CELEX: 51978PC0702
Language: en
Date: 1978-12-13
Title: PROPOSAL FOR A COUNCIL DIRECTIVE ON THE APPROXIMATION OF THE LAWS OF THE MEMBER STATES RELATING TO CERTAIN TYPES OF SIMPLE PRESSURE VESSELS

No C 37/2                               Official Journal of the European Communities                              10. 2. 79
                                                                II
                                                         (Preparatory Acts)
                                                 COMMISSION
               Proposal for a Council Directive on the approximation of the laws of the Member States
                                       relating to certain types of simple pressure vessels
                            (Submitted by the Commission to the Council on 18 December 1978)
THE COUNCIL OF THE EUROPEAN                                         which the said pressure vessels must satisfy in order
COMMUNITIES,                                                        to be placed on the market and taken into service
                                                                    after an inspection and the affixing of the prescribed
                                                                    marks;
Having regard to the Treaty establishing the
European Economic Community, and in particular                      Whereas, in order to take account of technical
Article 100 thereof,                                                progress, the technical requirements relating to
                                                                    pressure vessels must be adapted promptly; whereas
                                                                    the procedure laid down in Article 20 of the
Having regard          to    the    proposal      from    the
                                                                    Directive must be applied;
Commission,
                                                                    Whereas pressure vessels may deviate in design and
Having regard to the opinion of the European                        in the method of their manufacture from certain
Parliament,                                                         requirements, notably those laid down in 2.1 to 2.4
                                                                    of the Annex, provided that they are no less safe;
Having regard to the opinion of the Economic and                    whereas the procedure laid down to that end in the
Social Committee,                                                   Directive must accordingly be applied,
Whereas in each Member State mandatory
provisions determine the characteristics of con-
struction and verification of unfired welded steel                  HAS ADOPTED THIS DIRECTIVE:
pressure vessels of simple geometry; whereas these
requirements differ from one Member State to
another; whereas such differences hinder trade, thus                                        Article 1
directly affecting the functioning of the common
market;                                                              1.   This Directive shall apply to all fixed or
                                                                    movable unfired welded steel pressure vessels of
Whereas Council Directive 76/767/EEC (*) of 27                      simple geometry, as defined in Article 2, intended to
July 1976 laid down in particular the procedures of                 contain compressed air or non-corrosive, non-toxic
                                                                    compressed gases.
EEC pattern approval and EEC verification to which
such pressure vessels are subject;
                                                                    2.    The pressure vessels referred to in the first
                                                                    paragraph are hereinafter called 'vessels'.
Whereas, in accordance with that Directive, it is
necessary to determine the technical requirements
                                                                    3.    The following are excluded:
                                                                    — specially designed vessels for the conveyance of
(') OJ N o L 262, 27. 9. 1976, p. 153.                                  gases,
 ---pagebreak--- 10. 2. 79                          Official Journal of the European Communities                           N o C 37/3
— vessels intended to equip the brake circuits of                                     Article 4
     motor vehicles and their trailers,
— fire-extinguisher vessels.                                  The amendments necessary to adapt the Annex and
                                                              Appendices to technical progress shall be adopted in
                                                              accordance with the procedure laid down in Article
                         Article 2                            20 of Directive 76/767/EEC.
For the purpose of this Directive, 'vessel' means any
vessel:
(a) — comprising a right cylindrical portion with                                     Article 5
         axisymmetrical dished heads on the same
         axis, the concave sides of which face inwards,       Derogations from the provisions of 2.1 to 2.4 of the
         or with flat heads,                                  Annex may be granted pursuant to Article 17 of
                                                              Directive 76/767/EEC.
     — comprising two axisymmetrical dished heads
         on the same axis;
(b) having only circular penetrations and nozzles
                                                                                      Article 6
     (though for cleaning or inspection purposes, in
     particular, these may be elliptical) with axes
     perpendicular to the wall of the cylindrical             N o Member State shall, on grounds relating to its
     portion of the vessel and sufficiently far apart to      design and inspection, refuse, prohibit or restrict the
     be considered separately for purposes of stress          placing on the market and taking into service of a
     analysis.                                                vessel which complies with the requirements of
                                                              Directive 76/767/EEC and of the present Directive.
However, penetrations, notably for drainage
purposes, may be provided on the walls of the dished
heads as long as they are not more than 15 mm in
diameter. Such penetrations need not be perpen-                                       Article 7
dicular to the walls of the dished heads.
                                                              1.    Each Member State shall, within 18 months
The dished heads referred to in this Article shall be         after notification of this Directive, bring into force
of one piece.                                                 the laws, regulations and administrative provisions
                                                              necessary in order to comply therewith and shall
                                                              forthwith inform the Commission thereof.
                         Article 3
                                                              2.    With effect from the notification of this
The vessels referred to in Article 1 shall be subject         Directive, each Member State shall ensure that every
to:                                                           draft law, regulation or administrative provision that
(a) EEC pattern approval and EEC verification                 it is intended to adopt in the field covered by this
     where the product of P x V(') exceeds 200 bar            Directive is notified to the Commission in good time
      x litres;                                               to enable it to comment thereon.
(b) EEC verification where the product of P x V
     does not exceed 200 bar x litres.
                                                                                      Article 8
 (') P = pressure, V = volume.                                This Directive is addressed to the Member States.
 ---pagebreak--- N o C 37/4                          Official Journal of the European Communities                             10. 2. 79
                                                 TECHNICAL ANNEX
                                                       CHAPTER I
                                                DESIGN OF VESSELS
            1.      Limits of application
                   The technical Annex of this Directive applies to the vessels referred to in Article 1 for
                   which:
                   — the maximum working pressure does not exceed 30 bar,
                   — the volume does not exceed 3 000 litres,
                   — the product P x V does not exceed 10 000 bar x litres,
                   — the actual thickness of the shell rings and dished ends does not exceed 16 mm,
                   — the actual thickness of the shell rings and dished ends is not less than 2 mm,
                   — the actual thickness of the flat end plates does not exceed 25 mm,
                   — the length of the cylindrical part does not exceed 12 times its average diameter,
                   — the diameter of the openings does not exceed 0'3 times the average diameter of the
                        cylindrical part,
                   — the diameter of the flanges does not exceed 300 mm,
                   — the circular or elliptical inspection openings do not exceed 400 mm at their widest
                        point,
                   — the minimum working temperature is not less than — 20 or — 10 °C,
                   — the maximum working temperature does not exceed + 300 °C.
          • 2.      Materials
                    Castings may not under any circumstances be used for the manufacture of the pressure
                    parts.
            2.1.    Pressure parts
                   The steels used for the fabrication of the pressure parts must meet the following
                    conditions.
            2.1.1. Vessels required to have a minimum working temperature o f — 20 °C.
                   The grades and qualities of steel required are as follows:
                   (a) plate
                        Euronorm 28-69:                        Fe 37-2 kW; Fe 37-2 kP; Fe 42-2 k W ;
                                                               Fe 42-2 kP; Fe 47-2 kW; Fe 47-2 kP;
                   (b) seamless tubes
                        standard ISO/2604/11-1975:             TS 6; TS 10; TS 15;
                   (c) welded tubes
                        standard ISO/2604/111-1975:            T W 6 ; T W 1 0 ; T W 15;
                   (d) forgings
                        standard ISO/2604/1-1975:              F 9;
                   (e) projections
                        Euronorm 25-72:                        Fe 360 D ; Fe 430 D.
 ---pagebreak--- f
  10. 2. 79                       Official Journal of the European Communities                                   N o C 37/5
            2.1.2. Vessels required to have a minimum working temperature of — 10 °C. •
                   T h e grades and qualities of steel required are as follows:
                   (a) plate
                        Euronorm 28-69:                            Fe 37; Fe 42;
                   (b) seamless tubes
                        standard ISO/2604/11-1975:                 T S 4; T S 6; T S 10;
                                                                   T S 13; T S 14; T S 15;
                   (c) welded tubes
                         standard ISO/2604/111-1975:               T W 4, T W 5, T W 6, T W 9;
                                                                   TW 10; TW 13; TW 14; TW 15;
                   (d) forgings
                         standard ISO/2604/1-1975:                 F 8; F 9;
                   (e) projections
                         Euronorm 25-72:                           Fe 310; Fe 360; Fe 430.
            2.2.   Welded flanges: these shall be made of steel of the grade and quality specified in 2.1 or of
                   a carbon or carbon-manganese steel of which the chemical composition of the melt and
                   the mechanical properties fall within the limit values shown in the table below.
                         °/„C         % Mn              VoSi        °/„S        R g max.   RR max.   Elongation
                                                                  or % P
                         max.          max.             max.       max.          N/mm!     _N/mm'     min. ( % )
                         0-20          1-6             0-40        0-05           265       440          22
            2.3.   Fastenings
                   T h e bolts, screws, studs and nuts must conform to the specifications of ISO standards
                   R 8 9 8 / I — 1968, R 8 9 8 / I I — 1969 and 898/IV — 1972.
                   T h e categories of steel specified in these standards may be used provided that the
                   minimum elongation after rupture of these steels is not less than 16 % .
            2.4.   Attachments
                   All unpressurized parts welded to the body of the vessel shall be of materials compatible
                   with the steel of the vessel to which they are welded.
            2.5.   Ordering
            2.5.1. W h e n ordering the base materials, the vessel manufacturer shall specify the type of
                   product together with its dimensions, characteristic and the grade and quality of the steel.
            2.5.2. H e shall also specify the type of documents which must accompany the delivery in
                   accordance with 2.6 of this Directive.
            2.6.   Type of documents
            2.6.1. Inspection certificate
                   T h e inspection certificate in accordance with the provisions of Euronorm 21-76 is
                   required for the steel specified in 2.1.
            2.6.2. Certificate of conformity with the order
                   T h e certificate of conformity with the order, in accordance with the provisions of
                   Euronorm 21-76, is required for the steels specified in 2.2 and the products referred to in
                   2.4 of this Directive.
 ---pagebreak--- N o C 37/6                          Official Journal of the European Communities                                10. 2. 79
           2.6.3. The documents referred to in 2.6.1 and 2.6.2 shall indicate the marks affixed to the
                  products delivered in such a way that the documents can be correlated with the products
                  without risk of error.
           2.7. ' Identification
                  All the products used in the manufacture of the pressure vessels shall be identifiable.
           3.     Calculation of pressure parts
           3.1.   Definitions
           3.1.1. Design pressure
                  This is the pressure value. selected by the manufacturer, on his own responsibility, and
                  used in the formulae for calculating the pressure parts.
           3.1.2. Design temperature
                  This is a temperature value selected by the manufacturer on his own responsibility. It
                  enables the stress value to be determined at the temperature concerned.
           3.2.   Thickness of the pressure parts
                  The thickness of the pressure parts shall not be less than those calculated with the
                  formulae given in Annex I.
                  In these formulae no allowance is made for corrosion thickness. If, however, an allowance
                  is made for extra thickness to take account of corrosion, the amount of such an allowance
                  shall be indicated on the data plate affixed to the vessel.
           3.2.1. The permissible stress f to be used in the formulae for calculating the pressure parts shall
                  be whichever is the lower of the following values:
                  The yield strength R E T used to calculate the permissible stress of the parts under pressure
                  shall be one of the following values:
                  — when a steel does not have an upper and lower yield point, the normal proof stress
                      R 0 2 is taken,
                  — when a steel has a lower and upper yield point, the value to be taken is either:
                      — ReL
                      or
                      0 92 R e H provided that the value R e H has been determined from the load-extension
                      diagram,
                      or
                      R
                        0.2,
                  — when the design temperature is above 50 °C, the yield strength is taken as the 0 2 %
                      proof stress at the temperature concerned.
           3.2.2. For butt welds the coefficient z used to calculate the pressure parts shall be taken as equal
                  to:
                  — z = 1; z = 0 85 or z = 0 7.
 ---pagebreak--- 10.2.79                      Official Journal of the European Communities                                 N o C 37/7
                                                    CHAPTER II
                                            MANUFACTURE VESSEL
        4.   General
        4.1. The base products, the filler products, the welding and fabricating processes and the
             inspection methods shall be such as to ensure that the vessels produced satisfy the
             requirements of this Directive.
        4.2. The welding techniques employed must have undergone an acceptance test beforehand in
             accordance with the provisions of Annex III.
        4.3. The welds must be effected by welders who are qualified in accordance with the
             provisions of Annex V.
        4.4. Any welding procedure ensuring complete penetration is permissible.
        4.5. Inspection holes and flanges
             If inspection holes or flanges are required, they shall be carried out in accordance with
             the specifications in sections 5 and 6 of Annex I.
        5.   Preparation and welding of assemblies under pressure
        5.1, Forming of the plate
             The forming of the plate shall not give rise to defects that might be detrimental to safety.
             A forming process during which the temperature of the metal is below the transformation
             point AC) is known as cold forming.
             In the case of cold forming, if the value
                                               x 100 is greater than 3
              normalizing heat treatment must be given.
              e r : actual thickness of the plate,
              rj: the smallest radius of curvature.
        5.2.  Bevelling of plate
              Where plates of different thickness are welded by a circumferential butt weld, the
              thickness plate must be bevelled over a length not less than three times the width of the
              bevel.
        5.3.  Welding of plate
              Only butt welds with complete penetration are permissible for the circumferential and
              longitudinal welds.
              However, circumferential welds with hammered edges are permissible if the thickness of
              the plates does not exceed 8 mm.
              For longitudinal joints, if a backing plate is used it must be removed after welding and
              before non-destructive testing.
              For circumferential joints, if a backing plate is used and cannot be removed, satisfactory
              penetration of the backing plate must be ensured.
              When backing plates are removed, they must not cause excessive deformation.
              The material of the backing plate must be a kind which does not adversely affect the
              weld.
              Connections between nozzles or penetrations and the shell ring and between the shell ring
               and/or the flat end plates in the case of fillet welds shall be such as to ensure complete
               fusion at the root.
 ---pagebreak--- N o C 37/8                         Official Journal of the European Communities                                      10. 2. 79
           5.4.   Alignment of the plates
           5.4.1. For longitudinal joints and for circumferential joints welded on one side only, the median
                  axes of the plates shall be aligned with a tolerance of ± 10 % of the thickness of the
                  thickest plate.
                  In the case of a circumferential joint welded in both sides, a larger tolerance is permissible
                  provided a sound bead is obtained on the other side.
           5.4.2. Alignment of surfaces with plates of different thicknesses.
                  The maximum error in the alignment of the surfaces of the plates is one quarter of the
                  thickness of the thickest plate.
                  If this error is exceeded, the surface shall be bevelled in accordance with the specifications
                  in 5.2.
                                                     _o                                                           _o
                                                        _0.
                                                            -<U
                                 Longitudinal joints                         C i r c u m f e r e n t i a l joints
                         b
                           l < e 710                                 Welded on one side only: b , < e 710
                                                                     Welded on two sides: no limit
                         b 2 < e 74 for e ' < 16 mm                  b2 < e 74 if e ' < 16 mm
                         h
                           i < 3 mm for e ' < 16 mm
           5.5.   Appearance of weld bead
                  All welds must have a regular surface and display no lack of thickness; they must blend
                  with the surfaces of the plates without undercuts or unacceptable faults.
                  The weld reinforcement must not exceed the higher of the following two values: one
                   tenth of the width of the bead or 1 mm. A double reinforcement is permissible at the point
                   of overlap at the end of the bead.
                  The maximum height of the sealing run bead, if any, is the higher of the following two
                  values: one tenth of the thickness of the plate or 1 mm.
 ---pagebreak--- 10.2.79                      Official Journal of the European Communities                                   No C 37/9
        5.6.   Repairs to welds
               The weld must be entirely renewed after removal of the defective section and not repaired
               by refilling.
               With the exception of local retouching by manual welding, all repairs must be carried out
               by the same process as used for the original weld.
               No other process may be used until the inspection authorities have been notified, have
               given their consent and have approved the process.
        5.7.   Shape tolerance
        5.7.1. Ovality
               The defect of ovality is defined by the difference between the maximum and minimum
               diameters divided by half their sum.
               This ratio must not exceed 1 % in any cross section of the vessel. At the nozzle locations,
               however, an ovality of up to 2 % is acceptable.
        5.7.2. Straightness
               The deflection of any generatrix of the cylindrical part of the vessel when empty and not
               under pressure must not exceed 0 3 %.
        5.7.3. Irregularities of profile
               Irregularities in the profile (checked by means of a gauge with a 20° aperture) must not
               exceed 5 % of the minimum thickness of the plate plus 3 mm. This maximum value shall
               be increased by 25 % if the length of the irregularity does not exceed one quarter of the
               length of the cylindrical shell component contained between two circumferential joints,
               with a maximum of 1 m.
        6.     Welding of accessories not subject to pressure
               The design of accessories such as supports, handles, hoisting eyes, stiffeners, etc. must be
               such as to allow them to be welded to pressure parts. Welding must be carried out in
               accordance with the specifications in 5.5.
                                                    CHAPTER III
                                            EEC PATTERN APPROVAL
        7.     Application for EEC pattern approval
               The application and the correspondence relating to it must comply with the requirements
               laid down in section 1 of Annex I to Council Directive 76/767/EEC of 27 July 1976.
        8.     Examination for EEC pattern approval
        8.1.   The examination for EEC pattern approval shall be carried out on the basis of the
               technical file and specimen vessels.
        8.2.   — The applicant shall make available 10 vessels representative of the planned production.
                   The inspection body shall select three vessels on which the prescribed verification and
                   tests will be carried out.
                   However, for vessels produced in small quantities, the applicant shall make available
                   the number of vessels required for the verifications and tests stipulated in this
                   Directive.
               — For vessels to be produced in small quantities, the applicant shall make available the
                   number of vessels considered necessary by the inspection body for the verifications and
                   tests stipulated in this Directive.
 ---pagebreak--- N o C 37/10                              Official Journal of the European Communities                                 10. 2. 79
             8.3.      Examination of the technical file
                       This examination shall include:
                       (a) verification that the steels have been selected in accordance with the requirements laid
                            down in 2.1, 2.2, 2.3 and 2.4;
                       (b) checking of the conformity documents specified in 2.6;
                       (c) checking of the design of the vessels in accordance with the requirements laid down in
                            Annex I, sections 5 and 6;
                       (d) checking of the location provided for the EEC marks and inscriptions in accordance
                            with Chapter V;
                       (e) verification of the certificates for the welding technique and the welders' qualifications
                            required for the welding methods to be used for production;
                       (f) verification that the design calculations have been carried out in accordance with the
                            requirements laid down in section 3 and in Annex I, sections 1 , 2 , 3 and 4.
             8.4.      Inspections and tests to be performed on finished vessels.
             8.4.1.   Test on finished vessels
                       (a) 100 % radiographic examination of the butt welds on the vessels made available to the
                            inspection body;
                       (b) one hydrostatic test on each vessel selected by the inspection body;
                       (c) a pressure cycling test on one vessel of the vessel to be produced have flat end plates
                            and fillet welds.
             8.4.2.   Checks on good workmanship
                      The checks on good workmanship shall include in particular:
                      — checking of the design of the welded joints in accordance with the requirements of
                           sections 4, 5 and 6,
                      — checking of the thickness of the pressure parts in accordance with the requirements of
                           section 3 and of Annex I, sections 1 , 2 , 3 and 4.
            8.5.      Inspections and tests to be performed on specimens taken from a finished vessel.
                      The specimens shall be taken at the factory by the manufacturer in the presence of the
                      inspection body.
            8.5.1.    Tests on rings
                      The following tests shall be carried out on the rings which have been heat-treated:
                      (a) one tensile test;
                      (b) three impact tests.
            8.5.2.   Test on vessel ends
                     The following tests shall be carried out on vessel ends in all cases:
                     (a) one tensile test;
                     (b) three impact tests.
            8.5.3.   Test to be performed on welds
            8.5.3.1. Longitudinal and circumferential welds
                     The following tests shall be performed, at the discretion of the inspection body, on either
                     the longitudinal welds or the circumferential welds when the welding technique used is
                     the same for both.
                     When this is not the case, the tests shall be performed on both circumferential and
                     longitudinal welds
                     (a) one tensile test (perpendicular to the weld);
                     (b) one bend test on the underside of the weld;
 ---pagebreak--- 10. 2. 79                       Official Journal of the European Communities                                   N o C 37/11
                    (c) one bend test on the upper side of the weld;
                    (d) three impact tests in the weld;
                    (e) three impact tests in the heat-affected zone limited according to the diameter and
                         thickness of the ring;
                    (f) one hardness test; ,
                    (g) one macrographic examination.
          8.5.3.2. Nozzle, penetration and ring/flat-end welds
                   Ultrasonic inspection of these welds shall be performed on each vessel made available to
                   the inspection body.
                   A macrographic examination shall be carried out on nozzle and penetration welds.
                   This examination shall also be carried out on ring/flat-end welds where a fillet weld is
                   used.
          8.5.4.   The impact tests for EEC pattern approval shall be carried out at — 20 °C if the minimum
                   working temperature is — 20 ° C and at 0 ° C if the minimum working temperature is
                   -10°C.
                   These tests shall be carried out if the plate is more than 5 mm thick.
          9.        EEC pattern approval certificate and mark
                   The EEC pattern approval certificate and the accompanying technical file must reproduce
                    the requirements specified in section 3 of Annex I to Council Directive 76/767/EEC.
                   The certificate must be in accordance with the specimen set out in Annex VI to this
                   Directive.
                   The certificate must contain in particular:
                   — the conclusions of the pattern examination,
                   — the expiry date of the EEC pattern approval in accordance with 10.3,
                   — the conditions which must be satisfied by the variants of a vessel in order that they
                        may be covered by the same EEC pattern approval in accordance with 10.2,
                   — the marks relating to the EEC pattern approval in accordance with section 5 of Annex
                        I to Council Directive 76/767/EEC and 14.1 of this Directive.
          10.      Characteristics of vessels covered by the same EEC type approval
          10.1.    EEC type approval may be granted for vessels consisting of:
                   (a) two ends and one or more rings; or
                   (b) two dished ends for which a cylindrical edge is provided in accordance with the
                        requirements of section 2 of Annex I.
          10.2.    The EEC pattern approval granted for one model of vessel may cover variants of this
                   model.
                   A family of vessels consists of one or more variants.
                   Vessels which differ from the model only in diameter and/or in the length of their
                   cylindrical part within the following limits form part of the same family:
                   (a) Variations in diameter
                        — variations in diameter are permitted but the actual thicknesses of the walls of the
                            vessels in any one family must be identical to the thicknesses of the walls of the
                             model,
 ---pagebreak--- N o C 37/12                        Official Journal of the European Communities                                10. 2. 79
                      — variations must meet the requirements in 3.2,
                      — the conditions regarding heat treatment in 5.1 must be observed;
                  (b) Variations in the length of the cylindrical part
                      — When the model consists of one or more shell rings in addition to the ends, vessels
                          in the same family must also consist of one or more shell rings,
                      — when the model consists solely of two dished ends in accordance with 10.1 (b),
                          vessels in the same family may not under any circumstances contain one or more
                          shell rings,
                      — if variations in the length of the vessel involve modifications in respect of openings
                          and penetrations (number, dimensions, spacing), these modifications shall be
                          shown on the drawing of each variant submitted with the application for pattern
                          approval and must meet the conditions laid down in this Directive.
            10.3. The period of validity of an EEC pattern approval certificate for these vessels shall be:
                  (a) vessels subject to pattern approval:
                      — five years, which may be extended by the Member State granting approval for
                          successive periods of a maximum of five years;
                  (b) vessels subject to pattern approval and verification:
                      — 10 years, which may be extended by the Member State granting approval for
                          successive periods of a maximum of 10 years.
                                                      CHAPTER IV
                                           EEC PATTERN VERIFICATION
            11.   Examination for conformity to an approved pattern
                  At the time of EEC verification, the inspection body shall verify that each vessel in the
                  batch conforms to the approved pattern, particularly as regards:
                  — the principal dimensions, the specified inscriptions, the pattern approval mark and the
                      location provided for the EEC verification marks in accordance with section 14,
                  — the validity of the certificates obtained regarding approval of the welding technique(s)
                      and the qualifications of the welders,
                  — the requirements specified in 5.4 to 5.7,
                  — the inspection body shall verify that the materials used are as specified in the technical
                      file accompanying the EEC pattern approval certificate in accordance with the
                      requirements in 2.7.
            12.   Test to be performed on coupon plates
                  The coupon plate shall be taken in the presence of the inspection body.
                  For each batch or part of 25 vessels built, a coupon plate representative of the batch or
                  part thereof shall be supplied.
                  For mass production, the number of vessels per batch shall be decided by the inspection
                  body.
                  The dimensions of the coupon plate shall be such that it is possible to take from it a
                  sufficient number of test pieces on which to perform the specified tests.
 ---pagebreak--- 10. 2. 79                     Official Journal of the European Communities                                  N o C 37/13
          12.1. Tests on welds
                The following test shall be carried out:
                 (a) one tensile test (perpendicular to the weld);
                 (b) one bend test on the underside of the weld;
                 (c) one bend test on the upper side of the weld;
                 (d) three impact tests in the weld.
                     — When a different welding technique is used for longitudinal and circumferential
                         welds, these tests shall be carried out on both types of weld,
                     — when the same technique is used for longitudinal and circumferential welds, these
                         tests shall be carried out on the longitudinal welds in each batch and on the
                         circumferential welds in every second batch,
                     — the impact tests stipulated for EEC pattern verification shall be carried out at
                         — 20 °C if the minimum working temperature is — 20 °C and at 0 °C if the
                         minimum working temperature is — 10 °C.
                These tests shall be carried out if the plate is more than 5 mm thick.
          13.   Non-destructive testing of vessels
          13.1. Radiographic examination
                The radiographic examination of butt welds shall be carried out in accordance with the
                requirements of Annex II under the following conditions:
                if 2 = 1                100 % radiographic examination of the welds for all vessels in the
                                        batch;
                if Z = 0 85             all welds made by the same technique shall be given a radiographic
                                        examination over 5 % of their length.
                                        This examination may be performed on one or more vessels but on
                                        each occasion the junctions of the main welds shall be included.
                                        However the percentage may be reduced to 2 % if at least one
                                        vessel is given a 100 % examination daily.
                if Z = 0 7              radiography is not required.
          13.2. Hydrostatic test
                This test shall be carried out in accordance with the requirements of 3.2 of Annex II on
                every vessel in the batch.
          13.3. Penetrant fluid weld test
                This test shall be carried out in accordance with the requirements of 2.4 in Annex II on
                nozzle and penetration welds and on ring/flat-end fillet welds on one vessel in each
                batch.
          13.4.  EEC pattern verification certificate and mark
                 If the results of the inspection are satisfactory, the inspection body shall issue the EEC
                verification certificate.
                The EEC verification certificate shall contain the information required by section 3 of
                Annex II to Council Directive 76/767/EEC.
 ---pagebreak---                                                 C ^ A ^ ^ ^
                                              DA^AI^^A^
^ ^ a r ^ s ^ ^ C s ^ m b ^ l s and inscriptions
  Nothing must be s t a m p e ^ o n t h e w a l l o f t h e p r e s s u r e p a r t s of the vessel^hemarl^s and
  inscriptions stipulated below shall be shown on t o a d a t a p l a t e ^
  A nonDdetachable data plate shall he placed on each vessel in a position that is visible
  when the vessel is installedD
          pattern approval mar^s
  Notwithstanding the requirements in section 3 of Annex I to Council Directive
           the manufacturer shall affix the ^ C pattern approval margin the following orders
  ^     for the vessel referred to in Article^^a^ of the Directives
        — the st^li^ed l e t t e r s
        — the number ^ d e n o t i n g this Directives
        — the capital l e t t e r s identifying t h e ^ t a t e which h a s g r a n t e d ^ C p a t t e r n a p p r o v a l
              and the last two digits of the ^ear in which approval was granted^
        — the ^ C pattern approval numbers
        — examples
  ^     for the vessels referred to in A r t i c l e ^ ^ o f the Directives
        — thest^li^edletter^surroundedb^ahexagon^
        — the n u m b e r ^ ^ d e n o t i n g this Directives
        — the capital l e t t e r s identifying the ^tate which has granted                       pattern approval
              and the last two digits of the ^ear in which approval was granted^
        — the                pattern approval numbers
        — examples
  ^ ^ v e r i f i c a t i o n marl^s
  Notwithstanding therequirements of s e c t i o n ^ o f Annex IltoCouncilDirective^^B^^B^B
           the inspection bod^ shall affix the               verification margin the following orders
  — the small l e t t e r s
  — the capital l e t t e r s identifying the ^tate in which the verification is carried out
       together^ where necessary with one or two numbers identifying a territorial
       subdivisions
  — the marl^ of the inspection bod^ affixed b^ the verifying agent^togetherwiththemarl^
       of the verifying agent if appropriated
  — asurrounding hexagons
  — the verification date^ear^ months d a ^
  — example^e^I^^
  Inscriptions
  — the value of the test pressure on the f o r m ^ ^ ^ ^^bar^
  — the value of the design pressure in the f o r m ^ ^ ^^bar^
 ---pagebreak--- 10. 2. 7 9                           Official Journal of the European Communities                                                 N o C 37/15
                      — the design t e m p e r a t u r e in the f o r m : T = . . . ° C ,
                      — the minimum w o r k i n g t e m p e r a t u r e in the f o r m : T m i n = . . . ° C ,
                      — the extra corrosion allowance in the f o r m : S = . . . mm,
                      — the volume of the vessel in the f o r m : V = . . . 1,
                      — the name o r m a r k of the m a n u f a c t u r e r or person responsible f o r placing the vessel o n
                        the market,
                      — the m a n u f a c t u r e r ' s serial number.
                      A specimen diagram of the marks and inscriptions is given below.
                                         £ 4 F 84 53                                            e F 1248         (2)   84/12/11
                                           Ph =       15 b a r                                    P      =         10 b a r
                                           T     =    200 ° C                                     T
                                                                                                      min =   1    y
                                                                                                                   o
                                           S     =    1 mm                                        V       =        2 0001
                                           Name/mark:
                                           No:       S C 7592 B
                     CALCULATION OF PRESSURE PARTS AND DIMENSIONING OF APERTURES
             I.I.          Calculation of cylindrical shell rings
                           T h e minimum thickness f o r pressure resistance is calculated by the following f o r m u l a :
                                                                            PD;
                                                                    \    2 0 f Z —P
              1.2.          Calculation of dished ends
                      Figure 1.1
                      Hemispherical end-plates
                      0 0 0 3 D 0 =£ e     0-16 D 0
                      Figure 1.2
                      Elliptical end-plates
                      Simultaneous limitations
                      0 003 D 0 s = e s = 0 08 D 0
                      H ^ 0 1 8 D0
 ---pagebreak--- N o C 37/16                 Official Journal of the European Communities                                           10.2.79
              Figure 1.3
              Torispherical end-plates
             Simultaneous limitations:
             0 0 0 3 D „ e S e s : 0 08 D»
                     r >01Do
                     R, =£ D„
                     H 2s 0-18 D()
                     r      2e
            T h e minimum thickness of these dished ends is calculated by the following f o r m u l a :
                                                   e =P D „ c
                                                         w
                                                              r
             In addition, the thickness of a torispherical end-plate must not be less t h a n :
                                                          P R
                                                e=
                                                     20 f - 0-5 P
            T h e shape f a c t o r C to be used f o r solid ends is given in T a b l e 1.1. Figure 1.4 contains a
            graphical representation of the values of C as a function of H / D f o r different values
            of P / 1 0 f.
            W i t h the exception of hemispherical end-plates, all ends of a thickness less than the
            thickness of the shell ring shall be provided with a cylindrical edge of a length not
            exceeding three times its thickness or 50 mm.
 ---pagebreak--- 10.2.79     Official Journal of the European Communities       No C 37/17
                        Shape factor C for dished heads
        0 2                 0 3                         0-6 0 5
                                   Figure 1.4
 ---pagebreak--- N o C 37/18                 Official Journal of the European Communities                   10. 2. 79
                                               TABLE 1.1
                     P/lOf - 0-001      P/lOf = 0-0012   P/lOf = 0-0015   P/lOf - 0-002
            H/D0     c/Do          c    e/Do          c  e/Do           c  e/Do          C
            0-180                                        0-00211     2-81 0-00255     2-55
            0-200                                                         0-00218     2-18
                    P/10 f = 0-003      P/lOf = 0-004    P/lOf = 0-005    P/lOf = 0-01
            H/D0    e/D0           c    e/Do          c  e/Do           c e/Do           c
            0-180   0-00340     2-27    0-00423    2-12  0-00500     2-00 0-0088      1-76
            0-190   0-00316     2 11    0-00395     1 98
            0-200   0-00290      193    0-00364     1 82 0-00433     173  0-0077      154
            0-210   0-00273      1-82   0-00342    1-71
            0-220   0-00256      1-71   0-00320    1 60  0-00382     1 53 0-0068      138
            0-230   0-00236      1-57   0-00295    148
            0-240   0-00220      147    0-00276    138
            0-250                                        0-00307     123  0-0055      1-10
            0-300                                        0-00220     0 88 0-00395     0-79
            0-350                                                         0-00325     0-65
            0-400                                                         0-0030      0-60
            0-450                                                         0-0028      0-56
            0-500                                                         0-0027      0-54
                    P/lOf = 0-02        P/lOf = 0-05     P/lOf = 0-1      P/lOf = 0-2
            H/Do    e/Do           C    e/Do          C  e/Do          c  e/Dg          C
            0-180   0-0160      1-60    0 0366     146   0-0730      146  0-147       1 47
            0-200   0-0141      1 41    0-0330     132   0-0650      1-30 0-130       1-30
            0-220   0-0125      125     0-0292     1-17  0-0585      117  0-118       118
            0-250   0-0102      102     0-0250     1-00  0-0500      1-00 0-101       101
            0-300   0-0077      077     0-0193     0-77  0-0385     077   0-077      0-77
            0-350 . 0-0065      065     0-0162     065   0-0325     0-65  0-065      0 65
            0-400   0-0059      0 59    0-0149     0-60  0-0295     0-59  0-059      0 59
            0-450   0-0056      0 56   0-0140      0 56  0-0280     0 56  0-056      0 56
            0-500   0-0054      0-54   0-0136      0-54  0-0270     0-54  0-054      0-54
                    P/lOf = 0-5
            H/D0    e/Do           C
            0-350   0-163       065
            0-400   0-150       0-60
            0-450   0-140       056
            0-500   0-136       0-54
 ---pagebreak--- 10.2.79              Official Journal of the European Communities                                     N o C 37/19
        1.3. Calculation of flat end-plates
             The minimum thickness of an unreinforced flat end-plate without aperture is
             calculated by the following formula:
                                           ef=QD   ,v     p
                                                        10 f
             in which C t is a shape factor which must have the following values:
             — Cj = 0 45 for the ends represented by Figures 1.5, 1.6 and 1.7,
             — Cj = 0*5 for the ends represented by Figure 1.8.
                          Figure 1.5                                           Figure 1.6
             Cylindrical body sealed by forging                      End machined from a forged blank
                                   2
                                   tf
                     r 5= 0-25 ef                                               r 3= 1-5 ef
                     r 2= 5 mm
                                                Figure 1.7
                                       Deep-drawn flat end-plate
                                                        0-25 ef s£ r s£ 2 ef
                                                        r 3= 5 mm
                                                                                          \
 ---pagebreak--- No C 37/20    Official Journal of the European Communities 10. 2, 79
                          Unbraced flat end-plates
           \           7
             &
             . .
               h          Conventional butt weld
                                       r « 0-2 "to 0-5 t
                                       / ) » *3 PD,/2t
                               Figure 1.8
 ---pagebreak--- 10. 2. 79                Official Journal of the European Communities                                  N o C 37/21
          1.4. Dimensioning of apertures in a cylindrical or spherical part.
               The diameter of the apertures shall not exceed 0"3 times the average diameter of the
               cylindrical part.
               The thickness eG of the wall in the vicinity of an aperture must not be less than:
                                                         PD;
                                                C
                                                  °   20 fZ Q — P
                T h e different types of stiffening that can be used are shown in Figures 1.9 to 1.13.
                                                    Figure 1.9
                                   Type I: general increase in wall thickness
                                                    Figure 1.10
                                           Type II: by a stiffening ring
                                                     Figure 1.11
                                           Type III: by a welded nozzle
                                     T h e following three cases are possible:
                                                                  t)d,                             0d.
                  en
                                                         yo
                                Set-on                 Set-in              Protruding
 ---pagebreak--- N o C 37/22              Official Journal of the European Communities                             10.2.79
                                              Figure 1.12
                                   Type IV: by an extruded nozzle
                                              Figure 1.13
                         Type V: by a welded nozzle and a stiffening ring
                                                   Set-in                   Protruding
            The weakening factor ZQ is given in Figure 1.14 for cylindrical parts and Figure 1.15
            for spherical parts as a function of the ratio:
                                   °       and for different values of —
                                                                       e
                           V ( D; + eD) eQ                              «
            taking account of the following restrictions:
            — For type I: the lowest curves are applicable
 ---pagebreak--- 10,2.79 Official Journal of the E u r o p e a n Communities      N o C 37/23
                   Factor Z„ for cylindrical shell rings
                                                  V (D, + e0) e<
                                Figure 1.14
 ---pagebreak--- No C 37/24 Official Journal of the European Communities           10. 2. 79
                     Factor Z„ for spherical parts
                                                         d,
                                                   V (Dj + eQ) e0
                              Figure 1.15
 ---pagebreak--- 10. 2. 79                            Official Journal of the European Communities                                                        N o C 37/25
                           — For type II:
                               the lowest curves are applicable
                               (— = o \ and : 3e 0          b=    V (Dj  + eQ) e(l
                                                     ep     e
                               the width b may be reduced to bj provided that the thickness of the stiffening ring
                               e p is increased to e p l in accordance with
                               b| epi ^ b e p with b, 3= 3e 0 and epi «£ e
                           — For type III:
                               ~ ^ 2 and 1„ = V d„ • en
                                the height l n may be reduced to ln, provided that the branch thickness e n is
                                increased to e n | in accordance with:
                               Li' eni ^ 1„ - en with ^ ^ 2
                                for a protruding branch, the thickness of the branch e n may be reduced by 20 %
                                provided that the protrusion m is not less than e n .
                           — For type IV:
                                the length     1„ = V dG • e„
                           — For type V:
                               the restrictions listed for types II and II are applicable.
          1.5.            Access and inspection apertures
          1.5.1.          All vessels must be provided with manholes a n d / o r inspection apertures located so that
                          the vessel may be examined visually.
                          The minimum number and type of apertures in the cylindrical part of a vessel are
                          given in Table 1.2.
                                                                    TABLE 1.2
                                                        Number and type of apertures
                                                   Length of                                   Minimum n u m b e r
                  Inside diameter
                                              cylindrical section
                        (D;)                                            Small sight Large sight
                                                      (L)                                         H a n d hole     H e a d hole Man hole
                                                                           hole        hole
               0 < D; <       300                                           2           0               0                 0        0
                                                                          notes
                                                                         1 and 2
           300 < Dj <         450                                           0           2               0                 0        0
                                                                                      notes
                                                                                     1 and 2
           450 <D{       <    800                 0 L < 1 500               0                2 or 1                       0        0
                                                                                     note 2        note 3
                                             1 500 L « 2 000                0           0                   2 or 1                 0
                                                                                                   note 3      | note 3
                                                    L > 2 000               0           0                   note 4                 0
                                                  0 L < 2 000               0            0                                1        0
                                                                                                   note 3           note 3
           800 < Dj < 1 500
                                                    L > 2 000               0            0                  note 4                 0
                    D; > 1 500                                              0            0               0                0        1
 ---pagebreak--- No C 37/26                             Official Journal of the European Communities                                  10. 2. 79
           Note 1: where the length exceeds 1 500 mm, additional sight holes must be provided.
           Note 2: the sight holes must be located near the ends (providing a view of the longitudinal weld).
           Note 3: a single head hole and a single hand hole which must be situated in the central third of the
                    vessel length.
           Note 4: the number of inspection holes must be increased accordingly. For a length of less than
                    3 000 mm, however, it is sufficient to site a head hole in the centre of the cylindrical
                    section. On the cylindrical section, the distance between two head holes must not exceed
                    3 000 mm and the distance between two hand holes 2 000 mm. T h e latter must each be
                    situated near an end.
           1.5.2.        Dimensions of apertures
           1.5.2.1.      Sight holes are apertures with an inside diameter of at least 30 mm (small sight holes)
                         or 50 mm (large sight holes). T h e flange height must not exceed the diameter of the
                         aperture.
           1.5.2.2.      H a n d holes are apertures through which the hand and a lamp can be inserted. A hand
                         hole must have an elliptical opening of at least 80 x 100 mm or an inside diameter of
                         100 mm.
                        T h e flange height must not exceed 65 mm or, if conical in shape, 100 mm. If only one
                         hand hole is provided, it must not be less than 100 x 120 mm or 120 mm inside
                        diameter.
           1.5.2.3.      H e a d holes are apertures through which the head, an arm and a lamp can be
                        introduced simultaneously. Their dimensions must be at least 220 x 320 mm or
                         320 mm inside diameter; the flange height must not exceed 100 mm.
           1.5.2.4.     M a n holes are apertures which a person not carrying any auxiliary equipment can
                        enter and leave the vessel. T h e y must not be less than 300 x 400 mm inside diameter.
                        T h e flange height must not exceed 150 mm or, if conical in shape, 170 mm.
           1.5.3.       Remarks
           1.5.3.1.     If for design reasons the maximum flange height given above has been exceeded, the
                        openings must be enlarged accordingly so as to give the same facilities for internal
                        inspection of the vessel.
           1.5.3.2.     T h e conditions set out in the tables are applicable subject to the provisions of section 1
                        of the Annex.
           1.6.         Flanges
                        Flanges must comply with a national standard and may be used only for the pressure
                        specified in that standard.
 ---pagebreak--- 10.2.79                    Official Journal of the European Communities                                          N o C 37/27
                                                         ANNEX II
                                                DESCRIPTION OF TESTS
        II. 1.     Mechanical tests
        II. 1.1.   The following tests shall be performed in accordance with the Euronorms specified:
                   — Tensile test
                       Euronorm No          2-57 for e > 3 mm,
                                          11-55 for e < 3 mm.
                   — Bend test
                      Euronorm No          6-55 for e > 3 mm,
                                          12-55 for e < 3 mm.
                   — Impact test
                      Euronorm No 45-63.
                   — Hardness test
                       Euronorm No 3-55.
        II. 1.2.   Acceptance criteria
        II. 1.2.1. Tensile test in welds and parent materials
                   The breaking load obtained must be at least equal to the minimum breaking load
                   specified for the plate.
        II. 1.2.2. Bend test on welds
                   Each test piece is placed on supporting roller so that the mandrel axis is in the centre
                   of the weld; the test piece must pass between the supports under the action of the
                   mandrel. The diameter of the mandrel and the space between the supporting rollers
                   shall be determined as follows depending on the thickness of the test piece 'e':
                                                           Table for bend tests
                         Minimum breaking load specified       Diameter of      Space between supporting rollers
                                  for the plate                  mandrel                at the end of test
                   Less than 440 N/mm 2                            2 e                       4-2 e
                   From 440 to 500 N/mm 2                          3 e                       52 e
                   After the test the outside surface of the test piece shall not exhibit any cracks or other
                   defects of a length exceeding 15 mm measured transversely to the test piece or 3 mm
                   measured in the longitudinal direction of the test piece. A premature rupture at the
                   corners of the test piece is not regarded as a reason for rejection.
        II. 1.2.3. Impact test on welds
                   Three test pieces are required. The impact test are carried out under the conditions set
                   out in the third indent of 12.1 in the Technical Annex.
                   The results are acceptable if the mean value is not less than 35 J/cm 2 and if at the
                   same time the lowest value is not less than 25 J/cm 2 .
 ---pagebreak--- No C 37/28                          Official Journal of the European Communities                                  10. 2. 79
           II.1.2.4.  Hardness test on welds
                      The maximum Vickers hardness of the weld metal and the metal in the heat-affected
                      zone may not exceed that of the parent metal by more than 80 and 100 units
                      respectively.
           II.2.      Non-destructive examination
           II.2.1.    Radiographic examination
           II. 2.1.1. Preparation
                      If need be, scores and irregularities on the two faces of the weld may be removed or
                      rectified by an appropriate mechanical process so that the radiographic image of these
                      irregularities cannot conceal or be confused with the image of a defect to be detected.
                      If so specified, the reinforcement on each bead must be reduced to 2 mm.
           II.2.1.2.  Procedure
                      Welds must be radiographed in accordance with ISO specifications R 1166 or R 1167
                      using classifications B or C or the techniques recommended in ISO 2405.
           II.2.1.2.  Identification of radiographs
                      Reference marks must be placed along the weld so as to identify each radiograph
                      according to its location.
                      Lead characters must be placed along the weld to give the following information on
                      each radiograph:
                      1. the area of the weld bead convered by the radiograph;
                      2. the location of the weld bead using appropriate letters for the various beads with a
                         number showing whether this bead is the first, second, third, etc.;
                      3. a serial number denoting the specific vessel to which the radiograph relates;
                      4. marking of weld repairs on the section of the welded connections shown in the
                         radiograph.
           II.2.1.4.  Image quality indicator (IQI)
                      The image quality indicator must comply with the requirements of ISO
                      recommendation R 1027 'Radiographic image quality indicators — principles and
                      identification'. If a wire-type indicator is used, the smallest wire diameter visible must
                      not exceed the values given below.
                      If the step-and-hole indicator is used, the diameter of the smallest visible hole must
                      not exceed the values given below.
                              Thickness of plate in mm          Wire-type indicator       Step-and-hole indicator
                                         e < 6                        0-10                        025
                                  6 < e < 8                           0 125                       032
                                  8 < e < 10                          0 16                        0-40
                                 10 < e < 16                          0-20                        0-50
           II.2.1.5.  Examination of radiographs
                      Weld radiographs should be examined on the original films in accordance with the
                      procedure recommended in ISO standard 2504.
 ---pagebreak--- 10.2.79                    Official Journal of the European Communities                                      N o C 37/29
        II.2.1.6. Interpretation of results
                  The following defects are not acceptable:
                  — any cracks or areas showing a lack of fusion at the weld root,
                  — any elongated inclusion which is greater in length than the thickness 'e' of the
                      plate and at least equal in width to the smaller of the following two values: 2 mm
                      or half the thickness 'e', where 'e' is the thickness of the materials adjacent to the
                     weld. If the weld consists of two different thicknesses, the larger is considered,
                  — any porosities greater than those shown in the charts in Figures II. 1, II.2 and II.3.
                                            Porosity charts for thicknesses of less than 6 mm
                      Assorted
                         •                                •                 e                •      •      •
                                              •*                                  #
                      Large
                      ¥                                 •                       #
                                                                                               #
                      Medium
                      Fine
                                                   5           :
                      I :       :        '                             ~
                      I.            •        . '            .
                                                               Figure II.l
                                          Porosity charts for thicknesses of 6 to 13 mm
                      Assorted
                      Large
                      Medium
                                                               Figure II. 2
 ---pagebreak--- N o C 37/30                       Official Journal of the European Communities                                  10. 2. 79
                                             Porosity charts for thicknesses exceeding 13 mm
                       Assorted
                       Large
                       Medium
                       Fine
                                                                   Figure II.3
            11.2.3.   Macrographic examination
                      The macrographic examination of a complete weld cross-section must reveal good
                      penetration and an absence of any fusion defects, significant inclusion or other defects.
                      In cases of doubt, a micrographic examination of the doubtful zone must be carried
                      out.
            11.2.4.   Penetrant fluid weld test
                      This shall be carried out in accordance with the specifications of ISO document DIS
                      2694 Annex J.
            11.2.5.   Ultrasonic test
            11.2.5.1. Techniques
                      The examination shall be carried out in accordance with the specifications in ISO
                      document DIS 2694.
            11.2.5.2. Unacceptable weld defects
                      The limits on linear defects specified in the first two indents of II.2.1.6 may be
                      regarded as valid for tests by magnetization and penetrant fluid tests. When the inter-
                      pretation of the defects reveals cracks, incomplete fusion or incomplete penetration,
                      these defects shall be regarded as unacceptable whatever their length.
 ---pagebreak--- 10. 2. 79                     Official Journal of the European Communities                                     N o C 37/31
          II.3.     Overall tests
          11.3.1.   Pressure cycling test
                    For this purpose, a hydraulic test is performed in cycles in which the pressure is
                    repeatedly built up from the initial or residual pressure to the test pressure.
                    The test parameters must comply with one of the following sets of conditions, the
                    choice being left to the Member State concerned:
                    1. — total number of cycles:       80 000,
                                                      2
                        — test pressure:                / i Ph 4- residual pressure,
                        — frequency:                   15 cycles per minute.
                    2. — total number of cycles:       15 000,
                        — test pressure:               Ph + residual pressure,
                        — frequency:                   5 cycles per minute.
                    The residual pressure (i.e. the pressure remaining after the vessel decompression phase)
                    must not exceed 5 % of the test pressure.
                    Throughout the test, the temperature measured on the outside wall of the vessel must
                    not exceed 50 °C.
                    The test is regarded as satisfactory if the vessel completes the specified number of
                    cycles without leaking.
          11.3.2.   Hydrostatic test
                    Every vessel must undergo a hydrostatic test at a pressure Ph which must not be less
                    than the value given by the equation set out below:
                    R E is the guaranteed minimum yield point at the test temperature;
                    R e t is the yield point at the working temperature;
                    P is the working pressure.
                    However, the pressure P^ must be such that it does not create in the vessel a general
                    membrane stress greater than 90 % of the minimum value of R E .
                    The test pressure must be iield at the specified value long enough to allow all the
                    surfaces aqd joints to be examined visually. The vessel must not show any sign of
                    general plastic deformation or leakage.
                    Every vessel tested which fails the hydrostatic test must be rejected.
          II.4.     Destructive testing
          II.4.1.   Hydraulic pressure bursting test
          II.4.1.1. Procedure
                    The hydraulic pressure bursting test must be performed in two successive stages using
                    an installation enabling the pressure to be built up regularly until the vessel bursts and
                    a graph showing the variation of pressure with time to be recorded.
                    In the initial stage, the rate of pressure build-up to the value corresponding to the
                    onset of plastic deformation must be equal to about five bar.
 ---pagebreak--- No C 37/32                            Official Journal of the European Communities                               10. 2. 79
                        With the test, it must be possible to determine:
                        (a) the pressure at which plastic deformation commences;
                        (b) the bursting pressure;
                        (c) local and overall deformation of the vessel.
           II.4.1.2.    Test acceptance criteria
                        The measured bursting pressure (Pr) must be higher than the calculated theoretical
                         minimum bursting pressure (P rt ).
                        This theoretical pressure is calculated from the minimum thickness obtained by
                        applying the formula set out in Annex I and from the vessel's calculated minimum
                        guaranteed tensile strength (R r ) according to the formula:
                                                          p   20' R*
                                                            "  D- e
                                                          zlMVEX///
                                                      COUPON PLATE
           Quality control is carried out on one or more coupon plates.
           To represent the longitudinal joint, the coupon plate shall consist of an extension piece added to
           the joint in question and welded at the same time. Furthermore the parent material and thickness
           of the coupon plate shall be identical with those of the shell ring.
           No coupon plate need be provided for circumferential joints if the welding procedure and
           technique are the same for both types of joint.
           If the method of welding circumferential joints differs from that used for longitudinal seams, a
           separate coupon plate must be prepared by the same welding procedure as used for the circum-
           ferential welds on the vessel. This coupon plate shall consist of two sections of tube of the same
           material, thickness and diameter as for production, welded together by a circumferential weld.
           The dimensions of the coupon plate shall be such that a sufficient number of test pieces can be
           taken to carry out the tests specified in section 12.
                                    ACCEPTANCE OF THE WELDING PROCEDURE
           IV. 1.        General
                         By having the welding procedure accepted, the manufacturer must prove that he is
                         capable of welding materials to be used for the construction of the pressure vessels to
                         be produced.
                         For that purpose he shall carry out test welds in accordance with the following
                         specifications.
                         The test welds shall consist of the execution of butt welds and fillet welds. These
                         welds must be representative of the production welds on all parts subjected to pressure
                         in the vessels.
 ---pagebreak--- 1Q. 2. 79                    Official Journal of the European Communities                                      N o C 37/33
          IV.2.     Execution of the welds
          IV.2.1.   Parent metal
                    The plates and tubes used for the welding procedure acceptance tests shall be of the
                    same grade and shall conform to the same specifications as the plates and tubes used
                    in actual production. However, acceptance for a given grade is also valid for grades
                    having a lower impact strength and less favourable chemical composition.
          IV.2.2.   Filler products
                    The weld filler materials, i.e. electrodes and combinations of wire, powder and
                    shielding gas, must be the same for acceptance of the welding procedure as for actual
                    production.
          IV.2.3.   Type of edge preparation
                    In manual welding, the type of preparation (single or double V, single or double U
                    and straight bevel) may be changed in production welding without necessitating reac-
                    ceptance of the welding procedure.
                    In the case of semi-automatic welding, any change in the type of edge preparation
                    requires a fresh acceptance test.
          IV.2.4.   Welding method
                    The welding method and, in the case of semi-automatic or automatic welding, the
                    type of welding equipment must be the same for the acceptance test as for actual
                    production.
          IV.2.5.   Validity of the welding procedure
          IV.2.5.1. A fresh acceptance test is required if:
                    (a) in arc welding, the current range and welding speed and, in submerged arc
                         welding, the range of voltages used are appreciably modified;
                    (b) in the arc welding of a simple butt joint, the back support is added or removed;
                    (c) in the oxyacetylene welding of a simple butt joint, a back support is added;
                    (d) in the case of machine welding, multi-pass welding on each face is replaced by
                         one-pass welding on each face;
                    (e) if the shielding gas is changed or not used.
          IV.2.5.2. Longitudinal and circumferential joints
                    If a test plate is welded to represent longitudinal joints, there is no need for a test on
                    the circumferential joints provided that the welding method, procedure and techniques
                    are the same for the two types of joint.
                    If the method of welding circumferential joints differs from that used for longitudinal
                    joints, a test piece consisting of two tubular sections assembled by means of a circum-
                ,   ferential weld must be produced in accordance with the procedure used for the circum-
                    ferential welds on the vessel.                          ,
          IV.2.6.   Dimensions of the test assembly
                    The dimensions of the test assembly shall be such that it is possible to take a sufficient
                    number of test pieces to carry out the tests specified in 2.7 of Annex IV.
 ---pagebreak--- N o C 37/34                            Official Journal of the European Communities                                10.2.79
             IV.2.7.     Inspection and testing
             IV.2.7.1.   Butt welds
                         The tensile, bend, impact and hardness tests shall be carried out in accordance with
                         the specifications in II. 1.1 of Annex II.
                         The inspections and tests to be carried out are as follows:
                          (a) a radiographic examination
                               the radiographic examination shall be carried out on the full length of the welds
                               and before test pieces are taken;
                          (b) one tensile test
                               the tensile test piece shall be cut transversely to the weld;
                          (c) three impact tests in the weld;
                          (d) one bend test on the underside of the weld;
                          (e) one bend test on the upper side of the weld;
                          (f) a macrographic examination;
                         (g) one hardness test.
             IV.2.7.2.   Fillet welds
                         The examinations to be carried out are as follows:
                         (a) a visual examination;
                         (b) a macrographic examination.
            IV.2.8.      Acceptance criteria
            IV.2.8.1.    The acceptance criteria for the tensile, bend, impact and hardness tests are specified in
                         II. 1.2 of Annex II.
            IV.2.8.1.1.  The radiographic examination shall be carried out in accordance with II.2.1 of
                         Annex II:
            IV.2.8.1.2.  The macrographic examination shall be carried out in accordance with II.2.3 of
                         Annex II.
                                  QUALIFYING TESTS FOR WELDERS OR OPERATORS
            The qualifying tests for welders or operators shall be carried out in exactly the same way and
            under the same conditions as the welding procedure acceptance tests.
            The requirements for th^ qualifying tests for welders or operators are the same as for the welding
            procedure acceptance tests.
            Welders or operators must undergo fresh qualifying tests if the welding procedure has to be re-
            accepted as a result of a change in one of the conditions specified in 2.5 of Annex IV.
            Welders or operators must qualify if they have not been engaged on the same type of work in the
            construction of pressure vessels during the previous six months.
 ---pagebreak--- 10. 2. 79                                     Official Journal of the European Communities                                                                 N o C 37/35
                                                                                   ANNEX         VI
                                                  EEC PATTERN APPROVAL CERTIFICATE
                          issued p u r s u a n t t o C o u n c i l D i r e c t i v e s 7 6 / 7 6 7 / E E C of 27 J u n e 1976 a n d . . . of
                                                                                Pressure vessels
          Approval N o :                                          Date:
          T y p e of vessel:                                      ' D e s c r i p t i o n of the-vessel o r v a r i a n t a p p r o v e d '
                                                                 Capacity:                    L:           thickness:
                                                                 Pmax:                        D:
          Manufacturer or agent:                                 'Name            and      address     of  the  manufacturer or             his authorized
                                                                 agent'
          E E C pattern approval m a r k :                       Article 3 ( a )            £     4 F 8453
                                                                 A r t i c l e 3 (b) ( ^ )        4 F 8453
          Validity:                                              5 y e a r s / 1 0 years
          Any further information may
          be o b t a i n e d f r o m :                           N a m e a n d a d d r e s s of t h e i n s p e c t i o n a u t h o r i t y
          D o n e at                            (date)
                                                                                                                              (Signature)