SIST EN 13480-3:2018/A3:2020

SLOVENSKI STANDARD
01-oktober-2020
Kovinski industrijski cevovodi - 3. del: Konstruiranje in izračun - Dopolnilo A3
Metallic industrial piping - Part 3: Design and calculation
Metallische industrielle Rohrleitungen - Teil 3: Konstruktion und Berechnung
Tuyauteries industrielles métalliques - Partie 3 : Conception et calcul
Ta slovenski standard je istoveten z: EN 13480-3:2017/A3:2020
ICS:
23.040.10 Železne in jeklene cevi Iron and steel pipes
77.140.75 Jeklene cevi in cevni profili Steel pipes and tubes for
za posebne namene specific use
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13480-3:2017/A3
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2020
EUROPÄISCHE NORM
ICS 23.040.01
English Version
Metallic industrial piping - Part 3: Design and calculation
Tuyauteries industrielles métalliques - Partie 3 : Metallische industrielle Rohrleitungen - Teil 3:
Conception et calcul Konstruktion und Berechnung
This amendment A3 modifies the European Standard EN 13480-3:2017; it was approved by CEN on 12 July 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This amendment 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-CENELEC Management Centre has the
same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13480-3:2017/A3:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modification to Clause 2, Normative references . 4
2 Modification to 5.2.4, Steel castings . 4
3 Modification to Annex A, Dynamic effect . 4
4 Modification to Clause G.3, Physical properties of steels . 27
5 Introduction of a new Clause G.4, Material properties of carbon steel at elevated
temperatures . 27
6 Introduction of a new Annex R, Surveillance of components operating in the creep
range . 28
7 Modification to Bibliography . 32

European foreword
This document (EN 13480-3:2017/A3:2020) has been prepared by Technical Committee CEN/TC 267
“Industrial piping and pipelines”, 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 February 2021, and conflicting national standards shall
be withdrawn at the latest by February 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a standardization request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of
EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
EN 13480-3:2017.
This document includes the text of the amendment itself. The amended/corrected pages of
EN 13480-3:2017 will be published as Issue 4 of the European Standard.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
1 Modification to Clause 2, "Normative references"
Add the following normative reference:
“EN 12516-2:2014, Industrial valves — Shell design strength — Part 2: Calculation method for steel valve
shells”.
2 Modification to 5.2.4, "Steel castings"
Clause 5.2.4 shall read as follows:
“5.2.4 Steel castings
For steel castings, allowable stresses are specified in EN 12516-2:2014.”
3 Modification to Annex A, "Dynamic effect"
Replace the existing Annex A with the following:
Annex A
(informative)
Dynamic effect
A.1 General
A.1.1 Introduction
In addition to the static conditions and cyclic pressure and temperature loadings covered by 4.2, piping
may be subjected to a variety of dynamic loadings. Dynamic events should be considered in the design of
the piping. However, unless otherwise specified, such consideration may not require detailed analysis.
The effects of significant dynamic loads should be added to the sustained stresses in the design of the
piping. Continuous dynamic loads should be considered in a fatigue analysis.
Analysis methods are proposed in A.2.
However vibration may be more difficult to predict and recommendations for installations are also
provided in a design guidelines A.1.2.
A vibration risk assessment may be performed, based on the combined knowledge of vibration sources
and the dynamic properties of the piping system (A.2.7).
The piping system dynamic properties may also be used to judge the dynamic quality of the layout, to
locate vibration measures and damages.
A.1.2 Vibration design guidelines
A.1.2.1 General
The following guideline may be used to get a reduction in the number of pipework circuits that exceed
vibratory acceptance criteria.
Three aspects are faced to optimize the vibrational behaviour of the piping system:
— the definition of the operation of circuits;
— the recommendation for pumps, valves, and orifice plates;
— the installation of piping and their supports.
A.1.2.2 Operation of the circuit
A.1.2.2.1 Functional analysis
To minimize the potential crack initiation on small bore pipe connections to large pipes or valves, it is
essential to conduct a complete functional analysis of the system. This should include, in particular, the
periodic testing and condition monitoring during operation and the ambient environment in extreme
conditions. This procedure applies even if the operating times in some configurations are low (of the
order of a few minutes per cycle).
The adequacy of the equipment and the installation for every operational modification should be
assessed.
A.1.2.2.2 Partial flow or overflow operation
The operation of pumps with partial flow or overflow leads to significant flow fluctuations. Partial flow
or overflow refers to an operation of the pumps outside of the field of maximum efficiency (areas 1 and
2 of Figure A.1.1.1-1), in theory close to the nominal value (point 8 of Figure A.1.1.1-1), and leading to a
high fluid excitation source (curve 6 of Figure A.1.1.1-1) compared with the nominal value.

Key
X flowrate 4 basic vibration limit
Y1 head 5 best efficiency point, flowrate
Y2 vibration 6 typical vibration vs. flowrate curve showing
maximum  allowable vibration
1 allowable operating region of flow
7 head-flowrate curve
2 preferred operating region of flow
8 best efficiency point, head and flowrate
3 maximum allowable vibration limit at flow
limits
Figure A.1.1.1-1 — Relationship between flow and vibration
The operation of pumps with partial flow or overflow should be avoided. The periodic testing should be
positioned where possible in the operating conditions that are least damaging from a vibratory stand
point. When these configurations cannot be achieved, the operating times should be limited.
Pump by-passes (feedback of the discharge to the vacuum or to the tank) fitted with ahead loss unit may
be implemented, but should ensure that regulation of the flow during discharge remains close to the
nominal value. In this case, particular care should be taken to ensure that the vibratory design of these
by-pass lines comply with the rules for valves and installation.
Size the zero flow rate lines used in the context of the pump periodic testing to be on an operating level
close to the nominal value in accordance with the periodic testing rules.
The pump should have a flow rate above 70 % and below 110 % of the nominal flow rate of the pump.
If the equipment is known, the partial flow rate may possibly be defined by the manufacturer.
A.1.2.2.3 Cavitation
Cavitation is known to lead to excessive vibrations in the pipework circuits (cavitation of orifice plates,
cavitation of butterfly valves and vacuum orifice plates under vacuum conditions).
It is important to note that in cavitation conditions, the operating conditions cannot be ranked. The
experience feedback from vacuum conditions or from the operation of plants, does indeed show that
changes in vibratory levels are not correlated with the increase or decrease in cavitation indexes from
the literature
Cavitation should be prevented or at least limited. This rule is generally complied with through the choice
of equipment (A.1.2.3). However, it is absolutely necessary for the operation managers to provide the
consultants with the worst case head losses and flow rates. To this end, it should take into account all the
operating configurations (normal, disturbed, occasional, accidental, periodic testing) in accordance with
A.1.2.2.1.
The Installation Rules for water hammer recommendations concerning the cavitation should be applied.
A.1.2.2.4 Connected small bore pipes
The reduction in the number of connected small bore pipes leads directly to the reduction of the risk of
cracking by vibratory fatigue, thus the number of functional connected small bore pipes should be
minimized.
Slope reversals should be reduced so as to minimize the number of connected small bore pipes for drains
and vents.
A.1.2.2.5 Flow velocity
The following flow velocity values are recommended.
For liquids:
— Normal velocity < 3 m/s
— Exceptional velocity or pressure greater than 50 bar < 5 m/s
For air and gases:
— Flow velocity < 40 m/s
For steam as function of specific volume:
— 0,02 m /kg: 35 – 45 m/s
— 0,05 m /kg: 40 – 50 m/s
— 0,1 m /kg: 45 – 55 m/s
— 0,2 m /kg: 50 – 60 m/s
A.1.2.3 Equipment
A.1.2.3.1 Pumps and compressors
The cracking of connected small bore pipes may be due to excessive vibrations of such components. The
damage from these vibrations is amplified when they coincide with the vibratory modes of the piping.
The vibratory design rules of pumping/compression systems, should be taken into account, in particular
the non-concurrence of frequency between the pump/compressor peaks and the vibratory modes of
pump/compressor-header assemblies.
The excitation frequencies, resulting from pump speed and number of blades (for centrifugal pumps),
should be checked for their effect on the piping system by determining the natural frequencies or by
means of harmonic excitation.
Piston pumps and compressors cause strong pressure pulses inducing high vibrations. The experience
feedback shows that post installation, it is very difficult to limit the vibrations of headers and connected
small bore pipes induced by this type of component.
In general, the use of piston pumps/compressors should be avoided.
However, if strong functional requirements impose the use of this type of component, validated pulsation
dampers or acoustical filters should be proposed by the manufacturer.
In general, adding head losses in a circuit is equivalent to increasing the level of vibratory sources,
reducing efficiency and therefore increasing operating cost.
The use of orifice plates in order to adjust the pump characteristics for the pipework circuit head losses
is not recommended. However, for some pipework circuits, the opening of valves may be limited in order
to prevent the operation of pumps outside their normal range.
Furthermore, the impeller diameter reduction automatically leads to a reduction in pump performance
and an increase in the corresponding hydro acoustic source.
It is recommended to avoid where possible the use of oversized pumps leading to the pointless addition
of head losses in the pipew
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