Unfired pressure vessels - Part 3: Design

Vessels on brackets- Revision of clause 16

Unbefeuerte Druckbehälter - Teil 3: Konstruktion

Récipients sous pression non soumis à la flamme - Partie 3 : Conception

Nekurjene tlačne posode - 3. del: Konstruiranje - Dopolnilo A16

General Information

Status
Not Published
Public Enquiry End Date
02-Dec-2019
Technical Committee
Current Stage
98 - Abandoned project (Adopted Project)
Start Date
24-Nov-2022
Due Date
29-Nov-2022
Completion Date
24-Nov-2022

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SLOVENSKI STANDARD
SIST EN 13445-3:2014/oprA16:2019
01-november-2019
Neogrevane (nekurjene) tlačne posode - 3. del: Konstruiranje - Dopolnilo A16
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/prA16
ICS:
23.020.32 Tlačne posode Pressure vessels
SIST EN 13445-3:2014/oprA16:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 13445-3:2014/oprA16:2019

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SIST EN 13445-3:2014/oprA16:2019


DRAFT
EUROPEAN STANDARD
EN 13445-3:2014
NORME EUROPÉENNE

EUROPÄISCHE NORM
prA16
October 2019
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 draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 54.

This draft amendment A16, if approved, will modify the European Standard EN 13445-3:2014. If this draft becomes an
amendment, 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.

This draft amendment was established by CEN 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.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.


EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-3:2014/prA16:2019 E
worldwide for CEN national Members.

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)
Contents Page
European foreword . 3
1 Modification to 7.6.5, Junctions - general . 4
2 Modification to Clause 16, Additional non-pressure loads . 4
3 Modifications to 16.6.2, Additional specific symbols and abbreviations . 4
4 Modifications to 16.6.8, Single line loads (see Figures 16.6-2 and 16.6-3) . 4
5 Modification to 16.7.5, Load limits for shell . 5
6 Modification to 16.10.1, General . 5
7 Modifications to 16.10.2, Additional specific symbols and abbreviations (see Figure
16.10-1) . 5
8 Modification to 16.10.3, Conditions of applicability. 11
9 Modifications to 16.10.4, Applied forces . 11
10 Modifications to 16.10.5, Load limits of the shell . 16
11 Addition of a new Subclause 16.10.6, Support brackets . 24
12 Addition of a new Subclause 16.10.7, Design of welds . 28
13 Modifications to 16.12.5.4.2, General condition of applicability for the types . 30
14 Modifications to 16.12.5.4.3, Checks for type 1 – Simple bearing plate . 30
15 Modifications to 16.12.5.4.4.1, Checks for the bearing plate . 31
16 Modification to 16.12.5.4.4.2, Checks for the gussets . 32
17 Modifications to 16.12.5.4.4.3, Checks of the skirt at gussets . 32
18 Modification to 16.12.5.4.5.1, Check for the bearing plate . 32
19 Modifications to 16.12.5.4.5.2, Check for top plates . 32
20 Modifications to 16.12.5.4.5.5, Checks for type 4 – Bearing plate with top ring plate . 33
21 Modifications to 16.12.5.4.5.6, Check of the skirt at top ring plate . 34
22 Addition of a new Subclause 16.15, Global loads on conical shells and conical
transitions without knuckles . 35
23 Modifications to Annex L - Basis for design rules related to additional non-pressure
loads . 41



2

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EN 13445-3:2014/prA16:2019 (E)
European foreword
This document (EN 13445-3:2014/prA16:2019) has been prepared by Technical Committee CEN/TC 54
“Unfired pressure vessels”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
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 EN 13445-
3:2014.

3

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EN 13445-3:2014/prA16:2019 (E)
1 Modification to 7.6.5, Junctions - general
Add the following NOTE:

NOTE If this requirement for the distance to another cone/cylinder junction is not fulfilled a conical shell and
conical transition without knuckles can be designed according to 16.15.”.
2 Modification to Clause 16, Additional non-pressure loads
Replace “Equation (***)” with “Formula (***)” and “Equations (***)” with “Formulae (***)”.
3 Modifications to 16.6.2, Additional specific symbols and abbreviations
Add the following definitions:

F is the resulting force due to the constant radial line load acting on a shell (see Figures 16.6.-2
L
and 16.6-3), F > 0 radial outwards, F < 0 radial inwards;
L L
M is the resulting moment due to the variable radial line load acting on a shell (see Figures 16.6-
L
2 and 16.6-3);”.
Replace the definition of υ with the following one:
1

υ is the ratio between local membrane stress and absolute value of local bending stress;”.
1
4 Modifications to 16.6.8, Single line loads (see Figures 16.6-2 and 16.6-3)
Amend Formula (16.6-14) as follows:

υλmin 0,08⋅ ;,0 20 for F > 0 and all values of M (16.6-14a)
L L
( )
11
υλ=−⋅min 0,08 ;,0 20 for F < 0 (16.6-14b)”.
L
( )
1 1
Amend Formula (16.6-18) as follows:

for F > 0 and all values of M (16.6-18a)
υλmin 0,08⋅ ;,0 30 L L
( )
11
υλ=−⋅min 0,08 ;,0 30 for FL < 0 (16.6-18b)”.
( )
1 1
Amend the last sentence in step 4) as follows:
4
=
=

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EN 13445-3:2014/prA16:2019 (E)

with bending limit stress σ from 16.6.6 with υ and υ for F and with υ and the absolute value of
b,all 1 2 L,max 1
|υ | for M .”.
2 L,max
5 Modification to 16.7.5, Load limits for shell
Amend step 4) as follows:

4) With the appropriate value of λ, and the absolute values of |υ | and |υ |, calculate the bending
1 2
limit stress from 16.6.6, Formula (16.6-6);”.
6 Modification to 16.10.1, General
Replace Subclause 16.10.1 with the following one:

This clause gives rules for the design of vertical cylindrical shells supported by brackets.
Rules for the design of the support brackets are given in 16.10.6. Four types of bracket are considered,
as shown in Figure 16.10-1. Rules for the design of vertical vessels with legs located on the dished end
are given in 16.11. The design of support legs is not included.”.
7 Modifications to 16.10.2, Additional specific symbols and abbreviations
(see Figure 16.10-1)
Replace Subclause 16.10.2 with the following one:

16.10.2 Additional specific symbols and abbreviations
The following symbols and abbreviation are in addition to those in Clause 4.
A is the cross-section area of bracket or reinforcing plate attachment weld;
w
a is the eccentricity of normal force in gusset plate (see Figure 16.10-10);
e
a is the eccentricity of applied load in gusset plate (see Figure 16.10-10);
s
a is the distance from centre of vertical force to shell or reinforcing plate (see Figure 16.10-1);
1
a is the distance from centre of resultant horizontal force to shell or reinforcing plate (see
2
Figure 16.10-7);
a is the distance from centre of vertical force to shell or reinforcing plate, measured along
3
centre-line of gusset plate (see Figure 16.10-10);
b is the width of idealized rectangular gusset plate (see Figure 16.10-10);
s
b is the width of bearing plate (see Figure 16.10-1);
1
5

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b is the width of reinforcing plate (see Figure 16.10-1);
2
b is the height of reinforcing plate (see Figure 16.10-1);
3
b is the distance between centres of gusset plates (see Figure 16.10-1);
4
b is the bolt centre-to-centre distance for type A, B or C brackets with one gusset plate or type D
5
brackets;
D is the equivalent calculation diameter (see 16.6.3);
eq
D is the cylindrical shell inside diameter;
i
d is the diameter of bolt holes;
h
E is the modulus of elasticity of gusset plate;
e is the analysis thickness of shell;
a
e is the nominal thickness of shell;
n
e is the analysis thickness of gusset plate (see Figure 16.10-1);
s
e is the analysis thickness of bearing plate (see Figure 16.10-1);
1
e is the analysis thickness of reinforcing plate (see Figure 16.10-1)
2
F is the global axial force defined in Table 22–1 as vertical force F for the different load
V
condition status, positive when acting downwards; F is the sum of F and F ;
1 2
F is the global axial force acting on the part of the vessel above underside of bearing plates,
1
positive when acting downwards;
F is the global axial force acting on the part of the vessel below underside of bearing plates,
2
positive when acting downwards; this force will normally include the weight of the vessel
contents;
F is the preloading force on one anchor bolt;
A
F is the largest bolt force on one anchor bolt due to global axial force F and global moment M ;
B A
F is the global horizontal force defined in Table 22–1 as lateral force F for the different load
H H
condition status;
F is the radial horizontal force acting at base of support bracket i, positive when acting inwards;
Hi
F is the maximum allowable radial horizontal force at base of support bracket;
Hi,max
F is the resultant horizontal force acting at base of support bracket i;
Hi,R
F is the maximum allowable resultant horizontal force at base of support bracket;
Hi,R,max
F is the tangential horizontal force acting at base of support bracket i;
Hi,T
F is the maximum allowable tangential horizontal force at base of support bracket;
Hi,T,max
6

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F is the normal force acting on gusset plate (see Figure 16.10-10);
Ns
F is the maximum allowable normal force acting on gusset plate;
Ns,max
F is the upward vertical force acting on support bracket i;
Vi
f is the nominal design stress for gusset plate as defined in Table 5.3.2.4-1 depending on load
s
condition;
f is the nominal design stress for bearing plate as defined in Table 5.3.2.4-1 depending on load
1
condition;
f is the nominal design stress for reinforcing plate as defined in Table 5.3.2.4-1 depending on
2
load condition;
f is the yield strength for gusset plate;
y
h is the vertical distance from neutral axis of support bracket to underside of bearing plate or
base of leg (see Figure 16.10-2 and Figure 16.10-6);
h is the vertical distance from underside of bearing plate to base of leg (see Figure 16.10-2);
A
h is the vertical distance from underside of bearing plate to location of horizontal neutral axis of
S
bracket joint to shell or reinforcing plate (see Figure 16.10-2);
h is the height of support bracket (see Figure 16.10-1);
1
h is the depth of support bracket measured from outside of shell or reinforcing plate (see Figure
2
16.10-1);
h is the width of contact between bearing plate and support structure (see Figure 16.10-9);
3
h is the horizontal distance from outside of shell or reinforcing plate to inner edge of gusset
4
plate at attachment to bearing plate (see Figure 16.10-10);
h is the horizontal distance from outside of shell or reinforcing plate to outer edge of gusset
5
plate at attachment to bearing plate (see Figure 16.10-10);
h is the horizontal distance from inner edge of gusset plate to centre-line of idealized
6
rectangular gusset plate at attachment to bearing plate (see Figure 16.10-10);
I is the second moment of area of cross-section of each leg about an axis yy normal to surface of
yy
vessel;
I is the second moment of area of cross-section of each leg about a horizontal axis zz parallel to
zz
surface of vessel;
k is a coefficient;
K … K are coefficients;
1 17
K is a coefficient;
1U
l is the length of idealized rectangular gusset plate (see Figure 16.10-10);
s
7

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M is the total global moment at centre-line of vessel at underside of bearing plates (see
A
16.10.4.1), defined in Table 22–1 as bending moment M for the different load condition
B
status; M is the difference between the moments M and M acting above and below
A A1 A2
underside of bearing plates;
M is the global moment at centre-line of vessel acting on the part of the vessel above underside
A1
of bearing plates;
M is the global moment at centre-line of vessel acting on the part of the vessel below underside
A2
of bearing plates;
M is the global moment at centre-line of vessel at base of legs (see 16.10.4.1);
Ab
M is the longitudinal moment acting on support bracket;
L
M is the maximum allowable longitudinal moment on support bracket;
L,max
M is the circumferential moment acting on support bracket;
U
M is the maximum allowable circumferential moment on support bracket;
U,max
n is the number of support brackets;
n is the number of bolts for each support bracket;
B
n is the number of gusset plates per support bracket;
s
P is the calculation pressure or test pressure;
1
R is the radius to outside of shell or reinforcing plate;
o
W is the elastic section modulus of bracket or reinforcing plate attachment weld in longitudinal
L
direction;
W is the elastic section modulus of bracket or reinforcing plate attachment weld in
U
circumferential direction;
β is the angle between direction of force F and a line normal to surface of shell (see Figure
Hi,max
16.10-8);
γ & γ are partial safety factors;
M0 M1
δ is the angle in radians between direction of global horizontal force F and centre-line of
H
support bracket i (see Figure 16.10-3);
λ & λ are factors;
1 2
λ is the non-dimensional slenderness of gusset plate;
3
θ is the angle between bearing plate and normal force in gusset plate (see Figure 16.10-10);
σ is the bearing pressure;
B
σ is the bending limit stress for shell;
b,all
8

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EN 13445-3:2014/prA16:2019 (E)
σ is the global membrane stress in shell in longitudinal direction;
mx
σ is the global membrane stress in shell in circumferential direction;
my
σ is the allowable stress in bracket or reinforcing plate attachment welds;
w,all
σ is the combined stress in bracket or reinforcing plate attachment welds;
w,eq
σ is the stress in bracket or reinforcing plate attachment welds due to longitudinal moment;
wL
σ is the stress in bracket or reinforcing plate attachment welds due to circumferential moment;
wU
τ is the shear stress in bracket or reinforcing plate attachment welds;
w
υ & υ are factors;
1 2
υ & υ are factors;
1U 2U
ϕ is a factor;
χ is the reduction factor.”.
Delete Figure 16.10-1 and replace with the following one at the end of Subclause 16.10.2:


(a)
9

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)

(b)

(c)

(d)
Figure 16.10-1 – Support brackets for vertical vessels”.

10

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EN 13445-3:2014/prA16:2019 (E)
8 Modification to 16.10.3, Conditions of applicability
Amend Subclause 16.10.3 as follows:

16.10.3 Conditions of applicability
The following conditions shall apply:
a) 0,001 ≤ e / D ≤ 0,05 (where e is the nominal thickness of the shell and D is obtained from 16.6.3
n eq n eq
Formula (16.6-1) for cylindrical shells);
b) For bracket supports type A, B and C (Figure 16.10-1)
0,2 ≤ b / h ≤ 1,0 ;
4 1
c) For bracket supports type D (Figure 16.10-1)
0,5 ≤ b / h ≤ 1,5 ;
1 1
d) If a reinforcing plate is applied:
1,0 ≤ e / e ≤ 1,5 ;
2 n
b / h ≤ 1,5 ;
3 1
b / b ≥ 0,6 ;
2 3
e) The bracket is connected to a cylindrical shell;
f) The vertical bracket force F acts parallel to the shell axis;
Vi
g) h / h ≥ 1/3 (see Figure 16.10-1 and Figure 16.10-9).
3 2
The following requirements and recommendations shall also be taken into account:
h) Application of more than 3 brackets requires special care during assembly to guarantee a nearly
equal loading of all brackets;
i) Special consideration should be given to the stability of vessels with two brackets;
j) Type A supports are not recommended for vessels subject to significant horizontal loads.”.
9 Modifications to 16.10.4, Applied forces
Replace Subclause 16.10.4 with the following one:

16.10.4 Applied forces
16.10.4.1 Vertical forces
The applied vertical force F on the support brackets is obtained from Formula (16.10-1) or (16.10-2).
Vi
The global axial force F and the global moment M are defined in Table 22-1 as the vertical force F and
A V
11

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EN 13445-3:2014/prA16:2019 (E)
the bending moment M for the different load conditions. For brackets fixed to a rigid structure the
B
global moment M is calculated at the elevation of the underside of the bracket bearing plate, and for
A
brackets attached to support legs the moment M in Formulae (16.10-1) and (16.10-2) shall be replaced
A
by the global moment M calculated at the elevation of the base of the legs – see Figure 16.10-2.
Ab

Key
1  location of horizontal neutral axis of bracket joint to shell or reinforcing plate
Figure 16.10-2 — Forces and moments acting on a pressure vessel
12

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EN 13445-3:2014/prA16:2019 (E)
Case 1 Case 2



Figure 16.10-3 – Locations of support brackets for calculation of forces F , F and F
Vi Hi Hi,T
For vessels with two support brackets:
M
F
A
F ± (16.10-1)
Vi
2
D +⋅2 a + e + e
( )
i 1a 2
The above formula is applicable for cases where the global moment M acts only in the plane through
A
the centres of the support brackets, and is not applicable for the general case where M can act in any
A
direction (e.g. for wind or seismic loading).
For i = 1 (on the right hand side of the vessel in Figure 16.10-2) the global moment M will produce a
A
compressive load on the support bracket and for i = 2, on the other side of the vessel M will produce a
A
tensile load.
For vessels with three or more support brackets, as shown in Figure 16.10-3:
4⋅ M
F
A
F =+⋅cosδ (16.10-2)
Vi
n 
nD⋅ +⋅2 a + e + e
( )
i 1a 2

13
=

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EN 13445-3:2014/prA16:2019 (E)
where δ is the angle between the direction of the global horizontal force F and the centre-line of
H
support bracket i, as shown on Figure 16.10-3.
For Case 1, δ (in radians) is given by:

δ= i−⋅1 (16.10-3)
( )
n
For Case 2:
π 2π
δ= +−i 1⋅ (16.10-4)
( )
nn
For vessels with three support brackets there is an additional case, as shown in Figure 16.10-4 b):
For Case 3:
π 2π
δ= +−i 1⋅ (16.10-5)
( )
23
The largest value of F will occur when i = 1 for Case 1.
Vi
16.10.4.2 Horizontal forces
The horizontal forces on each support bracket are determined from Formula (16.10-6), (16.10-7) or
(16.10-8). The global horizontal force F is defined in Table 22-1 as the lateral force F for the different
H H
load conditions.
For vessels with two support brackets:
F
H
(16.10-6)
FF
Hii,T H
n
For i = 1 (on the right hand side of the vessel in Figure 16.10-2) F will be positive (acting inwards) and
Hi
for i = 2, on the other side of the vessel F will be negative.
Hi
For vessels with three or more support brackets attached to unbraced legs:
2⋅⋅FI
H zz
F ⋅cosδ (16.10-7)
Hi
nI⋅+ I
( )
yy zz
2⋅⋅FI
H yy
F ⋅sinδ (16.10-8)
Hi ,T
nI⋅+ I
( )
yy zz
where
δ is obtained from Formula (16.10-3), (16.10-4) or (16.10-5)
I is the second moment of area of the cross-section of each leg about an axis yy normal to the
yy
surface of the vessel (see Figure 16.10-3)
14
=
=
==

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I is the second moment of area of the cross-section of each leg about an axis zz parallel to the
zz
surface of the vessel
For brackets fixed to a rigid structure use I = I = 1,0 in the above formulae.
yy zz
The largest positive value of F will occur when i = 1 for Case 1. For vessels with an even number of
Hi
brackets the largest negative value of F will occur when i = (n/2 + 1) for Case 1, and for vessels with
Hi
three brackets the largest negative value of F will occur when i = 2 for Case 2.
Hi
The resultant horizontal force F acts at an angle β to the centre-line of the bracket, as shown in Figure
Hi,R
16.10-8 b):.
2 2
F FF+ (16.10-9)
Hi ,R HiiH ,T

F
Hi ,T

β= arctan (16.10-10)

F
Hi


(a)
15
=

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EN 13445-3:2014/prA16:2019 (E)

(b)

(c)
Figure 16.10-4 – Horizontal forces for vessels with 4, 3 and 2 support brackets”.
10 Modifications to 16.10.5, Load limits of the shell
Replace Subclause 16.10.5 with the following one:

16.10.5 Load limits of the shell
For design conditions P = P as defined in 5.3.10, K = 1,25 and f = f as defined in 6.1.3 at calculation
1 2 d
temperature.
For test conditions P = P as defined in 5.3.2.3, K = 1,05 and f = f as defined in 6.1.2 and 6.1.3 at test
1 test 2 test
temperature.
16.10.5.1 Vertical force
To obtain the load limit of the shell the following procedure shall be followed:
16

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EN 13445-3:2014/prA16:2019 (E)
1) Determine the type of bracket: type A, B, C or D (see Figure 16.10-1);
2) If a reinforcing plate is applied then go to step 7;
3) Determine the parameters K , λ , υ and υ :
16 1 1 2
a) for brackets type A, B and C:
h
1
λ = (16.10-11)
1
D ⋅ e
eq a
For type A replace h with (h – e ) in the above formula.
1 1 1
1
K = (16.10-12)
16
2
0,,36+ 0 40λλ+ 0,02
11
υλmin 0,08⋅ ;,0 30 (16.10-13)
( )
11
PD⋅
1 eq
σ = (16.10-14)
my
2⋅ e
a
σ
my
υ = (16.10-15)
2
Kf⋅
2
b) for bracket type D:
b
1
λ = (16.10-16)
1
D ⋅ e
eq a
1
K = (16.10-17)
16
2
0,,36+ 0 86λ
1
υλmin 0,08⋅ ;,0 30 (16.10-18)
( )
11
 
PD⋅
4⋅ M
1 eq 1
A1
 
σδ− ⋅+F ⋅cos (16.10-19)
mx1 1
 
4⋅ e π⋅⋅D e D
a eq a eq
 

PD⋅
4⋅ M
1 eq 1
A2

σδ− ⋅−F+ ⋅cos (16.10-20)
mx2 2

4⋅ e π⋅⋅D e D
a eq a eq

σ = max σσ; (16.10-21)
( )
mx mx1 mx2
The value of σb,all must be calculated for the relevant bracket location (see step 4 below). On
and
one side of the vessel (the right hand side in Figure 16.10-2) the global moments MA1
17
=
=
=
=

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)
M will produce a compressive longitudinal stresses in the shell and on the other side of the
A2
vessel M and M will produce a tensile stresses.
A1 A2
NOTE It is conservative to use the largest absolute value of σ for all bracket locations
mx
σ
mx
(16.10-22)
υ =
2
Kf⋅
2
4) With the appropriate values of υ and υ calculate the factor K and the allowable bending limit
1 2 1
stress σ :
b,all
2
1−υ
2
K = (16.10-23)
1
2

11
22
+⋅υ υ + +⋅υ υ + 1−υ ⋅υ

( )
1 2 1 2 2 1
33

σ = KK⋅⋅ f (16.10-24)
b,all 1 2
5) Calculate the vertical distance h from the underside of the bearing plate to the location of the
S
horizontal neutral axis of the bracket joint to shell or reinforcing plate:

Figure 16.10-5 – Vertical section through bracket for calculation of location of horizontal
neutral axis
For bracket type A (bearing plate not welded to shell or reinforcing plate):
he−
( )
11
h + e (16.10-25)
S1
2
18
=

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)
For bracket types B and C (see Figure 16.10-5):
2 2 2
be⋅ +⋅n h − e ⋅ e
)
1 1 s1( 1 s
h = (16.10-26)
S
 
2⋅ be⋅ +⋅n h − e ⋅ e
( )
11 s 1 1 s
 
For bracket type D:
h
1
(16.10-27)
h =
S
2
Calculate the vertical distance h from the neutral axis of the bracket to the underside of the
bearing plate or the base of the leg (see Figure 16.10-2).
For brackets fixed to a rigid structure:
hh= (16.10-28)
S
For brackets attached to the top of unbraced support legs:
hh+ h (16.10-29)
AS
6) Calculate the longitudinal moment and the maximum allowable moment.
M= Fa⋅− F⋅ h (16.10-30)
L Vii1 H
The values of F and F are calculated for the relevant bracket location using the formulae in
Vi Hi
16.10.4.1 and 16.10.4.2.
For brackets fixed to a rigid structure the largest longitudinal moment will occur when i = 1 for
Case 1. For brackets attached to the top of unbraced support legs the largest longitudinal
moment may occur at the opposite side of the vessel, i.e. when i = (n/2 + 1) for Case 1 for vessels
with an even number of brackets, or when i = 2 for Case 2 for vessels with three brackets.

Figure 16.10-6 – Longitudinal moment on support bracket
For bracket types A, B and C:
19
=

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)
2
σ ⋅⋅eh
 
b
b1,all a
4
M ×+min1;,0 5  (16.10-31)
L,max
 
K h
16  1
For type A replace h with (h – e ) in the above formula.
1 1 1
For bracket type D:
2
σ ⋅⋅eh
b1,all a
M = (16.10-32)
L,max
K
16
For brackets without reinforcing plates go to step 11.
7) For brackets with reinforcing plates determine the parameters K , λ , υ and υ :
17 1 1 2
b
3
λ = (16.10-33)
1
D ⋅ e
eq a
1
K = (16.10-34)
17
2
0,,36+ 0 50λλ+ 0,50
11
υ min 0,08⋅λ ;,0 40 (16.10-35)
( )
1 1
PD⋅
1 eq
σ = (16.10-36)
my
2⋅ e
a
σ
my
υ = (16.10-37)
2
Kf⋅
2
8) With the appropriate values of υ and υ calculate the factor K from Formula (16.10-23) and the
1 2 1
allowable bending limit stress σ from Formula (16.10-24).
b,all
9) Calculate the vertical distance h for brackets with reinforcing plates:
S
h
1
h = (16.10-38)
S
2
Calculate the vertical distance h from Formula (16.10-28) for brackets fixed to a rigid structure,
or from Formula (16.10-29) for brackets attached to the top of unbraced support legs.
10) Calculate the longitudinal moment and the maximum allowable moment:
M= F⋅+a e− Fh⋅ (16.10-39)
( )
L Vii12 H
The values of F and F are calculated for the relevant bracket location using the formulae in
Vi Hi
16.10.4.1 and 16.10.4.2.
20
=
=

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SIST EN 13445-3:2014/oprA16:2019
EN 13445-3:2014/prA16:2019 (E)
2
σ ⋅⋅eb
b3,all a
M = (16.10-40)
L,max
K
17
11) The follo
...

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