SIST EN 969:2009

SLOVENSKI STANDARD
01-junij-2009
1DGRPHãþD
SIST EN 969:1998
SIST EN 969:1998/A1:1999
Cevi, fitingi in dodatki iz duktilne litine za plinovode - Zahteve in postopki
preskušanja
Ductile iron pipes, fittings, accessories and their joints for gas pipelines - Requirements
and test methods
Rohre, Formstücke, Zuberhörteile aus duktilem Gusseisen und ihre Verbindungen für
Gasleitungen - Anforderungen und Prüfverfahren
Tuyaux, raccords et accessoires en fonte ductile et leurs assemblages pour
canalisations de gaz - Prescriptions et méthodes d'essai
Ta slovenski standard je istoveten z: EN 969:2009
ICS:
77.140.75 Jeklene cevi in cevni profili Steel pipes and tubes for
za posebne namene specific use
91.140.40 Sistemi za oskrbo s plinom Gas supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 969
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2009
ICS 23.040.10; 23.040.40 Supersedes EN 969:1995
English Version
Ductile iron pipes, fittings, accessories and their joints for gas
pipelines - Requirements and test methods
Tuyaux, raccords et accessoires en fonte ductile et leurs Rohre, Formstücke, Zuberhörteile aus duktilem Gusseisen
assemblages pour canalisations de gaz - Prescriptions et und ihre Verbindungen für Gasleitungen - Anforderungen
méthodes d'essai und Prüfverfahren
This European Standard was approved by CEN on 10 February 2009.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations 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 CEN Management Centre or to any CEN member.
This European 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 CEN Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 969:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .5
1 Scope .6
2 Normative references .6
3 Terms and definitions .7
4 Technical requirements .9
4.1 General .9
4.1.1 Ductile iron pipes and fittings .9
4.1.2 Surface condition and repair . 10
4.1.3 Types of joints and interconnection . 10
4.2 Dimensional requirements . 11
4.2.1 Wall thickness . 11
4.2.2 Diameter . 12
4.2.3 Length . 12
4.2.4 Straightness of pipes . 14
4.3 Material characteristics . 14
4.3.1 Tensile properties . 14
4.3.2 Hardness . 14
4.4 Coatings and linings for pipes . 15
4.4.1 General . 15
4.4.2 External coating of zinc with finishing layer . 16
4.5 Coatings for fittings and accessories. 16
4.5.1 General . 16
4.5.2 Paint coatings . 17
4.6 Marking of pipes and fittings . 17
4.7 Leak tightness . 18
5 Performance requirements for joints. 18
5.1 General . 18
5.2 Flexible joints . 18
5.2.1 General . 18
5.2.2 Test conditions . 19
5.2.3 Test parameters . 19
5.3 Restrained flexible joints . 20
5.4 Flanged joints as cast, screwed, welded and adjustable . 20
6 Test methods . 21
6.1 Pipe dimensions . 21
6.1.1 Wall thickness . 21
6.1.2 External diameter . 21
6.1.3 Internal diameter . 21
6.1.4 Length . 21
6.2 Straightness of pipes . 22
6.3 Tensile testing . 22
6.3.1 Samples . 22
6.3.2 Preparation of test bar . 22
6.3.3 Apparatus and test method . 23
6.3.4 Test results . 24
6.4 Brinell hardness . 24
6.5 Works leak tightness test for pipes and fittings . 24
6.5.1 General . 24
6.5.2 Centrifugally cast pipes . 24
6.5.3 Pipes not centrifugally cast and fittings . 25
6.6 Zinc mass . 25
6.7 Thickness of paint coatings . 26
7 Performance test methods . 26
7.1 Leak tightness of flexible joints to positive internal pressure . 26
7.2 Leak tightness of flexible push-in joints to positive external pressure . 27
7.3 Leak tightness and mechanical resistance of flanged joints . 28
8 Tables of dimensions . 28
8.1 Socket and spigot pipes . 28
8.2 Flanged pipes . 29
8.2.1 General . 29
8.2.2 Centrifugally cast pipes with welded flanges . 30
8.2.3 Centrifugally cast pipes with screwed flanges . 30
8.2.4 Pipes with integrally cast flanges . 30
8.3 Fittings for socketed joints . 30
8.3.1 General . 30
8.3.2 Flanged sockets . 30
8.3.3 Flanged spigots . 31
8.3.4 Collars . 32
8.3.5 Double socket 90° (1/4) bends . 33
8.3.6 Double socket 45° (1/8) bends . 33
8.3.7 Double socket 22°30' (1/16) bends . 34
8.3.8 Double socket 11°15' (1/32) bends . 35
8.3.9 All socket tees . 36
8.3.10 Double socket tees with flanged branch, DN 40 to DN 250 . 38
8.3.11 Double socket tees with flanged branch, DN 300 to DN 600. 40
8.3.12 Double socket tapers . 41
8.4 Fittings for flanged joints . 43
8.4.1 Double flanged 90° (1/4) bends . 43
8.4.2 Double flanged duckfoot 90° (1/4) bends . 43
8.4.3 Double flanged 45° (1/8) bends . 45
8.4.4 Double flanged 22°30' (1/16) bends . 46
8.4.5 Double flanged 11°15' (1/32) bends . 46
8.4.6 All-flanged tees, DN 40 to DN 250 . 47
8.4.7 All-flanged tees, DN 300 to DN 600 . 49
8.4.8 Double flanged tapers . 50
8.4.9 Blank flanges PN 10 . 51
8.4.10 Blank flanges PN 16 . 51
8.4.11 Reducing flanges PN 10. 52
8.4.12 Reducing flanges PN 16. 53
9 Evaluation of conformity . 54
9.1 General . 54
9.2 Initial performance testing . 54
9.2.1 General . 54
9.2.2 Characteristics . 54
9.2.3 Treatment of calculated values and design . 54
9.2.4 Sampling, testing and conformity criteria . 55
9.3 Factory production control (FPC) . 55
9.3.1 General . 55
9.3.2 FPC requirements for all manufacturers. 56
9.3.3 Manufacturer-specific FPC system requirements . 58
Annex A (normative) Longitudinal bending resistance of pipes . 60
Annex B (normative) Diametral stiffness of pipes . 61
Annex C (informative) Field of use, characteristics of soils . 63
Annex D (informative) Calculation method of buried pipelines, heights of cover . 64
D.1 Calculation method . 64
D.1.1 Calculation formula . 64
D.1.2 Pressure from earth loading . 64
D.1.3 Pressure from traffic loading . 65
D.1.4 Bedding factor, K . 65
D.1.5 Factor of lateral pressure, f . 65
D.1.6 Modulus of soil reaction, E' . 65
D.2 Heights of cover . 66
Annex ZA (informative) Clauses of this European Standard addressing essential requirements or
other provisions of EU Directives . 67
ZA.1 Scope and relevant characteristics . 67
ZA.2 Procedure for attestation of conformity of ductile iron pipes, fittings, accessories and
their joints for gas applications. . 69
ZA.2.1 System of attestation of conformity . 69
ZA.2.2 Declaration of conformity . 69
ZA.3 CE marking and labelling . 70
Bibliography . 73

Foreword
This document (EN 969:2009) has been prepared by Technical Committee CEN/TC 203 “Cast iron pipes,
fittings and their joints”, 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 September 2009, and conflicting national standards shall be
withdrawn at the latest by December 2010.
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 responsible for identifying any or all such patent rights.
This document supersedes EN 969:1995.
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association, and supports essential requirements of the EU Construction
Products Directive (89/106/EEC).
This European Standard is in conformity with the general requirements already established by CEN/TC 165
"Waste water engineering" in the field of sewerage.
Annex ZA includes the requirements of the mandate given under the EU Construction Products Directive
(89/106/EEC). Only if the requirements specified in Annex ZA are met, the CE marking will be effected.
For reasons of conformity with mandate M/131 “Pipes, tanks and ancillaries not in contact with water intended
for human consumption”, EN 969 has been revised by extension with Annex ZA (see Resolution CEN/BT
113/1994 and CEN/BT 63/1996) and Clause 9 for the evaluation of conformity.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

1 Scope
This European Standard specifies the requirements and associated test methods applicable to ductile iron
pipes, fittings, accessories and their joints used for the construction of pipelines outside buildings:
 to convey air or combustible gases (e.g. natural gas or town gas) at pressures up to 16 bar;
 to be installed below or above ground.
NOTE 1 A combustible gas is a gas or any fuel that is in gaseous state at a temperature of 15 °C at a pressure of 1 bar.
This European Standard applies to pipes, fittings and accessories which are:
 manufactured with socketed, flanged or spigot ends;
 normally delivered externally and internally coated;
 suitable for gas temperatures between − 15 °C and 50 °C.
This European Standard covers pipes, fittings and accessories cast by any type of foundry process or
manufactured by fabrication of cast components, as well as corresponding joints, in a size range extending
from DN 40 to DN 600 inclusive.
This European Standard specifies requirements for materials, dimensions and tolerances, mechanical
properties and standard coatings of ductile iron pipes and fittings. It also gives performance requirements for
all components including joints. Joint design and gasket shape are outside the scope of this European
Standard.
NOTE 2 In this European Standard, all pressures are relative pressures expressed in bars (100 kPa = 1 bar).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 545:2006, Ductile iron pipes, fittings, accessories and their joints for water pipelines — Requirements and
test methods
EN 681-1, Elastomeric seals — Material requirements for pipe joint seals used in water and drainage
applications — Part 1: Vulcanized rubber
EN 682, Elastomeric seals — Material requirements for seals used in pipes and fittings carrying gas and
hydrocarbon fluids
EN 1092-2, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN
designated — Part 2: Cast iron flanges
EN 10002-1, Metallic materials – Tensile testing — Part 1: Method of test at ambient temperature
EN ISO 4016, Hexagon head bolts — Product grade C (ISO 4016:1999)
EN ISO 4034, Hexagon nuts — Product grade C (ISO 4034:1999)
EN ISO 6506-1, Metallic materials — Brinell hardness test — Part 1: Test method (ISO 6506-1:2005)
EN ISO 7091, Plain washers — Normal series — Product grade C (ISO 7091:2000)
3 Terms and definitions
For the purposes of this European Standard, the following terms and definitions apply.
3.1
ductile iron
cast iron used for pipes, fittings and accessories in which graphite is present substantially in spheroidal form
3.2
pipe
casting of uniform bore, straight in axis, having either socket, spigot or flanged ends, except for flanged socket
pieces, flanged spigot pieces and collars which are classified as fittings
3.3
fitting
casting other than a pipe which allows pipeline deviation, change of direction or bore; in addition flanged
socket pieces, flanged spigot pieces and collars are also classified as fittings
3.4
accessory
any casting other than a pipe or fitting which is used in a pipeline, for example:
 glands and bolts for mechanical flexible joints (see 3.13)
 glands, bolts and locking rings for restrained flexible joints (see 3.14)
 pipe saddles for service cock connection
 adjustable flanges and flanges to be welded or screwed-on
NOTE Valves of all types are not covered by the term accessory.
3.5
flange
flat circular end of a pipe or fitting extending perpendicular to its axis, with bolt holes equally spaced on a
circle
NOTE A flange may be fixed (e.g. integrally cast or welded) or adjustable; an adjustable flange comprises a ring, in
one or several parts assembled together, which bears on an end hub and can freely rotate around the barrel axis before
jointing.
3.6
spigot
male end of a pipe or fitting
3.7
spigot end
maximum insertion depth of the spigot plus 50 mm
3.8
socket
female end of a pipe or fitting to make the connection with the spigot of the next component
3.9
gasket
sealing component of a joint
3.10
joint
connection between the ends of two pipes and/or fittings in which a gasket is used to effect a seal
3.11
flexible joint
joint which permits significant angular deflection both during and after installation and which can accept a
slight offset of the centreline
3.12
push-in flexible joint
flexible joint assembled by pushing the spigot through the gasket in the socket of the mating component
3.13
mechanical flexible joint
flexible joint in which sealing is obtained by applying pressure to the gasket by mechanical means, e.g. a
gland
3.14
restrained flexible joint
flexible joint in which a means is provided to prevent separation of the assembled joint
3.15
flanged joint
joint between two flanged ends
3.16
nominal size
DN
alphanumerical designation of size for components of a pipework system, which is used for reference
purposes. It comprises the letters DN followed by a dimensionless whole number which is indirectly related to
the physical size, in millimetres, of the bore or outside diameter of the end connections
[EN ISO 6708:1995]
3.17
nominal pressure
PN
alphanumerical designation used for reference purposes related to a combination of mechanical and
dimensional characteristics of a component of a pipework system. It comprises the letters PN followed by a
dimensionless number
[EN 1333:2006]
3.18
leak tightness test pressure
pressure applied to a component during manufacture in order to ensure its leak tightness
3.19
allowable operating pressure
PFA
maximum pressure that a component can withstand continuously in service
3.20
allowable maximum operating pressure
PMA
maximum pressure occurring from time to time, including surge, that a component is capable of withstanding
in service
3.21
allowable test pressure
PEA
maximum hydrostatic pressure that a newly installed component is capable of withstanding for a relatively
short duration, in order to insure the integrity and tightness of the pipeline
3.22
diametral stiffness of a pipe
characteristic of a pipe which allows it to resist ovalization under loading when installed
3.23
performance test
proof of design test which is done once and is repeated only after change of design
3.24
length
effective length of a pipe or fitting, as shown on the figures of Clause 8
NOTE For flanged pipes and fittings, the effective length L (l for branches) is equal to the overall length. For socketed
pipes and fittings, the effective length L (l for branches), is equal to the overall length minus the spigot insertion depth
U U
as given in the manufacturer’s catalogues.
3.25
deviation
design Iength allowance with respect to the standardized length of a pipe or a fitting
3.26
ovality
out of roundness of a pipe section; it is equal to:
 A − A 
1 2
 
 
A + A
1 2
 
where
A is the maximum axis, in millimetres;

A is the minimum axis, in millimetres.

4 Technical requirements
4.1 General
4.1.1 Ductile iron pipes and fittings
The supplier shall make available the allowable service pressure of his pipes and fittings.
Nominal sizes, thickness classes, lengths and coatings are specified in 4.1.1, 4.2.1, 4.2.3, 4.4 and 4.5
respectively. When, by agreement between manufacturer and purchaser (insofar as this agreement does not
conflict with any regulatory requirement), pipes and fittings with different wall thickness classes, lengths and/or
coatings and other types of fittings than those given in 8.3 and 8.4, are supplied with reference to this
standard, they shall comply with all the other requirements of this standard.
NOTE 1 Other types of fittings include angle branches, tees and tapers with other combinations DN × dn, etc.
The standardized nominal sizes DN of pipes and fittings are as follows: 40, 50, 60, 65, 80, 100, 125, 150, 200,
250, 300, 350, 400, 450, 500 and 600.
Annexes A and B, respectively, give the longitudinal bending resistance and the diametral stiffness of ductile
iron pipes.
NOTE 2 The maximum allowable pressure for gas application is 16 bar which gives a mechanical safety factor of at
least 2,25 * 3 = 6,75 for the DN 600 or more for smaller diameters (see Annex A of EN 545:2006 for the calculation
method).
NOTE 3 When installed and operated under the conditions for which they are designed (see Annex C and Annex D),
ductile iron pipes, fittings, accessories and their joints maintain all their functional characteristics over their operating life,
due to the constant material properties, to the stability of their cross section and to their design with high safety factors.
4.1.2 Surface condition and repair
Pipes, fittings and accessories shall be free from defects and surface imperfections which could lead to non-
compliance with Clauses 4 and 5.
When necessary, pipes and fittings may be repaired, for example by welding, in order to remove surface
imperfections and localized defects which do not extend through the entire wall thickness, provided that:
 the repairs are carried out according to the manufacturer’s written procedure;
 the repaired pipes and fittings comply with all the requirements of Clause 4 and Clause 5.
4.1.3 Types of joints and interconnection
4.1.3.1 General
Rubber gasket materials shall comply with the requirements of EN 681-1 or EN 682 depending on air or gas.
When materials other than rubber are necessary (e.g. for flanged joints), they shall comply with the
appropriate European Standard or, where no European Standard exists, the appropriate International
Standard.
4.1.3.2 Flanged joints
Flanges shall be constructed in such a way that they can be attached to flanges whose dimensions and
tolerances comply with EN 1092-2. This ensures interconnection between all flanged components (pipes,
fittings, valves, etc.) of the same PN and DN and adequate joint performance.
Bolts and nuts shall comply as a minimum with the requirements of EN ISO 4016 and EN ISO 4034 (grade
4.6). Where washers are required, they shall comply with EN ISO 7091.
Although it does not affect interconnection, the manufacturer shall state in his catalogues whether his products
are normally delivered with fixed flanges or adjustable flanges.
NOTE Flange gaskets may be one of any type given in EN 1514.
4.1.3.3 Flexible joints
Pipes and fittings with flexible joints shall comply with 4.2.2.1 for their spigot external diameter DE and their
tolerances. This offers the possibility of interconnection between components equipped with different types of
flexible joints. In addition, each type of flexible joint shall be designed to fulfil the performance requirements of
Clause 5.
NOTE 1 For interconnection with certain types of joints operating within a different tolerance range on DE, the
manufacturer’s guidance should be followed as to the means of ensuring adequate joint performance at high pressures
(e.g. measurement and selection of external diameter).
NOTE 2 For interconnection with existing pipelines which can have external diameters not in compliance with 4.2.2.1,
the manufacturer’s guidance should be followed as to the appropriate means of interconnection (e.g. adaptors).
NOTE 3 If components of different suppliers are used, care should be taken to ensure that the requirements of the
performance tests are met.
4.2 Dimensional requirements
4.2.1 Wall thickness
The nominal iron wall thickness of pipes and fittings shall be calculated as a function of the nominal size, DN,
by the following formula (K class formula), with a minimum of 6 mm for pipes and 7 mm for fittings:
e = K()0,5+ 0,001DN (1)
where
e is the nominal wall thickness, in millimetres;
DN is the nominal size;
K is a coefficient used for thickness class designation. It is selected from a series of whole numbers: e.g. 8,
9, 10, 11, 12, etc.
For pipes, the standardized thickness classes are given in 8.1. Other thicknesses are possible for pipes.
For the fittings, the thickness e given in tables and on figures of 8.3 and 8.4, is the nominal thickness
corresponding to the main part of the body. The actual thickness at any particular point requires to be
increased to meet localized high stresses depending on the shape of the casting (e.g. at internal radius of
bends, at the branch-body junction of tees, etc.).
The limit deviations on the nominal wall thickness of pipes and fittings shall be as given in Table 1. The
measurement of wall thickness shall be in accordance with 6.1.1.
Table 1 – Limit deviations on thickness of pipes and fittings
Dimensions in millimetres
Type of casting Nominal iron wall Limit deviation on the nominal wall
a
thickness
thickness
Pipes centrifugally cast ≤ 6,0 − 1,3
> 6,0 − (1,3 + 0,001 DN)
Pipes not centrifugally cast
≤ 7,0 − 2,3
and fittings
> 7,0 − (2,3 + 0,001 DN)
a
The lower limit only is given, so as to ensure sufficient resistance to internal pressure.
4.2.2 Diameter
4.2.2.1 External diameter
Subclause 8.1 specifies the values of the external diameter DE of the coated spigot ends of pipes and fittings
and their maximum allowable limit deviations, when measured using a circumferential tape in accordance with
6.1.2. These limit deviations apply to the spigot ends of all thickness classes of pipes and fittings.
NOTE 1 Certain types of flexible joints operate within a different range of tolerance (see 4.1.3.3).
For DN ≤ 300, the external diameter of the pipe barrel measured with a circumferential tape shall be such as
to allow the assembly of the joint over at least two thirds of the pipe length from the spigot when the pipe
needs to be cut on site.
For DN > 300, the above requirement applies to a minimum of 5 % of the pipes manufactured, defined by
agreement between manufacturer and purchaser insofar as any such agreement would not be in conflict with
any regulatory requirements. Such pipes shall be marked.
In addition, the ovality (see 3.26) of the spigot end of pipes and fittings shall:
 remain within the tolerance on DE (see Table 11) for DN 40 to DN 200;
 not exceed 1 % for DN 250 to DN 600.
NOTE 2 For specific projects, the purchaser should consider any requirement for pipes DN > 300 meeting the above
specification.
NOTE 3 The manufacturer’s guidance should be followed as to the necessity and means of ovality correction; certain
types of flexible joints can accept the maximum ovality without a need for spigot re-rounding prior to jointing.
4.2.2.2 Internal diameter
The nominal values of the internal diameter of centrifugally cast pipes, expressed in millimetres, are equal to
the numbers indicating their nominal size, DN.
Their lower limit deviation shall be – 10mm, which will only appear locally along the pipe length.
Compliance shall be demonstrated according to 6.1.3 or by calculation from the measurements taken for pipe
external diameter, iron wall thickness and lining thickness.
4.2.3 Length
4.2.3.1 Standardized lengths of socket and spigot pipes
Pipes shall be supplied in standardized lengths of 3 m, 5 m, 5,5 m and 6 m.
The deviations (see 3.25) on the standardized length L of pipes may be ± 100 mm.
u
Pipes shall be designed to a length taken in the range: standardized length plus or minus the permissible
deviation; they shall be manufactured to this design length plus or minus the limit deviation given in Table 4.
The manufacturer shall show his design lengths (see 3.24) in his catalogues.
The length shall be measured according to 6.1.4 and shall be within the limit deviations given in Table 4.
Of the total number of socket and spigot pipes to be supplied in each diameter, the percentage of shorter
pipes shall not exceed 10 %, in which case the length reduction shall be:
 up to 0,15 m for the pipes in which samples have been cut for testing (see 4.3);
 up to 2 m by increments of 0,5 m.
4.2.3.2 Standardized lengths of flanged pipes
Pipes shall be supplied to the standardized lengths given in Table 2.

Table 2 – Standardized lengths of flanged pipes
Dimensions in metres
a
Type of pipe
Standardized lengths L
With cast flanges 0,5 or 1 or 2 or 3
With screwed or welded flanges 2 or 3 or 4 or 5
a
See 3.24. Other lengths are available by agreement between manufacturer and purchaser.
4.2.3.3 Standardized lengths of fittings
Fittings shall be supplied to the standardized lengths as given in 8.3 and 8.4.
NOTE Two series of dimensions are shown, the series A corresponding to ISO 2531 and the series B, generally
limited up to DN 450.
The permissible deviations (see 3.25) on the standardized length of series A fittings shall be as given in
Table 3. No deviation is permitted for the fittings of series B. Fittings shall be designed to a length taken in the
range: standardized length plus or minus the permissible deviation; they shall be manufactured to this design
length plus or minus the limit deviations given in Table 4.
Table 3 – Permissible deviations on standardized lengths of fittings
Dimensions in millimetres
Type of fitting Deviation
Flanged sockets
Flanged spigots ± 25
Collars, tapers
Tees
+ 50 / − 25
Bends 90° (1/4)
± (15 + 0,03) DN
Bends 45° (1/8) ± (10 + 0,025) DN
Bends 22°30' and 11°15' (1/16 and 1/32)
± (10 + 0,02) DN
4.2.3.4 Limit deviations
The limit deviations on lengths shall be as given in Table 4.
Table 4 – Limit deviations on standardized lengths of pipes and fittings
Dimensions in millimetres
Type of castings Limit deviations
Socket and spigot pipes (full length or shortened)
− 30 / + 70
Fittings for socketed joints ± 20
a
Pipes and fittings for flanged joints
± 10
a
Smaller limit deviations are possible, but not less than ± 3 mm.
4.2.1 Straightness of pipes
Pipes shall be straight, with a maximum deviation of 0,125 % of their length.
The verification of this requirement is usually carried out by visual inspection, but in case of doubt or dispute,
the deviation may also be measured in accordance with 6.2.
4.3 Material characteristics
4.3.1 Tensile properties
Pipes, fittings and accessories of ductile iron shall have the tensile properties given in Table 5.
The tensile strength shall be tested in accordance with 6.3.
Table 5 – Tensile properties
Minimum tensile Minimum elongation after fracture, A
strength, R
m
Type of casting
MPa %
Pipes centrifugally cast 420 10
Pipes not centrifugally cast,
420 5
fittings and accessories
The 0,2 % proof stress (Rp 0,2) may be measured. It shall be not less than:
– 270 MPa when A ≥ 12 %;
– 300 MPa in other cases.
For centrifugally cast pipes, the minimum elongation after fracture shall be 7 % for thickness classes over K12.
4.3.2 Hardness
The hardness of the various components shall be such that they can be cut, drilled, tapped and/or machined
with normal tools. The reference test for hardness shall be the Brinell hardness test in accordance with 6.4.
The Brinell hardness shall not exceed 230 HBW for pipes and 250 HBW for fittings and accessories. For
components manufactured by welding, a higher Brinell hardness is allowed in the heat-affected zone of the
weld.
4.4 Coatings and linings for pipes
4.4.1 General
Unless otherwise requested, all pipes shall be delivered with an external coating of zinc with finishing layer in
accordance with 4.4.2 and an internal coating of paint in accordance with 4.5.2, or when pipes have to be
capable of carrying either gas or water, an internal cement mortar lining in conformity with EN 545.
The joint areas are generally coated as follows:
 external surface of spigots: zinc coating with finishing layer;
 flanges and sockets (face and internal surface): bituminous paint or synthetic resin paint, alone or as a
supplement to a primer or zinc coating.
The following coatings may also be supplied, depending on the external and internal conditions of use.
a) External coatings:
 zinc rich paint coating having a minimum mass of 150 g/m , with finishing layer;
 thicker metallic zinc coating having a minimum mass of 200 g/m , with finishing layer;
 polyethylene sleeve (as a supplement to the zin
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