EN 14638-3:2010

Transportable gas cylinders - Refillable welded receptacles of a capacity not exceeding 150 litres - Part 3: Welded carbon steel cylinders made to a design justified by experimental methods

This European Standard specifies minimum requirements concerning material, design, construction and workmanship, procedures and tests at manufacture of refillable transportable welded cylinders made of carbon steel, justified by experimental methods, of water capacities from 0,5 l up to and including 150 l for compressed or liquefied gases and of a test pressure up to 90 bar.
NOTE   This European Standard may also be used as a guideline for cylinders less than 0,5 l water capacity.
This European Standard is primarily intended for industrial gases other than LPG but may also be applied for LPG. However, for dedicated LPG cylinders see EN 14140 [5], prepared by CEN/TC 286.

Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Gefäße mit einem Fassungsraum von nicht mehr als 150 Liter - Teil 3: Flaschen aus geschweißtem Kohlenstoffstahl, ausgelegt nach experimentellen Verfahren

Diese Europäische Norm legt Mindestanforderungen an Werkstoff, Auslegung, Bau und Ausführung, Herstel-lungsverfahren und Herstellungsprüfungen von wiederbefüllbaren, ortsbeweglichen, geschweißten Flaschen aus Kohlenstoffstahl, ausgelegt nach experimentellen Verfahren, mit einem Fassungs¬raum von 0,5 l bis ein-schließlich 150 l für verdichtete und verflüssigte Gase mit einem Prüfdruck bis zu 90 bar fest.
ANMERKUNG   Diese Norm kann auch als Leitfaden für Flaschen mit einem Fassungsraum von weniger als 0,5 l angewendet werden.
Diese Europäische Norm gilt hauptsächlich für andere Industriegase als Flüssiggas (en: Liquified Petroleum Gas - LPG), kann jedoch ebenfalls für LPG angewendet werden. Für zugehörige LPG-Flaschen siehe hin-gegen EN 14140 [5], die vom CEN/TC 286 erarbeitet wurde.

Bouteilles à gaz transportables - Récipients soudés rechargeables d'une capacité inférieure ou égale à 150 litres - Partie 3: Bouteilles en acier carbone soudées conçues par des méthodes expérimentales

La présente Norme européenne spécifie les exigences minimales relatives au matériau, à la conception, à la
fabrication et à la mise en oeuvre, aux modes de fabrication et aux essais lors de la fabrication des bouteilles
transportables rechargeables, en acier au carbone soudées, conçues par des méthodes expérimentales, de
capacités équivalentes en eau comprises entre 0,5 l et 150 l inclus, destinées aux gaz comprimés ou liquéfiés
et soumises à une pression d’épreuve maximale de 90 bar.
NOTE La présente Norme européenne peut également servir de guide en matière de bouteilles de capacité
équivalente en eau inférieure à 0,5 l.
La présente Norme européenne s’applique principalement aux gaz industriels autres que le gaz de pétrole
liquéfié (GPL) mais peut également concerner le GPL. Toutefois, pour les bouteilles à gaz dédiées au GPL,
se reporter à l’EN 14140 [5], élaborée par le comité technique CEN/TC 286.

Premične plinske jeklenke - Ponovno polnljivi varjeni vsebniki s prostornino, ne večjo kot 150 litrov - 3. del: Varjene jeklenke iz ogljičnega jekla, izdelane po konstrukciji, potrjeni s preskušanjem

Ta evropski standard opredeljuje minimalne zahteve glede materiala, zasnove, izgradnje in strokovnosti, postopkov in preskusov pri proizvodnji ponovno polnljivih prenosnih varjenih jeklenk iz ogljičnega jekla, potrjenih s preskušanjem, s prostornino od 0,5 l do in vključno 150 l, za stisnjene ali utekočinjene pline in s preskusnim tlakom do 90 barov.

General Information

• Status: Published
• Publication Date: 24-Aug-2010
• Withdrawal Date: 27-Feb-2011
• ICS: 23.020.30 - Pressure vessels, gas cylinders
• ICS: 23.020.35 - Gas cylinders
• Technical Committee: CEN/TC 23 - Transportable gas cylinders
• Drafting Committee: CEN/TC 23/SC 1/WG 2 - Welded/brazed cylinders excluding cylinders for LPG
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 03-Sep-2021
• Completion Date: 14-Apr-2025
• Directive: 2008/68/EC - Directve 2008/68/EC of the European Parliament and of the council of 24 September 2008 on the inland transport of the dangerous goods
• Directive: 94/55/EC - Transport of dangerous goods by road
• Directive: 96/49/EC - Transport of dangerous goods by rail
• Directive: 96/86/EC - Transport of dangerous goods by road (94/55/EC Dir. amendment)
• Directive: 96/87/EC - Transport of dangerous goods by rail (96/49/EC Dir. amendment)
• Mandate: M/086 - Mandate to CEN for standardization in the field of transport of dangerous goods
• Ref Project: SIST EN 14638-3:2010 - Transportable gas cylinders - Refillable welded receptacles of a capacity not exceeding 150 litres - Part 3: Welded carbon steel cylinders made to a design justified by experimental methods

Relations

• Corrected By: EN 14638-3:2010/AC:2012 - Transportable gas cylinders - Refillable welded receptacles of a capacity not exceeding 150 litres - Part 3: Welded carbon steel cylinders made to a design justified by experimental methods
• Effective Date: 18-Jan-2012

Overview

EN 14638-3:2010 is a CEN European Standard covering transportable gas cylinders - specifically refillable, welded carbon steel cylinders with water capacities from 0.5 L up to 150 L and test pressures up to 90 bar. It defines minimum requirements for material, design, construction, workmanship, manufacturing procedures and tests where the cylinder design is justified by experimental methods (not solely by traditional calculation). The standard is primarily intended for industrial gases (may also apply to LPG, though dedicated LPG cylinders are covered by EN 14140).

Key topics

• Scope & applicability: Refillable welded receptacles ≤150 L; guidance for cylinders <0.5 L; primarily industrial gases.
• Materials & heat treatment: Accepted carbon steel grades (see EN 10028 series, EN 10120, EN 10268); requirements for traceability and ladle analysis certificates; guidance when heat treatment is omitted.
• Design justified by experimental methods: Experimental validation and stress analysis methodology to demonstrate functional performance.
• Welding & construction: Welding consumables and procedures, approval/qualification of welders and welding procedures (references to EN ISO 15614-1, EN 287-1).
• Testing at manufacture:
  • Prototype and batch tests
  • Production tests and failure handling
  • Non-destructive examination (NDE) of welds (visual, radiography, computed radiography - EN 1435, EN 14784)
  • Destructive sample tests (tensile, impact - EN ISO 6892-1, ISO 148)
• Quality control & documentation: Batch definition, certificates of conformity, marking and type-approval procedures.
• Special provisions: Annexes address NDE, visual acceptance/rejection criteria, elongation limits, and type-approval templates.

Applications and users

Who uses EN 14638-3:2010:

• Cylinder manufacturers (design, production, quality control)
• Welding and materials engineers validating cylinder integrity
• Quality managers and test laboratories performing prototype and batch testing
• Conformity assessment bodies, notified bodies and inspection authorities for type approval and certification
• Gas suppliers and industrial end-users specifying safe transportable cylinders for compressed or liquefied gases

Practical benefits:

• Ensures safe, repeatable manufacture of welded carbon steel cylinders
• Provides experimental design routes where analytical methods are insufficient
• Establishes NDE, testing and traceability practices required for regulatory compliance with transport of dangerous goods frameworks

Related standards

• EN 14140 (LPG cylinders)
• EN 1803 (periodic inspection and testing of welded carbon steel gas cylinders)
• EN 10028 series, EN 10120, EN 10268 (steel material standards)
• EN ISO 11114-1 (material compatibility with gases)
• EN ISO 15614-1, EN 287-1 (welding procedure and personnel qualification)
• EN 1435 / EN 14784 (radiographic and computed radiography NDE)

Keywords: EN 14638-3:2010, transportable gas cylinders, welded carbon steel cylinders, refillable welded receptacles, design justified by experimental methods, manufacturing tests, non-destructive examination.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Gefäße mit einem Fassungsraum von nicht mehr als 150 Liter - Teil 3: Flaschen aus geschweißtem Kohlenstoffstahl, ausgelegt nach experimentellen VerfahrenBouteilles à gaz transportables - Récipients soudés rechargeables d'une capacité inférieure ou égale à 150 litres - Partie 3 : Bouteilles en acier carbone soudées conçues par des méthodes expérimentalesTransportable gas cylinders - Refillable welded receptacles of a capacity not exceeding 150 litres - Part 3: Welded carbon steel cylinders made to a design justified by experimental methods23.020.30MHNOHQNHPressure vessels, gas cylindersICS:Ta slovenski standard je istoveten z:EN 14638-3:2010SIST EN 14638-3:2010en,fr,de01-november-2010SIST EN 14638-3:2010SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 14638-3
August 2010 ICS 23.020.30 English Version
Transportable gas cylinders - Refillable welded receptacles of a capacity not exceeding 150 litres - Part 3: Welded carbon steel cylinders made to a design justified by experimental methods
Bouteilles à gaz transportables - Récipients soudés rechargeables d'une capacité inférieure ou égale à 150 litres - Partie 3: Bouteilles en acier carbone soudées conçues par des méthodes expérimentales
Ortsbewegliche Gasflaschen - Wiederbefüllbare geschweißte Gefäße mit einem Fassungsraum von nicht mehr als 150 Liter - Teil 3: Flaschen aus geschweißtem Kohlenstoffstahl, ausgelegt nach experimentellen VerfahrenThis European Standard was approved by CEN on 23 July 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14638-3:2010: ESIST EN 14638-3:2010

Non-destructive examination (NDE) of welds . 28Annex B (normative)
Description, evaluation of manufacturing imperfections and conditions for rejection of welded carbon steel gas cylinders at time of final visual inspection by the manufacturer . 30Annex C (informative)
Certificate of conformity . 33Annex D (normative)
Specific requirements for cylinders manufactured with steel that has an elongation less than 14 % . 36Annex E (informative)
Type approval certificate . 38Bibliography . 39 SIST EN 14638-3:2010

Introduction The purpose of this European Standard is to provide a specification for the design, manufacture, inspection and approval of welded carbon steel gas cylinders for use in the countries of the CEN members. The specifications given in the present standard establish the methodology to be adopted to demonstrate that a cylinder conforms to the functional requirements demanded, based on experience of materials, design prescriptions, manufacturing processes and controls manufacturing. This European Standard specifies experimental methods and appropriate stress analysis calculations. It does not cover methods exclusively by means of traditional calculation. SIST EN 14638-3:2010

1 Scope This European Standard specifies minimum requirements concerning material, design, construction and workmanship, procedures and tests at manufacture of refillable transportable welded cylinders made of carbon steel, justified by experimental methods, of water capacities from 0,5 l up to and including 150 l for compressed or liquefied gases and of a test pressure up to 90 bar. NOTE This European Standard may also be used as a guideline for cylinders less than 0,5 l water capacity. This European Standard is primarily intended for industrial gases other than LPG but may also be applied for LPG. However, for dedicated LPG cylinders see EN 14140 [5], prepared by CEN/TC 286. 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 287-1, Approval testing of welders — Fusion welding — Part 1: Steels EN 462-1, Non-destructive testing — Image quality of radiographs — Part 1: Image quality indicators (wire type) — Determination of image quality value EN 462-2, Non-destructive testing — Image quality of radiographs — Part 2: Image quality indicators (step/hole type) — Determination of image quality value EN 473:2008, Non-destructive testing — Qualification and certification of NDT personnel — General principles EN 910, Destructive tests on welds in metallic materials — Bend tests EN 970, Non-destructive examination of fusion welds — Visual examination EN 1418, Welding personnel — Approval testing of welding operators for fusion welding and resistance weld setters for fully mechanized and automatic welding of metallic materials EN 1435:1997, Non destructive examination of welds — Radiographic examination of welded joints EN 1803, Transportable gas cylinders — Periodic inspection and testing of welded carbon steel gas cylinders EN 10028-1, Flat products made of steels for pressure purposes — Part 1: General requirements EN 10028-3, Flat products made of steels for pressure purposes — Part 3: Weldable fine grain steels, normalized EN 10028-5, Flat products made of steels for pressure purposes — Part 5: Weldable fine grain steels, thermomechanically rolled EN 10045-1, Metallic materials — Charpy impact test — Part1: Test method EN 10052, Vocabulary of heat treatment terms for ferrous products EN 10083-1, Steels for quenching and tempering — Part1: General technical delivery conditions SIST EN 14638-3:2010

(ISO 6892-1:2009) EN ISO 10692-2, Gas cylinders — Gas cylinder valve connections for use in the microelectronics industry — Part 2: Specification and type testing for valve to cylinder connections (ISO 10692-2:2001) EN ISO 11114-1, Transportable gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 1: Metallic materials (ISO 11114-1:1997) EN ISO 11117:2008, Gas cylinders — Valve protection caps and valve guards — Design, construction and tests (ISO 11117:2008) EN ISO 15614-1, Specification and qualification of welding procedures for metallic materials — Welding procedure test — Part 1: Arc and gas welding of steels and arc welding of nickel and nickel alloys
(ISO 15614-1:2004) ISO 148-1, Metallic materials — Charpy pendulum impact test — Part 1: Test method 3 Terms, definitions and symbols 3.1 Terms and definitions For the purpose of this document, the following terms and definitions apply. 3.1.1 yield strength stress value corresponding to the lower yield strength, ReL, or 0,92 × the upper yield strength, ReH, or for steels that do not exhibit a lower (ReL) and an upper (ReH) yield strength (sometimes named “lower and upper yield point” at tensile testing, the 0,2 % proof strength Rp0,2 3.1.2 normalizing heat treatment in which the steel is heated to a uniform temperature above the upper critical point (Ac3) of the steel and then cooled in still air or in a controlled atmosphere 3.1.3 stress relieving heat treatment given to the finished cylinder, the object of which is to reduce the residual stresses without altering the metallurgical structure of the steel, by heating to a uniform temperature below the critical point (Ac1, as defined in EN 10052) of the steel and cooling in a still atmosphere SIST EN 14638-3:2010

Minimum thickness, in millimetres, for calculation of weld clearance (see Figure 1) asi Calculated minimum thickness, in millimetres, at a determined area “i” of the cylinder abi Minimum thickness, in millimetres, at a determined area “i” of the cylinder (including any corrosion allowance) guaranteed by the manufacturer Ai Percentage elongation after fracture, at a determined area “i” of the cylinder i Area of the cylinder used
for the calculation under consideration L Original gauge length, in millimetres, in accordance with EN 10002-1 n Ratio of diameter of bend test former to the thickness of the test piece ph Test pressure, in bar, above atmospheric pressure pb Minimum burst pressure, in bar SIST EN 14638-3:2010

Actual burst pressure, in bar ReH
Upper yield strength, in MPa ReL
Lower yield strength, in MPa Rp0,2
0,2 % proof strength, in MPa Rpi0,2 Minimum value of 0,2 % proof strength in MPa, guaranteed by the cylinder manufacturer for the finished cylinder, at a determined area “i” of the cylinder Rmgi
Minimum guaranteed value of tensile strength, in MPa, for the finished cylinder, at a determined area “i” of the cylinder Rmai Actual value of tensile strength, in MPa, at a determined area “i” of the cylinder Regi Minimum guaranteed value of the yield strength (see 3.1.1), in MPa, for the finished cylinder, at a determined area “i” of the cylinder Reai
Actual value of yield strength, in MPa, at a determined area “i” of the cylinder s
Nominal butt weld thickness 4 Materials and heat treatment 4.1 General 4.1.1 The cylinder materials subject to pressure shall conform to EN 10028-1 and EN 10028-3, or
EN 10028-1 and EN 10028-5, or EN 10120 or EN 10268 or other carbon steel standards, provided that they satisfy the requirements of this European Standard. NOTE These materials correspond to the materials received by the manufacturer, before having been submitted to any manufacturing process. 4.1.2 Materials supplied for boss shall conform to EN 10083-1 or EN 10084. 4.1.3 The welding consumables shall be such that they are capable of giving consistent welds. The material characteristics on the welds shall be considered by design. 4.1.4 Grades of steel used for the cylinder manufacture shall be compatible with the intended gas service, e.g. corrosive gases, embrittling gases according to EN ISO 11114-1. 4.1.5 The manufacturer shall be able to guarantee cylinder steel casting traceability for each pressure retaining part. 4.1.6 All parts welded or in contact with the cylinder shall be made of compatible material with the cylinder without harming its characteristics or favouring corrosion processes. 4.1.7 The cylinder manufacturer shall obtain and provide certificates of the ladle analysis of the steel supplied for the construction of the pressure retaining parts of the cylinder and of welding consumables. 4.2 Heat treatment When the manufacturer considers that heat treatment is necessary, it should be in accordance with EN 10052. When no heat treatment is performed, because there is a risk of strain ageing, especially for SIST EN 14638-3:2010

Figure 1 — Weld clearance 6.2 Welding procedures Each manufacturer, before proceeding with the production of a given design of cylinder, shall qualify the welding procedures and welders according to EN ISO 15614-1 and EN 287-1 or EN 1418. Records of such qualification shall be kept on file by the manufacturer. 6.3 Pressure-retaining welded joints Except for the boss weldments, all welded joints shall be either of a butt or a joggle configuration (see Figure 2). For cylindrical shapes, longitudinal joints shall be butt welded. 6.4 Non-pressure-containing attachments 6.4.1 Non-pressure-containing parts such as footrings, handles and neckrings which are not submitted to pressure shall be made in accordance with 4.1.6. 6.4.2 Each attachment shall be designed to permit inspection of the welds, which shall be clear of longitudinal and circumferential joints, and so designed as to avoid trapping water. 6.4.3 A footring or other suitable supports shall be fitted when applicable to the cylinder to provide stability, and attached so as to permit inspection of the welds. The footring, if attached, shall have drainage and the space enclosed by the footring shall be ventilated. 6.4.4 In the case of cylinders subjected to a cold-forming, the non-pressure retaining attachments shall be welded to the cylinder preform before cold forming or cryoforming. 6.5 Valve protection 6.5.1 Valves of cylinders of more than 5 l water capacity shall be effectively protected from damage that could cause release of gas, either by the design of the cylinder (for example protective shroud) or by a valve protection device (see EN ISO 11117). 6.5.2 When a protective shroud is used, it shall fulfil the requirements of the drop test (see
EN ISO 11117).
Key 1 longitudinal joint
Key 2 circumferential joint a) b) SIST EN 14638-3:2010

a) Butt welds
b) Joggle welds Figure 2 — Illustration of welding penetration 6.7.2.4 Radiographic examination, or radioscopic examination, or NDT examination carried out using another suitable method shall be as specified in Annex A. 6.8 Dimensional tolerances 6.8.1 General The dimensional tolerances shall conform to the approved design drawing. In addition the following (6.8.2 to 6.8.4) shall apply for cylindrical shapes. 6.8.2 Out-of-roundness The out-of-roundness of the cylindrical shell shall be limited so that the difference between the maximum and the minimum outside diameter in the same cross-section is not more than 2 % of the mean of these diameters. 6.8.3 Straightness Unless otherwise agreed by the parties, the maximum deviation of the cylindrical part of the shell from a straight line shall not exceed 0,3 % of the cylindrical length. Unless otherwise specified on the manufacturing drawing, the maximum deviation of the cylindrical part of the shell from a straight line shall not exceed 0,3 % of the cylindrical length. 6.8.4 Verticality When the cylinder is standing on its base, the cylindrical shell and top valve openings shall be vertical to within 1 % of the cylindrical length. SIST EN 14638-3:2010

where
F
is the energy, in Joules; M
is the maximum operating mass of the cylinder, in kg. The striking velocity, v, shall be between 7 m/s and 8 m/s. Two un-pressurised cylinders shall be impacted at five different positions in accordance with 7.2.4.1.4. The tests shall be repeated with two further cylinders. These cylinders shall be pressurised with compressed air or any other inert gas to the maximum working pressure or 5 bar, whichever is the lower. NOTE Appropriate measures should be taken (e.g. in a cage) to ensure safe operation and to contain any energy that may be released, which is considerably more than that in the hydraulic test. If the cylinders withstand all of the impacts without leakage and with damage in excess of the criteria listed in EN 1803, then on completion of the impacts, both cylinders shall be subjected only to a burst test. The results shall be satisfactory when the burst pressure pba > 1,3 ph. If the cylinders withstand all of the impacts with visible damage below the rejection criteria (see EN 1803), then on completion of the impacts, one cylinder subject to a fatigue test in accordance with 7.2.3 but with only 6 000 cycles and one cylinder shall be subjected to a burst test in accordance with 8.2.1. 7.2.4.3 Edge impact test The impact energy, F, shall be determined by F = 12 M
where
F
is the energy, in Joules; M
is the maximum operating mass of the cylinder, in kg. The striking velocity, v, shall be between 4 m/s and 5 m/s. Two un-pressurised cylinders shall each be impacted with the edge parallel to the cylinder axis (see Figure 3). The cylinders shall then be impacted with the edge perpendicular to the cylinder axis. The tests shall be repeated with two further cylinders. These cylinders shall be pressurised with compressed air, or any other inert gas, to the maximum working pressure or 5 bar, whichever is the lower. NOTE Appropriate measures should be taken (e.g. in a cage) to ensure safe operation and to contain any energy that may be released, which is considerably more than that in the hydraulic test. If the cylinders withstand all of the impacts without leakage and with damage in excess of the criteria listed in EN 1803, then on completion of the impacts, both cylinders shall be subjected only to a burst test. The results shall be satisfactory when the burst pressure pba > 1,3 ph. SIST EN 14638-3:2010

1,2 mDimensions in millimetres R 3161628605025 a) Cylinder drop b) Striker details Figure 3 — Impact tests 7.2.5 Type approval certificate If the results are satisfactory, a type examination report shall be issued by the inspection body as a basis for the type approval certificate issued by the competent authority, a typical example of which is given in Annex E. 8 Production tests 8.1 Batch tests 8.1.1 General All production tests shall be carried out on finished cylinders. For the purpose of acceptance testing, the manufacturer shall provide:  the type approval certificate (7.2.5);  the certificates stating the cast analyses of the steel supplied for the construction of the cylinder;  a list of cylinders, stating serial numbers and stamp markings as required;  information that the threads are in accordance with 6.7. The manufacturer shall carry out the following tests on the cylinders selected:  mechanical testing specified in 8.1.3; 8.1.4; 8.1.5; SIST EN 14638-3:2010

Tables 1 to 3, shall be taken from each batch. 8.1.2.2 For acceptance purposes, the batch shall be divided into inspection lots not exceeding
1 000 cylinders. 8.1.2.3 For selection of sample cylinders for either burst or mechanical tests, each lot shall be sub-divided into batches of 250 cylinders during the first 3 000 cylinders and batches of 500 or
1 000 cylinders, depending on burst pressure, thereafter. 8.1.2.4 The reduced rate of sampling (see Tables 2 and 3) after the first 3 000 cylinders shall be subject to the manufacturer demonstrating that the batch production test results and manufacturing processes are consistently reliable without any major interruption of manufacture (see 8.1.2.7). This shall be considered as demonstrated if the corresponding tests on the first 3 000 cylinders are acceptable without having to repeat any test, except when the repetition is due to failure in the test performance (see 4.4.2). 8.1.2.5 In the case of unsatisfactory results in any of the tests, batch controls shall be carried out as it is done at the beginning of a fabrication, although the test repetitions are correct and the batch is accepted. 8.1.2.6 For a batch of less than 3 000 cylinders and for the first 3 000 cylinders of a batch greater than 3 000 cylinders, see Table 1: Table 1 — Cylinders per batch size Batch size Cylinders taken as samples Cylinder subjected to the Lots of 1 000 cylinders mechanical tests burst tests 1st
sub-lots 1 to 250 2 1
and
1 2nd
sub-lots 251 to 500 1
1 3rd
sub-lots 501 to 750 2 1
and
1 4th
sub-lots 751 to 1 000 1
For the next two lots of the 1 000 cylinders, repeat this sequence of tests. 8.1.2.7 For the next cylinders of a batch greater than 3 000 cylinders: a) for burst pressure less than 1,2 pb, see Table 2. SIST EN 14638-3:2010

and
1 2nd sub-lots 3 501 to 4 000 1 1 after 4 000
Repeat the above sequence
b) For burst pressures greater than 1,2 pb i.e. greater than 1,2 × 2,25 ph, see Table 3. Table 3 — Cylinders per batch size Batch size Cylinders taken as samples Cylinder subjected to theLots of 1 000 cylinders mechanical tests burst testssub-lots 3 001 to 4 000 2 1
and
1 after 4 000
Repeat the above sequence
At the beginning and the end of each shift, or alignment of the welding machine, an additional bursting test or NDT examination shall be carried out. In the case of continuous production, this may be limited to one test per shift. 8.1.3 Tensile test 8.1.3.1 The tensile test on final material shall be carried out on a test sample from a finished cylinder in accordance with EN ISO 6892-1. The tensile test transverse to the weld shall be carried out on a test sample having a reduced section 25 mm wide over a length of 15 mm beyond the edge of the weld. Outside this central part, the width of the test sample shall increase gradually. The two faces of the test sample formed by the inside and the outside of the cylinder shall not be machined. 8.1.3.2 The values obtained for the yield strength, tensile strength, shall be not less than 95 % of those actually recorded by the cylinder manufacturer at the prototype test for each determined area “i” in accordance with 5.2, and in no case be less than those given in EN 10028-1 and EN 10028-3, or EN 10028-1 and EN 10028-5, or EN 10120 or EN 10268 or other carbon steel standards, provided that they meet the requirements of this part of EN 14638. Lower values for mechanical properties shall result in a new prototype test from cylinders so affected. The minimum percentage elongation values shall be those guaranteed by the cylinder manufacturer for each determined area “i” given in the technical specification for the cylinder (see 7.1.1) and shall not be less than 14 %. However, a lower value than 14 % may also be applied, provided that appropriate measures (e.g. no fragmentation during burst testing, possible use of a safety relief device) are taken to compensate for these lower values and the specific requirements are verifiable in accordance with
Annex D. SIST EN 14638-3:2010
one tensile test piece 2 and 4 one tensile test piece, root bend test piece, face bend test piece 3
one tensile test piece. Required only if insufficient cylindrical length available
b) Test pieces in three-part cylinders Key 1 one tensile test piece 2 one tensile test piece, one root bend test piece, one face bend test piece 3 one tensile test piece, one root bend test piece, one face bend test piece. Required only if welded by a different process from the longitudinal weld (see 3.1.5) 4 impact test piece 5 one tensile test piece Figure 4 — Test pieces for cylindrical cylinders with an end concave to pressure NOTE For cylinders of a different shape, the principles of Figures 3 and 4 should be followed to determine the test piece position. SIST EN 1463
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