INTERNATIONAL STANDARD
Ductileironpipes fittings and accessoriesfor pressurepipelines
Tuyaux raccords et pieces accessoires en fonte ductile pour canalisations avecpression
Contents
1.1Scope1.2 Normative referencesDefinition.
Section 2: General specification
2.1 Types of joints2.2Standard iron thickness of pipes and fittings2.3 Marking.2.4Quality of pipes fittings and accessories2.5 Tolerances on joints2.6Tolerances on thickness... 32.7Manufacturinglengths2.8Deviations and tolerances on length 32.9Tolerances on the straightness of centrifugally cast pipes2..JTolerances on flanges.2.11 Tolerances on masses ..2.12 Tensile tests Test bars 42.13 Tensle tests Method and results 42.14Brinellhardness test
Section 3: Spigot and socket pipes
Section 4: Flanges
Section 5: Flanged pipes
Section 6:Fittings
2.15Maximum working pressure and internal pressure proof test2.16 Coating 2.17Inspection...... 66
3.1General - Pipes..3.2Standard working length3.3Deviations and tolerances on length .3.4Works test pressure.3.5 Dimensions and masses Class k = 9
4.1General - Flanges.4.2Tolerances on dimensions 94.3 Dimensions and drilling detrils of PN 10 flanges 104.4 Dimensions and drlling details of PN 16 flanges ... 124.5 Dimensions and drling detals of PN 25 flanges 144.6Dimensions and driling detals of PN 40 flanges 1618
5.1 General Flanged pipes 205.2Lengths and tolerances on length.
6.1General -Fittings 236.2Thickness6.3Deviations and tolerances on length6.4Works leak-tightness test 246.5Flanged socket. 246.6Flanged spigot 25266.7Collar .6.8 Double-socket 1/4 bend 276.9Double-socket 1/8 bend 276.10 Double-socket 1/16 bend 86.11Double-socket 1/32bend 86.12Double-socket tee with flanged branch 29
ISO 2531 : 1991 (E)
6.13 All-socket toe 336.14Double-sockettaper 346.15 Double-flanged taper6.16 Blank flange PN 10. 356.17 Blank flange PN 16. 366.18 Blank flange PN 25. 366.19 Blank flange PN 40.. 376.20 Reducing flange PN 10 376.21 Reducing flange PN 16 886.22 Reducing ffange PN 25 38Reducing flange PN 40 39396.24 Double-flanged 1/4 bend 406.25 Double-flanged 1/4 duckfoot bend. 406.26 Double-flanged 1/8 bend 416.27All-flangod tee 12
Foreword
ISO（the International Organizationfor Standardization）is a worldwide federation ofStandards isnormllycaried out through ISOtechnical mittees.Eachmember national standards bodies(ISOmember bodies).The work of preparingIntemationalthe right to berepresented on that mittee.International organizationsgovemmental and non-governmental in iaison with ISO also take part in the work.ISO collaborates closely with the International Electrotechnical Commission (IEC) on allmatters of electrotechnical standardization.
Draft International Standardsadopted by the technical mitteesare circulated tothe member bodies for voting.Publication as an Intemational Standard requires approval by at least 75 % of the member bodies casting a vote.
International Standard ISO2531was prepared by Technical Committee ISO/TC 5 FerroutlpeaneafifiinguCitC2Cstinieiand their joints.
constitutes a technical revision. In particular the scope has been extended to cover This fourth edition cancels and replaces the third edition (ISO 2531: 1986) of which itloose flanges.
