Bsi bs en 15776 2011 + a1 2015

1 Scope This European Standard specifies requirements for the design, material, manufacturing and testing of pressure vessels and pressure vessel parts made from materials for which deta

BSI Standards Publication

Unfired pressure vessels — Requirements for the design and fabrication of pressure vessels and pressure parts constructed from cast iron with

an elongation after fracture equal or less than 15 %

This British Standard is the UK implementation of

EN 15776:2011+A1:2015 It supersedes BS EN 15776:2011 which is withdrawn.

The start and finish of text introduced or altered by amendment is indicated in the text by tags Tags indicating changes to CEN text carry the number of the CEN amendment For example, text altered by CEN amendment A1 is indicated by .

The UK participation in its preparation was entrusted to Technical Committee PVE/1, Pressure Vessels.

A list of organizations represented on this committee can be obtained

on request to its secretary.

This publication does not purport to include all the necessary provisions

of a contract Users are responsible for its correct application.

© The British Standards Institution 2015

Published by BSI Standards Limited 2015 ISBN 978 0 580 86315 8

Amendments/corrigenda issued since publication

30 November 2015 Implementation of CEN amendment A1:2015

30 November 2015 Implementation of CEN correction notice

28 October 2015: Note 2 to entry added to subclause 3.1.1

NORME EUROPÉENNE

English Version

Unfired pressure vessels - Requirements for the design and

fabrication of pressure vessels and pressure parts constructed

from cast iron with an elongation after fracture equal or less than

15 %

Récipients sous pression non soumis à la flamme -

Exigences supplémentaires pour la conception et la

fabrication des récipients sous pression et des parties sous

pression moulés en fonte à allongement, après rupture,

inférieur ou égal à 15 %

Unbefeuerte Druckbehälter - Anforderungen an die Konstruktion und Herstellung von Druckbehältern und Druckbehälterteilen aus Gusseisen mit einer Bruchdehnung

von 15 % oder weniger

This European Standard was approved by CEN on 1 January 2011 and includes Amendment 1 approved by CEN on 24 August 2015 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a 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 European Standard 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, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M IT É E U R OP É E N D E N O RM A LIS A T IO N EURO PÄ ISC HES KOM ITE E FÜR NORM UNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2015 CEN All rights of exploitation in any form and by any means reserved Ref No EN 15776:2011+A1:2015 E

Contents Page

European foreword 4

Introduction 5

1 Scope 6

2 Normative references 6

3 Terms, definitions, units and symbols 7

3.1 Terms and definitions 7

3.2 Symbols 9

3.3 Inter relation of thicknesses definitions (!EN 13445-6:2014") 11

4 Materials, limitations and service conditions 11

4.1 Materials and limitations on temperature, maximum allowable pressure and energy content 11

4.2 Cyclic loading 13

5 Design requirements 14

5.1 Design principle 14

5.2 Conceptual design and construction drawings 14

5.3 Static loading 14

5.3.1 General 14

5.3.2 Design by formula (DBF) 14

5.3.3 Design by analysis (DBA) 15

5.3.4 Design by experiment (DBE) 15

5.4 Temperature reduction factor 16

5.5 Wall thickness reduction factor 16

5.6 Design for external pressure 16

5.7 Testing conditions 17

5.8 Design methods 17

5.8.1 General 17

5.8.2 Static loading 17

5.8.3 Dynamic loading 19

5.9 Construction details 24

5.9.1 Reinforcement of openings in cylinders, flat ends, dished ends, etc 24

5.9.2 Fillet radius 24

5.9.3 Dished cover 24

5.10 Technical documentation 24

5.10.1 General 24

5.10.2 Information to be contained in the technical documentation 24

5.10.3 Test reports 26

5.10.4 Technical/manufacturing schedule 26

5.10.5 Design review 26

6 Founding, material and casting testing 27

6.1 Founding 27

6.1.1 General 27

6.1.2 Welding 27

6.2 Material testing 27

Contents Page

European foreword 4

Introduction 5

1 Scope 6

2 Normative references 6

3 Terms, definitions, units and symbols 7

3.1 Terms and definitions 7

3.2 Symbols 9

3.3 Inter relation of thicknesses definitions (!EN 13445-6:2014") 11

4 Materials, limitations and service conditions 11

4.1 Materials and limitations on temperature, maximum allowable pressure and energy content 11

4.2 Cyclic loading 13

5 Design requirements 14

5.1 Design principle 14

5.2 Conceptual design and construction drawings 14

5.3 Static loading 14

5.3.1 General 14

5.3.2 Design by formula (DBF) 14

5.3.3 Design by analysis (DBA) 15

5.3.4 Design by experiment (DBE) 15

5.4 Temperature reduction factor 16

5.5 Wall thickness reduction factor 16

5.6 Design for external pressure 16

5.7 Testing conditions 17

5.8 Design methods 17

5.8.1 General 17

5.8.2 Static loading 17

5.8.3 Dynamic loading 19

5.9 Construction details 24

5.9.1 Reinforcement of openings in cylinders, flat ends, dished ends, etc 24

5.9.2 Fillet radius 24

5.9.3 Dished cover 24

5.10 Technical documentation 24

5.10.1 General 24

5.10.2 Information to be contained in the technical documentation 24

5.10.3 Test reports 26

5.10.4 Technical/manufacturing schedule 26

5.10.5 Design review 26

6 Founding, material and casting testing 27

6.1 Founding 27

6.1.1 General 27

6.1.2 Welding 27

6.2 Material testing 27

6.2.1 General 27

6.2.2 Frequency and number of tests 27

6.2.3 Inspection documents 28

6.3 Casting testing 28

6.3.1 General 28

6.3.2 Surface imperfections 28

6.3.3 Cracks, laps, cold shot and non-fused chaplets 28

6.3.4 Ultrasonic testing and/or sectioning 29

6.3.5 Liquid penetrant testing 29

6.3.6 Surface roughness 29

6.3.7 Minimum wall thickness 29

6.3.8 Wall thickness tolerances 29

6.3.9 Other dimensions 29

6.3.10 Qualification of testing personnel 29

7 Final assessment 30

7.1 General 30

7.2 Hydraulic test pressure 30

8 Pressure vessels assembled of a combination of parts in different materials 30

9 Marking and documentation 30

9.1 Marking of castings 30

9.2 Name plate for the complete pressure vessel 30

9.3 Documentation 31

Annex A (normative) Technical data for design calculations 32

Annex B (informative) Recommendations for in-service validation and inspection 35

B.1 Purpose 35

B.2 Tests during operation 35

Annex C (informative) Examples of fatigue design curves 36

Annex ZA (informative) Relationship between this European Standard and the Essential Requirements of EU Directive 97/23/EC 39

Bibliography 40

European foreword

This document (EN 15776:2011+A1:2015) 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 April 2016, and conflicting national standards shall be withdrawn at the latest by April 2016

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 supersede EN 15776:2011

This document includes Amendment 1 approved by CEN on 2015-08-24

The start and finish of text introduced or altered by amendment is indicated in the text by tags !" 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

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, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom

European foreword

This document (EN 15776:2011+A1:2015) 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 April 2016, and conflicting national standards shall be

withdrawn at the latest by April 2016

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 supersede EN 15776:2011

This document includes Amendment 1 approved by CEN on 2015-08-24

The start and finish of text introduced or altered by amendment is indicated in the text by tags !"

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

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, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom

Cast iron with elongation after fracture equal or less than 15 % may only be used for pressure equipment when operational and technical advantages are dictating its use instead of the cast iron grades given in !EN 13445-6:2014"with elongation after fracture higher than 15 %

1 Scope

This European Standard specifies requirements for the design, material, manufacturing and testing of pressure vessels and pressure vessel parts made from materials for which details are specified from the following material standards for specific grades which meet the criterion of an elongation after fracture less than or equal to 15 %:

— !EN 1561:2011", Founding — Grey cast irons;

— !EN 1563:2011", Founding — Spheroidal graphite cast irons;

— !EN 13835:2012", Founding — Austenitic cast irons

The allowed content of the vessel or pressure part is a fluid of group 2 only, according to the Directive 97/23/EC

2 Normative references

The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies

!EN 764-5:2014, Pressure equipment — Part 5: Inspection documentation of metallic materials and

compliance with the material specification"

!EN 1370:2011, Founding — Examination of surface condition"

!EN 1371-1:2011, Founding — Liquid penetrant testing — Part 1: Sand, gravity die and low pressure

die castings"

!EN 1559-1:2011", Founding — Technical conditions of delivery — Part 1: General

!EN 1559-3:2011", Founding — Technical conditions of delivery — Part 3: Additional requirements

for iron castings

!EN 1561:2011", Founding — Grey cast irons

!EN 1563:2011", Founding — Spheroidal graphite cast irons

!EN 12680-3:2011, Founding — Ultrasonic testing — Part 3: Spheroidal graphite cast iron castings"

!EN 13445-3:2014", Unfired pressure vessels — Part 3: Design

!EN 13445-5:2014", Unfired pressure vessels — Part 5: Inspection and testing

!EN 13445-6:2014", Unfired pressure vessels — Part 6: Requirements for the design and fabrication

of pressure vessels and pressure parts constructed from spheroidal graphite cast iron

!EN 13835:2012", Founding — Austenitic cast irons

!EN ISO 8062-3:2007", Geometrical Product Specifications (GPS) — Dimensional and geometrical

tolerances for moulded parts — Part 3: General dimensional and geometrical tolerances and machining allowances for castings (ISO 8062-3:2007)

1 Scope

This European Standard specifies requirements for the design, material, manufacturing and testing of

pressure vessels and pressure vessel parts made from materials for which details are specified from the

following material standards for specific grades which meet the criterion of an elongation after fracture

less than or equal to 15 %:

— !EN 1561:2011", Founding — Grey cast irons;

— !EN 1563:2011", Founding — Spheroidal graphite cast irons;

— !EN 13835:2012", Founding — Austenitic cast irons

The allowed content of the vessel or pressure part is a fluid of group 2 only, according to the

Directive 97/23/EC

2 Normative references

The following referenced documents are indispensable for the application of this document For dated

references, only the edition cited applies For undated references, the latest edition of the referenced

document (including any amendments) applies

!EN 764-5:2014, Pressure equipment — Part 5: Inspection documentation of metallic materials and

compliance with the material specification"

!EN 1370:2011, Founding — Examination of surface condition"

!EN 1371-1:2011, Founding — Liquid penetrant testing — Part 1: Sand, gravity die and low pressure

die castings"

!EN 1559-1:2011", Founding — Technical conditions of delivery — Part 1: General

!EN 1559-3:2011", Founding — Technical conditions of delivery — Part 3: Additional requirements

for iron castings

!EN 1561:2011", Founding — Grey cast irons

!EN 1563:2011", Founding — Spheroidal graphite cast irons

!EN 12680-3:2011, Founding — Ultrasonic testing — Part 3: Spheroidal graphite cast iron castings"

!EN 13445-3:2014", Unfired pressure vessels — Part 3: Design

!EN 13445-5:2014", Unfired pressure vessels — Part 5: Inspection and testing

!EN 13445-6:2014", Unfired pressure vessels — Part 6: Requirements for the design and fabrication

of pressure vessels and pressure parts constructed from spheroidal graphite cast iron

!EN 13835:2012", Founding — Austenitic cast irons

!EN ISO 8062-3:2007", Geometrical Product Specifications (GPS) — Dimensional and geometrical

tolerances for moulded parts — Part 3: General dimensional and geometrical tolerances and machining

allowances for castings (ISO 8062-3:2007)

3 Terms, definitions, units and symbols

3.1 Terms and definitions

For the purposes of this document, the following terms and definitions apply

3.1.1 grey cast iron

cast material, mainly iron and carbon based, carbon being present mainly in the form of flake (lamellar) graphite particles (!EN 1561:2011")

! Note 1 to entry:" Grey cast iron is also known as flake graphite cast iron, and less commonly as lamellar graphite cast iron

! Note 2 to entry: Grey cast irons contain 2,0 % - 4,5 % carbon and 1 % - 3 % silicon The structure consists of branched and interconnected graphite flakes in a matrix which is pearlite, ferrite or a mixture "

3.1.2 spheroidal graphite cast iron

cast material, mainly iron and carbon-based, the carbon being present mainly in the form of spheroidal graphite particles (!EN 1563:2011")

! Note 1 to entry:" Spheroidal graphite cast iron is also known as ductile iron, and less commonly as nodular iron

! Note 2 to entry: The mechanical properties of grey irons can be greatly improved if the graphite shape is modified if molten iron, having a composition in the range 3,2 % - 4,5 % carbon and 1,8 % - 2,8 % silicon, is treated with magnesium This produces castings with graphite in spheroidal form instead of flakes, known as nodular, spheroidal graphite or ductile iron Nodular irons are available with pearlite, ferrite or pearlite-ferrite matrices which offer a combination of greater ductility and higher tensile strength than grey cast irons."

3.1.3 austenitic cast iron

!cast material with an austenitic matrix which is iron and carbon and silicon based and alloyed with nickel and manganese, copper and/or chromium in order to stabilize the austenitic structure at room temperature

Note 1 to entry: The graphite can be present in flake or spheroidal form (EN 13835:2012)."

3.1.4 relevant wall thickness

!wall thickness representative of the casting, defined for the determination of the size of the cast samples to which the guaranteed mechanical properties apply"

3.1.5 critical zone

highly stressed area where a fracture is expected to occur in a burst test

NOTE 1 It can be caused, for example, by any of the following:

— sudden change in cross section;

— sharp edges;

— sharp radii;

NOTE 3 Additionally, thermal gradients and thermal stresses due to different operating wall temperatures are

to be considered in defining critical zones

3.1.6

purchaser

individual or organisation that buys pressure equipment, including assemblies or parts, for its own use

or on behalf of the user and/or operator

wall thickness factor

reduction factor applied to the nominal design stress to take account of reduced mechanical properties

— peak stresses;

— bending stresses;

— stresses due to other than membrane stress;

— changes in curvature

NOTE 2 A critical zone is analysed by any appropriate method, e.g holographic, interferometric method, strain

gauge methods, burst test, fatigue testing, FEM analysis, etc

NOTE 3 Additionally, thermal gradients and thermal stresses due to different operating wall temperatures are

to be considered in defining critical zones

3.1.6

purchaser

individual or organisation that buys pressure equipment, including assemblies or parts, for its own use

or on behalf of the user and/or operator

3.1.7

manufacturer

individual or organisation responsible for the design, fabrication, testing, inspection, installation of

pressure equipment and assemblies where relevant

NOTE 1 The manufacturer may subcontract one or more of the above mentioned tasks under its responsibility

wall thickness factor

reduction factor applied to the nominal design stress to take account of reduced mechanical properties

emax maximum local thickness at the location of a possible fatigue crack

emin minimum thickness as specified on drawing mm

ftest nominal design stress for testing condition MPa

mC exponent in equation of fatigue design curve

neq number of equivalent full pressure cycles

A, A 5 minimum elongation after fracture %

CC coefficient in equation of fatigue design curve

F test factor used in experimental fatigue assessment

Keff effective stress concentration factor

Kt theoretical elastic stress concentration factor

m c value from appropriate Tables 10, 11, 13, 14 in the appropriate

number of cycle number range used in fatigue calculations

N total number of envisaged types of pressure cycles with different amplitude

Nall allowable number of cycles obtained from the fatigue design curve

Symbol Quantity Unit

Nmin minimum number of cycles obtained in experimental fatigue

n i number of cycles with amplitude ΔPi

Pmax maximum permissible pressure b MPa a

!deleted text"

Rp0,2/T minimum 0,2 % - proof strength at temperature T in degrees Celsius MPa

Rz surface roughness parameter – peak – to - valley height µm

!RM3 average strength from 3 tensile test samples MPa"

TS max , TS min maximum / minimum allowable temperature °C

ΔσR stress range in fatigue design curve MPa

ε extra thickness due to casting process mm

Symbol Quantity Unit

Nmin minimum number of cycles obtained in experimental fatigue

n i number of cycles with amplitude ΔPi

Pmax maximum permissible pressure b MPa a

!deleted text"

Rp0,2/T minimum 0,2 % - proof strength at temperature T in degrees Celsius MPa

Rz surface roughness parameter – peak – to - valley height µm

!RM3 average strength from 3 tensile test samples MPa"

TS max , TS min maximum / minimum allowable temperature °C

ΔσR stress range in fatigue design curve MPa

ε extra thickness due to casting process mm

σe nominal design stress for external pressure MPa

a MPa for calculation purposes only, otherwise the unit shall be bar (1 MPa = 10 bar)

b See also !EN 13445-3:2014", Table 4-1

3.3 Inter relation of thicknesses definitions (!EN 13445-6:2014")

Key

e required thickness

ea analysis thickness

emin minimum thickness including corrosion allowance as indicated on drawings

eact actual thickness

c corrosion allowance

ε extra thickness due to casting process

δ casting tolerance

Figure 1

4 Materials, limitations and service conditions

4.1 Materials and limitations on temperature, maximum allowable pressure and energy content

!All material grades subject to internal or external pressure shall comply with EN 1561:2011 for grey cast iron, EN 1563:2011 for spheroidal graphite cast iron and EN 13835:2012 for austenitic cast iron The material grades and corresponding limitations are given in Table 2 and Table 3

Table 2 — Allowable material grades and limitations for grey cast iron and austenitic lamellar

graphite cast iron Material

standard Material designation temperature Design

range

TSmin /TSmax

Maximum allowable

pressure PS

Maximum energy content

- 10 ≤ T ≤ 200

EN-GJL-350 5.1303

EN 13835:2012 EN-GJLA-XNiCuCr15-6-2 5.1500 - 10 ≤ T ≤ 200

EN-GJLA-XNiMn13-7 5.1501

The product PS × V, and the design temperature range of Table 2 for a single casting may be exceeded

only for material grades EN-GJL-3001) and EN-GJL-3501) up to 300 °C and a product PS × V, as

appropriate, when all the following conditions are met:

— maximum allowable temperature TSmax ≤ 300 °C;

— maximum allowable pressure lowered from 25 bar to PS ≤ 15 bar;

— documented stress factor ≤ 2 throughout the casting;

— stress relief heat treatment is carried out when the maximum cooling rate in the mould exceeds 30

°C/h for the temperature range from 600 °C decreasing to 150 °C

NOTE An in-service inspection to Annex B of this standard may be considered to be mentioned in the operating instructions of the part or vessel

1) The requirements of particular material grades in this clause may allow the fabrication of paper cylinder and dryer rollers

Table 2 — Allowable material grades and limitations for grey cast iron and austenitic lamellar

graphite cast iron Material

standard Material designation temperature Design

range

TSmin /TSmax

Maximum allowable

pressure PS

Maximum energy content

- 10 ≤ T ≤ 200

EN-GJL-350 5.1303

EN 13835:2012 EN-GJLA-XNiCuCr15-6-2 5.1500 - 10 ≤ T ≤ 200

EN-GJLA-XNiMn13-7 5.1501

The product PS × V, and the design temperature range of Table 2 for a single casting may be exceeded

only for material grades EN-GJL-3001) and EN-GJL-3501) up to 300 °C and a product PS × V, as

appropriate, when all the following conditions are met:

— maximum allowable temperature TSmax ≤ 300 °C;

— maximum allowable pressure lowered from 25 bar to PS ≤ 15 bar;

— documented stress factor ≤ 2 throughout the casting;

— stress relief heat treatment is carried out when the maximum cooling rate in the mould exceeds 30

°C/h for the temperature range from 600 °C decreasing to 150 °C

NOTE An in-service inspection to Annex B of this standard may be considered to be mentioned in the

operating instructions of the part or vessel

1) The requirements of particular material grades in this clause may allow the fabrication of paper cylinder and dryer rollers

Table 3 — Allowable material grades and design limits for spheroidal graphite cast iron Material

standard

Material designation

Design temperature range

TSmin /TSmax

Maximum allowable pressure

PS

Maximum energy content

cycles neq with smaller amplitude according to Equation (1)

Table 4 — Full pressure cycle number for dynamic loading consideration Material grade

Maximum number of full pressure cycles without mandatory

fatigue analysis according to Equation (1)

(if stress factor η ≤ 3) Grades according to Table 2 8 000 Grades according to Table 3 50 000

The calculation of an equivalent number of full pressure cycles neq when the operating pressure is less than the maximum pressure shall be calculated according to Equation (1):

c m

where

N is the total number of envisaged types of pressure cycles with different amplitude;

ni is the number of cycles with amplitude ∆ Pi;

i

P

∆ is the pressure cycle amplitude;

max

P is the maximum permissible pressure, as defined in !EN 13445-3:2014", 3.16;

mC is the value from Table 10 (lamellar graphite cast iron grades) or Table 11 (spheroidal graphite

cast iron grades) in the appropriate number of cycle range value for 10 3 < N < 106 or

10 6 < N < 108 whichever is the case

NOTE A stress factor – defined in 3.1.11 (ratio of peak stress to total stress-defined in 3.1.12) − greater than

3, determined by any of the design methods given in 5.8, can be the result of inappropriate design By enlarging radii or other small changes, an acceptable design may be generated It is recommended to carry out a finite element analysis to determine areas with possible excessive stress concentrations !These area's may be also found in feets, supports, lifting lugs, etc which may influence stress distribution in the pressure part."

5 Design requirements

5.1 Design principle

The loadings to be accounted for shall be in accordance with !EN 13445-3:2014", Clause 5

The materials, limitations and service conditions of Clause 4 of this standard shall be considered

Design methods shall be in accordance with this European Standard and, when indicated in a clause of this standard, with the relevant clauses of !EN 13445-6:2014"

If the geometry of the component or the loading case does not allow calculation by the formulas given in

!EN 13445-3:2014", design by analysis (DBA) or design by experiment (DBE) shall be applied Depending on the complexity of the component, the loading conditions and the level of NDT, the designer may choose one of the following available design methods mentioned below Correlation between safety factor, testing factor and the method to assess dynamic loading is given in Table 5

5.2 Conceptual design and construction drawings

The manufacturer analysis of hazards identifying those which apply to the pressure vessel on account of pressure shall be documented and be of sufficient detail

Details of the conceptual design including the design methods adopted, performance criteria and construction drawings shall be provided Guidance about the detailed dimensional information that shall be provided is given in Annex B of !EN 13445-5:2014" Process diagrams, sub-assemblies or other data relevant to conceptual design shall also be maintained

13445-where

N is the total number of envisaged types of pressure cycles with different amplitude;

ni is the number of cycles with amplitude ∆ Pi;

i

P

∆ is the pressure cycle amplitude;

max

P is the maximum permissible pressure, as defined in !EN 13445-3:2014", 3.16;

mC is the value from Table 10 (lamellar graphite cast iron grades) or Table 11 (spheroidal graphite

cast iron grades) in the appropriate number of cycle range value for 10 3 < N < 106 or

10 6 < N < 108 whichever is the case

NOTE A stress factor – defined in 3.1.11 (ratio of peak stress to total stress-defined in 3.1.12) − greater than

3, determined by any of the design methods given in 5.8, can be the result of inappropriate design By enlarging

radii or other small changes, an acceptable design may be generated It is recommended to carry out a finite

element analysis to determine areas with possible excessive stress concentrations !These area's may be also

found in feets, supports, lifting lugs, etc which may influence stress distribution in the pressure part."

5 Design requirements

5.1 Design principle

The loadings to be accounted for shall be in accordance with !EN 13445-3:2014", Clause 5

The materials, limitations and service conditions of Clause 4 of this standard shall be considered

Design methods shall be in accordance with this European Standard and, when indicated in a clause of

this standard, with the relevant clauses of !EN 13445-6:2014"

If the geometry of the component or the loading case does not allow calculation by the formulas given in

!EN 13445-3:2014", design by analysis (DBA) or design by experiment (DBE) shall be applied

Depending on the complexity of the component, the loading conditions and the level of NDT, the

designer may choose one of the following available design methods mentioned below Correlation

between safety factor, testing factor and the method to assess dynamic loading is given in Table 5

5.2 Conceptual design and construction drawings

The manufacturer analysis of hazards identifying those which apply to the pressure vessel on account of

pressure shall be documented and be of sufficient detail

Details of the conceptual design including the design methods adopted, performance criteria and

construction drawings shall be provided Guidance about the detailed dimensional information that

shall be provided is given in Annex B of !EN 13445-5:2014" Process diagrams, sub-assemblies or

other data relevant to conceptual design shall also be maintained

5.3 Static loading

5.3.1 General

In order to design the part for static loading, the following shall be considered by the designer

5.3.2 Design by formula (DBF)

Equations for the calculation of the various components of the pressure part are given in !EN

13445-3:2014"and !EN 13445-6:2014", Annex G This Annex G gives additional equations for

non-standard shaped parts often used in casting design Nominal design stress for component forms other than bolts shall be calculated in accordance with Table 5 If design by experimental method is used, it shall be in conformity with 5.3.4 of this standard In general, the manufacturer shall specify to the casting manufacturer which zones are critical related to the design and design loads Other critical zones may be indicated by the casting manufacturer related to the casting process and shall be taken into account by the manufacturer

Table 5 — Safety factor and nominal design stress

Table 3

Material grades according to Table 2

Grade according to As cast

Stress relieve annealed

Rm is the tensile strength value for a given wall thickness according to Table A.1;

Rp0,2 is 0,2 % proof strength value according to Table A.4

where A5 is the elongation after fracture in percent according to !EN 1563:2011"and !EN 13835:2012"

* If a risk of stress corrosion cracking may exist, especially for austenitic grades at higher temperatures, a stress relief heat treatment is beneficial depending on the service conditions but is left to the agreement between the parties concerned

5.3.3 Design by analysis (DBA)

a) Decide whether the direct route (limit load, !EN 13445-3:2014", Annex B) or the stress categorization method (!EN 13445-3:2014", Annex C) will be followed Decide whether linear

or non-linear approach will be used;

b) base modelling and interpretation of calculation results shall be based on analysis thickness (ea) and material characteristics at operation temperature;

c) for interpretation of calculation results, follow the evaluation procedures and assessment criteria in order to evaluate the fitness for purpose of the real structure These design checks and related procedures are typical for the failure mode to be dealt with For the different failure modes, see

!EN 13445-3:2014"

5.3.4 Design by experiment (DBE)

Where design by equations (DBF) according to !EN 13445-3:2014"is not considered appropriate due to the complex shape of the component, then a hydraulic burst test to determine the analysis

thickness ea and the minimum thickness emin shall be performed according to the procedure in 5.8.2.4 This test is also a part of the technical documentation

NOTE 1 For vessels for which PS × V < 6 000 bar × L (600 MPa × L) an experimental method may be applied as

an alternative to the design by formulae (DBF) or design by analysis (DBA) methods

NOTE 2 For vessels for which PS × V ≥ 6 000 bar × L (600 MPa × L) the experimental method may be used in

addition to detailed design

5.4 Temperature reduction factor

For grey cast iron material grades according to !EN 1561:2011"and austenitic lamellar graphite cast iron material grades according to !EN 13835:2012"mechanical properties shall be considered

to remain constant for the temperature range - 10 °C up to 200 °C

For spheroidal graphite cast iron material grades according to !EN 1563:2011":

CT = 1 – 0,001(T - 20) for 20 °C < T ≤ 300 °C 2 ) (3) For austenitic spheroidal graphite cast iron material grades according to !EN 13835:2012":

CT = 1 – 0, 000 5 (T - 20) for 20 °C < T ≤ 540 °C (5)

5.5 Wall thickness reduction factor

For spheroidal graphite cast iron material grades according to !EN 1563:2011"and

!EN 13835:2012":

NOTE The wall thickness reduction factor for lamellar graphite cast iron grades according to

! EN 1561:2011"is already included in Table A.1 in this standard and needs no extra thickness correction factor

5.6 Design for external pressure

Design for external pressure shall be carried out according to !EN 13445-3:2014", Clause 8, with the following modifications:

Replace Equations 8.4.2-1, 8.4.2-2, 8.4.3-1, 8.4.3-2 by:

0,2/

e R p T C e

The minimum safety factor, which applies throughout this clause, is given by:

— for material grades according to Table 2:

— for material grades according to Table 3:

2) See Bibliography ref [13]

NOTE 1 For vessels for which PS × V < 6 000 bar × L (600 MPa × L) an experimental method may be applied as

an alternative to the design by formulae (DBF) or design by analysis (DBA) methods

NOTE 2 For vessels for which PS × V ≥ 6 000 bar × L (600 MPa × L) the experimental method may be used in

addition to detailed design

5.4 Temperature reduction factor

For grey cast iron material grades according to !EN 1561:2011"and austenitic lamellar graphite

cast iron material grades according to !EN 13835:2012"mechanical properties shall be considered

to remain constant for the temperature range - 10 °C up to 200 °C

For spheroidal graphite cast iron material grades according to !EN 1563:2011":

5.5 Wall thickness reduction factor

For spheroidal graphite cast iron material grades according to !EN 1563:2011"and

!EN 13835:2012":

NOTE The wall thickness reduction factor for lamellar graphite cast iron grades according to

! EN 1561:2011"is already included in Table A.1 in this standard and needs no extra thickness correction

factor

5.6 Design for external pressure

Design for external pressure shall be carried out according to !EN 13445-3:2014", Clause 8, with

the following modifications:

Replace Equations 8.4.2-1, 8.4.2-2, 8.4.3-1, 8.4.3-2 by:

0,2/

e R p T C e

The minimum safety factor, which applies throughout this clause, is given by:

— for material grades according to Table 2:

— for material grades according to Table 3:

2) See Bibliography ref [13]

5.7 Testing conditions

The test pressure may exceed the value given in Equation (15) either intentionally or occasionally

However, the nominal design stress for testing conditions, ftest shall not exceed the following values For material grades according to Table 2:

In order to design the part for static loading, the following options can be considered by the designer

5.8.2.2 Design by formula (DBF)

Formulas for the calculation of the various components of the pressure part are given in !EN 3:2014"

13445-5.8.2.3 Design by analysis (DBA)

For cast iron pressure vessels the general procedures and corresponding rules are covered by

!EN 13445-6:2014", Annex E "Design by analysis for castings" with the following modifications:

— additional to !EN 13445-6:2014", Annex E.2.1 "Design checks for normal operating load cases"

Material strength parameters (RM) and partial safety factors (γR) shall be as given in Table 6:

a) S according to Table 5

— additional to !EN 13445-6:2014", Annex E.2.2 "Design checks for testing load cases"

RM and γR shall be as given in Table 7 and Table 8:

Table 7 — RM and γ R for test load case lamellar cast iron grades

According to Table 3 Rp0,2/Ttest 1,33/Ce

5.8.2.4 Design by experiment (DBE)

Design by experiment shall be carried out according to !EN 13445-6:2014", 5.2.2.1.5, where:

— for material grades according to Table 2 of this standard, the following formula applies:

( ) 3 1/2,

n = 1 for curved surfaces (cylinders, spheres) or cones with angles α ≤ 60°, stayed surfaces and

stressed parts when it can be shown that the bending stress is less than 2/3 of the total stress;

n = 2 for all other surfaces except when it can be shown that the bending stress is less than 2/3 of

the total stress

5.8.2.5 !RM3" Determination and general test requirements

For determining !RM3" three tensile test specimen shall be performed in accordance with

!EN 1561:2011", !EN 1563:2011"or !EN 13835:2012"material standards for each of the required positions taken from the same cast

The specimen positions shall be in accordance with the specifications in the technical delivery conditions of the product form for materials for pressure equipment In addition to the requirements of the material, the manufacturer and the purchaser may agree on the properties required at stated positions in the casting These properties shall be determined by testing machined test pieces cut from the casting at these stated positions The mean value of the three specimens shall be used to determine

the ratio of !RM3"/Rm

Specimen may be taken before the burst test on an identical part or on the same part after burst test It

is not allowed to use scaled-down part of the part under investigation 3)

The position on the casting from where the sample is cut shall be in an area where the casting wall thickness is close to the relevant wall thickness of the casting For the purpose of determining the size of

3) When taking values after burst testing these may show lower tensile strength properties for some grades and should only

be used with caution in exceptional cases (single part or very large part, etc.)

Table 7 — RM and γ R for test load case lamellar cast iron grades

According to Table 3 Rp0,2/Ttest 1,33/Ce

5.8.2.4 Design by experiment (DBE)

Design by experiment shall be carried out according to !EN 13445-6:2014", 5.2.2.1.5, where:

— for material grades according to Table 2 of this standard, the following formula applies:

( ) 3 1/2,

n = 1 for curved surfaces (cylinders, spheres) or cones with angles α ≤ 60°, stayed surfaces and

stressed parts when it can be shown that the bending stress is less than 2/3 of the total stress;

n = 2 for all other surfaces except when it can be shown that the bending stress is less than 2/3 of

the total stress

5.8.2.5 !RM3" Determination and general test requirements

For determining !RM3" three tensile test specimen shall be performed in accordance with

!EN 1561:2011", !EN 1563:2011"or !EN 13835:2012"material standards for each of the

required positions taken from the same cast

The specimen positions shall be in accordance with the specifications in the technical delivery

conditions of the product form for materials for pressure equipment In addition to the requirements of

the material, the manufacturer and the purchaser may agree on the properties required at stated

positions in the casting These properties shall be determined by testing machined test pieces cut from

the casting at these stated positions The mean value of the three specimens shall be used to determine

the ratio of !RM3"/Rm

Specimen may be taken before the burst test on an identical part or on the same part after burst test It

is not allowed to use scaled-down part of the part under investigation 3)

The position on the casting from where the sample is cut shall be in an area where the casting wall

thickness is close to the relevant wall thickness of the casting For the purpose of determining the size of

3) When taking values after burst testing these may show lower tensile strength properties for some grades and should only

be used with caution in exceptional cases (single part or very large part, etc.)

the test pieces to be used, the purchaser shall, by the time of acceptance of the order, indicate to the manufacturer which are the important sections In the absence of any direction by the purchaser, the manufacturer may choose the size of the test piece to be used according the relevant standard

No specimen may show a lower value than the minimum value of Rm stated in the respective material standards of the material grade under investigation, taking into account the corresponding thickness The preferred test piece diameter is 14 mm, but, for technical reasons and for test pieces machined from castings, it is permitted to use a test piece of different diameter or equivalent diameter

Retesting shall be carried out if a test is not valid A test is not valid if there is:

— a faulty mounting of the test piece or defective operation of the test machine;

— a defective test piece because of incorrect pouring or incorrect machining;

— a fracture of the tensile test piece outside the gauge length;

— a casting defect in the test piece, evident after fracture

In all cases, a new test piece shall be taken from the same sample or a duplicate sample cast at the same time The result of the retest shall be used

5.8.2.6 Determination of the minimum hydraulic burst pressure and maximum allowable pressure for static loading

For the purposes of this standard the methods given in !EN 13445-6:2014", 5.2.2.1.6 to determine the minimum hydraulic burst pressure and maximum allowable pressure for static loading apply with the following modification:

Replace in formulae 5-3 and 5-4 n as follows:

— for material grades given in Table 2, n = 2 applies in all cases of curvature of the pressure part;

— for material grades given in Table 3, see 5.2.2.1.6 of !EN 13445-6:2014"

5.8.3 Dynamic loading 5.8.3.1 General

If the number of full pressure cycles or equivalent full pressure cycles according to Equation (1) exceeds the number of full pressure cycles for static loading considered in Table 4, a fatigue assessment of the complete design is required In order to design the part for dynamic loading, the following options can

be considered by the designer:

— a simplified fatigue assessment (maximum allowable number of equivalent pressure fluctuations);

or

— a detailed fatigue assessment (maximum allowable number of equivalent pressure fluctuations using detailed stress analysis which is less conservative than the simplified method)

5.8.3.2 Simplified fatigue assessment (SFA)

A simplified fatigue assessment will give a maximum allowable number of equivalent pressure fluctuations under service conditions

The assessment shall be performed according to !EN 13445-6:2014", Annex D with equation

modifications as listed in Table 9 and coefficients of Table 10 and Table 11 for mC and CC

Table 9 — Equations for simplified fatigue assessment Equation and definition in

D.6.1 Pseudo elastic stress range Δσ*

Replace

! EN 13445-6:2014", Annex D Equation 6.1 by

* max

P f P

η

Same as !EN 6:2014", D.6.1

13445-D.6.2, D.6.3 Correction factor for wall thickness fe f =e 1 for all

thicknesses

As ! EN 6:2014", D.6.2 and D.6.3

13445-D.6.4

temperature correction factor for

ferritic/pearlitic materials

T

f n.a As 6:2014", D.6.4 !EN

13445-D.6.4

temperature correction factor for pearlitic materials only

13445-D.6.8 Stress range, fatigue design

Replace

! EN 13445-6:2014", Annex D.6.8 by

Replace

! EN 13445-6:2014", D.6.8 by

1

C

C R m

C N

13445-*

c m

13445-*

c m C

13445-Table 9 — Equations for simplified fatigue assessment Equation and definition in

Table 3 of this standard

D.6.1 Pseudo elastic stress range Δσ*

Replace

! EN 13445-6:2014", Annex D Equation 6.1 by

* max

P f P

η

Same as !EN 6:2014", D.6.1

13445-D.6.2, D.6.3 Correction factor for wall thickness fe f =e 1 for all

thicknesses

As ! EN 6:2014", D.6.2 and D.6.3

13445-D.6.4

temperature correction factor

for ferritic/pearlitic

for pearlitic materials only

for austenitic materials

13445-D.6.8 Stress range, fatigue design

Replace

! EN 13445-6:2014", Annex D.6.8 by

Replace

! EN 13445-6:2014", D.6.8 by

1

C

C R

m

C N

13445-*

c m

13445-*

c m

13445-Equation 6.10

Table 10 — Coefficients of the fatigue design curves for lamellar graphite cast iron grades

according to Table 2 (NOTE) − Simplified assessment

Material grades according to Table 2

Constants of fatigue design curve

ΔσR – N Allowable stress range at N cycles MPa

10 3 < N < 106 10 6 < N < 108

ΔσD at N = 106 Δσcut at N = 108

As cast 7 1,440 10 0,797 0,200 × Rm 0,126 × Rm

Stress relieve annealed 7 1,830 10 1,012 0,254 × Rm 0,160 × Rm

NOTE See Table 2 of this standard for allowed lamellar graphite cast iron grades taken from

! EN 1561:2011"and !EN 13835:2012"

An example of a fatigue design curve for simplified assessment is given in informative Annex C

Table 11 — Coefficients of the fatigue design curves for spheroidal graphite cast iron grades according to !EN 1563:2011"and !EN 13835:2012"and Table 3 − Simplified assessment

Material grade according

to Table 2 Constants of fatigue design curve Δσ103 < N < 2 × 106 2 × 106 < N < 10R – N 8 range at N cycles MPa Allowable stress

5.8.3.3 Detailed fatigue assessment (DFA)

A detailed fatigue assessment returns a value of maximum allowable number of equivalent pressure fluctuations using detailed stress analysis in service conditions

The assessment shall be performed according to !EN 13445-6:2014", Annex D with modifications

to equations and coefficients of Table 13 and Table 14 for mC and CC as listed in Table 12, Table 13 and Table 14