EN 12516-2:2014/FprA1

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

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

Industrijski ventili - Trdnost ohišja - 2. del: Metoda za izračun ohišij jeklenih ventilov - Dopolnilo A1

General Information

• Status: Not Published
• Publication Date: 07-Feb-2022
• Withdrawal Date: 08-May-2022
• ICS: 23.060.01 - Valves in general
• Technical Committee: CEN/TC 69 - Industrial valves
• Drafting Committee: CEN/TC 69/WG 1 - Basic standards
• Current Stage: 5060 - Closure of Vote - Formal Approval
• Start Date: 05-Aug-2021
• Due Date: 04-Jan-2021
• Completion Date: 05-Aug-2021
• Directive: 2014/68/EU - Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Ref Project: SIST EN 12516-2:2015/kFprA1:2021 - Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells

Relations

• Merged Into: EN 12516-2:2014+A1:2021 - Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells
• Effective Date: 19-Jan-2023
• Amends: EN 12516-2:2014 - Industrial valves - Shell design strength - Part 2: Calculation method for steel valve shells
• Effective Date: 24-Oct-2018

Overview

EN 12516-2:2014/FprA1 is the CEN European standard amendment draft that defines the calculation method for the mechanical strength of steel valve shells subjected to internal pressure. Prepared by CEN/TC 69 (Industrial valves) with secretariat AFNOR, this document clarifies calculation principles, updates references and nominal design stress rules, and supports conformity with EU Directive 2014/68/EU.

This amendment (prA1) updates referenced standards, revises symbol tables and nominal design stresses, and modifies calculation clauses (including wall thickness checks, welding factors and crotch-area assessment). The draft is issued for enquiry and, if approved, becomes an amendment to EN 12516-2:2014.

Key Topics

• Scope and purpose: method for strength calculation of valve shells with respect to internal pressure, focused on steel materials.
• Calculation approach: two-step process -
  • determine wall thickness of the basic body and branches outside intersections; and
  • calculate and verify wall thickness in the crotch/intersection area, considering equilibrium of forces.
• Material and stress data: updated tables for nominal design stresses (allowable stresses), addressing a range of steel and austenitic material conditions and creep considerations.
• Weld and fabrication factors: use of a welding factor (k) dependent on weld type and inspection levels; inclusion of fabrication tolerances and corrosion allowances in thickness calculations.
• Symbols and units: comprehensive symbol table replacing the previous Table 1 to standardize variable names and units across calculations.
• Regulatory linkage: Annex ZA describes the relationship with essential requirements of Directive 2014/68/EU for pressure equipment.

Applications

This standard (and its amendment) is used by engineers, manufacturers and conformity assessors for:

• Designing and specifying steel valve shells to resist internal pressure safely.
• Determining minimum wall thicknesses for bodies, branches and crotch areas in valve designs.
• Preparing design documentation for conformity assessment against EU pressure equipment requirements (2014/68/EU).
• Establishing test and assembly conditions, including selection of nominal design stresses for materials and temperature/creep cases.

Practical benefits include improved accuracy in wall-thickness calculations, consistent application of welding and fabrication factors, and clearer traceability to regulatory requirements for pressure equipment.

Related Standards

• EN 12516-2:2014 (base document) - Part 2: Calculation method for steel valve shells
• EN 19:2016 - Industrial valves: marking of metallic valves (updated reference)
• EN 13445-3:2014/A3:2017 - Unfired pressure vessels: design (referenced for design stress rules)
• EN 12266 series - Test pressure and leak testing methods (referenced for test pressure calculation)

For designers and compliance teams, EN 12516-2:2014/prA1 is a key technical reference to ensure safe, standards-aligned steel valve shell design under internal pressure.

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 12516-2:2015/oprA1:2019
01-december-2019
Industrijski ventili - Trdnost ohišja - 2. del: Metoda za izračun ohišij jeklenih
ventilov - Dopolnilo A1
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/prA1:2019
ICS:
23.060.01 Ventili na splošno Valves in general
SIST EN 12516-2:2015/oprA1:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST EN 12516-2:2015/oprA1:2019

SIST EN 12516-2:2015/oprA1:2019

DRAFT
EUROPEAN STANDARD
EN 12516-2:2014
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
October 2019
ICS 23.060.01
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 draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 69.

This draft amendment A1, if approved, will modify the European Standard EN 12516-2:2014. If this draft becomes an
amendment, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
inclusion of this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

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 12516-2:2014/prA1:2019:2019 E
worldwide for CEN national Members.

SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
Contents
European foreword . 3
1 Modification to Clause 2. 4
2 Modifications to Clause 3. 4
3 Modification to Clause 4. 9
4 Modification to Clause 6.1 . 10
5 Modification to Clause 6.3 . 10
6 Modification to Clause 6.4 . 10
7 Modification to Clause 7.1 . 11
8 Modification to Clause 7.2.1 . 11
9 Modification to Clause 7.2.2 . 11
10 Modification to Clause 7.2.3 . 11
11 Modification to Clause 7.2.5.1 . 11
12 Modification to Clause 7.2.5.3 . 11
13 Modification to Clause 7.3 . 12
14 Modification to Clause 8.3.1 . 12
15 Modifications to Clause 8.3.3.2 . 13
16 Modification to Clause 10.3.1 . 13
17 Modification to Clause 10.3.2 . 13
18 Modification to Clause 10.4.1 . 14
19 Modification to Clause 10.5.1 . 14
20 Modification to Table A.1 . 15
21 Modifications to Annex ZA . 16
Annex ZA (informative) Relationship between this European Standard and the essential
requirements of Directive 2014/68/EU aimed to be covered . 17

SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
European foreword
This document (EN 12516-2:2014/prA1:2019) has been prepared by Technical Committee CEN/TC 69
“Industrial valves”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
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 2014/68/EU.
For relationship with EU Directive 2014/68/EU, see informative Annex ZA which is an integral part of
this document.
SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
1 Modification to Clause 2
Replace “EN 19:2002, Industrial valves — Marking of metallic valves” by “EN 19:2016, Industrial
valves — Marking of metallic valves”
Replace “EN 13445-3:2014, Unfired pressure vessels — Part 3: Design” by “EN 13445-3:2014/A3:2017,
Unfired pressure vessels — Part 3: Design”
2 Modifications to Clause 3
Replace Table 1 by the following.
“
Table 1 — Symbols characteristics and units
Symbol Unit Characteristic
a
mm lever arm for horizontal force
H
a
mm lever arm for bolt force
S
a
mm lever arm for vertical force
V
B — calculation coefficient to determine the thickness of the flange
B
— calculation coefficient for oval and rectangular cross-sections
1…3
B
— correction factor for oval flanges
B , B
— calculation coefficient for flat circular plates
FI FII
B
— calculation coefficient to determine the thickness of the flange
h
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
b
mm minor width in oval and rectangular cross section
b
mm major width in oval and rectangular cross section
b , b
mm width of the seal
D1 D2
b’
mm width in oval and rectangular cross section
b
mm width of the seal
D
b
mm effective width for reinforcement
s
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
c
mm fabrication tolerance
c
mm standardized corrosion and erosion allowance
d
mm outside diameter
o
SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
Symbol Unit Characteristic
d , d'
mm diameter in base body
0 0
d , d mm diameter for self-sealing closure
01 02
d
mm diameter in branch
d
mm diameter in further branch
d
mm outside diameter of collar flange
d
mm outside diameter of the plate/cover
A
d
mm outside flange diameter
a
d
mm inside diameter
i
d
mm diameter of the biggest inscribed circle
f
d
mm diameter in knuckle
k
d
mm diameter in corner welds
K
d
mm hole diameter
L
d'
mm reduced bolt hole diameter
L
d
mm mean diameter of the plate/cover
m
d
mm mean diameter of the face (see Figure 28)
mA
d'
mm mean diameter
m
d
mm mean diameter of the seal
D
d
mm required bolt diameter
s
d
mm bold circle diameter/reference circle diameter
t
d
mm diameter of centre of gravity
p
d
mm stuffing box outside diameter
ast
d
mm stuffing box inside diameter
ist
d
mm calculated bolt diameter without design allowance
S0
d
mm diameter of the vertical force at the cone
V
E MPa modulus of elasticity
E
MPa modulus of elasticity for material of the seal
D
e
mm wall thickness
n
e
mm wall thickness (final/actual)
an
e actual wall thickness less c and c
mm
acn 1 2
e
mm thickness of flange neck
acF
e calculated theoretical minimum wall thickness, without c and c
mm
cn 1 2
F
N minimum bolt force for the assembly condition
DV
SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
Symbol Unit Characteristic
F
N flange force
F
F
N horizontal component force
H
F
N bolt force for operating conditions
S
F
N minimum bolt force
SB
F
N bolt force for assembly conditions
S0
F
N tensile force
T
F
N vertical force at the cone
V
F
N additional force
Z
f MPa nominal design stress
maximum value of the nominal design stress for normal operating load
f
MPa
d
cases
f
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
h
mm minimum height for the seating shoulder
h
mm minimum height of the inserted ring
h
mm minimum depth of the sealing ledge
D
h
mm plate thickness
r
h
mm height of flange hub
A
h
mm plate thickness
c
h
mm thickness of flange
F
h
mm reduced plate thickness
N
k
— welding factor
c
l mm length
l
mm effective length for cylindrical bodies
0…3
l' mm length which is influenced by the entry nozzle
l’
mm length for calculating body shapes in cross section II
∩l3 mm length for calculating body shapes in cross section II
M Nm external moment
M summary of moments M , M , M
Nm
i P F M
M
Nm external moment
a
M
Nm moment for assembly condition
a0
M
Nm moment for operation condition
aB
SIST EN 12516-2:2015/oprA1:2019
EN 12516-2:2014/prA1:2019 (E)
Symbol Unit Characteristic
M
Nm single force (point force)
F
M
Nm maximum bending moment
max
M
Nm rim moment
M
M
Nm resulting moment from internal pressure
P
M
Nm bending moment in radial direction
r
M
Nm bending moment in tangential direction
t
m –– gasket coefficient
n –– number of bolts
n
–– load carrying factor
p MPa pressure
p
MPa calculation pressure
c
p
MPa design pressure
d
p
MPa contact pressure
F
PS MPa maximum allowable pressure
R mm radius for calculating load cases
R
MPa upper yield strength
eH
R
MPa upper yield strength at temperature t °C
eH/t
R
mm inner Radius of spherical cap
i
R
MPa tensile strength
m
R
MPa tensile strength at temperature t °C
m/t
R
MPa creep rupture strength for T hours at temperature t °C
m/T/t
R
MPa 0,2 % - proof strength
p0,2
R
MPa 0,2 % - proof strength at temperature t °C
p0,2/t
R
MPa 0,2 % - proof strength at test temperature t °C
p0,2/t Test
R
MPa 1,0 % - proof strength at test temperature t °C
p1,0/t Test
R
MPa
...