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PREDSTANDARD
december 2004
Prenosni plinski valji – Specifikacija za zasnovo in konstrukcijo ponovno
polnljivih nevarjenih jeklenk za prenosne gasilne naprave in za dihalne
aparate z vodno prostornino od 0,5 litra do 150 litrov
Transportable gas cylinders - Specification for the design and construction of
refillable seamless steel cylinders for portable fire extinguishers and bottles for
breathing apparatus of water capacities from 0,5 litre up to 15 litres
ICS 23.020.30 Referenčna številka
OSIST prEN 15047:2004(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
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EUROPEAN STANDARD
DRAFT
prEN 15047
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2004
ICS
English version
Transportable gas cylinders - Specification for the design and
construction of refillable seamless steel cylinders for portable
fire extinguishers and bottles for breathing apparatus of water
capacities from 0,5 litre up to 15 litres
Bouteilles à gaz transportables - Spécification pour la Ortsbewegliche Gasflaschen - Gestaltung und Konstruktion
conception et la fabrication de bouteilles à gaz von wiederbefüllbaren ortsbeweglichen nahtlosen
rechargeables et transportables en acier sans soudure Gasflaschen aus Stahl für Tragbare Feuerlösche und
d'extincteurs d'incedie portatif et bouteilles d'appareil Atmungapparat mit einem Fassungsraum von 0,5 l bis
respiratoir de capacité de l'eau comprise entre 0,5 l et 15 l einschließlich 15 l
inclus
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 23.
If this draft becomes a European Standard, 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.
This draft European Standard 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 Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15047:2004: E
worldwide for CEN national Members.
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prEN 15047:2004 (E)
Contents
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms, definitions and symbols.5
4 Material requirements .7
5 Design requirements .9
6 Construction and workmanship requirements.13
7 New design tests.19
8 Tests for steel cylinders.20
9 Tests on every cylinder.28
10 Failure to meet test requirements.29
11 Markings .30
12 Certificate .30
Annex A (normative) Description, evaluation of manufacturing defects and conditions for rejection of
seamless steel gas cylinders at time of visual inspection.31
Annex B (informative) Examples of wall thickness calculations.39
Annex C (informative) Examples of new design (type) approval and production testing certificates .41
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC (PED) .46
Bibliography .48
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prEN 15047:2004 (E)
Foreword
This document (prEN 15047:2004) has been prepared by Technical Committee CEN/TC 23 “Transportable gas
cylinders”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
This European standard has been prepared to address the essential requirements of the Pressure Equipment
Directive (PED) for portable, refillable seamless steel (with a high F-factor) fire extinguishers and breathing
apparatus of water capacities from 0,5 litre up to and including 15 litres.
Annex A is normative. Annexes B, C and ZA are informative.
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prEN 15047:2004 (E)
Introduction
The purpose of this standard is to provide a specification for the design, manufacture, inspection and approval of
refillable seamless high F-factor steel for use in portable fire extinguishers and breathing apparatus
The specification given is based upon knowledge of, and experience with, materials, design requirements,
manufacturing processes and control during manufacture, of cylinders in common use in the countries of the CEN
members.
This standard draws upon established practice as outlined in the ADR (European Agreement Concerning the
International Carriage of Dangerous Goods by Road) for determining the test pressure of gas cylinders (ADR, P200
4.1.4.1).
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prEN 15047:2004 (E)
1 Scope
This standard specifies minimum requirements for the material, design, construction and workmanship,
manufacturing processes and tests at manufacture of refillable seamless steel gas cylinders fitted with bursting disc
devices for portable fire extinguishers and breathing apparatus of water capacities from 0,5 litre up to 15 litres. This
standard is applicable to cylinders manufactured from steel with an R value of less than 1 100 MPa.
m
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references,
only the edition cited applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 629-1, Transportable gas cylinders — 25E taper thread for connection of valves to gas cylinders — Part 1:
Specification
EN 629-2, Transportable gas cylinders — 25E taper thread for connection of valves to gas cylinders — Part 2:
Gauge inspection
EN 10002-1, Metallic materials — Tensile testing — Part 1: Test method
EN 10003-1, Metallic materials — Brinell hardness test — Part 1: Test method
EN 10204:1991, Metallic Products — Types of inspection documents
EN 10028-1, Flat products made of steels for pressure purposes - Part 1: General requirements
EN ISO 11114-1:1997, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas
contents - Part 1: Metallic materials (ISO 11114-1:1997)
EN ISO 13341, Transportable gas cylinders — Fitting of valves to gas cylinders
prEN ISO 13769: 2004, Gas cylinders — Stamp marking
prEN ISO 15245-1, Transportable gas cylinders — Parallel threads for connection of valves to gas cylinders — Part
1: Specification
prEN ISO 15245-2, Transportable gas cylinders — Parallel threads for connection of valves to gas cylinders — Part
2: Gauge Inspection
EURONORM 6-55, Bend test for steel
3 Terms, definitions and symbols
For the purpose of this standard the following terms, definitions and symbols apply:
3.1 Terms and definitions
3.1.1
yield stress
value corresponding to the lower yield stress Re or, for steels that do not exhibit defined yield, the 0,2 % proof
L
stress Rp
0,2
3.1.2
normalizing
heat treatment in which a cylinder is heated to a uniform temperature above the upper critical point (AC , as
3
defined in EN 10052) of the steel and then cooled in still air
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prEN 15047:2004 (E)
3.1.3
quenching
hardening heat treatment in which a cylinder, which has been heated to a uniform temperature above the upper
critical point (AC , as defined in EN 10052) of the steel, is cooled rapidly in a suitable medium
3
3.1.4
tempering
softening heat treatment which follows quenching (or in some cases normalizing), in which the cylinder is heated to
a uniform temperature below the lower critical point (AC , as defined in EN 10052) of the steel
1
3.1.5
batch
a quantity of up to 200 cylinders, plus cylinders for destructive testing, of the same nominal diameter, thickness,
length and design made from the same steel cast and subjected to the same heat treatment for the same duration
of time
3.1.6
burst pressure
highest pressure reached in a cylinder during a burst test
3.1.7
working pressure
settled pressure at a uniform temperature of 15 °C and full gas content
3.1.8
test pressure
required pressure applied during a pressure test
3.1.9
design stress factor (F) (variable)
the ratio of equivalent wall stress at test pressure (p ) to guaranteed minimum yield stress (R )
h e
3.1.10
mass
the weight of a cylinder, expressed in kilograms, comprising the combined weight of cylinder and permanently
attached parts (eg foot ring, neck ring, etc) but without valve
3.2 Symbols
a Calculated minimum thickness, in millimetres, of the cylindrical shell
a' Guaranteed minimum thickness, in millimetres, of the cylindrical shell
A Percentage elongation, determined by the tensile test 7.2.2.2
b Guaranteed minimum thickness, in millimetres, at the centre of a convex base (see figure 1)
d Diameter of former, in millimetres figure 4
D Nominal outside diameter of the cylinder, in millimetres see figure 1
F Design stress factor (variable) see 3.1.9
H Outside height of domed part (convex head or base end), in millimetres (see figure 1)
n The ratio of the diameter of the bend test former to actual thickness of test piece (t)
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prEN 15047:2004 (E)
1)
P Measured burst pressure, in bar above atmospheric pressure
b
1)
P Lower cyclic pressure, in bar above atmospheric pressure
lc
1)
P Hydraulic test pressure, in bar above atmospheric pressure
h
P Maximum allowable pressure in bar for which the cylinder is designed, as specified in 5.2.
S
r Inside knuckle radius, in millimetres (see figure 1)
r Inside crown radius, in millimetres (see figure 1)
i
R Minimum guaranteed value of yield stress (see 3.1.1) in megapascals, for the finished cylinder
e
R Actual value of yield stress, in megapascals, determined by the tensile test 8.1.2.1
ea
R Minimum guaranteed value of tensile strength, in megapascals, for the finished cylinder
g
R Actual value of tensile strength, in megapascals, determined by the tensile test 8.1.2.1
m
S Original cross sectional area of tensile test piece, in square millimetres, according to EN 10002-1
o
T Maximum allowable temperature °C
s
t Actual thickness of test specimen, in millimetres
4 Material requirements
4.1 General provisions
4.1.1 Steels for the manufacture of gas cylinders shall meet the requirements of this standard.
4.1.2 The steel used for the fabrication of gas cylinders shall have acceptable non-ageing properties and shall
not be rimming quality. In cases where examination of this non-ageing property is required, the criteria by which it is
to be specified shall be agreed between the parties.
4.1.3 The cylinder manufacturer shall identify the cylinders with the cast of steel from which they are made.
4.1.4 Grades of steel used for cylinder manufacture shall be compatible with the intended gas service, e.g.
corrosive gases, embrittling gases. (See EN ISO 11114-1).
4.2 Controls on chemical composition
4.2.1 The chemical composition of all steels shall be specified and recorded, including:
– maximum sulfur and phosphorus content;
– carbon, manganese and silicon content;
– nickel, chromium, molybdenum and all other alloying elements intentionally added.
5
1)
1bar = 10 Pa = 0.1MPa
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prEN 15047:2004 (E)
The content of carbon, manganese, silicon and where appropriate, nickel, chromium and molybdenum shall be
given, with tolerances, such that the differences between the maximum and minimum values of the cast do not
exceed the values shown in table 1.
Table 1 — Chemical composition tolerances
Element Nominal content in % Maximum permissible range in %
Carbon < 0,30 % 0,06 %
0,07 %
≥ 0,30 %
Manganese All values 0,30 %
Silicon All values 0,30 %
Chromium < 1,50 % 0,30 %
0,50 %
≥ 1,50 %
Nickel All values 0,40 %
Molybdenum All values 0,15 %
NOTE The maximum permissible range for each element is not required to be centred on its
nominal content. As an example, for a steel with nominal carbon content of 0,10 %, the following
three maximum permissible ranges are equally acceptable:
+0,00 %, -0,06 % +0,00 %, -0,06 %
+0,06 %, -0,00 %
+0,03 %, -0,03 % +0,03 %, -0,03 %
The combined content of the following elements: V, Nb, Ti, B, Zr, shall not exceed 0,15 %.
4.2.2 Sulfur and phosphorus in the cast analysis of material used for the manufacture of gas cylinders shall not
exceed the values shown in table 2.
Table 2 — Sulfur and phosphorus limits
R in MPa
m
R < 950 950 ≤ R < 1 100
m m
Sulfur 0,020 % 0,010 %
Phosphorus 0,020 % 0,020 %
Sulfur + phosphorus 0,030 % 0,025 %
4.2.3 The cylinder manufacturer shall obtain and provide certificates of cast analyses of the steels supplied for
the manufacture of gas cylinders. Should check analyses be required, they shall be carried out either on specimens
taken during manufacture from material in the form as supplied by the steel maker to the cylinder manufacturer, or
from finished cylinders avoiding decarbonised zones from the cylinder surface. In any check analysis, the maximum
permissible deviation from the limits specified for cast analyses shall conform to the values specified in EN 10028-
1.
4.3 Heat treatment
4.3.1 The cylinder manufacturer shall provide a certificate stating the heat treatment process applied to the
finished cylinders.
4.3.2 Quenching in media other than mineral oil is permissible provided that the method produces cylinders free
of cracks. If the rate of cooling in the medium is greater than 80 % of that in water at 20 °C without additives, every
production cylinder shall be subjected to a non-destructive test to prove freedom from cracks.
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prEN 15047:2004 (E)
4.3.3 The tempering process for quenched and tempered cylinders and for normalized and tempered cylinders
shall achieve the required mechanical properties. The actual temperature to which a type of steel is subjected for a
given tensile strength shall not deviate by more than 30 °C from the temperature specified by the cylinder
manufacturer.
5 Design requirements
5.1 General provisions
5.1.1 The calculation of the wall thickness of the pressure containing parts shall be related to the yield stress (R ) of
e
the material.
5.1.2 For calculation purposes the value of the yield stress (R ) is limited to a maximum of 0,90 R .
e g
5.1.3 The internal pressure upon which the calculation of wall thickness is based shall be the hydraulic test
pressure (P ).
h
5.2 Calculation of cylindrical wall thickness
The guaranteed minimum thickness of the cylindrical shell (a') shall not be less than the thickness calculated using
the equation:
D 10.F.Re− 3.Ph
a = 1−
2 10.F.Re
where the value of F shall not exceed 0,875.
R / R shall be limited to 0,90.
e g
The calculated minimum thickness shall also satisfy the equation:
a ≥ D + 1 mm
100
With an absolute minimum of a = 1,5 mm.
Cylinders for CO fire extinguishers applications shall be designed for hydraulic test pressures related to selected
2
filling ratios. The test pressure shall not be less than the developed pressure at 65°C (see Table 3). For breathing
apparatus applications the test pressure shall not be less than 1,5 x working pressure (see 3.1.7).
Table 3 — Test pressure versus filling ratio for CO
2
Filling
P Minimum test pressure P
S h
(kg/l)
(bar) (bar)
0,667 136,8 200
0,675 138,4 200
0,750 173,5 250
When choosing the minimum guaranteed value of the thickness of the cylindrical shell (a'), the manufacturer shall
take into account all requirements for type and production testing, particularly the burst test requirements of 8.2.
For examples of wall thickness calculations see annex B.
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5.3 Calculation of convex ends (heads and base ends)
5.3.1 The shapes shown in figure 1 are typical for convex heads and base ends. Shapes A and B are base ends
formed from tubing, shapes D and E are base ends formed during the piercing of a billet, and shapes C and F are
heads.
5.3.2 The thickness (b) at the centre of the convex end shall be not less than that required by the following
criteria:
Where the inside knuckle radius (r) is not less than 0,075 D, then
b ≥ 1,5a for 0,40 > H/D ≥ 0,20
b ≥ a for H/D ≥ 0,40
In order to obtain a satisfactory stress distribution in the region where the end joins the cylindrical part, any
thickening of the end that may be required, shall be gradual from the point of juncture. For the application of this
rule, the point of juncture between the cylindrical part and the end is defined by the horizontal line indicating
dimension H in figure 1.
Shape B shall not be excluded from this requirement.
The cylinder manufacturer shall prove by the pressure cycling test as required in 8.3 that the design is satisfactory.
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Key
1 Cylindrical part
Figure 1 — Typical convex ends
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prEN 15047:2004 (E)
5.4 Calculation of concave base ends
When concave base ends are used, the dimensions defined in figure 2 shall be not less than the following
calculated values:
a = 2a ; a = 2a ; h = 0,12D ; r = 0,075D
1 2
Figure 2 — Concave base ends
In order to obtain a satisfactory stress distribution, the thickness of the cylinder shall increase progressively in the
transition area region between the cylindrical part and the base, and the wall shall be free from defects.
The cylinder manufacturer shall prove by the pressure cycling test for a new design as required in 7.1 that the
design is satisfactory.
5.5 Neck design
5.5.1 The external diameter and thickness of the formed neck end of the cylinder shall be designed for the torque
applied in fitting the valve to the cylinder. The torque may vary according to the diameter of thread, the form, and
the sealant used in the fitting of the valve. The torques specified in EN ISO 13341 shall not be exceeded, since this
could result in permanent damage to the cylinder. Where the cylinder manufacturer specifies a lower torque this
also shall not be exceeded. The manufacturer shall notify any such requirements to the purchaser of aluminium or
aluminium alloy cylinders for portable CO fire extinguishers.
2
5.5.2 The thickness of the wall in the cylinder neck shall be sufficient to prevent permanent expansion of the neck
during initial and subsequent fitting of the valve into the cylinder. Where the cylinder is specifically designed to be
fitted with neck reinforcement, such as a neck ring or shrunk-on collar this may be taken into account (see
EN ISO 13341).
5.5.3 Cylinders for portable CO fire extinguishers may be designed with one or two opening(s) along the central
2
cylinder axis only.
5.6 Foot-rings
When a foot-ring is provided, it shall be sufficiently strong to support the cylinder in a vertical orientation and made
of material compatible with that of the cylinder. The shape should be cylindrical and shall give the cylinder sufficient
stability. The foot-ring shall be secured to the cylinder by a method other than welding, brazing or soldering. Any
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prEN 15047:2004 (E)
gaps which may form water traps shall be sealed to prevent ingress of water, by a method other than welding,
brazing or soldering.
5.7 Neck-rings
When a neck-ring is provided, it shall be made of a material that is compatible with that of the cylinder, and shall be
securely attached by a method other than welding, brazing or soldering.
The manufacturer shall ensure that the axial load required to remove the neck-ring is greater than 10 times the
weight of the empty cylinder and not less than 1 000 N, also that the minimum torque required to turn the neck-ring
is greater than 100 N⋅m.
5.8 Design drawing
A fully dimensioned drawing shall be prepared which includes the specification of the material, and details of the
permanent fittings.
6 Construction and workmanship requirements
6.1 General
The cylinder shall be produced by:
— forging or drop forging from a solid ingot or billet; or
— manufacturing from seamless tube; or
— pressing from a flat plate.
Metal shall not be added in the process of closure of the end. Manufacturing defects shall not be corrected by
plugging of bases. Welding of seamless steel cylinders shall not be permitted under any circumstances.
Once the manufacturing route has been established and new design approval obtained, no other significant
changes to the process shall be permitted unless the product is submitted for re-approval.
6.2 Wall thickness
Each cylinder shall be examined for thickness and for external and internal surface defects. The wall thickness at
any point shall not be less than the minimum design thickness.
6.3 Surface defects
The internal and external surfaces of the finished cylinder shall be free from defects that would adversely affect the
safe working of the cylinder. See annex A. Such defects shall be removed by local dressing. The wall thickness of
any dressed area shall not be less than the minimum thickness specified.
6.4 Ultrasonic examination
6.4.1 General
Except as identified in 6.4.6, all cylinders shall be ultrasonically examined for defects. These tests are based on
techniques used by cylinder manufacturers. Other techniques of ultrasonic examination may be used, provided
these have been demonstrated to be suitable for the manufacturing method.
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6.4.2 Equipment and personnel requirements
The ultrasonic testing equipment shall be capable of at least detecting the reference standard as described in
6.4.3.2. It shall be serviced regularly in accordance with the manufacturers operating instructions to ensure that its
accuracy is maintained. Inspection records and approval certificates for the equipment shall be maintained.
The operation of the test equipment shall be by personnel certified at least to level 1 of EN 473 and supervised by
personnel certified at least to level 2 of EN 473.
The inner and outer surfaces of any cylinder which is to be tested ultrasonically shall be in a condition suitable for
an accurate and reproducible test.
For flaw detection the pulse echo system shall be used. For thickness measurement either the resonance method
or the pulse echo system shall be used. Either contact or immersion techniques of testing shall be used.
A coupling method which ensures adequate transmission of ultrasonic energy between the testing probe and the
cylinder shall be used.
6.4.3 Flaw detection of the cylindrical part
6.4.3.1 Procedure
The cylinders to be inspected and the search unit shall have a rotating motion and translation relative to one
another such that a helical scan of the cylinder will be described. The velocity of rotation and translation shall be
constant within ± 10 %. The pitch of the helix shall be less than the width covered by the probe (at least a 10 %
overlapping shall be guaranteed) and be related to the effective beam width such as to ensure 100 % coverage at
the velocity of rotation and translation used during the calibration procedure.
An alternative scanning method may be used for transverse defect detection, in which the scanning or relative
movement of the probes and the work piece is longitudinal, the sweeping motion being such as to ensure a 100 %
surface coverage with 10 % overlapping of the sweeps.
The cylinder wall shall be tested for longitudinal defects with the ultrasonic energy transmitted in both
circumferential directions and for transverse defects in both longitudinal directions.
For concave based cylinders where hydrogen embrittlement or stress corrosion may occur (see EN ISO 11114-1)
the transition region between the cylindrical part and cylinder base shall also be tested for transverse defects in the
direction of the base. For the area to be considered, see figure 3. The ultrasonic sensitivity shall be set at + 6 dB in
order to improve the detection of defects equivalent to 5 % of the cylindrical wall thickness in this thickened portion.
In this case, or when optional testing is carried out on the transition areas between the cylindrical part and neck
and/or cylindrical part and base, this may be conducted manually if not carried out automatically.
The effectiveness of the equipment shall be periodically checked by passing a reference standard through the test
procedure. This check shall be carried out at least at the beginning and end of each shift. If during this check the
presence of the appropriate reference notch is not detected then all cylinders tested subsequent to the last
acceptable check shall be retested once the equipment has been adjusted.
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prEN 15047:2004 (E)
Figure 3 — Base/cylindrical part transition region
6.4.3.2 Reference standard
A reference standard of convenient length shall be prepared by the manufacturer. The cylinder selected by the
manufacturer for the reference standard shall be dimensionally and acoustically representative of the cylinder to be
inspected, as demonstrable by the manufacturer. The reference standard shall be free from discontinuities which
may interfere with the detection of the reference notches.
Reference notches both longitudinal and transverse, shall be machined on the outer and inner surface of the
reference standard. The notches shall be separated such that each notch can be clearly identified.
Dimensions and shape of notches are of crucial importance for the adjustment of the equipment (see figures 4 and
5).
– The length of the notches (E) shall not be greater than 50 mm.
– The width (W) shall not be greater than twice the nominal depth (T). However, where this condition cannot be
met a maximum width of 1,0 mm is acceptable.
– The depth of the notches (T) shall be equal to 5 % ± 0,75 % of the nominal wall thickness (S), with a minimum
of 0,3 mm and a maximum of 1,0 mm, over the full length of the notch. Runouts at each end are permissible.
– The notch shall be sharp edged at its intersection with the surface of the cylinder wall. The cross section of the
notch shall be rectangular except where spark erosion machining methods are employed; then it is
acknowledged that the bottom of the notch will be rounded.
– The shape
...