Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells

This European Standard specifies the method for the strength calculation of the shell with respect to internal pressure of the valve.

Industriearmaturen - Gehäusefestigkeit - Teil 2: Berechnungsverfahren für drucktragende Gehäuse von Armaturen aus Stahl

Diese Europäische Norm legt das Verfahren zur Berechnung der Festigkeit des drucktragenden Gehäuses gegen den Innendruck der Armatur fest.

Robinetterie industrielle - Résistance mécanique des enveloppes - Partie 2 : Méthode de calcul relative aux enveloppes d'appareils de robinetterie en acier

La présente Norme européenne spécifie la méthode de calcul de la résistance de l'enveloppe par rapport à la pression intérieure de l’appareil de robinetterie.

Industrijski ventili - Trdnost ohišja - 2. del: Metoda za izračun ohišij jeklenih ventilov

General Information

Status
Published
Publication Date
14-Nov-2021
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
03-Nov-2021
Due Date
08-Jan-2022
Completion Date
15-Nov-2021

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SLOVENSKI STANDARD
SIST EN 12516-2:2015+A1:2021
01-december-2021

Industrijski ventili - Trdnost ohišja - 2. del: Metoda za izračun ohišij jeklenih

ventilov

Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells

Industriearmaturen - Gehäusefestigkeit - Teil 2: Berechnungsverfahren für
drucktragende Gehäuse von Armaturen aus Stahl

Robinetterie industrielle - Résistance mécanique des enveloppes - Partie 2 : Méthode de

calcul relative aux enveloppes d'appareils de robinetterie en acier
Ta slovenski standard je istoveten z: EN 12516-2:2014+A1:2021
ICS:
23.060.01 Ventili na splošno Valves in general
SIST EN 12516-2:2015+A1:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 12516-2:2015+A1:2021
---------------------- Page: 2 ----------------------
SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2021
EUROPÄISCHE NORM
ICS 23.060.01 Supersedes EN 12516-2:2014
English Version
Industrial valves - Shell design strength - Part 2:
Calculation method for steel valve shells

Robinetterie industrielle - Résistance mécanique des Industriearmaturen - Gehäusefestigkeit - Teil 2:

enveloppes - Partie 2 : Méthode de calcul relative aux Berechnungsverfahren für drucktragende Gehäuse von

enveloppes d'appareils de robinetterie en acier Armaturen aus Stahl

This European Standard was approved by CEN on 9 August 2014 and includes Amendment 1 approved by CEN on 6 September

2021.

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

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12516-2:2014+A1:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 7

2 Normative references .................................................................................................................................... 7

3 Symbols and units ........................................................................................................................................... 7

4 General conditions for strength calculation ....................................................................................... 13

5 Design pressure ............................................................................................................................................ 14

6 Nominal design stresses for pressure parts other than bolts ...................................................... 14

6.1 General ............................................................................................................................................................. 14

6.2 Steels and cast steels other than defined in 6.3, 6.4 or 6.5............................................................ 15

6.3 !Austenitic steel and austenitic cast steel with a minimum rupture elongation > 30

%" .................................................................................................................................................................. 16

6.4 !Austenitic steel and austenitic cast steel with a minimum rupture elongation > 35

%" .................................................................................................................................................................. 16

6.5 Ferritic and martensitic cast steel ......................................................................................................... 16

6.6 Creep conditions ........................................................................................................................................... 16

7 Calculation methods for the wall thickness of valve bodies ......................................................... 16

7.1 General ............................................................................................................................................................. 16

7.2 Wall thickness of bodies and branches outside crotch area ........................................................ 17

7.2.1 General ............................................................................................................................................................. 17

7.2.2 Cylindrical bodies or branches ............................................................................................................... 17

7.2.3 Spherical bodies or branches .................................................................................................................. 18

7.2.4 Conical bodies or branches ....................................................................................................................... 18

7.2.5 Bodies or branches with oval or rectangular cross-sections ....................................................... 20

7.3 Wall thickness in the crotch area ........................................................................................................... 27

7.4 Examples of pressure-loaded areas Ap and metallic cross-sectional areas Af ........................ 28

7.4.1 General ............................................................................................................................................................. 28

7.4.2 Cylindrical valve bodies ............................................................................................................................. 29

7.4.3 Spherical valve bodies ................................................................................................................................ 31

7.4.4 Oval and rectangular cross-sections ..................................................................................................... 32

7.4.5 Details ............................................................................................................................................................... 33

8 Calculation methods for bonnets and covers ..................................................................................... 36

8.1 General ............................................................................................................................................................. 36

8.2 Covers made of flat plates ......................................................................................................................... 36

8.2.1 General ............................................................................................................................................................. 36

8.2.2 Circular cover without opening, with ................................................................................................... 41

8.2.3 Circular covers with concentric circular opening, with ................................................................. 42

8.2.4 Non-circular covers (elliptical or rectangular) ................................................................................. 43

8.2.5 Special covers made of flat circular plates for specific load and clamping conditions ....... 44

8.3 Covers consisting of a spherically domed end and an adjoining flanged ring ....................... 59

8.3.1 General ............................................................................................................................................................. 59

8.3.2 Wall thickness and strength calculation of the spherical segment ............................................ 60

8.3.3 Calculation of the flanged ring................................................................................................................. 61

8.3.4 Reinforcement of the stuffing box area ................................................................................................ 63

8.4 Dished heads .................................................................................................................................................. 63

8.4.1 General remarks ........................................................................................................................................... 63

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SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)

8.4.2 Solid dished heads ........................................................................................................................................ 64

8.4.3 Dished heads with opening ....................................................................................................................... 65

8.4.4 Allowances on the wall thickness ........................................................................................................... 67

9 Calculation method for pressure sealed bonnets and covers....................................................... 68

10 Calculation methods for flanges .............................................................................................................. 70

10.1 General ............................................................................................................................................................. 70

10.2 Circular flanges .............................................................................................................................................. 70

10.2.1 General ............................................................................................................................................................. 70

10.2.2 Flanges with tapered neck ........................................................................................................................ 71

10.2.3 Flanges greater than DN 1 000................................................................................................................. 73

10.2.4 Welding neck with tapered neck according to Figure 48 ............................................................... 74

10.2.5 Weld-on flanges ............................................................................................................................................. 75

10.2.6 Reverse flanges .............................................................................................................................................. 78

10.2.7 Loose flanges .................................................................................................................................................. 78

10.3 Oval flanges ..................................................................................................................................................... 80

10.3.1 Oval flanges in accordance with Figure 54 .......................................................................................... 80

10.3.2 Oval flanges in accordance with Figure 55 .......................................................................................... 82

10.4 Rectangular or square flanges ................................................................................................................. 84

10.4.1 Rectangular or square flanges in accordance with Figure 57 ...................................................... 84

10.4.2 Rectangular slip-on flanges in accordance with Figure 58 ............................................................ 85

10.5 Calculation of the bolt diameter .............................................................................................................. 86

10.5.1 Design temperature ..................................................................................................................................... 86

10.5.2 Diameter of the nominal tensile stress ................................................................................................. 86

10.5.3 Load cases ........................................................................................................................................................ 86

10.5.4 Safety factors and allowances .................................................................................................................. 87

11 Calculation methods for glands ............................................................................................................... 87

11.1 Loads ................................................................................................................................................................. 87

11.2 Gland bolts ...................................................................................................................................................... 88

11.3 Gland flanges .................................................................................................................................................. 88

11.4 Other components ........................................................................................................................................ 88

12 Fatigue .............................................................................................................................................................. 88

13 Marking ............................................................................................................................................................ 88

Annex A (informative) Characteristic values of gaskets and joints ........................................................... 89

Annex B (informative) Calculation procedure ............................................................................................... 102

Annex ZA (informative) !Relationship between this European Standard and the essential

requirements of Directive 2014/68/EU aimed to be covered" ............................................ 104

Bibliography .............................................................................................................................................................. 105

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SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
European foreword

This document (EN 12516-2:2014+A1:2021) has been prepared by Technical Committee CEN/TC 69

“Industrial valves”, the secretariat of which is held by AFNOR.

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 2022, and conflicting national standards shall be withdrawn at

the latest by April 2022.

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 includes Amendment 1 approved by CEN on 6 September 2021.
This document supersedes !EN 12516-2:2014".

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 Standardization Request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of EU

Directive(s) / Regulation(s).

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

this document.

!In comparison with the previous edition EN 12516-2:2004, the following significant changes have been

made in the new edition EN 12516-2:2014:"
a) the normative references were updated;

b) all formulae and figures have been renumbered; in particular 10.6 “Design temperature” became 10.5

“Calculation of the bolt diameter”;
c) some formulae were changed:
1) Formulae (3) to (6) for calculated wall thickness have been added;

2) Formulae (9) and (10) for calculation of e in case of d / d > 1,7 have been added;

o i
3) Formulae (17) and (20) for conical bodies or branches have been added;
d) the figures were changed and/or updated:

1) a new Figure 1 “Composition of section thickness and tolerance allowances” has been added;

2) Figure 2 “Cone calculation coefficient” has been over-worked;

3) former Figures 6a and 6b are now combined in Figure 7 “Calculation coefficient B for rectangular

cross-sections”;

4) Figures 23, 24, and 25 used to establish the calculation coefficients C , C and C were moved to

x y z
8.2.1;
---------------------- Page: 6 ----------------------
SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
5) the new Figure 46 “Types of flange connections” has been added;
e) tables were updated:
1) Table 1 giving the symbols characteristics and units has been revised;

2) a column for test conditions in Table 2 “Nominal design stresses (allowable stresses)” has been

added;

3) Table 5 “Flat circular plates and annular plates — Bending moments as a function of load cases and

clamping conditions” has been revised;
4) Table 7 “Lever arms of the forces in the moment formulae” has been revised;

f) Clause 6 “Nominal design stresses for pressure parts other than bolts” now contains references to

PED 97/23/EC;

g) Clause 7 “Calculation methods for the wall thickness of valve bodies” has been restructured; and 7.1 now

contains information on calculation of the surface-comparison;

h) Subclauses 8.2.2 and 8.2.3 now draw a distinction between “direct loading” and “not subjected to direct

loading”; and 8.2.3 now contains a warning regarding the mean support diameter d ;

i) there is a new Subclause 8.3.3.5 regarding the diameter of centre of gravity;
j) Clause 10 “Calculation methods for flanges” has been over-worked;
k) the former informative Annex A “Allowable stresses” has been deleted;
l) the Annex “Characteristic values of gaskets and joints” has been over-worked;
m) Annex ZA has been updated.
EN 12516, Industrial valves — Shell design strength, consists of four parts:
— Part 1: Tabulation method for steel valve shells;
— Part 2: Calculation method for steel valve shells (the present document);
— Part 3: Experimental method;

— Part 4: Calculation method for valve shells manufactured in metallic materials other than steel.

Any feedback and questions on this document should be directed to the users’ national standards body. A

complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following

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

Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia,

Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

---------------------- Page: 7 ----------------------
SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
Introduction

EN 12516, Industrial valves — Shell design strength, is composed of four parts. EN 12516-1 and EN 12516-2

specify methods for determining the thickness of steel valve shells by tabulation and calculation methods

respectively. EN 12516-3 establishes an experimental method for assessing the strength of valve shells in

steel, cast iron and copper alloy by applying an elevated hydrostatic pressure at ambient temperature.

EN 12516-4 specifies methods for calculating the thickness for valve shells in metallic materials other than

steel.

The calculation method, EN 12516-2, is similar in approach to the former DIN 3840 where the designer is

required to calculate the wall thickness for each point on the pressure temperature curve using the

allowable stress at that temperature for the material he has chosen (see Bibliography, reference [1]). The

allowable stress is calculated from the material properties using safety factors that are defined in EN 12516-

2. The formulae in EN 12516-2 consider the valve as a pressure vessel and ensure that there will be no

excessive deformation or plastic instability.

The tabulation method, EN 12516-1, is similar in approach to ASME B16.34 (see Bibliography, reference [2])

in that the designer can look up the required minimum wall thickness dimension of the valve body from a

table. The internal diameter of the inlet bore of the valve gives the reference dimension from which the

tabulated wall thickness of the body is calculated.

The tabulated thicknesses in EN 12516-1 are calculated using the thin cylinder formula that is also used in

EN 12516-2. The allowable stress used in the formula is equal to 120,7 MPa and the operating pressure, p , in

MPa, varies for each PN and Class designation. EN 12516-1 gives these p values for all the tabulated PN and

Class designations.

EN 12516-1 specifies PN, Standard Class and Special Class pressure temperature ratings for valve shells with

bodies having the tabulated thickness. These tabulated pressure temperature ratings are applicable to a

group of materials and are calculated using a selected stress, which is determined from the material

properties representative of the group, using safety factors defined in EN 12516-1.

Each tabulated pressure temperature rating is given a reference pressure designation to identify it.

The tabulation method gives one thickness for the body for each PN (see EN 12516-1:2014, 3.1 PN (Body))

or Class designation depending only on the inside diameter, D , of the body at the point where the thickness

is to be determined.

The calculated pressure is limited by the ceiling pressure which sets up an upper boundary for high strength

materials and limits the deflection.

A merit of the tabulation method, which has a fixed set of shell dimensions irrespective of the material of the

shell, is that it is possible to have common patterns and forging dies. The allowable pressure temperature

rating for each material group varies proportionally to the selected stresses of the material group to which

the material belongs, using the simple rules above.

A merit of the calculation method is that it allows the most efficient design for a specific application using the

allowable stresses for the actual material selected for the application.

The two methods are based on different assumptions, and as a consequence the detail of the analysis is

different (see Bibliography, reference [3]). Both methods offer a safe and proven method of designing

pressure-bearing components for valve shells.
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SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
1 Scope

This European Standard specifies the method for the strength calculation of the shell with respect to internal

pressure of the valve.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated references,

the latest edition of the referenced document (including any amendments) applies.

!EN 19:2016, Industrial valves — Marking of metallic valves"

!EN 1092-1:2018, Flanges and their joints — Circular flanges for pipes, valves, fittings and accessories, PN

designated — Part 1: Steel flanges"

EN 1591-1:2013, Flanges and their joints — Design rules for gasketed circular flange connections — Part 1:

Calculation

EN 10269:2013, Steels and nickel alloys for fasteners with specified elevated and/or low temperature

properties

EN 12266-1:2012, Industrial valves — Testing of metallic valves — Part 1: Pressure tests, test procedures and

acceptance criteria — Mandatory requirements

EN 12266-2:2012, Industrial valves — Testing of metallic valves — Part 2: Tests, test procedures and

acceptance criteria — Supplementary requirements
!EN 13445-3:2014, Unfired pressure vessels — Part 3: Design"

!EN 16668:2016+A1:2018, Industrial valves — Requirements and testing for metallic valves as pressure

accessories"

!EN ISO 3506-1:2020, Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners —

Part 1: Bolts, screws and studs with specified grades and property classes (ISO 3506 1:2020)"

3 Symbols and units
The following symbols are used:
!Table 1 — Symbols and units
Symbol Unit Description
mm lever arm for horizontal force
mm lever arm for bolt force
mm lever arm for vertical force
B — calculation coefficient to determine the thickness of the flange
— calculation coefficient for oval and rectangular cross-sections
1…3

As impacted by EN 13445-3:2014/A1:2015, EN 13445-3:2014/A2:2016, EN 13445-3:2014/A3:2017, EN 13445-3:2014/A4:2018,

EN 13445-3:2014/A5:2018, EN 13445-3:2014/A6:2019, EN 13445-3:2014/A7:2019 and EN 13445-3:2014/A8:2019.

---------------------- Page: 9 ----------------------
SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
Symbol Unit Description
— correction factor for oval flanges
B , B
— calculation coefficient for flat circular plates
FI FII
— calculation coefficient to determine the thickness of the flange
B , B
— calculation coefficient for flat circular plates
MI MII
B , B
— calculation coefficient for flat circular plates
PI PII
b mm double flange width
mm minor width in oval and rectangular cross section
mm major width in oval and rectangular cross section
b , b
mm width of the seal
D1 D2
mm width in oval and rectangular cross section
mm width of the seal
mm effective width for reinforcement
C ,C ,C
— calculation coefficient for covers made of flat plates
x y z
C — calculation coefficient for lens-shaped gaskets
c mm design allowance for bolts
mm fabrication tolerance
mm standardized corrosion and erosion allowance
mm outside diameter
d , d'
mm diameter in base body
0 0
d , d mm diameter for self-sealing closure
01 02
mm diameter in branch
mm diameter in further branch
mm outside diameter of collar flange
mm outside diameter of the plate/cover
mm outside flange diameter
mm inside diameter
mm diameter of the biggest inscribed circle
mm diameter in knuckle
mm diameter in corner welds
mm hole diameter
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SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
Symbol Unit Description
mm reduced bolt hole diameter
mm mean diameter of the plate/cover
mm mean diameter of the face (see Figure 28)
mm mean diameter
mm mean diameter of the seal
mm required bolt diameter
mm bold circle diameter/reference circle diameter
mm diameter of centre of gravity
mm stuffing box outside diameter
ast
mm stuffing box inside diameter
ist
mm calculated bolt diameter without design allowance
mm diameter of the vertical force at the cone
E MPa modulus of elasticity
MPa modulus of elasticity for material of the seal
mm wall thickness
mm wall thickness (final/actual)
e actual wall thickness less c and c
acn 1 2
mm thickness of flange neck
acF
e calculated theoretical minimum wall thickness, without c and c
cn 1 2
N minimum bolt force for the assembly condition
N flange force
N horizontal component force
N bolt force for operating conditions
N minimum bolt force
N bolt force for assembly conditions
N tensile force
N vertical force at the cone
N additional force
f MPa nominal design stress
MPa
d maximum value of the nominal design stress for normal operating load
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SIST EN 12516-2:2015+A1:2021
EN 12516-2:2014+A1:2021 (E)
Symbol Unit Description
cases
MPa nominal design stress for design conditions at temperature t °C
d/t
g , g
mm welding throat depth
1 2
h mm plate thickness
mm minimum height for the seating shoulder
mm minimum height of the inserted ring
mm minimum depth of the sealing ledge
mm plate thickness
mm height of flange hub
mm plate thickness
mm thickness of flange
mm reduced plate thickness
...

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