CELEX: 51974PC0965
Language: en
Date: 1974-07-04
Title: PROPOSAL FOR A COUNCIL DIRECTIVE ON THE APPROXIMATION OF THE LAWS OF THE MEMBER STATES RELATING TO WELDED UNALLOYED STEEL GAS CYLINDERS

13. 9. 74                             Official Journal of the European Communities                           N o C 104/59
              Proposal for a Council Directive on the approximation of the laws of the Member States
                                      relating to welded unalloyed steel gas cylinders
                             (Submitted to the Council by the Commission       on 18 July 1974)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,                                                  Article 2
Having regard to the Treaty establishing the                     The cylinders which conform to the requirements set
European Economic Community, and in particular                   out in Annex to this Directive are EEC-type
Article 100 thereof;                                             cylinders.
                                                                                          Article 3
Having regard to the proposal from the Commission;
Having regard to the Opinion of the European                     N o Member State may, for reasons connected with
                                                                 construction or verification, prohibit or restrain the
Parliament;
                                                                 placing on the market and putting into appropriate
                                                                 service of EEC-type cylinders bearing the EEC
Having regard to the Opinion of the Economic and
                                                                 approval symbol and the EEC inspection mark,
Social Committee;                                                subject to the conditions provided for in Article 4.
Whereas in the Member States the construction and
controls of gas cylinders are subject to mandatory                                        Article 4
provisions varying from one Member State to
another, and consequently hinder trade in such                   An EEC-type cylinder shall be subject to:
vessels; that it is therefore necessary to undertake the
approximation of these provisions;                               (a) EEC approval:
                                                                      1. if its capacity is not more than one litre,
Whereas the Council Directive of                  , on the               irrespective of the hydraulic test pressure;
approximation of the laws of the Member States
relating to common provisions on pressure vessels                     2. if its capacity is more than one litre but not
and to the methods used for verifying these                              more than five litres and provided the
apparatus, lays down in particular the procedures of                     hydraulic test pressure is 15 bars or less.
EEC approval and inspection for these vessels;
                                                                 (b) EEC approval and EEC inspection:
whereas according to this Directive, it is advisable to
lay down the technical requirements to be complied                    1. if its capacity is more than one litre but not
with by EEC-type welded unalloyed steel gas                              more then five litres and provided the
cylinders with a capacity of 0-2 to 150 litres in order                  hydraulic test pressure is more than 15 bars;
to be put into circulation, marketed and used without
                                                                      2. if its capacity is more than five litres
restraint after having undergone inspection and
                                                                         irrespective of the hydraulic test pressure.
bearing accordingly the marks and the symbols,
                                                                                          Article 5
HAS ADOPTED THIS DIRECTIVE:
                                                                  1.   Member States shall put into force the laws
                         Article 1
                                                                 regulations and administrative provisions necessary
                                                                 to comply with this Directive within 18 months of its
This Directive applies to the unalloyed steel                    notification and        shall forthwith inform the
stress-resistant shells of welded gas cylinders, i.e.,           Commission thereof.
formed from several pieces likely to be refilled several
times, with a capacity ranging from 0-2 to 150 litres            2. Member States shall ensure that the texts of the
inclusive designed to contain compressed, liquified or           provisions of national law adopted by them in the
dissolved gases except liquified gases at very low               field governed by this Directive are communicated to
temperatures and acetylene. The design pressure for              the Commission.
these cylinders shall not exceed 60 bars.
                                                                                          Article 6
These welded gas cylinders are hereinafter called
'cylinders'.                                                     This Directive is addressed to the Member States.
 ---pagebreak--- N o C 104/60                    Official Journal of the European Communities                                  13. 9. 74
                                                       ANNEX      I
            1.    SYMBOLS AND TERMS, USED IN THIS ANNEX
            1.1.   The symbols used in this Annex have the following meanings:
                  Ph    = hydraulic test relative pressure (design pressure) in bars;
                  Pr    = cylinder bursting relative pressure measured in the bursting test, in bars;
                  Prt   = calculated minimum theoretical rupture relative pressure, in bars;
                  Re    = minimum value of the yield stress (Reh or R p 0-2) guaranteed by the cylinder
                            manufacturer, in N/mm 2 ;
                  R ra = minimum value of the tensile strength guaranteed by the cylinder manufacturer,
                           in N / m m 2 ;
                  Rt    = actual tensile strength, in N / m m 2 ;
                  a     = minimum thickness of the cylindrical shell wall, in mm;
                  D     = nominal outside diameter of the cylinder, in mm;
                  R     = inside radius of curvature of convex base;
                  r     = inside radius of junction of convex base;
                   H    = outside height of dished ends;
                  h     = height of cylindrical part of dished ends;
                  L     = length of cylinder stress-resistant shell;
                  A     = elongation value (%) of parent metal;
                  Vo    = initial volume of the cylinder at the start of the bursting pressure test;
                  V     = final volume of the cylinder on bursting.
            1.2.  Yield Stress
                  The term 'yield stress' means the upper yield stress (Reh)-
                  For steels that do not exhibit a defined elastic limit, however, the value to be used is
                  the conventional yield stress R p 0-2 i.e., the value of the stress (a) which gives rise to
                  a non-proportional elongation equal to 0-2% of the gauge length of the test-piece.
            1.3.  Normalization
                  The term 'normalization' relates to the heat treatment to which a completed cylinder is
                  subjected, during which the cylinder is heated to a uniform temperature higher than
                  the steel's highest critical point (Acs) and then cooled in still air.
            1.4.  Stress relieving
                  The term 'stress relieving' relates to the heat treatment to which a completed cylinder
                  is subjected, during which the cylinder is heated to a" temperature below the steel's
                  lowest critical point (AC1) in order to reduce the residual stresses.
           2.     TECHNICAL REQUIREMENTS
           2.1.   Materials
           2.1.1. The material used for the manufacture of the cylinder stress-resistant shells shall be
                  steel as specified by EURONORM 120-72.
 ---pagebreak--- 13. 9. 74                        Official Journal of the European Communities                              N o C 104/61
          2.1.2.   All components of the cylinder body and the parts welded thereto shall be made of
                   mutually compatible materials.
          2.1.3.   The filler materials shall be compatible with the steel so as to form welds with
                   properties equivalent to those specified for the parent metal.
          2.1.4.   The cylinder manufacturer shall obtain and provide cast analysis certificates in respect
                   of the steels supplied for the manufacture of the cylinder stress-resistant shells.
          2.1.5.   The inspection authority shall have the opportunity of making independent analyses.
                   These analyses shall be carried out either on specimens taken from the materials as
                   supplied to the cylinder manufacturer or on the finished cylinders.
          2.1.6.   The manufacturer shall make available to the inspection authority the results of
                   metallurgical and mechanical tests and analyses carried out on welds and shall also
                   describe the welding methods and processes adopted which can be regarded as repre-
                   sentative of the welds made during production.
          2.2.     Heat treatment
                   When heat treatment has been applied, the manufacturer shall state the type of treatment
                   employed (normalization or stress-relieving), the temperature and duration thereof and
                   the quenching technique used.
          2.3 v    Calculation of the parts under pressure
          2.3.1.   The wall thickness at any point on the stress-resistant shell shall not be less than that
                   calculated by the formula:
                                                                Ph • D
                                                             20 Re
                                                                     +Ph
                                                              1-3
                   The value of R e shown in the formula shall in no case be greater than 0-75 R m .
          2.3.2.   The minimum wall thickness shall in no case be less than:
                   — 1-5 mm for cylinders with a capacity of less than 6-5 litres;
                   — 1-9 mm for cylinders with a capacity equal to or more than 6-5 litres but less than
                       30 litres and whenever the ratio L/D < 2;
                   — whichever of 1-9 mm or 0-136 ]^D is the higher for cylinders with a capacity equal
                       to or more than 6-5 litres but less than 30 litres, when the ratio L/D ^ 2, and for
                       cylinders with a capacity of 30 litres or more.
          2.3.3.   The dimensions of the dished ends of cylinders shall fulfil the following conditions:
                   if torispherical: R < D      r ^ 0-10 D     h > 4a     H > 0-25 D;
                   if ellipsoidal:    H ^ 0-25 D    h ^ 4a.
          2.3.4.   The cylinder body, valve excluded, may be up of two or three parts. The ends shall be
                   in one piece and convex.
          2.4.     Construction and workmanship
          2.4.1.    General  requirements
          2.4.1.1  The manufacturing facilities and techniques and the inspection methods used in pro-
                   duction shall be such as to ensure that cylinders conforming to the provisions of this
                   Directive are produced.
          2.4.1.2. Drawings shall contain all important particulars, such as dimensions, materials, openings
                   and the locations of markings and symbols.
          2.4.1.3. The manufacturer shall ensure through proper supervision over the manufacture that
                   wall thicknesses are at least equal to the dimensions shown on the drawing.
          2.4.1.4. The surfaces of the plates of the cylindrical body and pressed parts shall be clean
                   and free from serious defects.
 ---pagebreak--- No C 104/62                       Official Journal of the European Communities                                 13. 9. 74
           2.4.2.    Welding conditions
           2.4.2.1. The manufacturer shall have at his disposal staff specializing in welding operations
                    and supervision and in non-destructive testing.
           2.4.2.2. The manufacturer shall be an expert in the techniques used in the fabrication and
                    welding processes. He shall notify the Member State of any amendment or major
                    extension to his manufacturing programme.
           2.4.3.    Welding specifications
           2.4.3.1. There shall be no butt welds in the stress-resistant shell in any area where a change
                    in profile occurs.
           2.4.3.2. There shall be no superimposition of an angle weld over a butt weld and there shall
                    be a space of at least 10 mm between them.
           2.4.3.3. The parts that make up the stress-resistant shell (ends, rings and orifice bases) shall
                    be welded in accordance with Figs. 1, 2 and 3 of this Annex, viz.:
                    — Longitudinal weld (Fig. 1),
                    — Circumferential weld (Fig. 2),
                    — Valve sleeve weld (Fig. 3).
                    The maximum permissible malalignment of the joint faces shall be one-fifth of the
                    thickness (l/5a).
           2.4.4.    Welding of fittings
           2.4.4.1. The steel footrings, handles and protective collars shall be assembled by angle welding,
                    the contact surfaces with the stress-resistant shell being provided by the cross-section
                    of the item to be assembled.
                    The welding shall be along the entire length of the seam but not necessarily on both
                    sides.
           2.4.4.2. Such identification plates as are required, shall be welded to the stress-resistant shell
                    over their entire peripheries. In order to allow air to be expelled during heat treatment,
                    each identification plate shall be provided with a hole through it which is suitably
                    plugged once the heat treatment is complete.
          2.4.5.     Welding techniques and methods
          2.4.5.1.  Butt welding shall be carried out by an automatic technique.
          2.4.5.2.  All traces of oil, grease and rust shall be eliminated from the welding edges before
                    welding.
          2.4.5.3.  Complete penetration of the weld seam shall be obtained over the entire thickness and
                    length of the joints
          2.4.5.4.  The techniques and methods used shall be such that the welds are seen to be smooth
                    and regular and free from incisions, craters, deviations or undercuts.
                    With regard to butt welds, any barrelling shall not be greater in height than one-
                    quarter of the width, except for the overlay at the end of the seam, where a reinforce-
                    ment, which shall be entirely devoid of craters, is permissible.
                    Angle welds shall be seen to be regular and smooth and devoid of craters at the extre-
                    mities. The joint made between welded pieces shall be progressive and free from
                    incisions and undercuts.
          2.4.5.5.  Before the ends are squeezed, a visual examination of the longitudinal weld shall be
                    carried out on both of its faces in order to ensure that the weld shows a continuous
                    penetration without any deviation of the weld seam.
          2.4.5.6.  All the pressurized parts of the cylinder shall be inspected internally at each stage in
                    manufacture and inspected externally after the final assembly, the purpose of these
                    inspections being to ascertain that the cylinder is free from any surface or welding
                    defect liable to endanger safety.
 ---pagebreak--- 13. 9. 74                        Official Journal of the European Communities                               N o C 104/63
          2.4.6.    Cylindricity
                   The out-of-roundness of the cylindrical part shall be limited to such a value that the
                   difference between the maximum and minimum outside diameter in the same cross-
                   section is not more than 1% of the average of those diameters.
          2.4.7.   Fittings
          2.4.7.1. The cylinder-carrying handles or rings shall be fabricated and welded to the cylinder
                   body in such a way as not to cause dangerous concentrations of stresses or form traps
                   for water.
          2.4.7.2. The footring must be sufficiently strong and made of metal compatible with that
                   of the cylinder and give the cylinder sufficient stability. The top edge of the footring
                   must fit the stress-resistant shell perpendicularly and be welded to it in such a way as
                   to prevent the formation of water traps. The footring must contain ventilation holes.
          2.4.7.3. Any other material, however, may be used for the manufacture of the footrings and
                   cylinder-carrying handles or rings, provided that their strength is assured and that all
                   risk of the cylinder end corroding is removed.
          2.4.8.   Protection of the cock or valve
                   The cylinder cock or valve shall be effectively protected, either through the way in
                   which it is designed or through the design of the cylinder itself (e.g., with a protective
                   collar), or by means of a protective cap or cover secured by a safe device.
          3.       TESTS
          3.1.     Mechanical tests
          3.1.1.    General requirements
          3.1.1.1. The mechanical tests, where not covered by the requirements contained in this Annex,
                   shall be carried out in accordance with the E U R O N O R M Nos:
                   (a) 2-57 and 11-55 for the tensile test, where a       3 mm and a < 3 mm respectively;
                   (b) 6-55 and 12-55 for the bend test, where a ^       3 mm and a < 3 mm respectively.
          3.1.1.2. All the mechanical tests for checking the properties of the parent metal and filler
                   material used for the stress-resistant shells of the gas cylinders shall be carried out
                   on test pieces taken from the finished cylinders.
          3.1.2.    Types of test and evaluation of test results
          3.1.2.1. Each sample cylinder shall be subjected to the following tests:
                   A. For cylinders containing only circumferential welds (two pieces), on test pieces taken
                       from the places shown in Fig. 1 of this Annex:
                        1 tensile test: parent metal in the longitudinal direction (a),
                        1 tensile test: perpendicular to the circumferential weld (b),
                        1 bend test:    top of circumferential weld (c),
                        1 bend test:    bottom of circumferential weld (d);
                    B. For cylinders with longitudinal and circumferential welds (three pieces), on test
                       pieces taken from the places shown in Fig. 5 of this Annex:
                        1 tensile test: parent metal of the cylindrical part (a),
                        1 tensile test: parent metal from bottom (b),
                        1 tensile test: perpendicular to the longitudinal weld (c),
                        1 tensile test: perpendicular to the circumferential weld (d),
 ---pagebreak--- N o C 104/64                           Official Journal of the European Communities                               13. 9. 74
                           1 bend test:      top of longitudinal weld (e),
                           1 bend test:      bottom of longitudinal weld (f),
                           1 bend test:      top of circumferential weld (g),
                            1 bend test:     bottom of circumferential weld (h).
            3.1.2.1.1. Test pieces which are not sufficiently flat must be flattened by cold pressing.
            3.1.2.1.2. In all test pieces containing a weld, the weld is machined until it is flush with the
                       surface of the plate.
           3.1.2.1.3. Any cut across the weld in a test piece must be sound and compact throughout.
            3.1.2.2.   T e n s i l e test
            3.1.2.2.1. The procedure for carrying out the tensile test shall be as given in the appropriate
                       EURONORM in compliance with subsection 3.1.1.1.
                       The two faces of the test piece which are respectively the inside and outside walls
                       of the cylinder shall not be machined.
            3.1.2.2.2. The elongation of the parent metal (in percent) shall not be less than:
                                                                          1 000   R
                                                                  A =           ~   t
                                                                                c
                       The values of coefficient c are respectively 25 and 20 for wall thicknesses of less than
                       3 mm and 3 mm or above.
                       In no case must the elongation in percent be less than that given in the following
                       table:
                                                                       Rt < 500 N/mm»       Rt > 500 N/mm!
                       3 mm          a ^ 5 mm                               27                   19
                       a < 3 mm                                             22                   15
            3.1.2.2.3. The 'perpendicular to the weld' tensile test shall be carried out on a test piece having a
                       thinned cross-section 25 mm in width and 15 mm in length measured from either
                       edge of the weld, as shown in Fig. 6 of this Annex. Beyond this central part the
                       width of the test specimen must increase progressively.
            3.1.2.2.4. The observed values of the elastic limit and the tensile strength should be at least
                       equal to those guaranteed for the parent metal irrespective of where the rupture is
                       produced in the cross-section of the central part of the test piece.
            3.1.2.3.   Bend test
            3.1.2.3.1. The procedure for carrying out the bend test shall be as given in the appropriate
                       EURONORM in compliance with subsection 3.1.1.1.
            3.1.2.3.2. The test piece shall remain uncracked when bent inwards around a former until the
                       interior edges are at a distance apart not greater than the diameter of the former.
            3.1.2.3.3. The ratio (n) between the diameter of the former and the thickness of the test piece
                       shall conform to the values given in the following table:
                                                Actual tensile strength                        Value of n
                                                     Rt N/mm 2
                                  up to 440 inclusive                                              2
                       above 440 to 520 inclusive                                                  3
                       above 520                                                                   4
 ---pagebreak--- 13. 9.74                        Official Journal of the European Communities                               N o C 104/65
         3.2.     Bursting test under hydraulic pressure
         3.2.1.    Test conditions
         3.2.1.1. The bursting test under hydraulic pressure shall be carried out in two successive
                  stages by means of an apparatus such that the pressure in the cylinder increases
                  regularly until the cylinder bursts and that the curve of the pressure variation with
                  time is recorded.
         3.2.1.2. During the Stage 1, the rate of pressure increase until the point at which plastic
                  deformation begins shall be about 1 bar/s.
                  As from that pressure value (Stage 2), the rate of pumping shall be increased to twice
                  what it was in Stage 1 and kept at a steady value until the cylinder bursts.
         3.2.2.   Performance of test
                  The bursting test under hydraulic pressure shall afford:
                   (a) an examination of the pressure/time curve telling the pressure at which plastic
                       deformation of the cylinder commences, the bursting pressure and the deformation
                       of the cylinder during the test,
                   (b) a measurement of the volume of water used between the time when the pressure
                       starts to rise and the time of bursting, giving the volumetric expansion of the
                       cylinder,
                  (c) an examination of the fracture and the shape of its edges.
         3.2.3.    Test acceptance conditions
         3.2.3.1. The pressure observed at the initiation of the plastic deformation shall be not less than
                  four-thirds of the hydraulic test pressure.
         3.2.3.2. The measured bursting pressure (Pr) shall be greater than the calculated minimum
                  theoretical bursting pressure (Prt).
                  This theoretical pressure shall be calculated from the minimum effective thickness 'a'
                  and the guaranteed minimum tensile strength (Rm) used for the cylinder calculation,
                  according to the formula:
                                                        p,    20 a Rm
                                                        P
                                                          " " "d^T
                  The measured bursting pressure (Pr) shall not be less than nine-fourths of the test
                  pressure (Ph).
         3.2.3.3. The specific change in volume of the cylinder (        /     at the time of bursting shall
                  not be less than 20 %.                           A      ° '
         3.2.3.4. The bursting test shall not cause any fragmentation of the cylinder.
         3.2.3.5. The main fracture shall not be of the brittle type, i.e., the edges of the fracture shall
                  not be radial but shall be sloped in relation to a diametrical plane and shall display
                  a striction throughout their thickness.
         3.2.3.6. The fracture shall not reveal a characterized defect in the metal.
         3.2.3.7. In the case of a three-piece cylinder the burst shall not originate in one of the ends,
                  a longitudinal weld or a circumferential weld (unless the burst is perpendicular
                  thereto). The last requirement also applies to a two-piece cylinder.
         3.3.     Hydraulic test
         3.3.1.   The hydraulic test pressure shall equal the design pressure (Ph).
         3.3.2.   The water pressure in the cylinder shall increase regularly until the test pressure is
                  reached.
 ---pagebreak--- N o C 104/66                    Official Journal of the European Communities                                    13. 9. 74
            3.3.3. The cylinder shall remain under the test pressure for a sufficient length of time to
                   demonstrate that the pressure shows no tendency to fall and that leaktightness has
                   been achieved.
            3.3.4. Any cylinder which does not satisfy these test requirements shall be rejected.
            4.     EEC APPROVAL
            4.1.   The applicant for approval shall submit the documentation necessary for the inspection
                   prescribed below, together with three prototype cylinders which are entirely represen-
                   tative of future output and any additional information required by the Member
                   State.
            4.2.   In the course of the EEC approval process, the Member State shall:
                   — verify that the calculations set out in section 2.3 are correct;
                   — verify that the provisions set out in sections 2.1, 2.2 and 2.4 have been fulfilled;
                   — perform on the cylinders submitted as prototype:
                       (a) the test set forth in section 3.1 on one cylinder,
                       (b) the test set forth in section 3.2 on another cylinder.
                   —- issue in the EEC approval certificate conforming to the model provided for in
                       Annex II to this Directive.
            5.     EEC INSPECTION
            5.1.   For the purpose of the EEC inspection the cylinder manufacturer shall make available
                   to the inspection authority:
            5.1.1. the EEC approval certificate;
            5.1.2. the cast analysis certificates in respect of the steels supplied for the construction of the
                   stress-resistant shells of the cylinders;
            5.1.3. the means of identifying the cast of steel used for each cylinder;
            5.1.4. the documents relating to the heat treatment provided in section 2.2;
            5.1.5. the results of non-destructive tests carried out during production and the welding
                   methods used to ensure good reproducibility of cylinders during manufacture;
            5.1.6. a list of the cylinders, stating the numbers and markings as required in section 6.
            5.2.   EEC inspection procedure
            5.2.1. The inspection authority shall:
                   — ascertain.that an approval certificate has been obtained and that the cylinders con-
                       form thereto;
                   — check the documents giving data concerning the materials and the manufacturing
                       processes, in particular those specified in section 2.1.6;
                   — ascertain whether the technical requirements set out in section 2 have been met, and
                       in particular verify by means of an external visual examination of each cylinder
                       and an internal sampling examination of between 5 and 10% of the cylinders in
                       each batch whether the construction as well as the inspections carried out by the
                        manufacturer are satisfactory;
                   — be present at the tests prescribed in sections 3.1 and 3.2 and check their progress;
                   — spot-check whether the information supplied by the manufacturer in the list specified
                       in subsection 5.1.6 is correct. Between 5 and 10% of the cylinders in each batch
                       shall be subjected to this check;
                   — issue the EEC inspection certificate conforming to the model set out in Annex III
                       to this Directive
 ---pagebreak--- 13.9.74                     Official Journal of the European Communities                                        N o C 104/67
        5.2.2. For the purpose of carrying out the two types of tests specified in sections 3.1 and
               3.2 a random sample shall be taken from each batch of cylinders of indentical shape,
               all having been made from the same materials (steel plates identical as to properties
               and supplier and the same filler material) and produced on a continuous basis using
               the same welding techniques and inspections as well as an identical heat treatment,
               the number of cylinders comprised in the sample being as shown in the following
               table:
                                                                                  No of cylinders subjected to:
                                                                 No of
                                                               cylinders          Mechanical         Bursting
                                                                sampled             tests              test
               Batch of 402 cylinders
               or part batch thereof                               2                 1                  1
               Batch of 1 206 (3 X 402)
               cylinders                                           6                 2                 4
               Batch of 2 412 (6 X 402)
               cylinders                                           12                3                 9
               Depending on the batch, the cylinders sampled shall be subjected to the tests specified
               in section 3.1 (mechanical tests) and to the test specified in section 3.2 (bursting test)
               in accordance with the breakdown in the table above.
               In the case of three-piece cylinders, the cylinders taken as samples from each batch
               shall undergo a prior radiographic test on each weld joint comprising 100 mm of the
               longitudinal weld and 50 mm (25 mm on each side of the joint) of the circumferen-
               tial weld (Fig. 8 in this Annex) in order to check compliance with the conditions
               specified in subsections 2.4.5.3 and 2.4.5.4.
               If one of the tests fails even partially to give satisfaction, the same number of cylinders
               shall be taken at random from the same batch and subjected to the type of test
               which was failed.
               If any of these further cylinders fails to give satisfaction, all the cylinders in that batch
               shall be unconditionally rejected.
        5.2.3. The selection of specimens and all the tests shall be carried out in the presence of a
               representative of the inspection authority.
        5.2.4. All the cylinders in the batch shall be subjected to a hydraulic test as specified in
               section 3.3 in the presence of and under the supervision of a representative of the
               inspection authority.
        5.3.   Exemption from the EEC inspection
               For any cylinders covered by Article 4 (a) of this Directive and in conformity with
               the provisions set out in Article 15 (a) of the Council Directive of           on the approxi-
               mation of the laws of the Member States relating to the common provisions for
               pressure vessels and to the methods of inspection and testing of such vessels, all the
               test and inspection operations prescribed in section 5.2 shall be carried out by the
               manufacturer on his responsibility.
               The manufacturer shall provide the inspection authority with all the documents and
               the test and inspection reports.
               The presence of a representative of the inspection authority referred to in sections 5.2.3
               and 5.2.4 of this Annex shall not be required.
 ---pagebreak--- N o C 104/68                     Official Journal of the European Communities                                  13. 9. 74
            6.     MARKING
            6.1.    When all the prescribed checks have been carried out by the inspection authority,
                   and provided that the results are satisfactory, the inspection authority shall issue a
                   certificate stating the checks which have been carried out.
            6.2.   The markings shall be grouped together and none may be stamped on the stress-
                   resistant shell of a cylinder.
            6.3.   Any identification plate required shall be affixed to the top head and have a minimum
                   thickness of 3 mm.
           6.4.    Each cylinder shall be stamped with the symbol               specified in section 5.3 of
                   Annex I to the Council Directive of             on the approximation of the laws of the
                   Member States relating to the common provisions for pressure vessels and to the
                   methods for the inspecting and testing of such vessels for cylinders covered by
                   Article 4 (a) of this Directive and the symbol of the EEC type-approval
                   specified in section 5.1 of Annex I followed by the EEC type-test symbol 'e' specified
                   in section 3.1.1.1 (a) of Annex II to the Directive quoted above for cylinders covered
                   by Article 4 (b) of this Directive.
                   These symbols shall be followed by the following markings:
            6.5.   Markings based on the construction
           6.5.1.  Relating to the metal
                   A number indicating the value of R c in N/mm 2 on which the calculation was based.
                   The symbol N (cylinder in a normalized condition), or the symbol S (cylinder in a
                   stress-relieved condition).
           6.5.2.  Relating to the hydraulic test
                   The value of the test pressure in bars marked in large digits at the centre and
                   above it the date of the initial hydraulic test (month and year).
           6.5.3.  Relating to the cylinder type
                   Below the figures to the test pressure, the weight of the cylinder (less its cock or valve)
                   in kg, and the minimum capacity of the cylinder in litres guaranteed by the manu-
                   facturer.
                   The weight and the capacity shall be expressed to three significant figures, the third
                   figure being arrived at by 'rounding down' for the capacity and 'rounding up' for the
                   weight.
            6.5.4.  Relating to the origin
                   The manufacturer's mark and the serial number.
            6.5.5. Example:
                                                        OA/72
                                             £e    250 N 6 0      ....6-851
                                                       704/40-5
 ---pagebreak--- 13. 9. 74 Official Journal of the European Communities No C 104/69
                              Figure 1
                         Longitudinal weld
                                              f
                              Figure 2
                                              V
                        Circumferential weld
                              Figure 3
                         Valve sleeve weld
 ---pagebreak--- No C 104/70                       Official Journal of the European Communities                              13. 9. 74
                    Tensile test piece                                          (a) Tensile test piece
                    Bend test piece
                    (top of weld)
                (d) Bend test piece
                    (bottom of weld)
                                                       Figure 4
                                      Test pieces taken from two-piece cylinders
                (c) Tensile test piece
                (e) Bend test piece
                    (top of weld)
                    Bend test piece
                    (bottom of weld)                                                       (a) Tensile test
                                                                                           (b) Tensile test
                               "X—
          Tensile test piece
          Bend test piece
          (top of weld)
          Bend test piece
          (bottom of weld)
                                                       Figure 5
                                     Test pieces taken from three-piece cylinders
 ---pagebreak--- 13. 9.74          Official Journal of the European Communities                     N o C 104/71
                                       Figure 6
         The 'perpendicular to the weld' tensile test piece (Subsection 3.1.2.2.3)
                                      25
 ---pagebreak--- N o C 104/72   Official Journal of the European Communities     13. 9. 74
                                    Figure 7
                                 Cylinder end
             100 mm                   100 mm
                                    Figure 8
               Dimensions of weld joints undergoing radiography
 ---pagebreak--- 13. 9 . 7 4                         Official Journal of the European Communities                               N o C 104/73
                                                        ANNEX II
                                             EEC APPROVAL^CERTIFICATE
            Inspecting Authority:                                           Application of Council Directive
                                                                            No                          of
            Date:.                                                          EEC Approval Code No
            Designation of cylinders:                                       Capacity:
            Manufacturer's name and address:
            The undersigned hereby declares that he has checked that the verifications, tests and inspections
            specified in section 4.2 of Annex I to Council Directive No       of          have been successfully
            performed.
            Cylinders of the accepted model •! a r e      subject to EEC inspection
                                               [ are not
            General observation: the drawing jvhich was the subject of approval is annexed hereto.
            Signed and certified this             day of              at
                                                                               (Signature and capacity)
 ---pagebreak--- No C 104/74                        Official Journal of the European Communities                              13. 9. 74
                                                     ANNEX 111
                                          EEC INSPECTION CERTIFICATE
          Inspecting Authority:                                         Application of Council Directive
                                                                        No                  of
          Date:                                                         EEC Approval Code No
          Designation of cylinders:                                     EEC Type-testing Code No . . . .
                                                                        Capacity:
                                                                        Manufacturing batch No
          Manufacturer's name and address:
          The undersigned hereby declares that he has checked that the verifications, tests and inspections
          specified in section 5.2 of Annex I to Council Directive No     of          have been successfully
          performed.
          Special observations:
          General observations:
          Signed and certified this                  day of                  at
                                                                           (Signature and capacity)