No C 89/2 Official Journal of the European Communities 15.4.86 
II 
(Preparatory Acts) 
COMMISSION 
Proposal for a Council Directive on the harmonization of the laws of the Member States 
relating to simple pressure vessels 
COM(86)l 12 final 
(Submitted by the Commission to the Council on 7 March 1986) 
(86/C 89/02) 
THE COUNCIL OF THE EUROPEAN COMMUNITIES, 
Having regard to the Treaty establishing the European 
Economic Community, and in particular Article 100 
thereof, 
Having regard to the proposal from the Commission, 
Having regard to the opinion of the European Par­
liament, 
Having regard to the opinion of the Economic and 
Social Committee, 
Whereas Member States have the responsibility of 
ensuring the safety on their territory of persons, 
domestic animals and property with regard to the 
hazards resulting from the leakage or bursting of simple 
pressure vessels; 
Whereas in each Member State mandatory provisions 
define in particular the safety level required of simple 
pressure vessels by specifying design and operating 
characteristics, conditions of installation and use and 
inspection procedures before and after placing on the 
market; whereas these mandatory provisions do not 
necessarily lead to different safety levels from one 
Member State to another but do by their disparity hinder 
trade within the Community; 
Whereas the national provisions ensuring such protection 
must be harmonized in order to guarantee the free 
movement of simple pressure vessels without lowering 
existing and justified levels of protection in the Member 
States; 
Whereas Community legislation as it stands at present 
provides that, notwithstanding one of the fundamental rules of the Community, namely the free movement of 
goods, barriers to intra-Community movement resulting 
from disparities in national laws on the marketing of 
products have to be accepted in so far as those provisions 
may be recognized as necessary to satisfy essential 
requirements; whereas the harmonization of laws in the 
present case must therefore be confined to those 
provisions needed to satisfy the essential safety 
requirements for simple pressure vessels; whereas because 
they are essential these requirements must replace the 
corresponding national provisions; 
Whereas this Directive therefore contains only 
mandatory and essential requirements; whereas to facili­
tate proof of conformity with the essential requirements 
it is necessary to have harmonized standards at European 
level in particular as to the design, operation and instal­
lation of simple pressure vessels so that products 
complying with them may be assumed to conform to the 
safety requirements; whereas these standards harmonized 
at European level are drawn up by private bodies and 
must remain non-mandatory texts; whereas for that 
purpose the European Committee for Standardization 
(CEN) and the European Committee for Electro-
technical Standardization (CENELEC) are recognized as 
the competent bodies for the adoption of harmonized 
standards in accordance with the general guidelines for 
cooperation between the Commission and those two 
bodies signed on 13 November 1984; whereas for the 
purposes of this Directive a harmonized standard is a 
technical specification (European standard or harmo­
nization document) adopted by one or both of those 
bodies upon a remit from the Commission in accordance 
with the provisions of Council Directive 83/189/EEC (') 
and the abovementioned general guidelines; 
Whereas pending the adoption of harmonized standards 
for the purposes of this Directive it is desirable to faci­
litate the free movement of goods by accepting within 
the Community products in conformity with the selected 
(') OJ No L 109, 26. 4. 1983, p. 8. 
15.4.86 Official Journal of the European Communities No C 89/3 
national standards, as a transitional measure, through a 
Community inspection procedure ensuring that the 
national standards satisfy the essential requirements of 
this Directive; whereas for that purpose, in view of the 
general and horizontal role played by the Standing 
Committee set up by Article 5 of Directive 83/189/EEC 
in the Community standardization policy and in 
particular its role in the formulation of standardization 
remits, and in the operation of the standstill arrangement 
as regards European and national standardization, this 
Committee is the ideal body for Community verification 
of the conformity of national standards; 
Whereas a check on compliance with these technical 
requirements is necessary to provide effective protection 
for users and third parties; whereas the existing 
inspection procedures differ from one Member State to 
another; whereas in order to avoid multiple inspections, 
which are in effect barriers to the free movement of 
vessels, arrangements should be made for the mutual 
recognition of inspection procedures by the Member 
Staters; whereas, in order to facilitate the mutual 
recognition of inspection procedures, harmonized 
Community procedures should be set up and the criteria 
for appointing the bodies responsible for carrying out 
tests, surveillance and verification should be harmonized; 
Whereas the presence on a simple pressure vessel of the 
EC mark indicates that it satisfies the provisions of this 
Directive and therefore makes it unnecessary, on import 
and placing into service of the vessel, to repeat the 
inspections already carried out; whereas nevertheless 
simple pressure vessels might represent a safety hazard; 
whereas provision should therefore be made for a 
procedure to reduce this harzard, 
HAS ADOPTED THIS DIRECTIVE: 
CHAPTER I 
Scope and provisions on marketing and freedom of 
movement 
Article 1 
1. This Directive applies to simple pressure vessels 
manufactured in series and intended for normal use. It 
defines the essential safety requirements and inspection 
procedures relating thereto. 
2. For the purposes of this Directive, a simple pressure 
vessel means any welded vessel subjected to an internal 
pressure greater than atmospheric pressure which is 
intended to contain compressed air or a compressed non-
corrosive, non-inflammable, non-toxic gas, whose critical 
temperature is less than —10 °C, but which is not 
intended to be fired. Moreover: 
— the parts and assemblies contributing to the strength 
of the pressure vessel shall be made either of non-
alloy, carbon or carbon/manganese quality steel, or 
of non-alloy aluminium or aluminium/magnesium 
alloy, 
— the vessel shall have a simple geometry enabling 
simple-to-use production processes to be used, 
— the design pressure of the vessel shall not exceed 30 
bars and the product of that pressure and the 
capacity of the vessel (P x V) shall not exceed 
10 000 bar/litres, 
— the minimum working temperature shall lie between 
— 10 °C and —50 °C and the design temperature 
shall not exceed 300 °C for steel and 100 °C for 
aluminium vessels. 
3. Vessels especially designed for the conveyance of 
compressed gases and fire extinguishers do not fall 
within the scope of this Directive. 
Article 2 
1. The vessels referred to in Article 1 may be placed 
on the market and taken into service only if they do not 
compromise the safety of persons, domestic animals or 
property when properly stored and maintained and when 
used for the purposes for which they are intended. 
2. Any additional conditions laid down at national 
level in respect of installation, maintenance and use must 
not involve modifications to vessels which comply with 
this Directive. 
Article 3 
The following shall not compromise the safety of 
persons, domestic animals or property when properly 
installed and used for the purposes for which they are 
intended: 
— vessels which satisfy the essential safety requirements 
set out in Annex I, 
— vessels in respect of which the product of P and V 
does not exceed 20 bar/litres, which are manu­
factured in accordance with the relevant sound 
engineering practice and bear markings concerning 
their service pressures and temperatures, and the 
means of identifying the manufacturer. 
Article 4 
Member States shall not impede the placing on the 
market and the taking into service on their territory of 
vessels which satisfy the requirements of this Directive. 
Article 5 
1. Member States shall presume compliance with the 
essential safety requirements referred to in Article 3, in 
No C 89/4 Official Journal of the European Communities 15.4.86 
respect of vessels bearing the EC mark denoting 
conformity: 
(a) with the relevant national standards transposing the 
harmonized standards, the reference numbers of 
which have been published in the Official Journal of 
the European Communities; Member States shall 
publish the reference numbers of such national 
standards; 
(b) or with the relevant national standards referred to in 
paragraph 2 in so far as, in the areas covered by such 
standards, no harmonized standards exist. 
2. Member States shall communicate to the 
Commission the texts of their national standards, as 
referred to in paragraph 1 (b), which they regard as 
complying with the basic requirements referred to in 
Article 3. The Commission shall forward such texts 
forthwith to the Member States. In accordance with the 
procedure provided for in Article 6 (2), it shall notify the 
Member States of those national standards in respect of 
which there is a presumption of conformity with the 
essential requirements referred to in Article 3. 
Member States shall publish the reference numbers of 
those standards. The Commission shall also publish them 
in the Official Journal of the European Communities. 
3. Member States shall accept that vessels in respect of 
which the manufacturer has not applied, or has applied 
only in part, the standards referred to in paragraph 1 
should be regarded as satisfying the essential 
requirements referred to in Article 3 where, after receipt 
of an EEC-type examination certificate, their conformity 
with the approved specimen has been certified by the 
affixation of the EC mark. 
Article 6 
1. Where a Member State or the Commission 
considers that the harmonized standards referred to in 
Article 5 (1) (a) do not entirely meet the essential 
requirements referred to in Article 3, the Commission or 
the Member State concerned shall bring the matter 
before the Standing Committee set up under Directive 
83/189/EEC, hereinafter referred to as 'the Committee', 
giving the reasons therefor. The Committee shall deliver 
an opinion without delay. 
Upon receipt of the Committee's opinion, the 
Commission shall inform the Member States whether or 
not it is necessary to withdraw those standards from the 
publications referred to in Article 5 (1) (a). 
2. After receipt of the communication referred to in 
Article 5 (2) the Commission shall consult the 
Committee. Upon receipt of the latter's opinion, the 
Commission shall, within one month, inform the 
Member States whether or not the national standard in 
question shall enjoy the presumption of conformity and, 
if so, whether the references thereof must be published 
nationally. If the Commission or a Member State considers that a 
national standard no longer satisfies the necessary 
conditions for presumption of compliance with the 
essential safety requirements referred to in Article 3, the 
Commission shall consult the Committee. Upon receipt 
of the latter's opinion, the Commission shall inform the 
Member States whether or not the standard in question 
shall continue to enjoy a presumption of compliance and, 
if not, that it must be withdrawn from the publications 
referred to in Article 5 (2). 
Article 7 
1. "Where a Member State ascertains that vessels 
bearing the EC mark and used in accordance with their 
original purpose are likely to compromise the safety of 
persons, domestic animals or property, it shall take all 
appropriate measures to withdraw those products from 
the market, prohibit the placing thereof on the market or 
restrict free movement thereof. 
The Member State concerned shall immediately inform 
the Commission of any such measure, indicating the 
reasons for its decision, and in particular whether non­
compliance is due to: 
(a) failure to meet the essential requirements referred to 
in Article 3, where the vessel does not meet the 
standards referred to in Article 5 (1); 
(b) incorrect application of the standards referred to in 
Article 5 (1); 
(c) shortcomings in the standards referred to in Article 5 
(1) themselves. 
2. Where the decision referred to in paragraph 1 is 
attributed to shortcomings in the standards, the 
Commission, after consulting the parties concerned, shall 
bring the matter before the Committee within two 
months if the Member State which has taken the 
measures intends to uphold them. If the Commission, 
after consulting the Committee, finds that the action is 
justified, it shall immediately so inform the Member 
State that took the action and the other Member States 
and shall initiate the procedures referred to in Article 6. 
3. Where a vessel which does not comply bears the 
EC mark, the competent Member State shall take appro­
priate action against whomsoever has affixed the mark 
and shall inform the Commission and the other Member 
States thereof. 
4. The Commission shall ensure that the Member 
States are kept informed of the progress and outcome of 
this procedure. 
15.4. 86 Official Journal of the European Communities No C 89/5 
CHAPTER II 
Certification procedures 
Article 8 
1. Prior to production of pressure vessels manu­
factured : 
(a) in accordance with the standards referred to in 
Article 5 (1), the manufacturer, or his representative 
established within the Community, shall, at his own 
choice, either: 
— inform an approved inspection body as referred 
to in Article 9 and forward to it the design and 
manufacturing record referred to in Annex II.2, 
or 
— submit for the EC-type examination referred to 
in Article 10 a specimen vessel; 
(b) not in accordance, either in whole or in part, with 
the standards referred to in Article 5 (1), the manu­
facturer, or this representative established within the 
Community, must submit a specimen of the vessel for 
the EC-type examination referred to in Article 10. 
2. Vessels manufactured in accordance with the 
standards referred to in Article 5 (1) or with the 
approved specimen shall, prior to their being placed on 
the market, be subjected: 
(a) to the EC verification referred to in Article 11 where 
the product of P and V exceeds 3 000 bar/litres; 
(b) at the choice of the manufacturer, where the product 
of P and V does not exceed 3 000 bar/litres and 
does exceed 20 bar/litres, either 
— to the EC declaration of conformity referred to 
in Article 12, when the approved inspection body 
contacted has adequate means of carrying out the 
EC surveillance referred to in Article 14, or 
— to the EC verification referred to in Article 11. 
3. Member States having approved inspection bodies 
on their territory shall ensure that, at the latest four 
years after the date of adoption of this Directive, at least 
one of those bodies has the means to conduct the EC 
surveillance referred to in Article 14. 
4. The records and correspondence relating to the 
certification procedures referred to in paragraphs 1 and 
2 shall be written in an official language of the Member 
State in which the approved body is established. 
Article 9 
1. Each Member State shall notify the Commission 
and the other Member States of the approved inspection 
bodies responsible for carrying out the certification pro­
cedures referred to in Article 8 (1) and (2). The 
Commission shall publish a list of these bodies, for infor­
mation purposes, in the Official Journal of the European 
Communities and shall ensure that the list is updated. However, if a Member State has not approved any 
inspection bodies on its territory, it shall notify at least 
one such body approved by another Member State. 
2. Annex III sets out the minimum criteria which 
Member States must meet as regards approval of 
inspection bodies. 
3. A Member State which has approved an inspection 
body must withdraw approval if it finds that the body no 
longer meets the criteria listed in Annex III. It shall 
immediately inform the Commission and the other 
Member States accordingly. 
4. Only a Member State on whose territory an 
approved inspection body is established may withdraw 
that approval or make it subject to restrictions. 
5. An approved inspection body may carry out the 
inspections referred to in this Directive throughout the 
territory of the Community. It may, without 
relinquishing its responsibility, delegate to another 
approved body certain tasks that are incumbent upon it. 
EC-TYPE EXAMINATION 
Article 10 
1. EC-type examination is the procedure by which an 
approved inspection body ascertains and certifies that a 
specimen of a vessel satisfies the essential safety 
requirements applicable to it. 
2. The application for EC-type examination shall be 
lodged by the manufacturer or by his authorized repre­
sentative with a single approved inspection body in 
respect of a specimen of vessel or of a specimen 
representing a family of vessels. That official represen­
tative shall be established in the Community. 
The application shall include: 
— the name and address of the manufacturer or of his 
authorized representative, and the place of manu­
facture of the vessels, 
— the design and manufacturing record referred to in 
Annex II.2. 
It shall be accompanied by a vessel which is represen­
tative of the production envisaged. 
3. The approved body shall carry out the EC-type 
examination in the manner described below. 
It shall examine not only the design and manufacturing 
record, in order to check its conformity, but also the 
vessel submitted. 
When examining the vessel, the body shall: 
(a) verify that the vessel has been manufactured in 
conformity with the design and manufacturing 
record and may be used in complete safety under its 
intended service conditions; 
No C 89/6 Official Journal of the European Communities 15.4.86 
(b) perform appropriate examinations and tests on each 
type of weld and on the base materials; 
(c) check, where appropriate, whether the quality of the 
protective anti-corrosion coating is adequate for the 
intended use of the vessel. 
4. If the specimen complies with the essential 
requirements referred to in Article 3 the approved body 
shall draw up an EC-type examination certificate which 
shall be forwarded to the applicant. That certificate shall 
state the conclusions of the examination, indicate any 
conditions to which its issue may be subject and be 
accompanied by the descriptions and drawings necessary 
for identification of the approved specimen. 
The approved body referred to above shall send a copy 
of the certificate to the other approved bodies, which 
may, on request, obtain a copy of the design and manu­
facturing record and the reports on the examinations and 
tests carried out. The Commission and the Member 
States may, on request, obtain a copy of the certificate, 
the design and manufacturing record and the reports. 
5. A body which refuses to issue, or withdraws, an 
EC-type examination certificate shall so inform the 
Member State which approved it. The latter shall inform 
the other Member States and the Commission, giving the 
reasons for the decision. 
EC VERIFICATION 
Article 11 
1. The purpose of EC verification is to check and 
certify that series-manufactured vessels comply with the 
standards referred to in Article 5 (1) or with the 
approved specimen. It shall be performed by an approved 
inspection body in accordance with the provisions set out 
below and shall be denoted by the EC mark provided for 
in Article 16, affixed to the certified vessels by that body. 
2. Verification shall be performed on batches of 
vessels submitted by their manufacturer or by an au­
thorized representative thereof established within the 
Community. Batches shall be accompanied by the EC 
type-approval certificate referred to in Article 10, or if 
the vessels are not manufactured to conform with an 
approved specimen, by the manufacturing record 
referred to in Annex II.2. In the latter case the approved 
body shall, prior to EC verification, examine the record 
in order to check its conformity. 
3. When a batch is examined, the inspection body 
shall check that the vessels have been manufactured in 
conformity with the design and manufacturing record and shall perform a hydraulic test on each vessel at a 
pressure Ph equal to 1,35 times the vessels design 
pressure in order to check its leaktightness. Moreover, 
the inspection body shall carry out suitable tests on test 
pieces selected by the manufacturer from a representative 
production test piece or vessel in order to examine weld 
quality. The tests shall be carried out on longitudinal 
welds. However, where differing welding techniques are 
used for longitudinal and circular welds, the tests shall 
be repeated on the circular welds. 
EC DECLARATION OF CONFORMITY 
Article 12 
1. The EC declaration of conformity is the procedure 
whereby the manufacturer certifies vessels to be in 
conformity with the standards referred to in Article 5 (1) 
or with an approved specimen and becomes subject to 
EC surveillance. 
2. Manufacturers fulfilling the obligations arising out 
of Article 13 shall affix the EC mark provided for in 
Article 16 to vessels which he declares to be in 
conformity. 
3. The purpose of EC surveillance is to ensure, as 
required by Article 14, that the manufacturer duly fulfils 
the obligations arising out of Article 13. Surveillance 
shall be performed by the approved body which issued 
the EC-type examination certificate referred to in Article 
10 where the vessels have been manufactured in 
accordance with an approved specimen or by the 
approved body to which the design and manufacturing 
record was sent in compliance with Article 8 (1) (a), first 
indent. 
Article 13 
Where a manufacturer makes use of the procedure 
referred to in Article 12, he must, before commencing 
manufacture, send the body responsible for EC sur­
veillance a document describing the manufacturing 
processes and all of the predetermined, systematic 
measures taken to ensure compliance of the pressure 
vessels with the standards referred to in Article 5 (1) or 
the approved specimen. 
This document shall include, in particular: 
(a) a description of the means of manufacture and 
inspection appropriate to the construction of the 
vessels; 
(b) an inspection document describing the examinations 
to be carried out during manufacture, together with 
the procedures therefor; 
(c) an undertaking to carry out the examinations and 
tests in accordance with the inspection document 
referred to above and to have a hydrostatic test 
15.4.86 Official Journal of the European Communities No C 89/7 
carried out on each vessel manufactured at a test 
pressure equal to 1,35 times the design pressure in 
order to check its leak tightness. 
These examinations and tests shall be carried out by 
qualified staff who are sufficiently independent from 
the production personnel, and shall be covered by a 
report; 
(d) the addresses of the places of manufacture and 
storage and the date on which manufacture is to 
commence. 
Moreover, manufacturers shall authorize access to the 
said places of manufacture and storage by the body 
responsible for EC surveillance, for inspection purposes, 
shall allow that body to select sample vessels and shall 
provide it with all necessary information, and in 
particular: 
— the design and manufacturing record, 
— the inspection report, 
— the EC-type examination certificate, where appro­
priate, 
— a report on the examinations and tests carried out. 
Article 14 
1. The inspection body responsible for EC surveillance 
must, before any manufacture takes place, examine both 
the document referred to in Article 13 and the design 
and manufacturing record referred to in Annex II.2 in 
order to check their conformity when vessels are not 
manufactured in accordance with an approved specimen. 
Moreover, during manufacture that body shall: 
— ensure that the manufacturer actually checks vessels 
produced in series in accordance with Article 13 (c), 
— conduct random spot checks on the places of manu­
facture or storage of a vessel for inspection purposes. 
2. The body referred to in paragraph 1 shall supply 
the Member State which approved it, and, on request, 
the other approved bodies, the other Member States and 
the Commission, with a copy of the inspection report. 
Article 15 
Where it is established that the EC mark has been 
wrongly affixed to vessels because: 
— they do not conform to the approved specimen, 
— they conform to an approved specimen which does 
not meet the essential requirements referred to in 
Article 3, 
— they do not conform to the relevant standards 
referred to in Article 5(1), 
— the manufacturer has failed to fulfil his obligations 
under Article 13, the body responsible for EC surveillance must report to 
the Member State concerned and, where appropriate, 
withdraw the EC-type examination certificate. 
Article 16 
1. The EC mark and the inscriptions provided for in 
Annex II.2 shall be affixed in a visible, easily legible and 
indelible form to a data plate attached to the vessel in 
such a way that it cannot be removed. 
The EC mark shall consist of the symbol C€. 
The stylized letter € shall contain in its lower part the 
last two digits of the year in which the mark was affixed. 
In shall be accompanied by the mark of the approved 
inspection body responsible for EC verification or EC 
surveillance. 
2. The affixing to vessels of marks or inscriptions that 
are likely to be confused with the EC mark shall be 
prohibited. 
CHAPTER III 
Final provisions 
Article 17 
Member States shall regularly inform the Commission of 
the activities carried out in pursuance of this Directive by 
the bodies which they have approved in order to enable 
it to ensure that the inspection and surveillance proce­
dures are implemented correctly and without discrim­
ination. 
Article 18 
Any decision taken by a Member State or an approved 
inspection body pursuant to this Directive shall state the 
exact grounds on which it is based. Such a decision shall 
be notified as soon as possible to the party concerned, 
who shall at the same time be informed of the judicial 
remedies available to him under the laws in force in the 
Member State in question and of the time limits to which 
such remedies are subject. 
Article 19 
1. Member States shall bring into force the laws, regu­
lations and administrative provisions necessary in order 
to comply with this Directive by 30 June 1988. They 
shall inform the Commission thereof. 
2. Member States shall ensure that the texts of the 
provisions of national law which they adopt in the field 
covered by this Directive are communicated to the 
Commission. 
Article 20 
This Directive is addressed to the Member States. 
No C 89/8 Official Journal of the European Communities 15.4.86 
ANNEX I 
The essential requirements necessary to ensure a proper level of intrinsic safety of the vessels are set out 
below. 
1. MATERIALS 
Manufacturers shall take account of 1.1 to 1.3 in selecting the appropriate materials as a function 
of the intended use of the vessels. Those materials supplied for assembly manufacture which 
contribute to the strength of the vessel under pressure shall be accompanied by an inspection slip 
drawn up by the producer of the material. 
1.1. Pressurized parts 
The material referred to in Article 1 used for manufacturing the pressurized parts must be: 
— capable of being welded by appropriate welding processes, 
— ductile and tough, so that a rupture at minimum working temperature, does not give rise to 
either fragmentation or brittle-type fracture, 
— unaffected by ageing. 
They must also comply with the special provisions set out in 1.1.1 and 1.1.2. 
1.1.1. Steel vessels 
Non-alloy carbon or carbon/manganese-quality steels shall: 
(a) be killed or semi-killed and be supplied after normalization treatment or in an equivalent 
state; 
(b) the carbon content per product shall not exceed 0,25 %, 
(c) have the same mechanical properties per product as follows: 
— the minimum tensile strength Rm must not be more 460 N/mm2, 
— the elongation after rupture A on test pieces taken in the length must be not less than 
22 %, 
— the average failure energy KCV must not be less than 35 J/cm2 on test pieces taken in the 
length at minimum service temperature. This shall only be required of steels intended for 
the manufacture of vessels whose minimum service temperature is less than — 10° C and 
whose wall thickness is more than 5 mm. 
1.1.2. Aluminium vessels 
Non-alloy aluminium shall have an aluminium content of at least 99,5 % and aluminium/ 
magnesium alloy shall display adequate resistance to intercrystalline corrosion. These materials 
should be supplied in an annealed state and their lead content for each product shall not be less 
than 0,05 %. 
1.2. Fasteners 
Bolts and nuts should be made of a material as specified in 1.1 or, as in the case of steel, of 
carbon or carbon/manganese steels whose elongation after rupture A on test pieces taken in the 
length should be at least 16 %. 
1.3. Non-pressurized parts 
All unpressurized parts of welded vessels must be of materials that are compatible with that of the 
components to which they are welded. 
2. VESSEL DESIGN 
The vessels must withstand, at maximum working temperature, a pressure of not less than 1,5 
times the design pressure without exhibiting signs of plastic deformation and 2,5 times the design 
pressure before rupture. These qualities must be maintained throughout the period of use intended 
of the vessel. According to the working temperature and pressure adopted, the minimum thickness 
of the pressurized parts must be determined taking account the state of stresses due to internal 
15.4.86 Official Journal of the European Communities No C 89/9 
pressure and to geometric discontinuties, the level of permissible stresses indicated in section 2.1 
and, where appropriate, the provisions set out in sections 2.2 and 2.3. However, the effective wall 
thickness adopted must be not less than 2 mm in the case of steel vessels and 3 mm in the case of 
aluminium vessels. 
2.1. Permissible stresses 
The permissible general membrane stress shall not exceed the lower of the values 0,6 RET or 0,3 
R-m-
The sum of the local membrane and bending stresses must not exceed 0,9 RET-
The sum of the primary bending stresses must not exceed 1,8 RET-
The manufacturer shall declare the limit value for yield strength RET or of breaking strength Rm 
used to determine these permissible stresses. 
2.2. Design coefficient 
Where the cylindrical portion of the vessel has a longitudinal weld, its thickness must not be less 
than 1,15 times the minimum thickness for the compressive strength of the vessel when the 
welding process used is non-automatic. 
2.3. Corrosion protection 
Adequate protection against corrosion must be provided for pressurized parts, either by increasing 
the minimum thickness for the compressive strength by at least 1 mm or by means'of a suitable 
coating. 
2.4. Apertures 
The vessels shall be provided with connecting pieces and with appropriately positioned inspection 
and drainage ports. 
3. VESSEL MANUFACTURING PROCESSES 
Vessels shall be constructed in accordance with the manufacturing drawings prepared by the 
manufacturer. 
The intended manufacturing processes and inspection methods shall be such that the manufacturer 
is able to guarantee the safety of the units manufactured. 
The design of the joints and execution of the welds of the pressurized parts must guarantee 
welded joints which have mechanical characteristics at least equal to those of the base materials. 
3.1. Preparation of the plates 
The forming and chamfering of the plates must not give rise to surface defects, cracks, or to any 
change in their mechanical characteristics likely to be detrimental to the safe use of the vessels. 
3.2. Welds 
Welded assemblies contributing to the strength of a pressurized vessel shall be executed by welders 
or operators qualified up to an appropriate level of skill in accordance with the approved welding 
procedures. These approvals and qualification tests must be carried out by an approved inspection 
body. 
Manufacturers shall take all necessary steps to ensure that welded joints contain no fusion, 
penetration or joint defects or any cracks. In addition, welds must contain no elongated inclusions 
longer than 6 mm, or blow holes with a diameter greater than 0,3 e mm, 'e' being the thickness of 
the welded joint. Moreover, any group of inclusions or blow holes, the sum of whose lengths and 
diameters exceeds e mm over a weld length equal to 12 e mm, is unacceptable. 
Manufacturers shall perform non-destructive tests during manufacture as follows in order to 
maintain weld quality: 
(a) non-automatic welds: 
at least 5 % of the length of the longitudinal welds on each vessel shall be examined, 
including the weld junctions; 
(b) automatic welds: 
at the beginning of each day, and after readjusting the machines, the longitudinal welds and 
the weld junctions of the first vessel welded shall be examined. 
No C 89/10 Official Journal of the European Communities 15.4.86 
4. PLACING IN SERVICE OF THE VESSELS 
4.1. Installation of vessels 
When the vessels are installed, care should be taken that their internal pressure cannot exceed the 
maximum working pressure by more than 10 %. The latter pressure must not be greater than the 
design pressure. 
Moreover, vessels shall be installed in such a way that they are not subjected to vibrations or 
stresses other than those generated by the internal pressure. 
4.2. Use and conditions for the maintenance 
Steps must be taken to ensure that the area of use and conditions for maintenance of the vessels 
are made quite clear and that the vessels are used as intended. 
PS 
Tmax 
Tmin 
V 
S in bar, 
in °C, 
in °C, 
inl, 
in mm ANNEX II 
1. Data plate 
The data plate shall bear the EC mark provided for in Article 16, together with the following infor­
mation: 
— the maximum working pressure, 
— the maximum working temperature, 
— the minimum working temperature, 
— the capacity of the vessel, 
— any extra corrosion allowance, 
— the name or mark of the manufacturer, 
— the EC type-approval number, where appropriate. 
2. Design and manufacturing record 
The design and manufacturing record shall comprise: 
The description of the techniques and operations employed in order to meet the essential requirements 
referred to in Article 3 for the standards referred to in Article 5(1) and in particular: 
(a) a detailed manufacturing drawing of the vessel; 
(b) document describing: 
— the planned use of the vessel, 
— the materials used, 
— any information relevant to the design of the vessel, 
— the welding processes used and the checks carried out, 
— the conditions of installation and maintenance required to ensure adequately safe use of 
vessels; 
(c) the certificates relating to the suitable qualification of the welding operation and of the welders or 
operators; 
(d) the inspection slip for the materials used in the manufacture of pressurized assemblies, filled in by 
the materials producer, in which he sets out the results of the routine in-plant inspection test 
relating to chemical composition and mecnanical properties performed on materials made by the 
same production process as the supply, but not necessarily on the materials delivered. 
3. Definitions and symbols 
3.1. Definitions 
(a) The design pressure 'P' is the pressure chosen by the manufacturer and used to determine the 
thickness of the pressurized parts. 
(b) The maximum working pressure 'PS' is the maximum pressure which may be exerted under 
normal conditions of use. 
(c) The design temperature 'T' is the temperature chosen by the manufacturer and used to determine 
the permissible stress. 
15.4. 86 Official Journal of the European Communities No C 89/11 
(d) The minimum working temperature is the lowest stabilized temperature in the wall of the vessel 
under normal conditions of use. 
(e) The maximum working temperature is the highest stabilized temperature which the wall of the 
vessel may attain under normal conditions of use. 
(f) The yield strength 'RET' IS the value at temperature T, either: 
— of the upper yield point ReH, for a material with both a lower and an upper yield point, or 
—- of the proof stress Rp 0j2. 
(g) Families of vessels: 
vessels which differ from the specimen only in diameter and/or in the length of their cylindrical 
portion within the following limits form part of the same family provided that the permissible 
stresses referred to in Section 2.1 in Annex I are not exceeded: 
— where a specimen consists of one or more shell rings in addition to the ends, variants in the 
family must comprise at least one ring, 
— where a specimen consists of two dished ends, variants in the family must have no shell rings. 
Variations in length causing the apertures and penetrations to be modified must be shown in 
the drawing for each variant. 
(h) A batch of vessels shall consist at the most of 3 000 vessels of the same model made, within the 
meaning of Article 10 (2), the same day or on consecutive days. 
(i) There is series manufacture within the meaning of this Directive if several vessels to the same 
model are manufactured the same day or on consecutive days. 
3.2. Symbols 
A 
P 
PS 
Ph 
Rp0,2 
RET 
RE 
Rm 
S 
T 
Tmax 
Tmin 
V = 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= 
= elongation after rupture (L0 = 5,65 
design pressure, 
working pressure, 
hydrostatic test pressure, 
proof stress at 0,2 %, 
yield strength at temperature T, 
yield strength, 
effective tensile stength, 
corrosion allowance, 
design temperature, 
maximum working temperature, 
minimum working temperature, 
capacity of the vessel, fsj, % 
bar 
bar 
bar 
N/mm2 
N/mm2 
N/mm2 
N/mm2 
mm 
°C 
°C 
°C 
1 
ANNEX III 
Minimum criteria to be taken into account by Member States when appointing inspection bodies 
1. The inspection body, its director and the staff responsible for carrying out the verification tests shall not 
be the designer, manufacturer, supplier or installer of vessels which they inspect, nor the authorized 
representative of any of those parties. They shall not become directly involved in the design, con­
struction, marketing, or maintenance of the vessels, nor represent the parties engaged in these activities. 
This does not preclude the possibility of exchanges of technical information between the manufacturer 
and the inspection body. 
2. The inspection body and its staff must carry out the verification tests with the highest degree of pro­
fessional integrity and technical competence and must be free from all pressures and inducements, par­
ticularly financial, which might influence their judgment or the results of the inspection, especially from 
persons or groups of persons with an interest in the result of verifications. 
No C 89/12 Official Journal of the European Communities 15.4. 86 
3. The inspection body must have at its disposal the necessary staff and possess the necessary facilities to 
enable it to perform properly the administrative and technical tasks connected with verification; it must 
also have access to the equipment required for special verification. 
4. The staff responsible for inspection must have: 
— sound technical and professional training, 
— satisfactory knowledge of the requirements of the tests they carry out and adequate experience of 
such tests, 
— the ability to draw up the certificates, records and reports required to authenticate the performance 
of the tests. 
5. The impartiality of inspection staff must be guaranteed. Their remuneration must not depend on the 
number of tests carried out, nor on the results of such tests. 
6. The inspection body must take out a third-party insurance policy unless civil liability is assumed by the 
State in accordance with national law, or the Member State itself is directly responsible for the tests. 
7. The staff of the inspection body shall be bound to observe professional secrecy with regard to all infor­
mation gained in carrying out the tasks (except vis-a-vis the competent administrative authorities of the 
State in which its activities are carried out) under this Directive and the separate Directives or any 
provision of national law giving effect to them.