EN 13480-3:2002/A5:2012

SLOVENSKI STANDARD
SIST EN 13480-3:2002/kFprA5:2011
01-september-2011
.RYLQVNLLQGXVWULMVNLFHYRYRGLGHO.RQVWUXLUDQMHLQL]UDþXQ
Metallic industrial piping - Part 3: Design and calculation
Industrielle metallische Rohrleitungen - Teil 3: Konstruktion und Berechnung
Tuyauteries industrielles métalliques - Partie 3: Conception et calcul
Ta slovenski standard je istoveten z: EN 13480-3:2002/FprA5
ICS:
77.140.75 Jeklene cevi in cevni profili Steel pipes and tubes for
za posebne namene specific use
SIST EN 13480-3:2002/kFprA5:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN 13480-3:2002/kFprA5:2011

SIST EN 13480-3:2002/kFprA5:2011

EUROPEAN STANDARD
FINAL DRAFT
EN 13480-3:2002
NORME EUROPÉENNE
EUROPÄISCHE NORM
FprA5
June 2011
ICS 23.040.01
English Version
Metallic industrial piping - Part 3: Design and calculation
Tuyauteries industrielles métalliques - Partie 3: Conception Industrielle metallische Rohrleitungen - Teil 3: Konstruktion
et calcul und Berechnung
This draft amendment is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee
CEN/TC 267.
This draft amendment A5, if approved, will modify the European Standard EN 13480-3:2002. 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland 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

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13480-3:2002/FprA5:2011: E
worldwide for CEN national Members.

SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
Contents Page
Foreword .5
1 Modification to Clause 2 .6
2 Modification to 3.2 .6
3 Modification to 4.1 .6
4 Modification to 4.2.3.3 .6
5 Modification to 4.2.3.4 .7
6 Modification to 4.2.5 .7
7 Modification to 4.6 .7
8 Modification to 5.2.2.1 .7
9 Modification to 5.3.2.1 .7
10 Modification to 6.4.2.1 .8
11 Modification to 6.4.5 .9
12 Modification to 6.4.6.1 . 10
13 Modification to 6.4.7.2 . 10
14 Modification to 6.4.8.1 . 10
15 Modification to 6.4.10 . 10
16 Modification to 6.6 . 11
17 Modification to 7.1.3 . 13
18 Modification to 7.2.3.3 . 13
19 Modification to 7.2.3.4 . 13
20 Modification to 8.1 . 13
21 Modification to 8.3.5 . 14
22 Modification to 8.3.8 . 15
23 Modification to 8.4.3 . 16
24 Modification to 9.3.2 . 19
25 Modification to 9.3.3 . 20
26 Modification to 9.3.4 . 20
27 Modification to 10.3.2.6 . 20
28 Modification to Clause 11 . 21
11 Integral attachments . 21
29 Modification to 12.1.3 . 32
30 Modification to 12.2.4.2 . 32
31 Modification to 12.2.5 . 32
32 Modification to 12.2.6 . 33
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
33 Modification to 12.2.8 . 33
34 Modification to 12.3.1 . 34
35 Modification to 12.3.2 . 34
36 Modification to 12.3.3 . 34
37 Modification to 12.3.4 . 34
38 Modification to 12.3.5 . 35
39 Modification to 12.5 . 35
40 Modification to 13.1.1 . 35
41 Modification to 13.1.2 . 36
42 Modification to 13.1.3 . 36
43 Modification to 13.1.5.1 . 39
44 Modification to 13.1.5.3 . 39
45 Modification to 13.3.1 . 40
46 Modification to 13.3.3.3 . 41
47 Modification to 13.3.3.6 . 41
48 Modification to 13.3.3.7 . 41
49 Modification to 13.3.3.9 . 41
50 Modification to 13.3.5 . 41
51 Modification to 13.3.6 . 41
52 Modification to 13.4.1 . 43
53 Modification to 13.5.1.2 . 44
54 Modification to 13.5.1.3 . 44
55 Modification to 13.5.1.6 . 44
56 Modification to 13.5.2.2 . 44
57 Modification to 13.5.2.3 . 44
58 Modification to 13.5.3 . 45
59 Modification to 13.5.4 . 45
60 Modification to 13.5.4.1 . 45
61 Modification to Annex A . 45
62 Modification to Annex B . 45
63 Modification to C.1.6 . 48
64 Modification to Clause D.3. 49
65 Modification to D.4.2 . 49
66 Modification to D.4.3 . 49
67 Modification to D.5.3 . 49
68 Modification to G.2.1 . 49
69 Modification to Annex H . 49
70 Modification to Clause I.3 . 53
71 Modification to Clause J.1 . 58
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
72 Modification to Clause J.4 . 58
73 Modification to Annex L . 58
Annex L (informative)  Buckling of linear type supports . 59
74 Modification to Annex M . 63
75 Modification to Annex N . 64
76 Modification to Annex O . 64
77 Modification to Clause P.1 . 76
78 Modification to P.3.1 . 76
79 Modification to Clause Q.1 . 76
80 Modification to Q.2.1 . 76
81 Modification to Q.2.3 . 76
82 Modification to Clause Q.4 . 76
83 Modification to Q.7.2 . 76
84 Modification to Q.8.1 . 77
85 Modification to Q.9.1 . 77
86 Modification to Annex ZA . 77
87 Modification to Bibliography . 77

SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
Foreword
This document (EN 13480-3:2002/FprA5:2011) has been prepared by Technical Committee CEN/TC 267
“Industrial piping and pipelines”, the secretariat of which is held by AFNOR.
This document is currently submitted to the Unique Acceptance Procedure.
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 this document.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
1 Modification to Clause 2
Add the following normative references:
EN 1515-2:2001, Flanges and their joints - Bolting - Part 2: Classification of bolt materials for steel flanges, PN
designated
EN 1515-3:2005, Flanges and their joints - Bolting - Part 3: Classification of bolt materials for steel flanges,
class designated
EN 1515-4:2010, Flanges and their joints - Bolting - Part 4: Selection of bolting for equipment subject to the
Pressure Equipment Directive 97/23/EC
2 Modification to 3.2
Add the following line in the Table 3.2-1 "General symbols and units" between the symbols f and p :
cr c
Design stress for flexibility analysis MPa (N/mm²)
f
f
3 Modification to 4.1
In sub-clause 4.1, in the first sentence, replace "cold spring" by "cold pull". The sentence shall read as follows:
The calculation rules in this document shall apply for operating and testing conditions as well as preset, cold
pull conditions, flushing and cleaning conditions.
4 Modification to 4.2.3.3
The sub-clause 4.2.3.3 shall read as follows:
The set (p , t ) to be considered for the dimensioning of the elements of a piping system shall correspond to
o o
the most severe conditions of pressure and temperature which prevail simultaneously over a long time in the
piping section under consideration. Thus for the thickness calculation of a component, the simultaneous
conditions of pressure and temperature to be considered are the conditions which lead to the greatest
thickness.
For all piping system elements, an allowable maximum pressure, based on
a) specified material (mechanical properties),
b) a given temperature,
can be easily determined by taking into account the applicable safety factors.
Temporary deviations e.g. due to pressure surge or operation of control release valve (safety valve) shall not
be taken into account if the calculated stresses from such variations do not exceed the allowable stress by
more than 10 % for less than 10 % of any 24 h operating period.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
5 Modification to 4.2.3.4
The sub-clause 4.2.3.4 shall read as follows:
For all pressure temperature conditions (p , t ) specified in 4.2.3.3 calculation pressures p shall be
o o c
determined.
The calculation pressure p shall be not less than the associated operating pressure p , taking into account
c o
the adjustments of the safety devices. The conditions (p , t ) resulting in the greatest wall thickness shall be
o o
considered with both of the following minimum conditions:
1) p = p = PS with the associated t as defined in 4.2.3.5;
c o c
2) t as defined in 4.2.3.5 for t = TS with the associated p = p .
c o c o
NOTE If there is a condition where p = PS and t =TS only this condition has to be calculated.
o o
When the calculation temperature t is such that the creep rupture strength characteristics are relevant for the
c
determination of the nominal design stress, the calculation pressure shall be considered equal to the operating
pressure (p ) which is associated with the corresponding temperature (t ).
o o
6 Modification to 4.2.5
In sub-clauses 4.2.5.1, 4.2.5.2.3 and 4.2.5.4, the indent "cold spring" shall read as follows:
— cold pull.
7 Modification to 4.6
In the first paragraph, a second sentence shall be added and shall read as follows:
This may be completed or replaced by a "design by analysis" as described in EN 13445-3, Annex B and
Annex C.
Clauses 6, 7, 8, 9, 10 and 11 describe the "design by rules" of piping components under static and cyclic
loadings. The « design by rule » can be completed or replaced by a « design by analysis » as described in
EN 13445-3, Annex B and Annex C, where applicable.
8 Modification to 5.2.2.1
In this sub-clause, the first indent shall read as follows:
— for A ≥ 35 %
and the second indent shall read as follows:
— for 35 % > A ≥ 30 %
9 Modification to 5.3.2.1
After the Table 5.3.2-1, the text shall read as follows:
If the design lifetime is not specified, the mean creep rupture strength at 200 000 h shaII be used.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
In cases where the 200 000 h values are not specified in the material Standards, the mean creep rupture
strength at 150 000 h or 100 000 h shall be used.
If a design lifetime between 100 000 h and 200 000 h is specified, and a lifetime monitoring system is
provided, divergent from Table 5.3.2-1, a safety factor SF = 1,25 may be used.
CR
In cases where design Iifetimes shorter than 100 000 h are specified, one of the following methods shall be
used:
a) If a lifetime monitoring System is not provided, the safety factor SF shall be equal to 1,5 and shall be
CR
applied to the mean creep rupture strength at the relevant lifetime of at least 10 000 h;
b) If a lifetime monitoring system is provided, a safety factor of SF = 1,25 may be specified with regard to
CR
the mean creep rupture strength at the relevant lifetime of at least 10 000 h. In no case shall the 1 %
creep strain limit (mean value) at 100 000 h be exceeded.
The creep rupture strength associated to the specified lifetime shall be interpolated based on a logarithmic
time axis as well as a logarithmic stress axis (double logarithmic interpolation scheme).
10 Modification to 6.4.2.1
Replace Figures 6.4.2-1 and 6.4.2-2 as follows:
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

Figure 6.4.2-1 – Geometry of cone/cylinder intersection without knuckle – Large end

Figure 6.4.2-2 — Geometry of cone/cylinder intersection with knuckle – Large end
11 Modification to 6.4.5
After the equation (6.4.5-2), add the following text:
The length of the cone can be reduced to less than 2l if both of the following conditions are fulfilled:
 the wall thickness e , calculated in accordance with 6.4.6 or 6.4.7, is existent along the whole length of
the cone;
 the junction at the small end of the cone is sufficiently dimensioned according to 6.4.8.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
12 Modification to 6.4.6.1
The indent 2) shall read as follows:
2) the weld at the junction shall be subject to 100 % non-destructive examination, either by radiography or
ultrasonic techniques, unless the design is such that the thickness at the weld exceeds 1,4e, in which case
j
the normal rules for the relevant design shall be applied.
13 Modification to 6.4.7.2
After equation (6.4.7-1), correct equation (6.4.7-2) as follows:
0,028r
α
i
ρ = (6.4.7-2)
D e 1+ 1/ cosα
c j
14 Modification to 6.4.8.1
Replace Figure 6.4.8.1-1 as follows:

Figure 6.4.8.1-1 — Geometry of cone/cylinder intersection: small end
15 Modification to 6.4.10
After equation (6.4.10-4), add a new equation (6.4.10-5) as follows:
e {e ;e }          (6.4.10-5)
r=max cyl j
With e according to 6.1 and e according to equation (6.4.7-4).
cyl j
After the last sentence of clause 6.4.10, add the new Figures 6.4.10-1 and 6.4.10-2 as follows:
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

Figure 6.4.10-1 — Special forged reducer

Figure 6.4.10-2 — Special forged reducer (alternative solution)

16 Modification to 6.6
The clause 6.6 shall read as follows:
6.6.1 General
The rules of this sub-clause are to check the mechanical resistance of the flange connection subjected to
static loads. It is also in the responsibility of the designer to ensure the adequacy of the flange connection
(gasket type and characteristics, etc) with the operating conditions, in particular with regards to any specific
required tightness.
If there is a specific requirement on tightness for the flange connection, this shall be calculated in accordance
with EN 1591-1, using Annex P.
The designer shall consider section loadings caused by the connected piping system.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
The classification of material for flanges, bolts and nuts is given by EN 1515-2 (PN flanges) and EN 1515-3
(Class flanges). The selection of bolting shall comply with Annex D or Annex Q and EN 1515-4.
6.6.2 Symbols
For the purposes of 6.6, the symbols given in Table 6.6.2-1 shall apply in addition to those given in
Table 3.2-1.
Table 6.6.2-1 — Additional symbols for the purposes of 6.6
Symbol Description Unit
P Equivalent design pressure MPa (N/mm )
eq
P Internal calculation pressure MPa (N/mm )
F Pulling axial force (to be a positive value in equation) N
M External bending moment N mm
G Diameter of gasket load reaction mm
6.6.3 Standard flange
A standard steel flange connection in accordance with defined material requirements, giving the maximum
allowable pressure with regards to the flange materials and the design temperature, may be used within the
construction of piping subjected to internal pressure, without the necessity of carrying out a calculation to
verify its resistance when the following conditions are met:
a) For each normal working condition, the design pressure shall not exceed the maximum allowable
pressure specified.
b) For conditions where the flange connection is simultaneously subjected to internal pressure, axial load
and bending moment, the equivalent design pressure, P , according to equation (6.6.2-1) shall not exceed
eq
the limits specified in a) or b).
16 M
4F
P = P + +                                   (6.6.2-1)
eq
2 3
πG πG
Where:
G is the diameter of circle on which applies the compression load of the gasket.
c) The gasket types, for each PN, are specified in EN 1514-1 to EN 1514-8.
d) The strength of the bolting for the flange connection, for each PN, shall be as indicated in EN 1515-1 to 4.
e) The difference of temperature between the flanges and the bolting shall not exceed, for a given situation,
50 °C.
f) If the design temperature is ≥ 120 °C, the thermal expansion coefficient of the flange material shall not
exceed the thermal expansion coefficient of the bolt material by more than 10 %.
6.6.4 Non-standard flange
If a non-standard flange is used, the design shall be done by applying the calculation method in
EN 1591-1, using for example Annex P, or by applying the algorithm shown in the Taylor-Forge method, using
for example Annex D.
NOTE 1 The Taylor-Forge method does not ensure tightness.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
NOTE 2 The algorithm given in EN 1591-1 includes a consideration of section loadings.
NOTE 3 The bolt torque should be specified by the designer. Attention should be paid in such cases to the method of
tightening. Guidance of scatter band when applying the different methods of tightening are given in EN 1591-1.
17 Modification to 7.1.3
The beginning of the sub-clause 7.1.3 shall read as follows:
This sub-clause shall apply provided that the following conditions are simultaneously fulfilled:
r ≤ 0,2D
i i
r ≥ 0,06D
i i
r ≥ 2 e
i
0,001D ≤ e ≤ 0,08D
i i
R ≤ D
i o
After equation (7.1.3-8), the NOTE shall read as follows:
NOTE Where e > 0,005 D , it is not necessary to calculate e or p .
kn y i kn b kn b
18 Modification to 7.2.3.3
Equation (7.2.3-15) shall read as follows:
 
D + e e e
3 3
i eq eq eq
2 4
 
F = U g +()2g − g − 2J H ² − 3()2 −ν g g   (7.2.3-15)
 
8 16 e D + e D + e
eq i eq i eq
 
(7.2.3-15)
Equation (7.2.3-16) shall read as follows:
 
 
e
eq
2 4
 
 
G =()2g − g − 2J H          (7.2.3-16)
   
8 D + e
i eq
 
 
 
19 Modification to 7.2.3.4
After equation (7.2.3-28), the sentence shall read as follows:
The minimum wall thickness of the cylindrical part, e , shall be in accordance with 6.1 and for nominal design
eq
stress f = min (f ; f ). The minimum radius of the stress-relief groove, r , shall be max (0,25 e , 5 mm) (see
1 2 i eq
Figure 7.2.3-5).
20 Modification to 8.1
Delete "NOTE 2" and the designation "NOTE 1" shall be indicated as "NOTE" only.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
21 Modification to 8.3.5
The last paragraph of 8.3.5 shall read as follows:
For oblique branch connections to cylindrical or spherical shells, the angle between the normal to the wall of
the shell and the axis of the branch, ϕ, shall be between 0 ° and 45 °(see Figures 8.4.3-3, 8.4.3-4 and
8.4.3-5).
Add new NOTES beneath the Figures 8.3.3-2 and 8.3.3-3 as follows:

SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
a) set through b) set in
NOTE  Consideration should be given to the effect of the flow for design of set through nozzles.
Figure 8.3.3-2 — Reinforcement by reinforcing pads
a) set on b) set in c) set through
NOTE 1 The increase wall thickness can be on the inside or the outside of the branch.
NOTE 2  Consideration should be given to the effect of the flow for design of set through nozzles.
Figure 8.3.3-3 — Reinforcement by increase in wall thickness of the branch
22 Modification to 8.3.8
Before the last sentence of the clause 8.3.8, add the sentence as follows:
The areas A and A shall be multiplied by a factor of 0,9 if the actual wall thickness of the extrusion is
fs fb
unknown.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
23 Modification to 8.4.3
In the indent a), the equation (8.4.3-3) shall read as follows:
p p
   
c c
 f − A + f − A ≥ p A (8.4.3-3)
b f s f c p
b s
2 2
   
At the end of the indent b) "Reinforcement by reinforcing pads", just before the equation (8.4.3-7), the text
shall as follows:
If the design stress of the branch, f , and/or of the reinforcing pad f , is less than that of the shell, f , the
b pl s
following condition shall be satisfied instead of that of equation (8.4.3-6):
After the equation (8.4.3-7), add the note as follows:
NOTE In no case a design stress of the branch f or a design stress of the reinforcing pad f higher than f
b pl s
shall be considered.
At the end of the indent c) "Oblique branch connections in cylindrical and conical shells", delete the equation
(8.4.3-9) and the text above, and before the Figures 8.4.3-3 and 8.4.3-4 modify the sentence as follows:
The angle ϕ shall be defined as shown in Figure 8.4.3-3 or 8.4.3-4: 0° < ϕ ≤ 45°.
After this sentence, replace the new Figures 8.4.3-3 and 8.4.3-4 as follows:
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

NOTE  Consideration should be given to the effect of the flow for design of set through.
Figure 8.4.3-3 — Reinforcement of oblique branch connection in cylindrical or conical shell
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

a) Cross section view b) Section X-X
Figure 8.4.3-4 — Reinforcement of non radial branch connection in cylindrical or conical shell

SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
At the end of the indent d) "Oblique branch connections in spherical shells and dished ends", delete the
equation (8.4.3-10) and the text above, and replace the new Figure 8.4.3-5 as follows:

Figure 8.4.3-5 — Reinforcement of oblique branch connection in spherical shells and dished
ends
24 Modification to 9.3.2
Equation (9.3.2-1) shall read as follows:
S e
a
p = (9.3.2-1)
y
R
m
Equation (9.3.2-2) shall read as follows:
E e ε
a
t
p = (9.3.2-2)
m
R
m
Equation (9.3.2-3) shall read as follows:
 
 
 
 
e 2
1  1 
a 2 2
ε = + ()n −1+ Z (9.3.2-3)
 
cyl
2 2 2 2
Z 2 ()
 12R 1−ν 
2  
m
n
n −1+
 cyl 
cyl
 
2 + 1
 
 2 
 Z 
 
 
 
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
25 Modification to 9.3.3
Add the following line in the Table 9.2.1-1 "Additional symbols for the purposes of clause 9" between the
symbols n and p :
cyl n
p specified external design pressure N/mm² (MPa)

Equation (9.3.3-3) shall read as follows:
S e R
s a f
p = (9.3.3-3)
ys
R (1−ν / 2)
m
Equation (9.3.3-5) shall read as follows:
δ = max{}λ (R − R ) − X + e / 2 ; X (9.3.3-5)
m f c a c
Equation (9.3.3-6) shall read as follows:
 
 
e e 
 
a a
 
L + A + λ()R − R
 
e s s
 
 
2 2
 
 
 
 
X =               (9.3.3-6)
e
A
e
26 Modification to 9.3.4
Equations (9.3.4-2) and (9.3.4-3) shall read as follows:
where C shall be:
— for Figures 9.3.4-1 a), b) and d):
3 3
h e + 8e w
s w f
f
C =  (9.3.4-2)
r [] 6h e + 12 e w ()2h + e
i s w f f s f
— for Figures 9.3.4-1 c):
 
4h ⋅ e + 3e ⋅ w
e w
s w f f
f f
C = ⋅ (9.3.4-3)
 
h ⋅ e + 3e ⋅ w
r [] 6 h e + 6 e w ()2h + e  s w f f 
i s w f f s f  
27 Modification to 10.3.2.6
Replace the existing last paragraph of 10.3.2.6 with the following:
Special requirements shall be imposed on the form of welds. Residual welding stresses shall be minimized by
heat control during welding and the welding sequence. All heat treatments shall be performed in accordance
with EN 13480-2.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
28 Modification to Clause 11
Replace the existing Clause 11 with the following:
11 Integral attachments
11.1 General
Integral attachments are forged attachments or attachments welded on the pressure-loaded wall of a straight
pipe which transfer piping loadings to the steel framework or concrete.
NOTE No major discontinuity, either with regard to the geometry and/or with regard to the material, should be closer
0,5
 e D 
n m
to the attachment than 2,5  where the dimensions of the pipe apply. The material of integral attachments
 
 
should be chosen in such a way that no major difference exists with respect to the pipe material, the thermal expansion
coefficient and the modulus of elasticity. Furthermore, the design stress of the attachment should be similar to that of the
pipe material. If major deviations occur, special attention should be paid to choosing the appropriate design stress.
For piping operating in the creep range, it is highly recommended to use the same material for the integral
attachment as for the pipe, welds shall be full penetration welds.
Attachments with small lever arms may be designed in shear only when the shear stress is similar to the
bending stress. If they are welded to thin walled pipes with D /e ≥ 10 bending stresses in the pipe wall shall
m n
be determined and assessed.
The calculation of hollow circular attachments is described in 11.4 and 11.6, for calculation of rectangular
attachments, see 11.5 and 11.6.
Loads on the attachments cause stresses in the pipe wall. Equations to determine these stresses are given in
11.4 and 11.5. The attachment stresses are then added to the piping system stresses at the attachment. The
piping system stresses are determined for straight pipe. The equations, including the attachment stress terms,
are given in 11.6.
There are additional equations given in 11.4 and 11.5 for attachments that shall also be checked for
attachment stresses. These are based on the absolute values of maximum loads occurring simultaneously for
all specified service loading conditions.
11.2 Allowable stresses
The design stress shall be calculated in accordance with Clause 5.
Membrane stresses due to integral attachments shall be considered as local. Bending stresses caused by the
same source and acting across the wall thickness of the pipe shall be classified as secondary stresses.
Stresses acting over the wall thickness of the pipe shall be combined with stresses resulting from :
 internal pressure;
 external loadings;
and shall comply with the following:

SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
in case of sustained loads;
P + P + P ≤ 1,5 f
h
m b L
P + P + P ≤ 1,8 f in case of sustained and occasional loads;
m b L h
in case of exceptional loads;
P + P + P ≤ 2,7 f
m b L h
in case of restrained thermal expansion of the piping system;
Q ≤ f
a
P + P + P + Q ≤ f + f in case of sustained loads and restrained thermal expansion of the
h
m b L a
piping system.
where
P is the primary membrane stress;
m
P is the primary local membrane stress;
L
P is the primary bending stress;
b
Q is the secondary bending stress.
For determination of f , f see equations (12.1.3.1) to (12.1.3.4), the design stress f is defined in Clause 5.
a h
For pure shear stresses (average value), the equivalent stress σ shall be calculated according to the von
eq
Mises theory, and shall be limited to 1,5 f for time-independent design.
11.3 Symbols
For the purposes of 11.4 to 11.6, the symbols given in Table 11.3-1 shall apply in addition to those given in
3.2.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
Table 11.3-1 — Additional symbols for the purposes of 11.4 to 11.6
Symbol Description Unit
A half cross section area of circular hollow attachment mm²
m
A cross section area of circular hollow attachment mm²
t
A total fillet weld throat area mm²
w
d attachment inside diameter for circular hollow attachment mm
i
d attachment outside diameter for circular hollow attachment mm
o
D outside diameter of run pipe mm
o
e nominal run pipe wall thickness mm
n
e
nominal attachment wall thickness mm
n,t
design stress (see 5.2) N/mm
f
f
allowable stress range (see 12.1.3) N/mm
a
f design stress in the creep range (see 5.3) N/mm
CR
f allowable stress at maximum metal temperature (see 12.1.3) N/mm
h
L
half length of attachment in circumferential direction of the run pipe for rectangular mm
attachment
L half length of attachment in longitudinal direction of the run pipe for rectangular attachment mm
M longitudinal bending moment applied to the attachment (vector normal to the attachment N mm
L
and run pipe centre line)
M circumferential bending moment applied to the attachment (vector parallel to the run pipe N mm
N
centre line)
M
torsional moment applied to the attachment (vector normal to the run pipe centre line) N mm
T
p calculation pressure N/mm
c
Q circumferential shear load applied to the attachment N
Q
longitudinal shear load applied to the attachment N
R mean radius of run pipe mm
m
W thrust load applied to the attachment (vector normal to the run pipe centre line) N
Z section modulus of run pipe
mm
Z section modulus of fillet or partial penetration weld about the neutral axis of bending
WL mm
parallel to L
Z section modulus of fillet or partial penetration weld about the neutral axis of bending
WN mm
parallel to L
Z Torsional section modulus of fillet or partial penetration weld for torsional loading
WT mm
M , M , M , Q , Q and W are determined at the surface of the pipe, associated to the load cases.
L N T 1 2
M **, M **, M **, Q **, Q ** and W** are absolute values of maximum loads occurring simultaneously at the surface of the
L N T 1 2
pipe under all loading conditions.
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

11.4 Hollow circular attachments
11.4.1 Limitations
The attachment shall be welded to the pipe by a full penetration weld or a fillet weld along the entire outside
circumference (see Figure 11.4.1-1).
The axis of the attachment shall be normal to the run pipe.
The parameters, calculated in 11.4.2 shall conform to the following limitations:
4,0 ≤ γ ≤ 50,0 (11.4-1)
0,2 ≤ τ ≤ 1,0 (11.4-2)
0,3 ≤ β ≤ 1,0 (11.4-3)
Full penetration weld Fillet weld
Key
a attachment
b weld
c pipe wall
Figure 11.4.1-1 — Hollow circular attachment welds

11.4.2 Preliminary calculations
M , M , M Q , Q , and W are determined at the surface of the pipe associated to the relevant load cases.
L N T, 1 2
M **, M **, M **, Q **, Q ** and W** are absolute values of maximum loads occurring simultaneously under
L N T 1 2
all specified service loading conditions.
The dimensions d and d are defined in Figure 11.4.2-1.
i o
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)

Key
(a) pipe
(b) attachment
Figure 11.4.2-1 — Loading and dimensions of attachments

π
2 2
A =()d − d (11.4.2-1)
t o i
Z = 2 ⋅ I / d (11.4.2-2)
t t o
4 4
I =()π / 4 [(d / 2) −(d / 2) ]
(11.4.2-3)
t o i
A = A / 2 (11.4.2-4)
m t
γ = D /()2e (11.4.2-5)
o n
τ = e / e (11.4.2-6)
n,t n
β = d / D (11.4.2-7)
o o
n n n
1 2 3
C = A()2γ β τ , but not less than 1,0 (11.4.2-8)
o
 
 d 
 
o
J = min Z ;π  e (11.4.2-9)
 T n
 
 
 
 
The equation (11.4.2-8) shall be used to calculate C , C and C using factors given in Table 11.4.2-1. The
W L N
maximum values of C , C and C , calculated for the pipe and the attachment, shall be subsequently used.
W L N
SIST EN 13480-3:2002/kFprA5:2011
EN 13480-3:2002/FprA5:2011 (E)
Table 11.4.2-1 — Factors for hollow circular attachments
A n n n
Index part β range
o 1 2 3
a
pipe 0,3 to 1,0 1,40 0,81 1,33
C
W
b
attachment 0,3 to 1,0 4,00 0,55 1,00
pipe 0,3 to 1,0 0,46 0,60 -0,04 0,86
C
L
attachment 0,3 to 1,0 1,10 0,23 -0,38 0,38
pipe 0,3 to 0,55 0,51 1,01 0,79 0,89
C
N
attachment 0,3 to 0,55 0,84 0,85 0,80 0,54
pipe >0,55 to 1,0 0,23 1,01 -0,62 0,89
C
N
attachment >0,55 to 1,0 0,44 0,85 -0,28 0,54
a n −1,2β
replace β with e
b n −1,35β
replace β with e
C = 1,0 for β ≤ 0,55 (11.4.2-10)
T
C = C for β = 1,0, but not less than 1,0 (11.4.2-11)
T N
C should be linearly interpolated for 0,55 < β < 1,0, but not less than 1,0.
T
B = 0,5 C , but not less than 1,0          (11.4.2-12)
W W
B = 0,5 C , but not less than 1,0 (11.4.2-13)
L L
B = 0,5 C , but not less than 1,0 (11.4.2-14)
N N
B = 0,5 C , but not less than 1,0 (11.4.2-15)
T T
K = 2,0 for fillet welds
T
K = 1,8 for full penetration, or partial penetration welds.
T
NOTE Fillet welds and partial penetration welds are not allowe
...