Welding Fabrication Standards - EWF

Welding Fabrication Standards Page 64
a cylindrical part of circular cross section is closed by outwardly dished and/or flat ends which
revolve around the same axis as the cylindrical part;
− two outwardly dished ends revolving around the same axis;
Moreover, the field of application of the standard considers the following technical conditions are
met:
− the vessel is subjected to an internal gauge pressure greater than 0,5 bar;
− the parts and assemblies contributing to the strength of the vessel under pressure are made
either of non-alloy quality steel or of non-alloy aluminium or non-age hardening aluminium
alloys;
− the maximum working pressure is 30 bar and the product of that pressure and the capacity of
the vessel (PS x V) is greater than 50 bar litres and not exceeding 10 000 bar litres;
− the minimum working temperature -50° C and maximum working temperature not higher than
300°C for steel and 100°C for aluminium or aluminium alloy vessels.
It does not apply to vessels specifically designed for nuclear use, to vessels specifically intended
for installation for the propulsion of ships and aircraft, or to fire extinguishers.
Aspects of Quality Assurance are dealt with in various clauses and annexes of this Standard, even
if there is no specific requirements as relates to the application of quality management standards.
Therefore the fulfilment of EN ISO 3834 10 can only be suggested, and is not compulsory.
As concerns specific requirements for welding activities, the following apply:
− there shall be no welding carried out on the pressurised parts of a vessel once the hydraulic
test has been successfully completed; however reinforcing plates for supports and brackets
are not considered to be pressurised parts;
− if a manual root on the reverse side is made prior to a second run made by an automatic
process then the root weld shall be taken back to the sound metal to remove any inclusion i.e.
slag, etc.;
− welding procedures shall be qualified by welding procedure test or previous satisfactory
experience;
− the testing and qualification of welding procedures, welders and welding operators shall be
carried out by an approved inspection body.
The standards also reports specific testing criteria and relevant acceptance depending on the type
of joint, stresses and materials considered in the design phase.
10
The EN ISO 3834 part 3 or part 4 seem to be enough significant to guarantee proper management of
welding operations.
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