SIST-TP CEN/TR 14585-3:2018

SLOVENSKI STANDARD
SIST-TP CEN/TR 14585-3:2018
01-februar-2018
9DORYLWLNRYLQVNLFHYQLVHVWDYLYWODþQLKFHYRYRGLKGHO0HWRGHQDþUWRYDQMD
Corrugated metal hose assemblies for pressure applications - Part 3: Design methods
Gewellte Metallschlauchleitungen für Druckanwendungen - Teil 3: Auslegungsverfahren
Tuyauteries métalliques flexibles onduleuses pour applications sous pression - Partie 3:
Méthode de conception
Ta slovenski standard je istoveten z: CEN/TR 14585-3:2017
ICS:
23.040.10 Železne in jeklene cevi Iron and steel pipes
SIST-TP CEN/TR 14585-3:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CEN/TR 14585-3:2018


CEN/TR 14585-3
TECHNICAL REPORT

RAPPORT TECHNIQUE

October 2017
TECHNISCHER BERICHT
ICS 23.040.70
English Version

Corrugated metal hose assemblies for pressure
applications - Part 3: Design method
Tuyauteries métalliques flexibles onduleuses pour Gewellte Metallschlauchleitungen für
applications sous pression - Partie 3: Méthode de Druckanwendungen - Teil 3: Auslegungsverfahren
conception


This Technical Report was approved by CEN on 25 September 2017. It has been drawn up by the Technical Committee CEN/TC
342.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 14585-3:2017 E
worldwide for CEN national Members.

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Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 7
5 Materials . 10
5.1 General requirements . 10
5.2 Suitable materials . 10
5.3 Other materials . 13
5.4 Corrosion . 13
5.5 Low temperature application . 13
5.6 Material documentation . 15
6 Design methods . 15
6.1 General . 15
6.2 Basic design criteria . 16
6.2.1 Design conditions . 16
6.2.2 Temperatures . 16
6.2.3 Additional loadings . 16
6.2.4 Structural conditions . 17
6.2.5 Dimensions . 17
6.3 Design on the basis of nominal pressures PN . 19
6.4 Allowable stresses . 19
7 Calculation design method . 20
7.1 General . 20
7.2 Corrugated metal hose . 21
7.2.1 Scope . 21
7.2.2 General factors . 22
7.2.3 Limiting conditions. 24
7.2.4 Pressure capacity of the corrugated metal hose braided or unbraided . 26
7.3 Braid . 28
7.3.1 Scope . 28
7.3.2 General factors . 28
7.3.3 Limiting design conditions . 30
7.3.4 Pressure capacity of the braid . 31
7.4 Metal hose assembly . 31
7.4.1 General . 31
7.4.2 Burst pressure of the corrugated hose . 32
7.4.3 Burst pressure of the braid . 33
7.4.4 Burst pressure of the metal hose assembly . 33
7.5 Flanges and other end fittings . 34
Annex A (informative) Calculation coefficients C , C , C . 35
p f d
A.1 Graphs of coefficients . 35
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A.2 Polynomial approximation of the coefficients . 38
A.2.1 Coefficients C . 38
p
A.2.2 Coefficients C . 39
f
A.2.3 Coefficients C . 39
d
A.2.4 Intermediate values . 40
Annex B (informative) Main information to be supplied to the hose manufacturer. 41
B.1 Main design conditions . 41
B.2 Additional information/requirements dependent on application . 41
Bibliography . 42

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European foreword
This document (CEN/TR 14585-3:2017) has been prepared by Technical Committee
CEN/TC 342 “Metal hose, hose assemblies, bellows and expansion joints”, the secretariat of which is
held by SNV.
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.
4

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Introduction
Technical Committee CEN/TC 342 “Metal hose, hose assemblies, bellows and expansion joints” is
carrying out a revision of EN 14585-1:2006 and CEN/TR 14585-2:2006 to include calculation methods
for the combined structure of hose and braid for:
— pressure resistance;
— fatigue life;
— allowable displacements.
The selection of materials for corrosive environments and the calculation of fluid pressure drops are
also being included.
It is appreciated that these studies are ambitious and will involve much new analyses so that this
revision will take some time.
Whilst continuing to work on this revision, CEN/TC 342 decided that the key aspects of the calculation
method should be circulated as an informative Technical Report CEN/TR 14585-3, which is limited to
the pressure resistance of the combined structure of hose and braid. This approach will enable
manufacturers and Notified Bodies to use and gain experience of the calculation method and any
feedback can be taken into account in the revision of EN 14585, harmonized to the Pressure Equipment
Directive 2014/68/EU.
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1 Scope
This Technical Report provides guidance on the design of corrugated metal hose assemblies for
pressure applications, i.e. maximum allowable pressure PS greater than 0,5 bar. Allowable stresses are
consistent with the requirements of the Pressure Equipment Directive 2014/68/EU.
2 Normative references
Not applicable.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 7369 and the following
apply.
3.1
metal hose assembly
assembly of a corrugated metal hose with its end fittings
Note 1 to entry: In the context of Pressure Equipment Directive [1], a metal hose assembly is a component of
piping and not a PED assembly.
3.2
maximum allowable pressure PS
maximum pressure for which the metal hose assembly is designed
3.3
maximum/minimum allowable temperature TS
maximum and minimum temperature for which the metal hose assembly is designed
3.4
nominal pressure PN
dimensionless alphanumerical designation which is a convenient rounded number commonly used for
reference purposes of piping components and stock parts; for this Technical Report PN represents the
maximum allowable pressure at 20 °C as specified by the metal hose assembly manufacturer
3.5
test pressure PT
pressure at which the pressure metal hose assembly is pressure tested (normally at ambient
temperature)
3.6
main pressure bearing parts
parts, such as corrugated metal hose, braid, pipe ends, the failure of which may result in a sudden
discharge of pressure energy
3.7
pressure bearing parts
parts, such as swivel nuts, flanges, threaded fittings, that are not main pressure bearing parts defined in
3.6 and the failure of which may not lead to a sudden discharge of pressure energy
3.8
attachments to pressure parts
parts, such as ferrules, that are directly welded to parts defined in 3.6 or 3.7
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3.9
other parts
parts, such as external protection, anti-kink device, braid protecting spiral, which are not parts
according to 3.6 to 3.8
3.10
equipment manufacturer
natural or legal person responsible for the values of the parameters PS and TS
Note 1 to entry: This may be the manufacturer or planner of the piping for which the metal hose assembly is
designed.
3.11
hose manufacturer
natural or legal person responsible for the design and the manufacturing of the corrugated metal hose
and/or the metal hose assembly
3.12
hydraulic forming (longitudinal welded)
corrugating a tube by pressurizing the inside against external tooling which allows this corrugated tube
to be axially shortened during the process
3.13
roll forming (longitudinal welded)
corrugating a tube by rolling from the outside to the inside and allowing or forcing this corrugated tube
to be axially shortened during the process
3.14
helical crest welded (resistance welded)
profiling a strip, rolling it over helically and finally welding the overlaps
3.15
strand
group of parallel wires used for plain braid or wires woven together to form a braided strand
3.16
braided braid
braid that is manufactured from previously braided strands
4 Symbols and abbreviations
For the purposes of this document, the symbols listed in Table 1 apply.
Table 1 — Symbols
Symbol Description Unit
A elongation at rupture according to EN ISO 6892–1 %
2
A cross sectional metal area of one corrugation; see Formula (3a) and 3b) mm
c
2
A hose effective area; see Formula (5) mm
e
2
a Braid wire cross section; see Formula (29) mm
w
b width of corrugation crest; see Figures 2 a) and 2 b) mm
c
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Symbol Description Unit
b nominal width of material (strip) according to EN ISO 9445-1 mm
n
b width of corrugation root; see Figures 2 a) and 2 b) mm
r
b width of a strand; see Figure 4 mm
s
C , C factors used to determine the calculation coefficients C , C , C ; see —
1 2 p f d
Formulae (6) and (7)
CB braid coverage; see Formula (38) —
C , C , C calculation coefficients (see Annex A) —
p f d
stacking factor for crossing braid wires and strands; see Formula (26) —
c
st
D inside diameter of the corrugated metal hose; see Figures 2 a) and 2 b) mm
i
D mean diameter of the corrugated metal hose; see Formula (8) mm
m
D outside diameter of the corrugated metal hose; see Formulae (9a) and mm
o
(9b)
d diameter of the braid wire; see Figure 4 mm
w
d mean diameter of a braid layer; see Formula (30) mm
B
2
E modulus of elasticity of hose material at room temperature N/mm (MPa)
2
E modulus of elasticity of hose material at design temperature N/mm (MPa)
t
e nominal thickness of hose material; see Figures 2 a) and 2 b) mm
e nominal thickness of one ply mm
p
e* equivalent wall thickness, corrected for thinning during forming; see mm
Formula (11)
e * equivalent thickness of one ply with thinning correction; see mm
p
Formulae (10a) and (10b)
F force due to pressure effect (pressure thrust); see Formula (12) N
p
2
f allowable general membrane stress at design temperature; see Table 7 N/mm (MPa)

2
f allowable general membrane stress at test conditions; see Table 7 N/mm (MPa)
T
G degree of load; see 5.5 and Formula (1) —
σ
hs thickness of a strand; see Formula (27) mm
K axial spring rate of one corrugation; see Formula (21) N/mm
ax(1)
K forming factor; see Formulae (18) and (19) —
f
k reduction factor for circumferential stress due to braid; see Formula (32) —
Θ
k derating factor for the pressure at operating temperature t ; see 6.3 —
p,t
l axial pitch of the braid; see Figure 4 and Formula (24) mm
B
l active corrugated length of a metal hose mm
c
n number of plies of a corrugated metal hose —
p
n number of braid strands —
s
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Symbol Description Unit
n number of wires in one braid strand —
w
2
P pressure resulting in an initial remaining (plastic) elongation of 1 %; see N/mm (MPa)
1,0
Formula (22)
2
P primary meridional bending stress N/mm (MPa)
m,b
2
P primary meridional membrane stress N/mm (MPa)
m,m
2
PΘ primary circumferential stress N/mm (MPa)
2
a maximum allowable pressure N/mm (MPa)
PS
PT test pressure bar
P maximum allowable pressure at operating temperature t; see bar
t, max
Formula (2)
q corrugation length; see Figures 2 a) and 2 b) mm
R to R bend radii of hose assemblies; see Table 5 mm
1 4
2
R minimum specified value of upper yield strength at design temperature N/mm (MPa)
eH, t
2
R minimum specified value of tensile strength at design temperature N/mm (MPa)
m, t
2
R minimum specified value of tensile strength at room temperature N/mm (MPa)
m, 20
2
R minimum specified value of 0,2 % proof strength at design temperature N/mm (MPa)
p 0,2, t
2
R minimum specified value of 1 % proof strength at design temperature N/mm (MPa)
p 1,0, t
r mean radius of torus at crest and root of U-shaped corrugations; see mm
m
Figures 2 a) and 2 b) and Formulae (4a) and (4b)
t operating temperature °C
t nominal thickness of the material (strip) mm
n
w corrugation height, see Figures 2 a) and 2 b) and Formula (13) mm
α initial braid angle; see Figure 4 and Formula (25) degree or
radian
β initial side wall angle of the corrugation; see Figure 3 and Formula (14) degree
0
Δl elastic hose elongation due to pressure; see Formula (20) mm
el
Δl plastic hose elongation due to pressure; see Formula (46) mm
pl
η load carrying efficiency of braid layer; see 7.3.2.4 -
λ relative plastic elongation; see Formula (46) -
ν value of Poisson's ratio for stainless steel of 0,3 -
2
σ (P) stress depending on P N/mm (MPa)
2
σ longitudinal stress in the braid wire; see Formula (39) N/mm (MPa)
w
Subscripts: o outside
0 initial p ply
B braid pl plastic
H hose r root
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Symbol Description Unit
t test condition t temperature
b bending or burst condition w wire
c corrugation or crest Δ difference
el elastic λ relative elongation
i inside or running index Θ circumferential
m membrane, meridional or mean Σ sum
n number of or upper summation index
a 2
All pressures for calculation purpose are in N/mm (MPa).

5 Materials
5.1 General requirements
Materials for the manufacture of hose assemblies including filler metal should be selected on the basis
of their suitability for fabrication, e.g. forming, joining, and for the conditions under which they will be
used.
When combining different materials, special care should be taken regarding compatibility with each
other.
5.2 Suitable materials
Materials suitable for hoses assemblies are given as follows:
a) materials suitable for corrugated metal hoses and their temperature limits are given in Table 2;
b) materials suitable for braid, fittings, and additional parts are given in Table 3.
Table 2 — Materials for corrugated metal hoses and their temperature limits
Material Temperature °C
Document
Type Number Steel name Minimum Maximum
a
1.4306 X2CrNi19–11 550
– 273
a
1.4401 X5CrNiMo17–12–2 550
– 196
a
1.4404 X2CrNiMo17–12–2 550
– 273
stainless
a
1.4435 X2CrNiMo18–14–3 550
– 273
austenitic EN 10028–7
a
1.4539 X1NiCrMoCu25–20–5 550
– 196
steels
a
1.4541 X6CrNiTi18–10 550
– 273
a
1.4547 X1CrNiMoCuN20–18–7 500
– 196
a
1.4571 X6CrNiMoTi17–12–2 550
– 273
600
X10NiCrAlTi32–21 EN 14917, B (2.1)
heat resistant
1.4876 – 196
austenitic steels b
X10NiCrAlTi32–21 (H) EN 14917, B (2.2)
900
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Material Temperature °C
Document
Type Number Steel name Minimum Maximum
2.4360 NICu30Fe – 196 425 EN 14917, B (3)
2.4610 NiMo16Cr16Ti – 196 400 EAM-0526–28
EAM-0526–43–1,
– 10 450
EAM-0526–43–2
2.4816 NiCr15Fe
EN 14917:2009+A1:
b
(– 273)
Nickel (900)
2012, Annex J
alloys
2.4819 NiMo16Cr15W – 196 400 EAM-0526–18
– 196 450 EAM-0526–40
2.4856 NiCr22Mo9Nb
EN 14917:2009+A1:
b
(– 273)
(900)
2012, Annex J
2.4858 NiCr21Mo – 10 540 EN 14917, B (4)
Copper CW024A Cu-DHP (R200) - 180 250
CW452K CuSn6 (R350) - 250 500
c
EN 1652
Copper alloy CW503L CuZn20 (R270) - 200 300
CW508L CuZn37 (R300) - 200 500
a
Minimum temperature in accordance with EN 13445–2 / Annex B or EN 13480–2 / Annex B.
b
Special care should be exercised due to the risk of embrittlement when using the materials at elevated
temperatures above 550 °C.
c
Copper and copper alloys for general purpose (not harmonized to PED); Particular Material Appraisals
(PMA) are necessary for applications within the scope of the PED.

Table 3 — Materials for braid, fittings, ferrules, and additional parts
Component Material No Document
Pressure parts
1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571 EN 10088–3
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 Table 2
Braid
a
Cu-based material: CW450K, CW452K, CW508L
EN 12166
forged EN 10222–2 and −3
Carbon steel
flat products EN 10028–2
Fixed flange,
EN 10222–5,
Weld collar,
1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571
EN 10028–7
b
Floating flange
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 Table 2
Cu-based material: CW024A EN 1653+A1
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Component Material No Document
a
EN 12164
CW617N
a
EN 12165
Carbon steel EN 10253–2
1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571 EN 10253–4
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 Table 2
Thread nipple,
CW024A EN 1653+A1
Taper thread
a
nipple, EN 12164
CW602N
Threaded
a
CW608N EN 12165
connection,
CW614N a
EN 12167

copper-based material:
CW617N
Threaded fitting, a
EN 12168
c
Swivel nut
CC491K
(CuSn5Zn5Pb5-C)
EN 1982
CC499K
(CuSn5Zn5Pb2-C)
d
EN-JM1030 EN 1562
Malleable cast iron
seamless EN 10216–1 to −4
Carbon steel
welded EN 10217–3 to −5
seamless EN 10216–5
1.4301, 1.4306, 1.4401,
Pipe ends
1.4404, 1.4541, 1.4571
welded EN 10217–7
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 See Table 2
a
copper-based material: CW024A
EN 12449
Parts attached to pressure parts
1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571 EN 10028–7
Ferrule
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 See Table 2
(similar to braid
material)
a
Cu-based material: CW450K, CW452K, CW508L
EN 12166
e
Other parts
End ring, 1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571 EN 10028–7
Protective strip-
1.4876, 2.4360, 2.4816, 2.4819, 2.4856, 2.4858 See Table 2
wound hose,
Cu-based material: CW450K, CW452K, CW508L EN 1652
Anti-kink device
Braid protecting 1.4301, 1.4306, 1.4401, 1.4404, 1.4541, 1.4571,
EN 10088–3
helix 1.4310
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Component Material No Document
a
Not harmonized to PED; Particular Material Appraisals (PMA) are necessary for applications within the scope
of the PED.
b
Ferritic floating flanges should be protected to avoid contamination of adjacent stainless steel parts.
c
Swivel nuts may be made from free cutting materials.
d
Malleable cast iron parts should be made weldable by multiple tempering. The carbon content of the welding
zones should not exceed 0,3 %.
e
Other parts should be preferably made from materials similar to the braid material.

5.3 Other materials
Other materials may be used provided they fulfil the general requirements of 5.1.
5.4 Corrosion
The materials selected for the metal hose assembly should have adequate resistance to all the corrosive
agents likely to be encountered during the lifetime of the system, i.e. the transported fluid and/or the
environment. Consideration should be given to all corrosion risks including pitting corrosion, inter-
granular corrosion, crevice corrosion, contact corrosion and stress corrosion cracking.
Forming and welding processes may degrade the corrosion resistance of materials.
NOTE Corrugated metal hoses generally have a wall thickness substantially less than that of the rest of the
system with which they are used. Hence they are often manufactured from a material having a higher corrosion
resistance than that used in the associated piping.
5.5 Low temperature application
Fittings such as weld ends, flanges, and threaded fittings used for low temperature applications should
not go below the temperature limits given in Table 4. The lowest allowable working temperature is
depending on the degree of load G which is defined by the maximum quotient of the stress levels
σ
resulting from the calculation of pressure resistance and the allowable stresses related to the regarded
stress components:
 
G max P /;f P /;f P+ P / 1,5⋅ f (1)
( ) ( )
σ Θ m,m m,m m,b
 
 
13
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Table 4 — Materials for pressure-bearing parts at low temperature application
(Except corrugated hoses and braid)
Lowest allowable working
temperature in °C
N° Description European Standard
Degree of load G
σ
a a
1,0 0,75 0,25
Non-alloy and alloy steels with
specified properties at elevated
temperatures:
1
— flat products EN 10028–2
— seamless pipes EN 10216–2
– 10 – 60 – 85
b b b
— steel forgings EN 10222–2 (– 20) (– 70) (– 100)
Flat products for pressure purpose
from Nickel alloy steels with
c
2 EN 10028–4 t – 50 t – 80
min min
t
min
specified low temperature
properties
Seamless pipes for pressure
purpose, from non-alloy steels with
c
3 EN 10216–4 t – 50 t – 80
min min
t
min
specified low temperature
properties
Forgings for pressure purpose,
c
4 Nickel steels with specified low EN 10222–3 t – 50 t – 80
min min
t
min
temperature properties
Fittings for welding, with specified
c
5 EN 10253–2 t – 50 t – 80
t min min
min
low temperature properties
c
6 Fittings for welding, stainless steels EN 10253–4 t – 50 t – 80
min min
t
min
EN 10028–7
Austenitic stainless steels according
7 to Table 2 with minimum allowable EN 10216–5 – 196 – 255 – 273
temperature – 196 °C
EN 10217–7
a
Additional requirements for degree of load smaller than 1,0. No material shall be used for pressure-bearing
parts having an elongation after rupture A less than 14 % and an impact energy less than 27 J, measured on an ISO
V-notch test-piece at a temperature not greater than 20 °C and not higher than the lowest scheduled operating
temperature.
b
For materials suitable for use at −20 °C according to the relevant standard.
c
Lowest temperature of the regarded material according to the relevant standards.
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Pressure-bearing parts made from materials given in Table 4 may be used at low temperatures related
to a degree of load G < 1,0 if the following additional demands are fulfilled to achieve similar safety
σ
against brittle fracture:
a) The hose manufacturer should ensure that:
1) stress raisers are avoided with regard to design and manufacture;
2) no cracks are to be expected under work
...