Welding Fabrication Standards - EWF

Welding Fabrication Standards Page 62
6 European standard for manufacturing simple unfired
vessels to contain air or nitrogen.
6.1 Introduction
Meeting a variety of safety objectives, Directive 87/404/EEC (amended by Directive 93/68/EEC)
relating to simple pressure vessels came into force in the European Community on 1 July 1990. To
ensure the disposal of existing stocks before the application date of this directive, a transition
period was authorised until 1 July 1992, the date upon which the national regulations were
abrogated in all Member States.
This directive establishes the methods of inspection of these vessels, permitting them to be sold
and commissioned in all Member States and benefit from free circulation.
The Directive is applicable to series-produced simple pressure vessels introduced on the
European market, regardless of origin, if subjected to an internal pressure greater than 0.5 bar,
intended to contain air or nitrogen and not exposed to fire or flame.
Other limitations also apply in relation to the materials used, the shape of the vessels, the
maximum pressure, the product PS x V (working pressure –PS, volume -V), and the minimum and
maximum operating temperatures. The Directive also includes a list of exceptions.
The Directive introduces the following concepts:
− a classification of simple pressure vessels according to the risk created by the combination of
working pressure and volume, as expressed by PS x V;
− Essential safety requirements, compliance with which may be assumed further to the use of a
harmonised European standard, or by submitting a prototype representative of the production
under consideration, or a combination of both;
− Conformity assessment procedures by risk class, which give Manufacturers the option of
selecting the most stringent class. 4. “increased Manufacturer responsibility”. The
Manufacturer is now required to issue a declaration of conformity with the Directive for his
equipment;
− The obligation on the part of the Manufacturer to supply the user with a user manual
specifying the intended areas of use and the maintenance and installation conditions required
for safety purposes.
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