 5). 3) Those dimensions are not defined. They may vaty, depending on the manufacturer of the mechanical seal and should therefore bc obtained from the relevant suppliers literature. Page 7 EN 12756 : 2000 3.4 Surface c
31、ondition Surface conditions shall comply to the values given in Table 2. Table 2 - Surface condition I Secondary seal material I Elastomers) I Ra2,5 I Ra0,8 Non-elastomers or optional use of Ra 1,6 Ra 0,20 elastomers and non-elastomers 1) For explanation of elastomers refer to IS0 1382; symbols for
32、rubbers and latices, refer to IS0 1629. Figure 4 - Surface location Page 8 EN 12756 : 2000 Version N=N K=K 4 Standard designation - This section sets out a coding system for use in designating single and multiple seals by seal type, by nominal dimension, by orientation, and by the classes of materia
33、ls used. The system is intended to be typical of those in current use and will help in the transfer of information between suppliers and users. It is not intended to fully and unambiguously identify facets of a seal assembly. It is intended to help to identify and group seals for recording purposes
34、and for subsequent analysis. NOTE 4.1 Schematic representation of a designation for single mechanical seals It is not a requirement of this European Standard that seals are marked with a designation derived from this system. Term Standard Characteristics I Abbreviations Material key JUUC - u=u I I T
35、ype B=B Nominal diameter Nominal diameter (A three-digit number on principle, for two-digit numbers for d a preceded zero is to be inserted) Direction of rotation of the mechanical seal R Right hand rotation L Left hand rotation S Capability of rotation in either direction t o, of the mechanical sea
36、l = clockwise rotation of the seal unit when viewed from = anticlockwise rotation of the seal unit when viewed the seat from the seat J- uuuuu I (see clause 5) tl Retention against rotation of the seat O without retention 1 with retention 4.2 Example of designation for a single mechanical seal Desig
37、nation of a single mechanical seal of normal design (N) in form U with nominal diameter d, = 43 mm (043), right hand rotation (R), with securing of the atmospheric side seat against rotation (l), material of the seal face Chromium cast steel S, material of the seat Carbon, resin-impregnated B, mater
38、ial of flexible elements Fluorocarbon rubber V, material of the spring CrNiMo steel G and material of other components CrNiMo steel G: Mechanical seal EN 12756-NU043Rl-SBVGG or for short: GLRD EN 12756-NU043RI-SBVGG Page 9 EN 12756 : 2000 4.3 Schematic representation of designation for multiple mech
39、anical seals (DI Back-to-back arrangement)4) Term Standard Characteristics I Abbreviation Matenal key Mechanical seal EN12756 -I II luuuuuu-uuuuuuuu or for short: GLRD Type B=B atmosphereside u=u I I 1 Type B=B Nominal diameter Nominal diameter d of the mechanical seal (A three digit-number on princ
40、iple, for two-digit numbers for d a preceded zero is to be inserted) Direction of rotation of the mechanical seal R Right hand rotation = clockwise rotation of the seal unit at the atmosphere side when viewed from the seat side when viewed from the seat L Left hand rotation = anticlockwise rotation
41、of the seal unit at the atmosphere S Capability of rotation in either direction Retention against rotation of the seat on atmosphere side andlor the seat on product side O without retention 1 with retention of the seat on the atmosphere side 2 with retention of the seat on the product side 3 with re
42、tention of the seat on the atmosphere side and of the seat on the product side Retention of the seat on the product side against axial movement O wthout retention D with retention (see clause 5) Positions 1 to 5 for product side Positions 1 to 3 for atmosphere side 4.4 Example of designation for a m
43、ultiple mechanical seal (Dl) Designation of a multiple mechanical seal (Dl) type UU (UU) with nominal diameter dl = 43 mm (043), capability of rotation in either direction (S), with retention against rotation of the seat on atmosphere side (l), with retention against axial movement of the seat on th
44、e product side (D) and with the material key in accordance with clause 5 (VBVG G SBV) : Mechanical seal EN 12756-UUO43S1 D-VBVGGSBV or for short: GLRD EN 12756-UUO43S1 D-VBVGGSBV NOTE Multiple mechanical seals (D1 Back-to-back arrangement) consist of single mechanical seals, version K. For multiple
45、mechanical seals (DI) with shorter length the total length is not standardized. 4, see IS0 9905 and IS0 9908 Page 10 EN 12756 : 2000 5 Material key Material of seal face Material of seat Material of flexible elements Materiai of springs Material of other components (excluding cover and shaft sleeve)
46、 Table 3 - Explanation of symbols for material versions Position l/Position 2 Material) for rubbing surfaces Seal facekeat Manufactured carbons 4 Carbon, metal-impregnated B Carbon, resin-impregnated C Other carbons Metals D Carbon steel E Cr steel F CrNi steel G CrNiMo steel H Metals with carbide c
47、oatings K Hard-coating, metallic M High-nickel alloy N Bronze P Grey cast iron R Alloyed grey cast iron S Cr cast steel T Other metals Carbide (Tungsten carbides U, silicon carbides Q, other carbides J) U1 Tungsten carbides, Co-bonded U2 Tungsten carbides, Ni-bonded U3 Tungsten carbides, CrNiMo-bond
48、ed QI Sic Q3 Sic-C-Ci, composite Q4 C-Sic, surface-siliconised J Other catbides Q2 Sic-Si Metal oxides V Aluminium oxide W Chromium oxide X Other metal oxides Plastics (PTFE. reinforced Y, other plastics Z) Y1 PTFE, glass-fibre reinforced Y2 PTFE, carbon reinforced Z Other plastics 1) For more detai
49、led data refer to mechanica Position 3 vlaterial for flexible elements3) Elastomers, not sheathed4) 3 Butyl rubber (IIR) 5 Ethylene propylene rubber (EPPM) ( Other elastomers Elastomers, sheathed W Elastomers/PTFE sheathed Von-elastomers 2 Graphite i Other non-elastomers r PTFE darious materials J various materials for flexible elements ;eals manufacturers literature Carbon steel Cr steel CrNi steel CrNiMo steel High-nickel alloy Copper-tin alloy (Bronze) Other materials Position 4/Position 5 Materials) for other components, such as springs, met
