EN 13445-3:2002/A10:2008

SLOVENSKI STANDARD
01-junij-2008
1HRJUHYDQHWODþQHSRVRGHGHO.RQVWUXLUDQMH
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 13445-3:2002/A10:2008
ICS:
23.020.30
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 13445-3:2002/A10
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2008
ICS 23.020.30
English Version
Unfired pressure vessels - Part 3: Design
Récipients sous pression non soumis à la flamme - Partie Unbefeuerte Druckbehälter - Teil 3: Konstruktion
3: Conception
This amendment A10 modifies the European Standard EN 13445-3:2002; it was approved by CEN on 27 November 2006.
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 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 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: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-3:2002/A10:2008: E
worldwide for CEN national Members.

EN 13445-3:2002/A10:2007 (E)
Contents Page
Foreword.3
Annex GA (informative) Alternative design rules for flanges and gasketed flange connections.4
GA.1 Purpose.4
GA.2 Specific definitions.4
GA.3 Specific symbols and abbreviations .5
GA.3.1 Use of figures (General) .5
GA.3.2 Subscripts .5
GA.3.3 Symbols.6
GA.4 General.22
GA.4.1 Conditions of applicability.22
GA.4.2 Mechanical model.23
GA.4.3 Calculation method.24
GA.5 Parameters.24
GA.5.0 General.24
GA.5.1 Flange parameters.25
GA.5.2 Bolt and washers parameters.28
GA.5.3 Gasket parameters.29
GA.5.4 Lever arms.32
GA.6 Forces.33
GA.6.0 General.33
GA.6.1 Loads .33
GA.6.2 Compliance of the joint .34
GA.6.3 Elastic deformations .34
GA.6.4 Actual gasket forces.35
GA.6.5 Required gasket force .35
GA.6.6 Forces in assembly condition (ΙΙΙΙ = 0) .37
GA.6.7 Forces in subsequent conditions (ΙΙ = 1, 2, 3 …).38
ΙΙ
GA.7 Load limits.38
GA.7.0 General.38
GA.7.1 Bolts.39
GA.7.2 Bolt load contact pressure and washers .39
GA.7.3 Gasket.41
GA.7.4 Integral flange, stub or collar .42
GA.7.5 Blind flange .43
GA.7.6 Loose flange with stub or collar.44
GA.8 Supplements to the method .45
GA.8.1 Dimensions of standard metric bolts .45
GA.8.2 Bolting-up methods.46
GA.8.3 Flange rotations.47
GA.9 Gasket properties.48
GA.9.1 Basic explanations .48
GA.9.2 Tables for gasket properties.51
GA.10 Bibliography.63

EN 13445-3:2002/A10:2007 (E)
Foreword
This document (EN 13445-3:2002/A10:2008) has been prepared by Technical Committee CEN/TC 54
“Unfired pressure vessels”, the secretariat of which is held by BSI.
This Amendment to the European Standard EN 13445-3:2002 shall be given the status of a national standard,
either by publication of an identical text or by endorsement, at the latest by September 2008, and conflicting
national standards shall be withdrawn at the latest by September 2008.
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 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 97/23/EC.
For relationship with EU Directive 97/23/EC, see informative Annex ZA, which is an integral part of this
document.
The document includes the text of the amendment itself. The corrected pages of EN 13445-3 will be delivered
as issue 30 of the standard.
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.

Add the following Annex GA:
EN 13445-3:2002/A10:2007 (E)
Annex GA
(informative)
Alternative design rules for flanges and gasketed flange connections
GA.1 Purpose
This annex provides a calculation method for bolted, gasketed circular flange joints. It is applicable to flanges
and bolted domed ends, and it is an alternative to the methods in Clauses 11 and 12.
Its purpose is to ensure structural integrity and leak tightness for an assembly comprising two flanges, bolts
and a gasket. Flange loadings are shown in Figure GA.3-1. Different types of bolts and gaskets are shown in
Figures GA.3-2 to GA.3-3.
This annex does not consider bolted tubesheet flange connections with two gaskets and/or two different fluid
pressures. It also does not consider flange joints with integral tubesheet-flange-connections and such with two
shells connected to a flange (jacketed vessels or pipes).
NOTE This informative Annex is a further development of the Alternative method contained in Annex G. It may be
used particularly in the case of bolted flanged connections of vessels containing gases or vapours, for which it is
necessary to fix a maximum allowable leak rate in order to protect the environment. The gasket factors contained in
Tables GA.9.1 to GA.9.6 are partially based on research results, and partially on theoretical considerations. Use of such
factors should be made with caution, with the agreement - whenever possible - of the gasket manufacturer concerned.
GA.2 Specific definitions
The following terms and definitions apply in addition to those in 11.2.
GA.2.1
integral flange
flange either integral with or welded to the shell, see Figures GA.3-4 to GA.3-8
GA.2.2
blind flange
flat closure connected by bolts, see Figure GA.3-9
GA.2.3
loose flange
separate flange-ring abutting a stub or collar, see Figure GA.3-10
GA.2.4
hub
axial extension of a flange-ring, usual connecting flange-ring to shell, see Figures GA.3-4 and GA.3-5
GA.2.5
collar or stub
abutment for a loose flange, see Figure GA.3-10
GA.2.6
load condition
application of a set of applied simultaneous loads; designated by the identifier Ι
EN 13445-3:2002/A10:2007 (E)
GA.2.7
load change
change of load condition
GA.2.8
assembly condition
as defined in 11.2 and designated by Ι = 0 in this annex
GA.2.9
subsequent condition
load condition subsequent to the assembly condition, e.g. working condition, test condition, conditions arising
during start-up and shut-down, designated by Ι = 1, 2, 3…
GA.2.10
external loads
forces and/or moments applied to the joint by attached equipment, e.g. weight or thermal expansion of pipes
GA.2.11
compliance
inverse of the stiffness of the assembly, symbol Y, units mm/N
GA.2.12
flexibility modulus
inverse of the stiffness modulus of a component, excluding the elastic constants of the material; axial; symbol
X, units 1/mm; rotational: symbol Z; units 1/mm
GA.3 Specific symbols and abbreviations
GA.3.1 Use of figures (General)
Figures GA.3-1 to GA.3-10 serve only to illustrate the notation. They are not intended to give all the detail of
different designs. They do not illustrate all possible flange types for which the method is valid.
GA.3.2 Subscripts
Subscripts to indicate parts are always large (uppercase). Subscripts to indicate properties (behaviour) may
be small (lowercase). Subscripts written in brackets (Ι and/or J) may be waived.
A for Assembly load condition, Additional (F , M )
A A
B for Bolt
C for Contact (bolt/nut/washer/flange)
E for Equivalent or effective values (cylinder, gasket pressure)
F for Flange
G for Gasket
H for Hub
for
Ι Load condition identifier, written in brackets, (Ι = 0, 1, 2, 3 …)
J for Identification for parts of the one or other side of the flange connection, or for
cases to determine tightness parameters, written in bracket, (J = 1 or 2)
L for Loose flange, Loading
M for Moment
EN 13445-3:2002/A10:2007 (E)
P for Pressure (fluid pressure)
Q for Net axial force due to pressure
R for Net axial force due to external loads (Resultant)
S for Shell, Shaft, Shear, Subsequent load condition
U for Unloading
W for Washer
X for Flange weakest cross section
X, Y, for Subscript for components of additional loads (forces, moments)
Z
for Symbol for change or difference
∆
act for Actual (real, for several times calculated values the last calculated)
av for Average
d for Design, desired
e for Effective
i for Interim (calculated, not finally)
max for Maximum (also: mx)
min for Minimum
nom for Nominal
req for Required
t for Theoretical
0 for
Zero load condition (Ι = 0, see subscript Ι), also other use

GA.3.3 Symbols
Units are given in square brackets; [-] indicates that the quantity is dimensionless (dimension [1]).
Subscripts to the symbols are written as follows:
 First subscripts specify the structural element (e.g. F for flange or G for gasket) and the kind of quantity
(e.g. 3 for diameter 3 or E for effective).
 If an element exists more than once (e.g. two different flanges, numbered by J = 1 and J = 2), their
distinction may be specified by an additional subscript (number in brackets); however it is not necessarily
given.
 The last subscript specifies the load condition (Ι). If it is written, then always in brackets; however it is not
necessarily given. In some cases the both last subscripts look as follows: (J, Ι).
A is the effective total cross-section area [mm ] of all bolts, Equation (GA.5-43);
B
A , A is the radial cross-section area [mm ] of flange ring, loose flange, Equations (GA.5-7), (GA.5-
F L
11) and (GA.5-14);
A , A is the gasket area [mm ], effective, theoretical, Equations (GA.5-67) and (GA.5-56);
Ge Gt
A is the effective area [mm ] for the axial fluid-pressure force, Equation (GA.5-69);
Q
b is the width [mm] of the chamfer or radius on a loose flange, Figure GA.3-10;
EN 13445-3:2002/A10:2007 (E)
b , b are contact widths [mm], bolt side, flange side, see GA.5.2.3 and GA.7.2.2;
CB CF
b is the contact width common for bolt and flange side of a washer [mm], Equation (GA.5-49);
CC
b , b is the effective width [mm] of a flange, loose flange, Equations (GA.5-5) to (GA.5-12);
F L
b , b , b , b are gasket widths [mm], effective, interim, plastic, theoretical, Table GA.5-1,
Ge Gi Gp Gt
Equations (GA.5-54), (GA.5-65) and (GA.5-66);
b is the effective width [mm] of a washer, Equation (GA.5-45);
W
C is the deformation modulus [MPa] for loading of the gasket at zero compressive stress
(Q = 0), see GA.9.2;
C is the rate of change of the deformation modulus [-] for loading of the gasket with
compressive stress (Q > 0), see GA.9.2;
c , c , c , c , c , c , are correction factors [-], Equations (GA.5-26), (GA.5-58), (GA.7-1) to (GA.7-3),
A B C E F G
c , c (GA.7-5), (GA.7-10), (GA.7-12), (GA.7-24) and (GA.7-30) to (GA.7-33);
M S
d is the inside diameter of the flange ring [mm] or outside diameter of the central part of a blind
flange (with thickness e ). In no case it is greater than the inside diameter of the gasket [mm],
Figures GA.3-4 to GA.3-10;
d is the average diameter of hub, thin end [mm], Figures GA.3-4 and GA.3-5;
d is the average diameter of hub, thick end [mm], Figures GA.3-4 and GA.3-5;
d is the bolt hold circle diameter [mm], Figures GA.3-4 to GA.3-10;
d is the flange outside diameter [mm], Figures GA.3-4 to GA.3-10;
d is the diameter of bolt holes [mm], Figures GA.3-4 to GA.3-10, Equations (GA.5-2) and
(GA.5-3);
d is the inside diameter of a loose flange [mm], Figure GA.3-10;
d is the diameter of the position of the reaction between a loose flange and a stub or collar
[mm], Figure GA.3-1, Equations (GA.5-75) to (GA.5-81);
d is the outside diameter of stub or collar [mm], Figure GA.3-10;
d is the diameter of a central hole in a blind flange [mm], Figure GA.3-9;
d , d , d are bolt diameters (nominal, effective, waisted) [mm], Figure GA.3-2;
B0 Be BS
d is the maximum possible outside contact diameter [mm] between bolt head or nut and
B4
flange or washer; Equation (GA.5-48) and Table GA.8-1;
d , d are extreme contact diameters (inside, outside) [mm], see GA.5.2.3 and GA.7.2.2;
C1 C2
d , d are average contact diameters [mm], bolt side, flange side, see GA.5.2.3 and GA.7.2.2;
CB CF
d , d , d are gasket contact diameters (real contact at curved surfaces, theoretical inside,
G0 G1 G2
theoretical outside) [mm], Figure GA.3-3;
d , d , d are gasket calculation diameters (effective, interim, theoretical) [mm], Figure GA.3-4,
Ge Gi Gt
Table GA.5-1;
d , d , d , d , d , d are average diameters of a part or section (designated by the subscript) [mm],
E F L S W X
Equations (GA.5-6) to (GA.5-22) and (GA.7-26) to (GA.7-46);
d , d are washer diameters (inside, outside) [mm], Figure GA.3-1, Equations (GA.5-45) to
W1 W2
(GA.5-52);
D is the deformation modulus [MPa] for loading of the gasket, see GA.9.1;
G
E is the modulus of elasticity [MPa] for unloading/reloading of the gasket, see GA.9.1;
G
E , E E , E , E are the moduli of elasticity [MPa] for bolt, flange, loose flange, shell, washer;
B F, L S W
e is the wall thickness of central plate of blind flange (inside d ) [mm], Figure GA.3-9;
0 0
EN 13445-3:2002/A10:2007 (E)
e is the minimum wall thickness at thin end of hub [mm], Figures GA.3-4, GA.3-5;
e is the wall thickness at thick end of hub [mm], Figures GA.3-4, GA.3-5;
e , e is the wall thickness of equivalent cylinder for load limit and flexibility calculations
D E
respectively [mm], Equations (GA.5-16) and (GA.5-17);
e , e is the effective axial thickness of flange, loose flange [mm], Equations (GA.5-7) to (GA.5-
F L
14);
e is the gasket axial thickness [mm], Figure GA.3-3;
G
e is the theoretical thickness; normally this is the thickness given on drawing or
Gt
specification; for an exception see NOTE in GA.5.3.1; see also Figure GA.3-3;
e is the thickness actual after all load conditions, calculated for F = 0;
G(A) G(A)
e is the thickness (height) of a nut [mm], Figure GA.3-1, Equation (GA.7-2);
N
e is the portion of the flange thickness subject to radial pressure loading [mm],
P
Figures GA.3-4 to GA.3-10;
e is the portion of the flange thickness not subject to radial pressure loading [mm],
Q
Figures GA.3-4 to GA.3-10;
e is the shell thickness [mm], Figures GA.3-4 to GA.3-10;
S
e is the washer thickness [mm], Figure GA.3-1, Equation (GA.7-14);
W
e is the flange thickness at the weakest section [mm], Figure GA.3-9, Equation (GA.7-46);
X
F is the external axial force [N], Figure GA.3-1, tensile force positive, compressive force
A
negative, F = F ;
A Z
F is the total force of all bolts [N];
B
F is the gasket force [N];
G
is the minimum gasket force in assembly condition that guarantees that the required
F
G(0),∆
gasket force is maintained in all subsequent conditions [N], Equation (GA.6-24);
F is the axial fluid pressure force [N], Equation (GA.6-1);
Q
F is the axial force resulting from F and M [N], Equation (GA.6-4);
R A B
F is the resulting shearing force [N] at the gasket, Equation (GA.6-2);
S
F , F , F are the additional forces [N] in the directions X, Y, Z, Figure GA.3-1 and GA.6.1.2;
X Y Z
f , f , f , f , f , f are the nominal design stresses [MPa] for bolts, flange, loose flange, nuts, shell,
B F L N S W
washers;
h , h , h are lever arms (gasket, hub, loose flange) [mm], Figure GA.3-1, and Equations (GA.5-
G H L
72) to (GA.5-84);
h , h , h , h , h are lever arm corrections [mm], Equations (GA.5-27) to (GA.5-30), (GA.5-38), (GA.5-
P Q R S T
39) and (GA.5-70);
h is the maximum lever arm variation for loose flanges [mm], Equations (GA.5-80) to
V
(GA.5-84);
Ι is the load condition identifier [-], for assembly condition Ι = 0, for subsequent conditions
Ι = 1, 2, 3 …;
j , j are sign numbers for moment, shear force (+1 or –1) [-], Equations (GA.7-34) and
M S
GA.7-35);
K is the modulus of elasticity [MPa] for unloading/reloading of the gasket at zero
compressive stress (Q = 0), see GA.9.1;
K is the rate of change of the modulus of elasticity [-] for unloading/reloading of the gasket
with compressive stress (Q > 0), see GA.9.1;
EN 13445-3:2002/A10:2007 (E)
k , k , k , k are correction factors [-], Equations (GA.5-31) to (GA.5-34), (GA.7-36) and (GA.7-37);
Q R M S
l , I are bolt axial dimensions [mm], Figure GA.3-2 and Equations (GA.5-44) and (GA.6-6);
B S
l is the length of hub [mm], Figures GA.3-4 and GA.3-5;
H
M1, M2, MJ is an exponent for tightness calculations [-], case 1, case 2, general (J = 1, 2), see GA.6
and GA.9;
M is the external bending moment [Nmm], Equation (GA.6-3);
B
M is the bolt assembly torque [Nmm], Equation (GA.8-5);
t
M , M , M are the additional moments [Nmm] with the vector directions X, Y, Z, related to the mid-
X Y Z
plane of the gasket, Figure GA.3-1 and GA.6.1.2;
N1, N2, NJ is an exponent for tightness calculations [-], case 1, case 2, general (J = 1, 2), see GA.6
and GA.9;
N is the number of times that the joint is re-made during the service life of the flanges,
R
Equation (GA.6-34); without of influence on results for N ≤ 10;
R
n is the number of bolts [-], Equations (GA.5-1), (GA.5-4) and GA.5.2;
B
P is the fluid pressure [MPa], internal pressure positive, external negative, see GA.6.1;
p is pitch between bolts [mm], Equation (GA.5-1);
B
p is pitch of the bolt-thread [mm], Table GA.8-1;
t
Q, Q is the mean existing effective compressive stress in gasket [MPa] in load condition No.Ι;
(Ι)
Q is the minimum required compressive stress in gasket [MPa] for assembly condition, see
A,min
GA.6.5;
Q , Q , is a gasket material parameter for tightness [MPa], defining required values for
A0 A1
Q , Q assemblage, case 0, case 1, case 2, general (J = 1, 2), see GA.6 and GA.9;
A2 AJ
Q is the mean existing compressive stress in gasket [MPa], effective in load condition No. Ι
E (Ι)
for deformation with prevented sliding on surfaces, Equations (GA.5-59) to (GA.5-63);
Q is the minimum required compressive stress in gasket [MPa] for subsequent load
S,min
conditions, see GA.6.5;
Q is the resistance of the gasket against destruction or damage [MPa], excluding support
R
by friction on the contact flange surfaces, including safety margins, which are the same
for all load conditions, see GA.9.1;
q is a parameter [-] to determine the contact widths at washers, see GA.7.2.2;
r is the radius of curvature in gasket cross section [mm], Figure GA.3-3;
S is the strength of a washer [Nmm], Equation (GA.7-14); (S corresponds to a resistance W);
W
(TP) is the tightness parameter [not dimensionless], defined in GA.9.1.2;
special values are (TP) and (TP) (maximum values for the cases 1 and 2);
1mx 2mx
t , t , t , t , t , t are design temperatures (average for the part designated by the subscript) [°C],
B F G L S W
Equation (GA.6-5);
t is the temperature of the joint at bolting-up [°C], usually +20 °C;
U
is an axial deformation of the gasket [-], used for explanation in GA.9.1, U = ∆e /e ;
G G
W , W , W are resistances (of the part or section designated by the subscript) [Nmm], Equations
F L X
(GA.7-26), (GA.7-44), (GA.7-46) and (GA.7-48);
W is a special resistance of stub or collar [Nmm], supported by the resistance of the gasket
Q
Q , Equation (GA.7-50);
R
is an auxiliary parameter [-] to find the optimum load transfer position for loose flange
x
(Ι)
EN 13445-3:2002/A10:2007 (E)
with stub or collar, see GA.5.4.2 and GA.7.6.3;
X , X ,X are axial flexibility moduli of bolts, gasket, washer [1/mm], Equations (GA.5-44),
B G W
(GA.5-53) and (GA.5-68);
Y , Y , Y , Y are axial compliances of the joint [mm/N] corresponding to loads F , F , F , F ,
B G Q R B G Q R
Equations (GA.6-8) to (GA.6-11);
Z , Z are rotational flexibility moduli of flange, loose flange [1/mm ], Equations (GA.5-35),
F L
(GA.5-36) and (GA.5-40) to (GA.5-42);
-1
are average thermal expansion coefficients [K ], averaged between t and t , t , t ,
α , α , α , α , α
0 B F G
B F G L W
t , t ;
L W
are intermediate working variables [-], Equations (GA.5-15), (GA.5-23) to (GA.5-25),
β, γ, δ, ϑ , κ,
(GA.5-79), (GA.7-28) and (GA.7-29);
λ
is the change of the gasket thickness [mm] during bolt tightening in assemblage (up to
∆e
G(0)
the end of the load condition No. 0), Equation (GA.5-63);
is the change of the gasket thickness [mm] after assemblage up to the end of load
∆e
G(Ι)
condition No. Ι, Equation (GA.5-63);
is the overall axial thermal deformation [mm] relative to assemblage in load condition
∆U
T(Ι)
No. Ι, Equation (GA.6-5);
is the overall axial elastic and thermal deformation [mm] at the gasket relative to
∆U
G(Ι)
assemblage in load condition No. Ι, Equation (GA.6-12);
are the scatter values of the initial bolt load [-] for n bolts and 1 bolt, above and below
ε , ε , ε , ε -
n+ n- 1+ 1 B
the nominal value respectively, see GA.8.2;
Θ , Θ is the rotation of flange, loose flange, due to an applied moment [-],Equations (GA.8-7)
F L
and (GA.8-8);
is the coefficient of friction at the bolts, at the gasket [-], see GA.8, GA.9;
µ , µ
B G
is a diameter ratio for blind flanges [-], Equation (GA.5-37);
ρ
are load ratios (of the part or section designated by the subscript) [-], Equations
Φ , Φ , Φ , Φ ,
B C F G
(GA.7-1), (GA.7-4), (GA.7-7) to (GA.7-9), (GA.7-23), (GA.7-25) and (GA.7-43) to
Φ , Φ , Φ
L W X
(GA.7-49);
is the angle of inclination of a sealing face [rad or deg], Figure GA.3-3, Table GA.5-1;
ϕ
G
is the angle of inclination of the connected shell [rad or deg], Figures GA.3-6, GA.3-7,
ϕ
S
with sign convention;
Ψ is the load ratio of flange ring due to radial force [-], Equation (GA.7-38);
Ψ is the particular value of Ψ[-], Table GA.7-1.
Z
EN 13445-3:2002/A10:2007 (E)
F
A
d
W2(1)
P
d h
E(1) H(1)
e
E
M
M Z
Y
M
X
F
Z
F
F
Y
X
F
G
F
B
d
3e
d h
Ge G
F
F
G
B
F
Y
F
X
F
Z d
M
X
M M
d
Y Z h
E(2) h
L
H(2)
d
W2(2)
P
F
A
Figure GA.3-1 — Applied loads and lever arms (Integral flange and loose flange)
e e e e e
e
W(2) L(2) F(2) F(1) W(1)
N
EN 13445-3:2002/A10:2007 (E)
d
d d d
BO
BO BO B0
d
B2
d
B3
Z
d
BS
d
BS
a) Hexagon headed bolt b) Stud bolt c) Waisted stud d) View on 'Z'
Figure GA.3-2 — Bolt details
l
S
l
B
l
B
l
S
l l
5t B
EN 13445-3:2002/A10:2007 (E)
d d d
Gt Gt Gt
b /2 b /2 b /2
Gt Gt Gt
b /2
b /2 b /2
Gt
Gt Gt
j
d b d d
G1 Gt G1 G1
d
d d
G0
G2 G0
d
d
G2
G2
a) b) c)
d
d d
Gt
Gt Gt
b /2 b /2
Ge Ge
j
j
d b d b
G1 Gt G1 Gt
d b
G1 Gt
d d
G2 G2
d
G2
d) e) f)
Figure GA.3-3 — Gasket details
r2
r2
G
G
r2
r2
G
e
G
e
G
e
G e
G
e
G
e
G
EN 13445-3:2002/A10:2007 (E)
d
e =e
s 1
d
d
d e
0 2
d
d
a) Tapered hub with no thickening in the bore
d
e
s
e
d
d
d e
0 2
d
d
b) Tapered hub with thickening in the bore
Figure GA.3-4 — Integral hub flange on a cylindrical shell (continued on next page)
e = e l
F p H
e l
F H
EN 13445-3:2002/A10:2007 (E)
d
e =e
1 S
d
d
d e
0 2
d
d
c) Radiused cylindrical hub
Key
1 shell
2 hub
3 ring
Figure GA.3-4 — Integral hub flange on a cylindrical shell (concluded)

e = e l
F p H
EN 13445-3:2002/A10:2007 (E)
d
e
e =e
1 S
d d
0 5t
d
d
d
Key
1 shell
2 hub
3 ring
Figure GA.3-5 — Reverse integral hub flange on a cylindrical shell

l
5t
e = e l
F p H
e
S
-
S
EN 13445-3:2002/A10:2007 (E)
d = d
S E
j
d d 2
0 5t
d
d
a) Flange at the small end of the cone
d = d
S E
j
d
d
d
d
b) Flange at the large end of the cone
Key
1 shell
2 ring
Figure GA.3-6 — Flange integral with a conical shell
+
S
e
S
l
5t
e e
P Q
e
F
e = e
F P
e
S
r
K
-
S
EN 13445-3:2002/A10:2007 (E)
d = d
S E
d
j
d
d
d
a) Domed cover
d = d
S E
j
d
5t
d
d
d
b) Insert pad
Key
1 shell
2 ring
Figure GA.3-7 — Flange integral with a spherical shell
+
S
r
K
e
S
l
5t
e = e
F P
e e
P Q
e
F
EN 13445-3:2002/A10:2007 (E)
d = d
S E
e = e = e = e
S 1 2 E
d
5 2
d
d
d
Key
1 shell
2 ring
Figure GA.3-8 — Slip-on weld flange
e = e
F P
EN 13445-3:2002/A10:2007 (E)
d
d
d
d
X
d
d
Key
1 plate
2 ring
Figure GA.3-9 — Blind flange
e
X
e
O
e
F
EN 13445-3:2002/A10:2007 (E)
d
7, max
d
7, min
d b
6 0
d
d e = e
S 1
d
d
d
a) With stub flange
d
7, max
d
7, min
d b
6 0
d
e = e
S 1
d e
0 2
d
d
d
b) With collar
Key
1 shell
2 stub/collar
3 loose flange
Figure GA.3-10 — Loose flange
e = e e
L
F P
e = e e
F P L
EN 13445-3:2002/A10:2007 (E)
GA.4 General
GA.4.1 Conditions of applicability
GA.4.1.1 Geometry
The method applies when:
 whole assembly is (in essential) axisymmetric;
 there are two similar or dissimilar flanges, or one flange and a blind flange;
 there are four or more identical, uniformly distributed bolts;
 there may be washers on one side or on both sides of the connection;
 there is a circular gasket, located within the bolt circle on smooth surfaces and compressed axially;
 flange dimensions meet the following conditions:
0,2 ≤ b /e ≤ 5,0; 0,2 ≤ b /e ≤ 5,0; (GA.4-1)
F F L L
cosϕ ≥ 1/{1 + 0,01 · d /e} (GA.4-2)
S S S
NOTE Condition (GA.4-1) need not be met for a collar in combination with a loose flange.
The following configurations are excluded from the scope of the method:
 flanges of essentially non-axisymmetric geometry, e.g. split loose flanges, oval flanges or gusset
reinforced flanges;
 flange joints having metal to metal contact between the flanges or between the flanges and a spacer ring
fitted either inside or outside the gasket or inside or outside the bolts. An example is a spiral wound
gasket on a high pressure application.
GA.4.1.2 Material characteristics
Values of nominal design stress for bolts (GA.7) shall be determined as for shells in clause 6. This is valid also
for nuts and washers.
Material properties for gaskets may be taken from GA.9.
GA.4.1.3 Loads
The method applies to the following loads:
 fluid pressure: internal or external;
 external loads: axial force and bending moment, torsional moment and shear force also;
 thermal expansion of flanges, bolts, washers and gasket.
EN 13445-3:2002/A10:2007 (E)
GA.4.2 Mechanical model
The method is based on the following mechanical model:
 The geometry of both flanges and gasket is axisymmetric. Small deviations such as those due to a finite
number of bolts are permitted.
 Flange ring cross section remains undeformed. Only circumferential stresses and strains in the ring are
considered. Radial and axial stresses in the ring are neglected. This leads to the condition (GA.4-1).
 The hub at the flange ring is treated as a conical shell with linear variable wall thickness. Material and
temperature are the same as for the flange ring.
 The shell connected to the flange may be cylindrical, conical or spherical, always with constant wall
thickness. Membrane forces are calculated for the true shape; effects of bending and shear are
calculated for a cylindrical shell; for conical and spherical shells an equivalent cylindrical shell is used.
This leads to the condition (GA.4-2).
 The gasket is in contact with the flange faces over an annular area which the method determined. The
effective radial width b of the gasket, which may be less than its true width, is calculated for the
Ge
assembly condition (Ι = 0) and assumed to be unchanged for all subsequent load conditions (Ι = 1, 2 …).
The calculation of b includes elastic rotations of both flanges, and approximate elastic and plastic
Ge
deformations of gasket.
 Deformation of the gasket is different for loading and unloading/reloading:
For loading (increasing compressive gasket stress Q, actual Q) a deformation modulus
D = C + C · Q is used which includes all possible deformations (elastic and plastic, creep also).
G 0 1
For unloading (decreasing Q) and reloading (again increasing Q) an elastic modulus
E = K + K · Q is used which includes only elastic deformations and creep and depends on the
G 0 1 max
prior reached maximum Q .
max
 Thermal and mechanical deformations of flanges, shells, bolts, washers and gasket are taken into
account.
 Deformations of the whole flange connection are calculated axisymmetric. An external bending moment is
treated as an equivalent axial force transmitted by the bolts; see GA.6.1. Deformations due to shear
forces and torsional moment are neglected.
 Load changes between load conditions cause changes in the bolt and gasket forces. These are
calculated taking account the elastic deformations of all components. For the gasket also irreversible
deformations are considered. The required initial assembly force is calculated (see GA.6) to ensure
sufficient high gasket forces in all load conditions (to ensure leak tightness).
 Load limit checks are based on limit loads of each component. Excessive plastic deformations are
prevented. The load limit for gaskets, which depends on Q , is an approximation. Torsional moment and
R
shear force are respected only with their influence on the load limit of the gasket; their influences on load
limits of shell and flange are ignored.
The following are not taken into account in the model:
 Bolt bending stiffness and bending strength. Ignoring bolt bending is a conservative simplification.
Calculated tensile stiffness of bolts includes deformation of the bolt threads within a nut or tapped hole,
see Equation (GA.5-44).
 Creep of flanges and bolts. This is due to lack of relevant material data for creep deformation.
EN 13445-3:2002/A10:2007 (E)
 Different radial deformation of the flanges. Within two equal flanges this is not relevant as the radial
deformations are equal.
GA.4.3 Calculation method
GA.4.3.1 Required checks
 The assembly bolt loads shall be sufficiently large to ensure the leak tightness requirements for all
subsequent load conditions. Additionally it is recommended to specify the procedure of assemblage with
the required parameters (e.g. torque); see GA.6.
 The load ratios for bolts and gasket and for both flanges are to be checked for all load conditions
(assembly condition included); see GA.7.
GA.4.3.2 Load cases to be calculated
 Minimum required are calculations for the assembly condition; the main working condition and the initial
test condition. (If the test shall not be repeated at any time, the calculations may be separated into two
sets: A: Working plus assemblage; B: Test plus assemblage. The stronger of both assemblages is valid.)
 If more than one regular working condition exists, all these conditions are to be calculated together with
the main working condition. (Example: Cleaning of a vessel with steam; temperature higher and fluid
pressure lower than in the main working condition.)
 If in an exceptional condition leakage shall be prevented, this condition is to be calculated together with
the main working condition; however in this case a lower safety is acceptable, e.g. as for test condition.
Such an exceptional condition may be not only one with increased fluid pressure but also one with rapid
changes of temperatures during start-up or shut-down. There may be several such exceptional
conditions.
GA.4.3.3 Working with the method
 The calculations shall be made in the corroded condition (corrosion allowances are subtracted).
 The numbering of load conditions is arbitrary; assemblage always shall be designated by Ι = 0.
 The calculations shall be made as much as possible independent on the entire different load cases
(see GA.5). For several calculations the initial gasket load F shall be known, while the subsequent
G(Ι=0)
load cases (Ι > 1) are without influence (see also GA.5).
 It is recommended to calculate all load conditions together, using tables or lists or matrices, e.g. for each
load condition one column.
GA.5 Parameters
GA.5.0 General
All the following parameters are independent on all subsequent load conditions. A few parameters depend on
the initial gasket force after bolting up.
EN 13445-3:2002/A10:2007 (E)
GA.5.1 Flange parameters
GA.5.1.0 General
If both flanges of the flange connection are different they may be designated by an additional subscript
J (J = 1, 2), written in brackets. If both flanges are of the same type and have equal dimensions the following
parameters need to calculate only once (otherwise twice).
NOTE The flange dimensions are shown in Figures GA.3-4 to GA.3-10.
Specific flange types are treated as follows:
An integral flange is calculated as an equivalent ring with rectangular cross-section, with dimensions b and
F
e , connected at diameter d to a conical hub. The conical hub with the length I at diameter d is connected to
F 2 H 1
a shell of constant wall thickness e . Conical hub and flange ring are one part of the same material; the
S
material of the shell may be different. The conical hub may be absent and the flange ring is direct connected
to the shell (d = d , I = 0).
2 1 H
A blind flange is calculated as an equivalent ring with rectangular cross-section, with dimensions b and e ,
F F
connected at diameter d to a plate of constant thickness e . It may have a central opening of diameter d . A
0 0 9
possible connected nozzle at the opening is ignored in the calculation.
A loose flange is calculated as an equivalent ring with rectangular cross-section, with dimensions b and e ,
L L
without connection to a shell. The stub or collar is treated in the same way as an integral flange.
A screwed flange is calculated as a loose flange with inside diameter equal load transmission diameter equal
average thread diameter.
GA.5.1.1 Bolt holes
The pitch between bolts is given by:
p = π · d /n (GA.5-1)
B 3 B
The effective diameter of the bolt hole is:
d = d ⋅ d /p (GA.5-2)
5e 5 5 B
With blind holes, the hole diameter is assumed to be:
d = d · l /e (GA.5-3)
5 5t 5t Fb
The effective bolt circle diameter is:
d = d · (1 – 2/n) (GA.5-4)
3e 3 B
NOTE If d and n are equal for both flanges, also p and d are equal for both sides; however d may be different
3 B B 3e 5
(d ≠ d ).
5,1 5,2
GA.5.1.2 Flange ring
G.5.1.2.0 General
In Figures GA.3-4 to GA.3-10, the effective ring is indicated by chain dotted lines.
EN 13445-3:2002/A10:2007 (E)
The effective thickness e or e is the average thickness of the flange ring. It shall be obtained by dividing the
F L
radial gross cross-section area of the ring A or A (bolt holes or stud holes ignored) by the radial width of this
F L
section.
NOTE Since there are a large variety of shapes of cross sections, formulae are not given for calculation of A or A
F L
for specific flange types.
GA.5.1.2.1 Integral flange and blank flange (see Figures GA.3-4 to GA.3-9)
b = (d – d )/2 – d (GA.5-5)
F 4 0 5e
d = (d + d)/2 (GA.5-6)
F 4 0
e = 2 · A /(d – d) (GA.5-7)
F F 4 0
b = d = e = 0 (GA.5-8)
L L L
GA.5.1.2.2 Loose flange with stub or collar (see Figure GA.3-10)
b = (d – d)/2 (GA.5-9)
F 8 0
d = (d + d )/2 = d + b (GA.5-10)
F 8 0 8 F
e = 2 · A /(d – d) (GA.5-11)
F F 8 0
b = (d – d )/2 – d (GA.5-12)
L 4 6 5e
d = (d + d)/2 (GA.5-13)
L 4 6
e = 2 · A /(d – d) (GA.5-14)
L L 4 6
GA.5.1.3 Conical hub and connected shell
GA.5.1.3.1 If the flange has a conical (tapered) hub (integral with the flange ring and of the same material),
then the following parameters shall be calculated:
β = e /e (GA.5-15)
2 1
 
()β −1 ⋅I
 
H
e = e ⋅ 1+ (GA.5-16)
 
D 1
4 2 4
()β/3 ⋅(d ⋅ e) +(I)
 
1 1 H
 
 
()β −1 ⋅I
 
H
e = e ⋅ 1+ (GA.5-17)
 
E 1
()β/3 ⋅ d ⋅e +I
 
1 1 H
 
d = {min (d – e + e ; d + e – e ) + max (d + e – e ; d – e + e)}/2 (GA.5-18)
E 1 1 E 2 2 E 1 1 E 2 2 E
GA.5.1.3.2 If the flange has no hub, then the following is to be assumed:
e = e (GA.5-19)
E S
d = d (GA.5-20)
E S
EN 13445-3:2002/A10:2007 (E)
GA.5.1.3.3 For a blind flange (no connected shell) is to be assumed:
e = 0 (GA.5-21)
E
d = d (GA.5-22)
E 0
NOTE Equations (GA.5-21), (GA.5-22) apply whether the blind flange has an opening (with or without nozzle) or not.
GA.5.1.4 Flexibility-related flange parameters
NOTE When the gasket is of flat type, the parameter h below can be calculated only when d has been
Q Ge
determined, i.e. when the calculations in GA.5.3.2 has been performed.
GA.5.1.4.1 Integral flange, stub or collar
e ⋅ d
E F
γ = (GA.5-23)
b ⋅ d ⋅ cosϕ
F E S
d ⋅e
E E
ϑ = 0,550 ⋅cosϕ ⋅ (GA.5-24)
S
e
F
λ = 1− e /e = e /e (GA.5-25)
p F Q F
1+ γ ⋅ ϑ
c = (GA.5-26)
F
2 2 2 4
 
1+ γ ⋅ ϑ ⋅ 4 ⋅()1− 3 ⋅ λ + 3 ⋅ λ + 6 ⋅()1− 2 ⋅ λ ⋅ ϑ + 6 ⋅ ϑ + 3 ⋅ γ ⋅ ϑ
 
 
e
1− 2 ⋅ λ + ϑ
E
h = 1,100 ⋅ e ⋅ ⋅ (GA.5-27)
S F
d 1+ γ ⋅ ϑ
E
1− 2⋅λ − γ ⋅ϑ
h = e ⋅ (GA.5-28)
T F
1+
...