EN 13445-3:2014/A3:2017

SLOVENSKI STANDARD
01-maj-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/A3:2017
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/A3
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2017
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 A3 modifies the European Standard EN 13445-3:2014; it was approved by CEN on 2 July 2017.

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: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-3:2014/A3:2017 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modification to Clause 15 . 4
European foreword
This document (EN 13445-3:2014/A3:2017) 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 February 2018, and conflicting national standards shall be
withdrawn at the latest by February 2018.
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(s), 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 Clause 15
Replace Clause 15 by the following:
15 Pressure vessels of rectangular section
15.1 Purpose
This clause specifies requirements for the design of unreinforced and reinforced pressure vessels of
rectangular cross-section. For fatigue, designs shall be checked against Clause 18. Thermal loads or effects
are not considered in this clause.
15.2 Specific definitions
The following terms and definitions apply in addition to those in Clause 3. The governing stresses in this
clause are not structural stress within the meaning of Clause 18.
15.2.1
membrane stress
equivalent uniform stress through the wall of the vessel, see also C.4.4.2
15.2.2
bending stress
equivalent linear distributed stress through the wall of the vessel, see also C.4.4.3
15.3 Specific symbols and abbreviations
The following symbols and abbreviations apply in addition to those in Clause 4:
a is the inside corner radius;
A is the area in vessel’s longitudinal direction without hole between stiffeners or between stiffener
walls;
A is the area A reduced by hole;
h
A is the required reinforcing area;
rf
A1 is the cross-sectional area of a reinforcing member which is attached to the short side of a vessel;
A is the cross-sectional area of a reinforcing member which is attached to the long side of the vessel;
A is cross sectional area of short side stiffener webs at corner;
w1
A is cross sectional area of long side stiffener webs at corner;
w2
A’ is the area of that part of the composite section above or below the calculation point;
A’ is the area of the reinforcement web;
web
b is the unsupported width of a flat plate between reinforcing elements, see Figure 15.6–1;
b is the weld throat dimension of the continuous weld;
cw
b is the effective width of a plate in combination with a reinforcing member, see Figure 15.6–1;
e
b is the pitch between centrelines of reinforcing members on a vessel;
R
bv is the length of side wall (either h or H);
b is the weld throat dimension of the intermittent weld;
w
C is a shape factor determined from the long and short sides of an unsupported plate between
stiffeners, see Table 15.6–2;
c is the distance from the neutral axis of a section to the outer fibre of a section and is positive when
inwards;
d is either the diameter of an opening or the inside diameter of a welded connection if attached by a
full penetration weld;
G is the shear modulus (by steel appr. E/2.6);
g is the length of an unsupported span;
g is the gap between intermittent welds;
w
h is the inside length of the long side;
h is the distance between the neutral axes of reinforcing members on the long side;
H is the inside length of the short side;
H is the distance between the neutral axes of reinforcing members on the short side;
I is the applicable second moment of area;
I , I I is the second moment of area per unit width of a plate strip;
1 2, 3
I is the second moment of area of the combined reinforcing member and plate on the short side of
the vessel;
I is the second moment of area of the combined reinforcing member and plate on the long side of the
vessel;
J , J is the stress correction factors of short vessels;
1 2
j is the distance from the neutral axis of the centroid of A’;
j is the distance from the neutral axis of the centroid of A` ;
web web
k is a factor, see Formula (15.5.2–4) or (15.6.5–5);
k is factor, see Formula (15.5.3–13);
k2 is factor, see Formula (15.5.3–14);
K is a factor for unreinforced vessel to Figure 15.5–1, see Formula (15.5.1.2–12);
Lv is the length of vessel;
L is the half length of the shorter side of vessel (see Figure 15.5–1);
L is the half length of the longer side of vessel;
L is the distance from centreline of shorter side plate to calculation point (mid of ligament or weld
x
seam) in perpendicular direction to vessel axis;
L is the distance from centreline of longer side plate to calculation point (mid of ligament or weld
y
seam) in perpendicular direction to vessel axis;
l is the length of the intermittent weld;
w
M is the bending moment at the middle of the long side in transversal direction of vessel, it is positive
A
when the outside surface of the vessel (or reinforcement) has compressive stress. It is expressed as
bending moment per unit length (in N·mm/mm);
M is the bending moment in the corner of the vessel;
BC
M is the bending moment at the middle of the short side of the vessel;
D
M is the bending moment at distance L ;
X x
M is the bending moment at distance L ;
y y
N is factor, see Formula (15.5.3–10);
p is the hole pitch along the plate length, see Figure 15.5–2;
p is the diagonal hole pitch in triangular hole pattern, see Figure 15.5–2;
s
Q is the shear force;
S is the first moment of area of short side reinforcement cross section at corner in respect to outside
surface of shell plate;
S is the first moment of area of long side reinforcement cross section at corner in respect to outside
surface of shell plate;
t is the thickness of web;
w
W is the elastic section modulus of combined cross section;
W is the plastic section modulus of combined (shell wall +stiffener) cross section:
p
α is H / h;
α is H / h ;
1 1 1
α is L / L ;
2 2 1
β is the angle between the line of the holes and the long axis, see Figure 15.5–2;
θ is an angle indicating position at the corner of a vessel, see Figure 15.5–2;
μ is ligament efficiency;
σ is bending stress;
b
σ is membrane stress;
m
ϕ is a factor, see Formula (15.5.1.2–15);
15.4 General
The formulas given in this subclause shall be used for calculation of the membrane and bending stresses in
unreinforced and reinforced rectangular pressure vessels. The total stress at the point of consideration shall
be taken as the sum of the membrane stress and the bending stress at that location.
For pressure vessels provided with doors a special analysis shall be performed to detect any deformation in
the door and the edge of the vessel.
Special care should be taken in the choice of gasket for the door.
15.5 Unreinforced vessels
15.5.1 Unreinforced vessels without a stay
15.5.1.1 General
This method applies to vessels of the type shown in Figure 15.5-1. The given formulas are applicable to
vessels with length Lv < 4h. The use of method for shorter vessels is conservative. The walls of short vessels
with length Lv < 2h may be designed acc. to requirements in cl. 15.5.5.
It is assumed that the thicknesses of the short and long sides are equal. When they are not, the method
in 15.5.3 shall be used.
15.5.1.2 Unperforated plates
Where the thickness of the smaller side is not the same as the thickness of the longer side, the calculation
method in 15.5.3 shall be used.
For unreinforced vessels conforming to Figure 15.5-1, the membrane stresses are determined from the
following formulas:
at C,
Pa+ L
( )
σ = (15.5.1.2-1)
( )
m
C
e
at D,
σ = σ
( ) ( )
m m
DC
at B,
Pa+ L
( )
σ = (15.5.1.2-2)
( )
m
B
e
at A,
σσ=
( ) ( )
mm
AB
at a corner, e.g. between B and C, it is given by:
P
σ = a++LL (15.5.1.2-3)
( )
( )
m 2 1
BC−
e

The second moment of area is given by:
I = I = e /12 (15.5.1.2-4)
1 2
Figure 15.5-1 — Unreinforced vessels
The bending stresses shall be determined from the following formulas:
at C,
e
2
σ =± 2M + P 2aL⋅− 2aL⋅+ L (15.5.1.2-5)
( )
( )
bA 2 12

C

4I
at D,
e
 2 2 
σ =± 2M + P 2aL⋅− 2aL⋅+ L − L (15.5.1.2-6)
( )
( )
bA 2 12 1
 
D
 
4I
at A,
Me
A
σ =± (15.5.1.2-7)
( )
b
A
2I
at B,
e
σ =±+2M PL (15.5.1.2-8)
( )
( )
bA 2
B
4I
at the corner,
e
 
σ =± 22M + P aL cosθθ−−L (1 sin )+ L (15.5.1.2-9)
( ) ( )
{ }
bA 2 1 2
 
BC−
 
4I
For these formulas the following shall apply:
a) the maximum value of σ is given where θ= arctan LL/ (15.5.1.2-10)
( ) ( )
b 1 2
B−C
and
b) the bending moment M per unit length, is given by:
A
M PK⋅−() (15.5.1.2-11)
A 3
where
22 2 2 3 2 2
L 6ϕ ⋅α − 3πϕ + 6ϕ +α + 3α − 6ϕ−+2 15. πα ⋅ϕ+ 6ϕ⋅α
( )
1 2 22 2 2
(15.5.1.2-12)
K =
3 2α +πϕ+ 2
( )
L
α = (15.5.1.2-13)
L
a
ϕ= (15.5.1.2-14)
L
At a location, the maximum stress shall be obtained as stated in 15.4 by summarizing the membrane and
bending stresses.
=
15.5.1.3 Perforated plates
The vessel with perforated side plates shall fulfil the requirements of unperforated plates in 15.5.1.2. Side
plate of vessel (or pipe) may be perforated by row or rows of holes. The pattern of holes placing is triangular
or square. The ligament efficiency of a perforated side plate is given by:

 
pd−
p− d 1
s
 
µ= min ; (15.5.1.3-1)
 
ppcosβ
 s 

where β is the angle of hole pattern as defined in Figure 15.5-2.
Ligament efficiency μ is used to reduce the allowable stresses in 15.5.5 of membrane and bending stresses in
perpendicular direction to vessel axis. For short vessels acc. 15.5.4 the ligament efficiency shall be minimum
of those defined both in direction of longitudinal axis and perpendicular to longitudinal axis of the vessel and
only the first part of Formula (15.5.1.3-1) shall be used.
If the pitch and diameter varies in plate, the smallest value of μ shall be chosen. The strength at single
opening, even for opening in row of holes, shall be checked acc. to chapter 15.7.

Figure 15.5-2 — Unreinforced vessels with perforated sides
If the ligament efficiency μ is at least 0,2, the membrane stresses shall be determined at point of
consideration (mid of ligament) in direction perpendicular to vessel axis from the following formulas:
On longer side
(15.5.1.3-2)
σσ=
( ) ( )
mm
yB
...