EN 13445-3:2014/A5:2018

SLOVENSKI STANDARD
01-december-2018
1HRJUHYDQHQHNXUMHQHWODþQHSRVRGHGHO.RQVWUXLUDQMH'RSROQLOR$
Unfired pressure vessels - Part 3: Design
Unbefeuerte Druckbehälter - Teil 3: Konstruktion
Récipients sous pression non soumis à la flamme - Partie 3 : Conception
Ta slovenski standard je istoveten z: EN 13445-3:2014/A5:2018
ICS:
23.020.32 7ODþQHSRVRGH Pressure vessels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13445-3:2014/A5
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2018
EUROPÄISCHE NORM
ICS 23.020.30
English Version
Unfired pressure vessels - Part 3: Design
Récipients sous pression non soumis à la flamme - Unbefeuerte Druckbehälter - Teil 3: Konstruktion
Partie 3 : Conception
This amendment A5 modifies the European Standard EN 13445-3:2014; it was approved by CEN on 4 June 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-3:2014/A5:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modification to 5.4.2, Vessels of all testing groups, pressure loading predominantly
of non-cyclic nature . 4
2 Modifications to Clause 6, Maximum allowed values of the nominal design stress for
pressure parts . 4
3 Modifications to 17.1, Purpose . 5
4 Modifications to 17.2, Specific definitions . 5
5 Modification to 17.3, Specific symbols and abbreviations . 7
6 Modifications to 17.4, Conditions of applicability . 9
7 Modification to 17.5, General . 10
8 Modifications to 17.6, Determination of allowable number of pressure cycles . 16
9 Modifications to 17.9, Testing . 23
10 Addition of a new Annex U (informative), Guidance on negligibility of additional
thermal cycles in fatigue and ratcheting assessment . 23

European foreword
This document (EN 13445-3:2014/A5:2018) has been prepared by Technical Committee CEN/TC 54
“Unfired pressure vessels”, the secretariat of which is held by BSI.
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 May 2019, and conflicting national standards shall be
withdrawn at the latest by May 2019.
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 mandate 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, see informative Annex ZA, which is an integral part of
EN 13445-3:2014.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Modification to 5.4.2, Vessels of all testing groups, pressure loading
predominantly of non-cyclic nature
Replace the whole subclause with the following one:
“
5.4.2 Vessels of all testing groups, pressure loading predominantly of non-cyclic nature
The DBF requirements specified in Clauses 7 to 16, Annexes G and J, and in Clause 19 (for testing sub-
groups 1c and 3c only) and the DBA requirements of Annex B and Annex C provide satisfactory designs
for pressure loading of non-cyclic nature, i.e. when the number of full pressure cycles or equivalent full
pressure cycles is less than or equal to 500.
n ≤ 500 (5.4-1)
eq
The equivalent number of full pressure cycles n is given by:
eq
 
∆P
i
 
nn⋅ (5.4-2)
∑
eq i
 
P
 max 
In the above equation, P is the maximum permissible pressure P calculated for the whole vessel
max max
(see 3.16) in the normal operating load case (see 5.3.2.1).
For simplification, P may be replaced by the calculation pressure P.
max
NOTE The value of 500 equivalent full pressure cycles is only a rough indication. It can be assumed that for
components with irregularities of profile, strongly varying local stress distributions, subjected to additional non-
pressure loads, fatigue damage can occur before 500 cycles.
Cyclic thermal loads can be neglected if:
— for start-up and shutdown cycles, the number shall not exceed 2 000 and the rate of temperature
change at the surface shall be less than 60 °C per hour for ferritic steel sections. The designer can
specify a higher rate of surface temperature change based on favourable/good industry experience
and practice;
— if the requirements of Annex U are satisfied for operating conditions.
If these conditions on pressure and thermal loads are met, then no fatigue analysis is necessary and the
standard requirements of non-destructive testing given in EN 13445-5 shall be applied.
If these conditions cannot be met, then a fatigue assessment is necessary according to either Clause 17
or Clause 18.”.
2 Modifications to Clause 6, Maximum allowed values of the nominal design
stress for pressure parts
In 6.1.3 delete the following:
“For testing group 4 vessels, the maximum value of the nominal design stress for the normal operating
load cases shall be multiplied by 0,9.”.
a
In Table 6-1, delete the following Footnote :
a
" For testing group 4 the nominal design stress shall be multiplied by 0,9.”;
and re-name the following footnotes accordingly.
=
3 Modifications to 17.1, Purpose
Replace the whole subclause with the following one:
“
17.1.1 This clause specifies:
— an alternative to the 500 cycles rule stated in 5.4.2 for vessels predominantly subjected to pressure
fluctuations,
— a substitute to the 500 cycles rule stated in 5.4.2 for vessels subjected additionally to thermal
gradient fluctuations, and
— rules for the simplified assessment of fatigue damage due to both pressure and thermal gradients
fluctuations.
NOTE The rules in this clause are based on simplified and conservative assumptions. More precise, less
conservative results will usually be obtained by application of Clause 18.”.
In 17.1.2, replace the first sentence with the following one:
“
17.1.2 Other cyclic loads, e.g. due to variation of external loads, are normally to be assessed according
to Clause 18. However, it is permitted to take non-pressure cyclic loads into account in this clause by:”.
In 17.1.2, replace the NOTE with the following one:
“
NOTE This clause gives information for estimating the stress ranges due to pressure and thermal loads only.
When other loads are taken into account, the determination of the corresponding stress ranges is under the
responsibility of the Manufacturer.”.
4 Modifications to 17.2, Specific definitions
Replace Definition 17.2.7 by the following:
“
17.2.7
equivalent number of full pressure cycles
number n of full pressure cycles that cause the same damage as all the applied cycles of various
eq
sources and ranges
Note 1 to entry: For pressure loading only, n is given by Formula (17.5–1).
eq
Note 2 to entry: For pressure + thermal loading, is given by Formula (17.5–4).”.
n
eq
Replace Definition 17.2.9 by the following:
“
17.2.9
range
value from maximum to minimum (stress or load) in the cycle (twice the amplitude)”.
Replace Definition 17.2.10 by the following:
“
17.2.10
pseudo-elastic stress
stress calculated assuming purely linear elastic material behaviour”.
Replace Definition 17.2.13 by the following:
“
17.2.13
pressure stress factor
factor for determination of the maximum structural stress that may occur under pressure loading in a
vessel detail, due to the geometrical configuration of component(s)”.
Add the following new definitions after Definition 17.2.13:
“
17.2.14
thermal stress factor
factor for determination of the maximum structural stress that may occur under some thermal gradient
type in a vessel detail, due to the geometrical configuration of component(s)
17.2.15
adjacent point
point to be considered for determination of the metal temperature difference on which thermal stresses
are estimated.
Note 1 to entry: They are defined as any two points:
— on the inside and outside surfaces, for a gradient through the thickness;
— along the surface within a distance for a gradient along the longitudinal and/or circumferential
1,75 D ⋅ e
directions of a shell;
— along the surface within a distance 3,5R, for a gradient along the longitudinal and/or circumferential
directions of a flat end, where R is the radius of the point at the highest temperature in the flat end.
17.2.16
metal temperature difference between adjacent points
temperature difference between adjacent points, determined by reference to the metal temperature at
these points (not the fluid temperature at these points)
17.2.17
theoretical stress concentration factor
ratio of notch stress, calculated on purely elastic basis, to structural stress at same point".
Change accordingly the numbering for Definitions 17.2.14 to 17.2.17.
Replace Definitions 17.2.16 (to be renumbered as 17.2.20) with the following one:
“
17.2.20
critical area
area where the total cumulative fatigue damage (usage factor) exceeds the value D = 0,5”.
max
5 Modification to 17.3, Specific symbols and abbreviations
Replace the whole table with the following one:
"
Symbol Description Unit
C fatigue class C (see Table 17–4) MPa
lowest fatigue class C (see 17.5.4.1) MPa
C
min
allowable number of full pressure cycles
N
eq
D total fatigue damage index, see Formula (17.7–1)
maximum allowable value of total fatigue damage index in non-critical areas
D
max
correction factor to account for influence of wall thickness on fatigue resistance
C
e
CT correction factor to account for influence of temperature on fatigue resistance
E Young's modulus of the material MPa
effective stress concentration factor
K
f
theoretical stress concentration factor
K
t
k number of pressure ranges which together form the loading specification
N allowable number of cycles obtained from the relevant fatigue design curve (suffix i
th
refers to number for i stress range, ik= 1,. )
n number of applied stress cycles
(suffix i refers to number for i th stress range, iq= 1,. )
Symbol Description Unit
equivalent number of full pressure cycles
n
eq
number of applied pressure cycles
n
P
(suffix i refers to number for i th pressure range, iq= 1,. )
i
number of applied cycles of temperature difference
n
T
(suffix j refers to number for j th range of temperature difference, kq= 1,. )
k
number of applied cycles of combined pressure + temperature difference
n
PT
(suffix k refers to number for k th range of pressure + temperature difference,
kq= 1,. )
k
R radius of the point at the highest temperature in the flat end mm
r transition radius at junction of walls mm
metal temperature difference between adjacent points (see 17.2.15) °C
T
diff
minimum operating temperature during a cycle °C
T
min
maximum operating temperature during a cycle °C
T
max
T* assumed mean cycle temperature °C
u ovality (of circular cross section of a vessel)
α ther
...