SIST EN 14276-2:2020/oprA1:2023
(Amendment)Pressure equipment for refrigerating systems and heat pumps - Part 2: Piping - General requirements
Pressure equipment for refrigerating systems and heat pumps - Part 2: Piping - General requirements
1.1 This document specifies the requirements for material, design, manufacturing, testing and documentation for stationary piping intended for use in refrigerating systems, heat pumps and secondary cooling and heating systems. These refrigerating systems and heat pump systems are referenced in this document as refrigerating systems as defined in EN 378-1:2016.
The term "refrigerating system" used in this document includes heat pumps.
1.2 This document applies to piping, including welded or brazed attachments up to and including the flanges, screwed, welded or brazed connectors, or to the edge to be welded or brazed at the first circumferential joint connecting piping or other elements.
1.3 This document applies to the selection, application and installation of safety accessories intended to protect the piping during the various phases of the refrigeration cycle.
1.4 This document applies to the following piping:
- heat exchanger consisting of piping for the purpose of cooling or heating air where piping aspects are predominant;
- piping incorporated into an assembly (e.g. self-contained system, condensing unit);
- field erected piping.
1.5 This document applies to piping with an internal pressure down to -1 bar, to account for the evacuation of the piping prior to charging with refrigerant.
1.6 This document applies to both the mechanical loading conditions and thermal conditions as defined in EN 13445 3:2014/A5:2018 associated with refrigerating systems. It applies to piping subject to the maximum allowable temperatures for which nominal design stresses for materials are derived using EN 14276-1:2020 or as specified in this document. In addition, piping designed to this document will have a maximum design temperature not exceeding 200 °C and a maximum design pressure not exceeding 160 bar. Outside of these limits, the EN 13480 series can be used for the design construction and inspection of the piping. Under these circumstances, the unique nature of a refrigerating plant, as indicated in the introduction of EN 14276-1:2020, will also be taken into account.
1.7 This document applies to piping where the main pressure bearing parts are manufactured from metallic ductile materials as defined in Clause 4 and in EN 14276-1:2020.
Druckgeräte für Kälteanlagen und Wärmepumpen - Teil 2: Rohrleitungen - Allgemeine Anforderungen
Équipements sous pression pour systèmes de réfrigération et pompes à chaleur - Partie 2 : Tuyauteries - Exigences générales
Tlačna oprema za hladilne sisteme in toplotne črpalke - 2. del: Cevovodi - Splošne zahteve - Dopolnilo A1
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 14276-2:2020/oprA1:2023
01-september-2023
Tlačna oprema za hladilne sisteme in toplotne črpalke - 2. del: Cevovodi - Splošne
zahteve - Dopolnilo A1
Pressure equipment for refrigerating systems and heat pumps - Part 2: Piping - General
requirements
Druckgeräte für Kälteanlagen und Wärmepumpen - Teil 2: Rohrleitungen - Allgemeine
Anforderungen
Équipements sous pression pour systèmes de réfrigération et pompes à chaleur - Partie
2 : Tuyauteries - Exigences générales
Ta slovenski standard je istoveten z: EN 14276-2:2020/prA1
ICS:
23.020.32 Tlačne posode Pressure vessels
27.080 Toplotne črpalke Heat pumps
27.200 Hladilna tehnologija Refrigerating technology
SIST EN 14276-2:2020/oprA1:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 14276-2:2020/oprA1:2023
---------------------- Page: 2 ----------------------
SIST EN 14276-2:2020/oprA1:2023
DRAFT
EUROPEAN STANDARD
EN 14276-2:2020
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
July 2023
ICS
English Version
Pressure equipment for refrigerating systems and heat
pumps - Part 2: Piping - General requirements
Équipements sous pression pour systèmes de Druckgeräte für Kälteanlagen und Wärmepumpen -
réfrigération et pompes à chaleur - Partie 2 : Teil 2: Rohrleitungen - Allgemeine Anforderungen
Tuyauteries - Exigences générales
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 182.
This draft amendment A1, if approved, will modify the European Standard EN 14276-2:2020. 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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14276-2:2020/prA1:2023 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Contents
European foreword . 3
1 Modification to Clause 1 . 4
2 Modification to Clause 2 . 4
3 Modification to Clause 3 . 5
4 Modification to Clause 4 . 5
5 Modification to Clause 5 . 6
6 Modification to Clause 6 . 6
7 Modification to Clause 7 .33
8 Modification to Annex ZA .36
Annex ZA (informative) Relationship between this European Standard and the
essential requirements of EU Directive 2014/68/EU aimed to be covered .37
2
---------------------- Page: 4 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
European foreword
This document (EN 14276-2:2020/prA1:2023) has been prepared by Technical Committee
CEN/TC 182 “Refrigerating systems, safety and environmental requirements”, the secretariat of
which is held by DIN.
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(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an
integral part of this document.
3
---------------------- Page: 5 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
1 Modification to Clause 1
Update the following references throughout the clause:
— EN 378-1:2016+A1:2020;
— EN 13480-3:2017/A5:2022;
— EN 13480-3:2017, including A2:2020, A3:2020 and A1:2021;
— EN 14276-1:2020/prA1:2023.
2 Modification to Clause 2
Update the following references throughout the clause:
— EN 378-1:2016+A1:2020;
— EN 378-3:2016+A1:2020;
— EN 378-4:2016+A1:2019;
— EN 764-1:2015+A1:2016;
— EN 12735-1:2020;
— EN 13445-3:2021;
— EN 13445-5:2021;
1
— EN 13480-2:2017;
2
— EN 13480-3:2017;
— EN ISO 2553:2019;
— EN ISO 3452-1:2021;
3
— EN ISO 10893-8:2011;
4
— EN ISO 10893-11:2011;
— EN ISO 17640:2018;
1
Document impacted by A1:2018, A2:2018, A3:2018, A7:2020 and A8:2021
2
Document impacted by A1:2021, A2:2020, A3:2020, A4:2021 and A5:2022.
3
Document impacted by A1:2020.
4
Document impacted by A1:2020.
4
---------------------- Page: 6 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
5
— ISO 817:2014.
3 Modification to Clause 3
Replace definition 3.1.1 as follows:
3.1.1
coil
heat exchanger consisting of pipe or tubing (more particularly made from one or more bent pipes)
used to cool or heat air considered only as a piping
Add the following new definitions:
3.1.2
nominal diameter of the fitting
DN of the pipe connected to this fitting
3.1.3
fitting
device used in a tube system for the purpose of connecting the tubes or pipes either to each other
or to a component part of the piping
3.1.4
socket
type of end defined with its internal diameter
3.1.5
male end
type of end defined with its external diameter
3.1.6
reducer
fitting or an adapter used to enable connections between pipework components of different
nominal diameters
4 Modification to Clause 4
Update the following references throughout the clause:
— EN 14276-1:2020/prA1:2023;
1
— EN 13480-2:2017 ;
— EN 13445-2:2021.
In 4.3.1.2, replace “copper groups: 31, 32, 33, 34, 35t, included in EN 1653:1997, EN 12735-1:2016,
EN 12735 2:2016” with “copper groups: 31 to 38, included in EN 1653:1997, EN 12735-1:2020,
EN 12735-2:2016”.
5
Document impacted by A1:2017 and A2:2021.
5
---------------------- Page: 7 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Replace 4.3.2 as follows:
4.3.2 Special considerations including brittle fracture
The requirements of EN 14276-1:2020, shall apply as follows:
— For all materials: see 4.3.1.3 to 4.3.1.7;
— For steel: see 4.3.2;
— For aluminium: see 4.3.3;
— For copper: see 4.3.4.
The brittle fracture should be determined only when the material thickness can permit to make a
test piece according to EN ISO 148-1 with a minimum section size 5 mm × 10 mm
Delete 4.4 and replace 4.5 and 4.6 as follows:
4.4 Material documentation
The requirements of EN 14276-1:2020/prA1:2023, 4.4 shall apply.
4.5 Materials for non-pressure retaining parts
The requirements of EN 14276-1:2020/prA1:2023, 4.5 shall apply.
5 Modification to Clause 5
In the first line of Table 2 replace “EN 14276-2:2020” with “EN 14276-1:2020/prA1:2023, 5.2”.
6 Modification to Clause 6
Update the following references throughout the clause:
— EN 14276-1:2020/prA1:2023;
1
— EN 13480-2:2017 ;
— EN 13445-2:2021;
— EN 378-3:2016+A1:2020;
— EN 378-4:2016+A1:2019.
Replace 6.5 as follows:
6.5 Calculation temperature tc
The calculation temperature, t , shall be the maximum temperature likely to be reached at the
c
mid-thickness of the piping, under normal operating conditions, at the calculation pressure p . The
c
calculation temperature shall be determined as indicated below. Any heat transfer calculation
shall be performed on the assumption that there is no heat loss due to wind or other external
influence.
a) For externally uninsulated components, the calculation temperature shall be as follows:
1) For fluid temperatures below 40 °C, the calculation temperature for the component shall
be taken as the fluid temperature;
6
---------------------- Page: 8 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
2) For fluid temperatures of 40 °C and above, unless a lower average wall temperature is
determined with test or heat transfer calculation, the calculation temperature for
uninsulated components shall be not less than the following values, but not less than
40°C:
i) 95 % of the fluid temperature for valves, pipes, ends, welding fittings, and other
components having wall thickness comparable to that of the pipe;
ii) 90 % of the fluid temperature for flanges (except lap joint flanges) including those on
fittings and valves;
iii) 85 % of the fluid temperature for lap joint flanges;
iv) 80 % of the fluid temperature for bolting.
b) For externally insulated piping components, the component calculation temperature shall be
the fluid temperature TS unless calculations, tests, or service experience based on
max
measurements, support the use of another temperature. Where piping is heated or cooled
with tracing or jacketing, this effect shall be considered in establishing component calculation
temperatures;
c) Where the piping is heated or cooled with tracing or jacketing, the calculation temperature
shall be determined with test or taken to be equal to the temperature determined in a) or b)
+ 50 K.
The manufacturer when selecting the heater shall quantify the risk that exists of overheating for
the fluid or for the material and shall take appropriate measures to restrict this risk with for
example the inclusion of safety accessories and/or the inclusion of appropriate warning labels
and/or adding instructions to the documentation.
7
---------------------- Page: 9 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Replace Table 3 as follows:
Joint coefficients 1 1 0,85 0,7
a
Testing groups 1b 2b 3b 4
Permitted material
Steel group 1.1/1.2/8.1 1.1/1.2/8.1 1.1/1.2/8.1 1.1/1.2/8.1
Aluminium group 21 / 22 21 / 22 21 / 22 21 / 22
Copper group All All All all
Maximum thickness per material category
b
Steel group 1.1 / 8.1 Unlimited ≤ 50 ≤ 50 ≤ 16
b
Steel group 1.2 Unlimited ≤ 30 ≤ 30 ≤ 12
b
Aluminium group 21 Unlimited ≤ 40 ≤ 40 ≤ 20
22
b
Copper group all Unlimited ≤ 40 ≤ 40 ≤ 20
b b b
Welding process Unlimited Fully mechanical Unlimited Unlimited
c
welding only
b b b
Service temperatures Unlimited Unlimited Unlimited ̶ 50 °C + 200 °C
range
Groups of fluid 1/2 1/2 1/2 1/2
Extent of VT 100 % 100 % 100 % 100 %
d e
Extent of NDT other 100 % 100–10 % 10 % 0 %
than VT of governing
welded joints
a
Definition of testing groups with analogy with EN 13480-5:2017. All testing groups require visual
examination.
b
Unlimited means no additional restriction due to testing. The limitations mentioned in the table are
limitations imposed with testing. Other limitations given in various clauses of this document (such as
design, material limitations) shall also be taken in account.
c
Fully mechanized and/or automatic welding process where at least the weld head and the welding
consumable movement is mechanized.
d
First figure applies initially; second figure applies after experience. For definition of experience see
EN 13445-5:2021. The percentage relates to the percentage of welds of each individual vessel.
e
The extent of NDT other than VT can be substituted with destructive testing for group 2b.
Replace 6.9.1.2 as follows:
The piping is subject to a pressure not less than 3 times PS without rupture.
Test temperature is done at the ambient temperature.
If the design temperature exceeds 125°C, the piping is subject to a pressure not less than
f
test
3××PS .
f
8
---------------------- Page: 10 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Replace 6.9.1.3 as follows:
6.9.1.3 Type fatigue proof test
The test procedure and acceptance criteria are the following if the design temperature is not
higher than 125 °C:
a) 3 samples are tested at 2 times PS;
b) 3 other samples are subjected to the following test steps:
step 1: Test at PS without permanent deformation and leaks;
step 2: 250 000 cycles between 0,2 PS or lower and 0,7 PS or higher;
step 3: Test according to EN 14276-1:2020/prA1:2023, Formula (C.1).
During the test procedure, none of the 6 samples shall rupture, burst or leak.
The test procedure and acceptance criteria are the following if the design temperature is
above 125 °C:
f
test
c) 3 samples are tested at 2××PS ;
f
d) 3 other samples are subjected to the following test steps:
f
test
step 1: Test at ×PS without permanent deformation and leaks;
f
f
test
step 2: 250 000 cycles between 0,2 PS or lower and 0,7××PS or higher;
f
step 3: Test according to EN 14276-1:2020/prA1:2023, Formula (C.1).
During the test procedure, none of the 6 samples shall rupture, burst or leak.
Replace 6.9.2 as follows:
6.9.2 Design with formula (DBF)
6.9.2.1 Straight piping
The minimum required thickness without corrosion allowance and tolerances, e for a straight
c
pipe shall be calculated as follows:
where D /D ≤ 1,7, according to Formula (1) or (2).
o i
pD
co
e = (1)
c
2fZ+ p
c
pD
ci
e = (2)
c
2fZ− p
c
where D /D > 1,7, according to Formula (3) or (4).
o i
9
---------------------- Page: 11 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
D fz− p
oc
e 1− (3)
c
2 fz+ p
c
D fz+ p
ic
e −1 (4)
c
2 fz− p
c
6.9.2.2 Bend piping or elbow
The minimum required wall thickness without allowances and tolerances shall be calculated with:
on the intrados, according to Formula (5).
RD/ − 0,25
( )
o
ee= (5)
int c
RD/ − 0,5
( )
o
on the extrados, according to Formula (6).
RD/ + 0,25
( )
o
ee= (6)
ext c
RD/ + 0,5
( )
o
where:
e is calculated in accordance with 6.9.2.1 for straight pipe, in mm.
c
e minimum required thickness without allowances and tolerances for a bend on the
int
intrados, in mm.
e minimum required thickness without allowances and tolerances for a bend on the
ext
extrados, in mm.
R radius of bend or elbow, in mm.
Key
D external diameter of tube in mm
e
R radius of curvature for tube in mm
Figure 2 — Bend piping
10
=
=
---------------------- Page: 12 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
For copper alloys other than copper group 31, the minimum required thickness before the
bending without corrosion allowance, for a bend pipe shall be determined as follows:
PD × D
ee
e 1+ (7)
2 ×fz× +P 4R
For copper group 31, the Formula (1) or (2) shall apply if calculation was made for annealed
conditions and if there is no heat treatment in the bending zone. Otherwise, Formula (5), (6) or
(7) shall be used.
Additional methods of calculating the wall thickness of pipe bends and elbows shall be in
accordance with EN 13480-3:2017, Annex B.
6.9.2.3 Reducers
6.9.2.3.1 Conditions of applicability
Requirements are given in 6.9.2.3.4 to 6.9.2.3.8 for right circular cones and cone/cylinder
intersections where the cone and the cylinder are on the same axis of rotation. Requirements for
offset cones are given in 6.4.2.3.9.
The requirements do not apply to:
— Cones for which the half angle at the apex of the cone is greater than 60°;
— Cones for which:
e cosα
a
≤ 0,001 (8)
D
c
— Short cones joining a jacket to a shell.
Limits on the minimum distance from other major discontinuities are given in individual clauses.
6.9.2.3.2 Specific definitions
Junction between the cylinder and the cone intersection of the mid-thickness lines of cylinder and
cone, extended if necessary where there is a knuckle (see Figure 3 and Figure 4 for examples at
the large end).
Figure 3 — Geometry of cone/cylinder intersection without knuckle – Large end
11
=
---------------------- Page: 13 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Figure 4 — Geometry of cone/cylinder intersection with knuckle – Large end
6.9.2.3.3 Specific symbols and abbreviations
For the purposes of 6.9.2.3, the symbols given in Table 4 shall apply in addition to those given in
Table 1.
12
---------------------- Page: 14 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Table 4 — Additional symbols for the purposes of 6.9.2.3
Symbol Description Unit
D the mean diameter of the cylinder at the junction with the cone; mm
c
D the outside diameter of the cone; mm
e
D the inside diameter of the cone; mm
i
D a diameter given with Formula (14); mm
K
D the mean diameter of the cone; mm
m
e required thickness of cone as determined in 6.9.2.3.4 mm
con
e required thickness of cylinder as determined in 6.9.2.1; mm
cyl
e a required or analysis thickness at a junction at the large end of a mm
j
cone;
e required thickness of cylinder at junction; mm
1
e analysis reinforcing thickness in cylinder; mm
1a
e required thickness of cone and knuckle at junction; mm
2
e analysis reinforcing thickness in cone; mm
2a
F the nominal design stress. In the design of junctions to 6.9.2.3.6 to MPa
6.9.2.3.9 it is the lowest of the values for the individual component
parts;
l length along cylinder; mm
1
l length along cone at large or small end; mm
2
r inside radius of knuckle mm
i
α the semi angle of cone at apex (degrees); degree
β a factor defined in 6.9.2.3.6; -
βΗ a factor defined in 6.9.2.3.8; -
γ a factor defined in 6.9.2.3.7; -
β a factor defined in 6.9.2.3.7; -
τ a factor defined in 6.9.2.3.8. -
6.9.2.3.4 Conical shells
The required thickness at any point along the length of a cone shall be calculated from Formula (9)
or Formula (10).
pD
ci
e = (9)
con
2fz− p
c
pD 1
ce
e = (10)
con
2f z+ p cosα
c
where D and D are the inner or outer diameter respectively at the point under consideration.
i e
For a given geometry, as given in Formula (11).
13
---------------------- Page: 15 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
2fze cosα
con
P = (11)
max
D
m
where D is the mean diameter at the point under consideration in mm.
m
At the large end of a cone attached to a cylinder it is permissible to make substitutions, as stated
in Formulae (12) to (14).
DD= (12)
ik
DD+ 2e cosα (13)
ek 2
D (DD+ ) / 2 (14)
m ie
where
D= De−− 2r 1− cosαα−l sin (15)
( )
Kc 12i
For r see Figure 4.
i
NOTE 1 The thickness given with this section is a minimum. Thickness may have to be increased at
junctions with other components, or to provide reinforcement at nozzles or openings, or to carry non-
pressure loads.
NOTE 2 Since the thickness calculated above is the minimum allowable at that point along the cone, it is
permissible to build a cone from plates of different thickness provided that at every point the minimum is
achieved.
6.9.2.3.5 Junctions – General
The requirements of 6.9.2.3.6, 6.9.2.3.7 and 6.9.2.3.8 apply when the junction is more than 2 l
1
along the cylinder and 2 l along the cone from any other junction or major discontinuity, such as
2
another cone/cylinder junction or a flange, where:
l = De (16)
11c
De
c 2
l = (17)
2
cosα
The length of the cone can be reduced to less than 2 l if both of the following conditions are
2
fulfilled:
— the wall thickness e , calculated in accordance with 6.9.2.3.6 or 6.9.2.3.7, is existent along the
2
whole length of the cone;
— the junction at the small end of the cone is sufficiently dimensioned according to 6.9.2.3.8.
14
=
=
---------------------- Page: 16 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
6.9.2.3.6 Junction between the large end of a cone and a cylinder without a knuckle
6.9.2.3.6.1 Conditions of applicability
The requirements of 6.9.2.3.6.2 and 6.9.2.3.6.3 apply provided that all the following conditions are
satisfied:
— the joint is a butt weld where the inside and outside surfaces merge smoothly with the
adjacent cone and cylinder without local reduction in thickness; and
— the weld at the junction shall be subject to 100 % non-destructive examination, either with
radiography or ultrasonic techniques, unless the design is such that the thickness at the weld
exceeds 1,4 e , in which case the normal rules for the relevant design shall be applied.
j
6.9.2.3.6.2 Design
The required thickness e1 of the cylinder adjacent to the junction is the greater of ecyl and ej
where ej shall be determined with the following procedure:
1 D tanα
c
β=⋅ − 0,15 (18)
3 e
1+1/ cosα
j
pDβ
cc
e = (19)
j
2f
The answer is acceptable if the value given with Formula (19) is not less than assumed in
Formula (18).
β can also be read from the graph in Figure 5.
This thickness shall be maintained for a distance of at least 1,4 l from the junction along the
1
cylinder.
15
---------------------- Page: 17 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Figure 5 — Values of coefficient β for cone/cylinder intersection without knuckle
The required thickness e of the cone adjacent to the junction is the greater of econ and ej. This
2
thickness shall be maintained for a distance of at least 1,4 l from the junction along the cone, see
2
Figure 5
It is permissible to redistribute the reinforcement in the following way, provided that the
minimum thicknesses given with 6.9.2.1 and 6.9.2.3.4 continue to be met.
The thickness for the cylinder may be increased near the junction and reduced further away
provided that the cross-sectional area of metal provided with the cylinder within a distance 1,4 l
1
from the junction is not less than 1,4 e l . In addition, the thickness of the cone may be increased
1 1
near the junction and reduced further away provided that the cross-sectional area of metal
provided with the cone within a distance 1,4 l from the junction is not less than 1,4 e l .
2 2 2
6.9.2.3.6.3 Rating
The maximum permissible pressure for a given geometry shall be determined as follows:
a) apply Formula (11) to cylinder;
2fze
a
P =
(20)
max
D
c
b) apply Formula (11) to the cone;
c) determine the analysis reinforcing thickness e of the cylinder at the junction;
1a
16
---------------------- Page: 18 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
d) determine the analysis reinforcing thickness e of the cone at the junction;
2a
Apply Formula (11) with thickness e and diameter D ;
2a m
Find e , the lesser of e and e ;
j 1a 2a
Calculate β from Formula (17), then,
2fe
j
P = (21)
max
βD
c
the maximum permissible pressure is the lowest of the pressures determined in a), b), e) and g).
The following procedure may be used to find the analysis reinforcing thickness at c) or d) above:
Assume e (the initial choice should be the thickness at the junction).
1a
Calculate
l =1,4 De (22)
1 Ca1
If the thickness is constant within the distance l then e is confirmed.
1 1a
If not, calculate the metal area A1 within the distance l1 from the junction.
Obtain a better estimate with:
e = Al/ (23)
1a 1 1
The answer is acceptable if it is not greater than e assumed in 1).
1a
If the answer is unacceptable, return to 1).
Use a similar procedure to find e making.
2a
De
ca2
l =1,4 (24)
2
cosα
6.9.2.3.7 Junction between the large end of a cone and a cylinder with a knuckle
6.9.2.3.7.1 Conditions of applicability
This subclause applies provided that all the following conditions are satisfied:
a) the knuckle is of toroidal form and merges smoothly with the adjacent cone and cylinder and
b) the inside radius of curvature of the knuckle, r < 0,3 Dc.
i
NOTE This subclause does not prescribe a lower limit to the radius of curvature of the knuckle.
6.9.2.3.7.2 Design
The value of e shall be determined with the following procedure:
j
Assume a value of e and calculate:
j
1 D tanα
c
β=⋅− 0,15 (25)
1
3 e
j
1+
cosα
17
---------------------- Page: 19 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
0,028 r α
i
ρ= (26)
De 1+1/ cosα
cj
ρ
γ 1+ (27)
0,2
1, 2 1+
ρ
pDβ
cc
e = (28)
j
2fγ
The answer is acceptable if the value given with Formula (28) is not less than that assumed.
The required thickness e of the cylinder adjacent to the junction is the greater of e and e .
1 cyl j
This thickness shall be maintained for a distance of at least 1,4 l from the junction and 0,5 l from
1 1
the knuckle/cylinder tangent line along the cylinder.
The required thickness e of the knuckle and the cone adjacent to the junction is the greater of e
2 con
and e . This thickness shall be maintained for a distance of at least 1,4 l from the junction and 0,7
j 2
l from the cone/knuckle tangent line along the cone.
2
6.9.2.3.7.3 Rating
The maximum permissible pressure for a given geometry shall be found as follows.
a) Determine e1a, the analysis thicknesses for the cylinder next to the knuckle, and e2a, the
analysis thickness for the knuckle and the adjacent part of the cone;
b) Check that the limitations of 6.9.2.3.7.1 are met;
c) Apply Formula (19) to the cylinder with e = e ;
a 1a
d) Apply Formula (10) to the cone with e = e ;
con 2a
e) Find e , the lesser of e and e ;
j 1a 2a
f) Find β and ϒ from Formulae (25) and (27), then
2feγ
j
P = (29)
max
βD
c
g) The maximum permissible pressure is the lowest of the pressures determined in c), d) and f).
6.9.2.3.8 Junction between the small end of a cone and a cylinder
6.9.2.3.8.1 Conditions of applicability
The requirements of 6.9.2.8.2 and 6.9.2.8.3 apply provided that all the following conditions are
satisfied:
— the required thickness of the cylinder e is maintained for a distance l and that of the cone e
1 1 2
is maintained for a distance l from the junction (see Figure 6); and
2
— the thicknesses meet the requirements of 6.9.2.1 and 6.9.2.3.4;
18
=
---------------------- Page: 20 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
Figure 6 — Geometry of cone/cylinder intersection: small end
6.9.2.3.8.2 Design
Required thicknesses e and e shall be found with the following procedure:
1 2
Assume values of e and e :
1 2
e
2
s= (30)
e
1
when s < 1
2
ss1+
τ s + (31)
cosα 2
when s ≥ 1
2
1+s
τ 1+ s (32)
2cosα
D tanα
c
β 0,4 + 0,5 (33)
H
e τ
1
If
2f ze
1
p ≤ (34)
c
Dβ
c H
then e and e are acceptable. If not, repeat with increased values of e and/or e .
1 2 1 2
NOTE The above procedure does not provide values for e and e independently. Any values may be
1 2
selected to suit the needs of the design, for example to obtain a favourable value of l1 or l2.
Provided that the requirements of 6.9.2.1 and 6.9.2.3.4 continue to be met, it is permissible to
modify a design according to the above rule in one of the following ways:
19
=
=
=
---------------------- Page: 21 ----------------------
SIST EN 14276-2:2020/oprA1:2023
EN 14276-2:2020/prA1:2023
a) Where e = e a knuckle of the same thickness may be included. l and l continue to be
1 2 1 2
measured from the junction (i.e. the point where the centre lines of cone and cylinder meet);
b) The thickness of the cylinder may be increased near the junction and reduced further away
provided that the cross-sectional area of metal provided with the cylinder within a distance
l from the junction is not less than l e . In addition, the thickness of the cone may be increased
1 1 1
near the junction and reduced further away provided that the cross-sectional area of metal
provided with the cone within a distance l from the junction is not less than l⋅e .
2 2 2
6.9.2.3.8.3 Rating
The maximum permissible pressure for a given geometry shall be:
2f ze
1a
P = (35)
max
Dβ
c H
β is found from Formulae (30) to (33) using e and e in place of e and e .
H 1a 2a 1 2
NOTE 1 The procedure for finding e and e is as provided in the NOTE to 6.9.2.3.6.3
1a 2a
NOTE 2 Analysis thicknesses may exceed the required thickness without leading to any increase in l or
1
l2.
6.9.2.3.9 Offset reducers
This subclause shall apply to offset reducers (see Figure 7). The cylindrical part
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.