# SIST EN 13445-3:2014/A8:2019

(Amendment)## Unfired pressure vessels - Part 3: Design

## Unfired pressure vessels - Part 3: Design

Revision of clause 16, 22 and annex W

## Unbefeuerte Druckbehälter - Teil 3: Konstruktion

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

## Neogrevane (nekurjene) tlačne posode - 3. del: Konstruiranje - Dopolnilo A8

### General Information

### Relations

### Standards Content (Sample)

SLOVENSKI STANDARD

SIST EN 13445-3:2014/A8:2019

01-maj-2019

1HRJUHYDQHQHNXUMHQHWODþQHSRVRGHGHO.RQVWUXLUDQMH'RSROQLOR$

Unfired pressure vessels - Part 3: Design

Unbefeuerte Druckbehälter - Teil 3: Konstruktion

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

Ta slovenski standard je istoveten z: EN 13445-3:2014/A8:2019

ICS:

23.020.32 7ODþQHSRVRGH Pressure vessels

SIST EN 13445-3:2014/A8:2019 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/A8:2019

EN 13445-3:2014/A8

EUROPEAN STANDARD

NORME EUROPÉENNE

April 2019

EUROPÄISCHE NORM

ICS 23.020.30

English Version

Unfired pressure vessels - Part 3: Design

Récipients sous pression non soumis à la flamme - Unbefeuerte Druckbehälter - Teil 3: Konstruktion

Partie 3 : ConceptionThis amendment A8 modifies the European Standard EN 13445-3:2014; it was approved by CEN on 19 November 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of

this amendment into the relevant national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.This amendment exists in three official versions (English, French, German). A version in any other language made by translation

under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the

same status as the official versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATION

COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13445-3:2014/A8:2019 E

worldwide for CEN national Members.---------------------- Page: 3 ----------------------

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EN 13445-3:2014/A8:2019 (E)

Contents Page

European foreword ....................................................................................................................................................... 3

1 Modifications to Clause 2, Normative references ................................................................................ 4

2 Modification to 5.3.1, Actions ...................................................................................................................... 4

3 Addition of a new Subclause 5.3.2.4, Load combinations ................................................................. 4

4 Addition of a new Subclause 6.7, Nominal design stress of anchor bolting ............................... 8

5 Modifications to 8.4, General ....................................................................................................................... 8

6 Modification to Subclause 16.4, Local loads on nozzles in spherical shells ............................... 8

7 Modification to 16.5, Local loads on nozzles in cylindrical shells .............................................. 18

8 Modification to 16.6.6, Bending Limit Stress ...................................................................................... 27

9 Modification to 16.7.2, Specific symbols and abbreviations ......................................................... 28

10 Modification to 16.7.4, Applied force .................................................................................................... 29

11 Modification to 16.7.5, Load limits for shell ....................................................................................... 29

12 Modification to 16.8.6.2, Vessel under external pressure ............................................................. 29

13 Modification to 16.8.7, Load limit at the saddle (without a reinforcing plate) ...................... 29

14 Modification to 16.12.4.1, Specific symbols and abbreviations ................................................... 29

15 Modification to 16.12.4.3, Check of the skirt in regions with openings .................................... 29

16 Modification to 16.12.5.1, Specific symbols and abbreviations ................................................... 30

17 Modifications to 16.12.5.2, Anchor bolt and concrete forces ....................................................... 30

18 Modification to 16.14, Global loads ........................................................................................................ 30

19 Modification to 16.14.2, Specific symbols and abbreviations ...................................................... 30

20 Modification to 16.14.8, Compressive stress limits ......................................................................... 32

21 Modification to 16.14.8.1, Calculation .................................................................................................. 32

22 Modification to 16.14.8.2, Tolerances ................................................................................................... 34

23 Modifications to 16.14.9, Wind and earthquake loads ................................................................... 38

24 Modification to Clause 22, Static analysis of tall vertical vessels on skirts ............................. 39

25 Modification to O.4.1, General.................................................................................................................. 49

26 Modification to O.4.2, Polynomial coefficients .................................................................................. 49

27 Modification to O.4.3, Figures for physical properties of steels .................................................. 50

28 Addition of a new Annex V (informative), Consider a buffer for unknown nozzleloads — Opening design for unknown nozzle loads ........................................................................ 50

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EN 13445-3:2014/A8:2019 (E)

European foreword

This document (EN 13445-3:2014/A8:2019) has been prepared by Technical Committee CEN/TC 54

“Unfired pressure vessels”, the secretariat of which is held by BSI.This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by October 2019, and conflicting national standards shall

be withdrawn at the latest by October 2019.Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of

EN 13445-3:2014.According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,

Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France,

Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,

Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

the United Kingdom.---------------------- Page: 5 ----------------------

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1 Modifications to Clause 2, Normative references

Add a footnote number “ ” after the reference “EN 1991-1-4:2005” and the corresponding footnote at the

bottom of the page:“ EN 1991-1-4:2005 is impacted by the stand-alone amendment EN 1991-1-4:2005/A1:2010 and the

corrigendum EN 1991-1-4:2005/AC:2010.”.In the reference to EN 1991-1-6, replace "EN 1991-1-6" with “EN 1991-1-6:2005”.

Add the following new reference at the appropriate place:

“EN 12195-1:2010, Load restraining on road vehicles — Safety — Part 1: Calculation of securing forces”.

2 Modification to 5.3.1, ActionsAdd the following note at the end of the subclause:

NOTE The combination of actions is given in 5.3.2.4.”.

3 Addition of a new Subclause 5.3.2.4, Load combinations

Insert the following new subclause:

5.3.2.4 Load combinations

5.3.2.4.1 General

Load combinations of non-pressure loads in Table 5.3.2.4-1 are used in connection with calculations

according to Clause 16 and Annex C (linear elastic behaviour). The basic calculation of pressure envelope

by design pressures and temperatures shall be made before Clause 16 (or Annex C) calculations. The load

combinations in Table 5.3.2.4-1 are minimum to be taken into account, if they are relevant. There may

also be other loads.5.3.2.4.2 Specific definitions

5.3.2.4.2.1 Dead loads

Maximum dead load (G ) is the weight of the whole un-corroded vessel with all internals (trays,

maxpacking, etc.), attachments, insulation, fire protection, piping, platforms and ladders.

Corroded dead load (G ) is defined as G but with the weight of the corroded vessel.

corr maxMinimum dead load (G ) is the weight of the un-corroded vessel during the installation phase, excluding

minthe weight of items not already mounted on the vessel before erection (e.g. removable internals,

platforms, ladders, attached piping, insulation and fire protection).NOTE A scaffold is normally self-supported. In this case, the weight of the scaffold is not included in the vessel

weight.Transport dead load (G ) is the case, when vessel has the removable internals and insulation already

transmounted on the vessel in the workshop.

5.3.2.4.2.2 Live loads

Live loads (L) used in this clause are weight loads of the contents (fluids or solids in the bottom of the

vessel, on trays and in packing) and traffic loads on platforms and ladders by personnel and machinery.

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5.3.2.4.2.3 Wind loads

Wind loads (W) are horizontal global pressure loads caused by wind and acting on the projected area of

the vessel and its attachments, as influenced by the force coefficients (see 22.4.4).

5.3.2.4.2.4 Earthquake loadsEarthquake loads (E) are quasi-static horizontal forces on the vessel sections caused by seismic

accelerations at the base of vessel calculated by the “lateral force method of analysis” (see 22.4.5).

5.3.2.4.2.5 Forces from attached external pipingReaction forces from attached external piping are forces resulting from weight (G), wind (W), earthquake

(E) and other additional forces (F) as far as they influence the global equilibrium of the vessel (see 22.4.6

for columns).NOTE Forces and moments on nozzles and supports on the vessel caused by attached external piping can act as

internal and/or external loads. Internal loads are those that cause local loads only and have no influence on the

global equilibrium because they are self-compensating. Furthermore, attached pipes can either load the vessel or

restrain it depending on their layout. Consideration of these aspects is given in the recommendations in 22.4.6.

5.3.2.4.3 Specific symbols and abbreviationsThe following specific symbols and abbreviations are used in Table 5.3.2.4-1 in addition to those in

Clause 4:E earthquake load (see 5.3.2.4.2.4)

F additional loads from piping (thermal expansion loads) (see 5.3.2.4.2.5)

f nominal design stress for operation conditions for anchor bolts, see Formula (6.7–1)

B,opG minimum dead loads (see 5.3.2.4.2.1)

min

G maximum dead loads (see 5.3.2.4.2.1)

max

G corroded dead loads (see 5.3.2.4.2.1)

corr

G transport dead loads (see 5.3.2.4.2.1)

trans

L live loads of each loading case (contents, etc.) (see 5.3.2.4.2.2)

P internal calculation pressure as defined in 5.3.10 for P > 0 (including hydrostatic pressure)

P external calculation pressure as defined in 5.3.10 for P < 0 (e.g. vacuum)W wind load (Clause 22 and EN 1991-1-4)

σ maximum allowable compressive stress for operation conditions in accordance with 16.14.8,

c,allwith σ as defined in 8.4 and with a safety factor of 1,5 in Formula (16.14–29)

σc,all,test maximum allowable compressive stress for test conditions in accordance with 16.14.8, with σe

as defined in 8.4 and with safety factor 1,05 in Formula (16.14–29)& operator which means: superposition of the different load types for the axial and lateral forces,

the bending moments and the resulting shear and longitudinal stresses using the beam theory

for non-pressure loads and the membrane theory for pressure loads---------------------- Page: 7 ----------------------

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Table 5.3.2.4–1 — Load combinations

Load Types of load Load combination Allowable tensile Allowable compressive Allowable tensile Explanations

Case included including weighting stress for shells stress for shells stress for anchor

factors boltsOperation with internal

LC0 P , G P and G f σ f

i max i max d c,all B,op

pressure

0,9·P and G and L and F Operation with internal

i max

LC1 P , G , L, F, W f σ f

i max d c,all B,op

and 1,1·W pressure and wind

P and G and L and F and Operation with external

e max

LC2 Pe, Gmax, L, F, W fd σc,all fB,op

1,1·W pressure and wind

Operation without pressure

LC3 G , L, F, W G and L and F and 1,1·W f σ f

max max d c,all B,op

but with wind

Shut down (no pressure,

LC4 G , W G and 1,1·W f σ l f contents and thermal

corr corr d c,al B,op

reactions)

LC5 G , W G and 0,7·W f σ f Installation

min min d c,all B,op

Operation with internal

LC6 P , G , L, E 0,9·P and G and L and E f σ 1,2· f

i max i max exp c,all,test B,op

pressure and earthquake

Operation with external

LC7 P , G , L, E P and G and L and E f σ 1,2· f

e max e max exp c,all,test B,op

pressure and earthquake

Operation without pressure

LC8 G , L, E G and L and E f σ 1,2· f

max max exp c,all,test B,op

but with earthquake

P , G , L , P and G and L and Test with test pressure, test

test max test test max test

LC9 f σ f

test c,all,test B,op

W 0,6·W filling and wind

LC10 G ≥ 1,5*G f σ N/A Lifting (Crane)

max max test c,all,test

LC11 G f σ N/A Transport

trans test c,all,test

Transport load case shall be taken into account on basis of manufacturer’s risk analysis for the vessel, if it proves to be critical for the vessel depending on the transport way

(road, ship or train). If no special regulations are specified the following transport loads shall be considered: downwards: 1,4 Gtrans, sidewards and upwards: 0,5*Gtrans driving

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direction: 0,8*G . The transport loads shall be agreed with transport company so that the transport will not damage the vessel (see EN 12195-1).

transReal operating pressure may be used instead of 0,9*P , if it is limited either naturally (e.g. steam temperature) or by safety related control and instrumentation system.

After exceptional load case the vessel shall have re-inspection.Remarks

For LC1 and LC2: If more than one combination of coincident design pressure and design temperature exists then all combinations shall be investigated.

Alternatively a single combination of the maximum pressure and maximum temperature of all the cases may be used. It is not certain that the governing condition of

coincident pressure and temperature is also governing for the load combinations.For LC1 and LC6: The factor 0,9 is applied to the internal calculation pressure P because the internal operating pressure is normally 10 % below PS due to the

pressure limiting device.For LC3 and LC8: These load cases are not required when both loading cases LC1 and LC2, or LC6 and LC7 are applicable, i.e. internal and external pressure are

applied.For LC5: The wind load in this case depends on configuration at this time (with or without scaffold, platforms, insulation). The reduced factor for the wind load is in

accordance with EN 1991-1-6:2005 for duration times < 12 months.For LC9: The reduced factor for the wind load is in accordance with EN 1991-1-6:2005 for duration times < 3 d.

In calculation of allowable bending stress σ for transport and lifting cases according to 16.6.6, the nominal design stress f can be used instead of f and K shall be

b,all test 2set equal 1,05.

The global effect of additional piping loads on shell stresses or anchoring shall be taken into account by designer, if considered relevant.”.

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4 Addition of a new Subclause 6.7, Nominal design stress of anchor bolting

Insert the following new subclause:

6.7 Nominal design stress of anchor bolting

The nominal design stress for the anchor bolts for the operation condition shall be calculated as follows:

p0,2/TB m/20f = min ; (6.7-1)

B,op

1,,65 2 062 5

where

TB is design temperature for anchor bolts

NOTE In most cases the design temperature TB of the anchor bolts will be 20 °C and will generally be much

lower than the design temperature of the vessel.”.5 Modifications to 8.4, General

Replace the first sentence of 8.4.2 with the following one:

8.4.2 For shells made in non-austenitic steels, excluding ferritic, martensitic and precipitation

hardened stainless steels in material group 7 and austenitic ferritic stainless steels in material group 10,

the nominal elastic limit shall be given by:”.Replace the first sentence of 8.4.3 with the following one:

8.4.3 For shells made in austenitic steels, ferritic, martensitic and precipitation hardened stainless

steels and austenitic ferritic stainless steels, the nominal elastic limit shall be given by:”.

6 Modification to Subclause 16.4, Local loads on nozzles in spherical shellsReplace Subclause 16.4 with the following one:

16.4 Local loads on nozzles in spherical shells

16.4.1 Purpose

This clause provides a method for the design of a spherical shell with a nozzle subjected to local loads

and internal pressure.In cases where the loads are unknown see Annex V.

16.4.2 Additional specific symbols and abbreviations

The following symbols and abbreviations are in addition to those in Clause 4 and 16.3:

d is mean nozzle diameter;d is inside nozzle diameter;

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d is outside nozzle diameter;

d is outside diameter of a reinforcing plate;

e is analysis thickness of the combined shell and reinforcing plate;

e is equivalent shell thickness;

e is nozzle thickness;

f is allowable design stress of nozzle material;

F is nozzle shear force;

F is axial nozzle force (positive when force is tensile or radially outwards);

F is maximum allowable axial force on the nozzle;

Z,max

L is width of the reinforcing plate;

M is bending moment in the nozzle at the junction with the shell;

M is maximum allowable bending moment in the nozzle at the shell junction;

B,max

M is torsional nozzle moment

R is mean shell radius at the nozzle;

scf , scf and scf are stress factors due to pressure, nozzle axial load and moment respectively;

P Z MΔσ is stress range due to pressure;

Δσ is stress range due to axial nozzle load range;

Δσ is stress range due to moment range;

κ is reinforcement rate factor;

λ is a geometric parameter applicable to nozzles in spheres;

τ is the shear stress in shell;

τ is the shear stress in shell caused by shear force;

τ is the shear stress caused by torsional moment;

Φ is load ratio.

16.4.3 Conditions of applicability

The following conditions apply:

/ R ≤ 0,1 ;

a) 0,001 ≤ ea

NOTE Values of e / R < 0,001 are acceptable provided that the shell wall deflection does not exceed half the

wall thickness.b) distances to any other local load in any direction shall be not less than ;

R⋅ e

c) nozzle thickness shall be maintained over a distance of l≥⋅de

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16.4.4 Summary of design procedure

The design procedure is as follows:

a) calculate the basic dimensions e and L from the following:

1) at the nozzle outside diameter, when a reinforcing plate is fitted:

(16.4-1)

e= ee+⋅min ;1

c a2

2) at the outside edge (d = d ) of a reinforcing plate, or when no reinforcing plate is fitted:

e = e (16.4-2)c a

Width L of the reinforcing pad given by:

L 0,5 dd− (16.4-3)

( )

2 e

b) calculate the maximum allowable individual loads (see 16.4.5);

c) check the load ratios and the interaction of the loads (see 16.4.6);

d) if no reinforcing plate or a reinforcing plate with L≥ Re()+ e is fitted, go to step 6;

e) calculate the maximum allowable individual loads at the edge of the reinforcing plate (d = d

and e = e ), and check the load ratios and the interaction of the loads using 16.4.5 and 16.4.6;

c af) calculate the equivalent shell thickness e (see 16.4.7.2) and check the combined stress range (see

16.4.7) in cases only where one of the ranges for pressure ∆P, force ∆F or moment ∆M (calculated

Z Baccording to Formulae (16.4-16) to (16.4-18) in 16.4.7.1) is larger than the extreme absolute values

of the pressure P, the force F or the moment M ;Z B

alternatively the combined stress range (see 16.4.7) may be applied when the external loads

contain portions from thermal expansions of attached piping; in this case the checks of 16.4.5 and

16.4.6 may be applied for the pressure and the mechanical portions of the external loads only but

the check of 16.4.7 shall be done for the ranges of the pressure and the combined mechanical and

thermal loads;g) check the nozzle longitudinal stresses (see 16.4.8);

h) if stresses or load ratios are excessive, increase the shell or nozzle thickness, or reduce the loads,

and return to step 1.Step f) shall be made only at the nozzle edge.

16.4.5 Maximum allowable individual loads

16.4.5.1 To determine the maximum allowable values of pressure, axial load and bending moment,

which may be independently applied to a nozzle the following procedure shall be applied.

16.4.5.2 Determine the reinforcement rate factor:---------------------- Page: 12 ----------------------

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2 fe.

κ = min ; 10, (16.4-4)

fe. d

For the calculation of the allowable loads at the edge of the reinforcing plate or for a nozzle on a shell

without an opening, the reinforcement factor κ is equal to 1.NOTE A shell without opening is used for trunnion loading.

16.4.5.3 Determine λ :

(16.4-5)

λ =

R⋅e

16.4.5.4 Calculate permissible pressure P from the general formula for reinforcement of isolated

maxopenings in Clause 9. It is reproduced here from 9.5.2 for convenience and the notation is in 9.3.

(Af + Af ). f + Af ⋅ f + Af ⋅ fs w s b ob p op

P = (16.4-6)

max

Ap + Ap + 0,5 Ap + 0,(5 Af + Af + Af + Af )

( )

s b φ s w bP

NOTE For application of this formula to different load cases, see 3.16, NOTE 1.

16.4.5.5 Determine the allowable axial nozzle load FZ,max either from Figure 16.4-1 or by calculation:

F = f⋅e 18, 2+ 24,. 1+⋅κ λ + 09, 1⋅κ .λ (16.4-7)Z,max c ( S S

Non-dimensional upper and lower bounds are given in Figure 16.4-1.

16.4.5.6 Either read the allowable bending moment M from Figure 16.4-2 or calculate it using:

B,max2 2

M = f⋅ e⋅ 4, 9+ 2,.0 1+⋅κ λ + 0, 91.κλ. (16.4-8)

( )

B,max c S S

Non-dimensional upper and lower bounds are given in Figure 16.4-2.

16.4.5.7 Shear stresses

τ = (16.4-8a)

π⋅⋅de

τ = (16.4-8b)

π⋅⋅de

ττ+τ (16.4-8c)

F Z

16.4.6 Combination of external loads and internal pressure

16.4.6.1 To determine the effects of the combination of pressure, axial load and bending moment

acting simultaneously, the following procedure shall be applied.---------------------- Page: 13 ----------------------

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If the axial force and the bending moment include portions from the thermal expansions of attached

piping, the applied loads need not include the thermal expansion effects. In this case the stress ranges

check Subclause 16.4.7 shall be applied taking into account the total loads including the thermal

portions (see 16.4.4 step f), second paragraph).16.4.6.2 Calculate the individual load ratios as follows:

(16.4-9)

Φ =

max

Φ = (16.4-10)

Z,max

Φ = (16.4-11)

B,max

Φ = (16.4-11a)

16.4.6.3 Check that each individual load ratio is limited as follows:

Φ ≤ 10, (16.4-12)

Φ ≤ 10, (16.4-13)

Φ ≤ 10, (16.4-14)

Φ ≤1,0 (16.4-14a)

16.4.6.4 Check that the interaction of all the loads meets the following:

max Φ +ΦΦΦ;; −⋅0,2Φ +Φ +Φ ≤1,0 (16.4-15)

( )

PZ Z P Z B T

The above formula is based on a linear interaction of pressure and axial load with the bending moment

and yields a conservative result. In specific cases design by analysis, as given in Clause 5, may show that

a circular interaction is less conservative.16.4.7 Stress ranges and their combination

16.4.7.1 From the minimum and maximum values of the pressure and local loads, determine the

following load ranges:ΔP = max (P ; 0) – min (P ; 0) (16.4-16)

ΔF = max (F ; 0) – min (F ; 0) (16.4-17)

Z Z Z

ΔM = max (M ; 0) – min (M ; 0) (16.4-18)

B B B

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ΔF = max (F ; 0) – min (F ; 0) (16.6-18a)

S S S

ΔM = max (M ; 0) – min (M ; 0) (16.4-18b)

Z Z Z

16.4.7.2 At the nozzle edge only, calculate the equivalent shell thickness e . This is equal to e unless

eq ca reinforcing plate of width L< Re()+ e is used, in which case eeq is given by:

e ⋅ L f

(16.4-19)

e=e+⋅min ;e min ;1

eq a 2

Re + e

( )

a 2

16.4.7.3 Determine the following stresses:

Due to the pressure range:

∆PR⋅

∆σ = scf (16.4-20)

Due to the range of the axial load:

∆σ = scf (16.4-21)

FZ Z

π⋅⋅de e

eq eq

Due to the moment range:

4∆M

B

∆σ = scf (16.4-22)

MB M

π⋅⋅de

where

scf , scf and scf are taken from Figures 16.4–3 to 16.4–8.

P Z M

NOTE The scf factors in Figures 16.4–3 to 16.4–8 are from BS 5500:1997, G2.5 (see L.2 - ref [6]).

Range of shear stresses2∆F

∆τ = (16.4-22a)

π⋅⋅de

2∆M

∆τ = (16.4-22b)

π⋅⋅de

∆∆ττ+∆τ (16.4-22c)

16.4.7.4 The equivalent stress range shall be restricted as follows:

∆∆σσ+ +∆σ +⋅43∆τ ≤ f (16.4-23)

( )

P FZ MB

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16.4.8 Nozzle longitudinal stresses

This subclause may be ignored for a nozzle intended to be attached to a piping of the same resistance

(thickness multiplied by allowable stress).16.4.8.1 Maximum longitudinal tensile stress in the nozzle shall be limited as follows:

Pd 4 M+ +≤ f (16.4-24)

4 e π de

π d e

F shall be set to zero when resulting in an axial compressive stress.

16.4.8.2 The longitudinal stability of the nozzle shall be checked (with P = 0) as follows:

||F+≤ 10, (16.4-25)

max max

F shall be set to zero when resulting in axial tensile stress. M and F are respectively the allowable

Z max maxglobal moment and force in the nozzle. They are calculated in 16.14.

Figure 16.4-1 — Non-dimensional graphical form of F

Z,max

(upper curve = maximum reinforced, lower curve = unreinforced)

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SIST EN 13445-3:2014/A8:2019

EN 13445-3:2014/A8:2019 (E)

Figure 16.4-2 ― Non-dimensional graphical form of M

B,max

(upper curve = maximum reinforced, lower curve = unreinforced)

Figure 16.4-3 ― Stress factor in sphere for internal pressure (flush nozzle)

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SIST EN 13445-3:2014/A8:2019

EN 13445-3:2014/A8:2019 (E)

Figure 16.4-4 — Stress factor in sphere for internal pressure (protruding nozzle)

Figure 16.4-5 — Stress factor in sphere for moment loading (flush nozzle)---------------------- Page: 18 ----------------------

SIST EN 13445-3:2014/A8:2019

EN 13445-3:2014/A8:2019 (E)

Figure 16.4-6 — Stress factor in sphere for moment loading (protruding nozzle)

Figure 16.4-7 — Stress factor in sphere for thrust loading (flush nozzle)

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SIST EN 13445-3:2014/A8:2019

EN 13445-3:2014/A8:2019 (E)

Figure 16.4-8 ― Stress factor in sphere for thrust loading (protruding nozzle)

”.

7 Modification to 16.5, Local loads on nozzles in cylindrical shells

Replace Subclause 16.5 with the following one:

16.5 Local loads on nozzles in cylindrical shells

16.5.1 Purpose

**...**

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