3. Definitions and symbols

The design pressure ‘P’ is the gauge pressure chosen by the manufacturer and used to determine the thickness of the vessel’s pressurised parts. The maximum working pressure ‘PS’ is the maximum gauge pressure which may be exerted under normal conditions of use of the vessel. The minimum working temperature T_(min) is the lowest stabilised temperature which the wall of the vessel may attain under normal conditions of use. The maximum working temperature T_(max) is the highest stabilised temperature which the wall of the vessel may attain under normal conditions of use. The yield strength ‘R_(eT)’ is the value at the maximum working temperature T_(max) of any of the following: the upper yield point R_(eH), for a material with both a lower and an upper yield point; the 0,2 % proof strength R_(p0,2); the 1,0 % proof strength R_(p1,0) in the case of non-alloy aluminium. Families of vessels: Vessels form part of the same family if they differ from the prototype only in diameter, provided that the permissible requirements referred to in points 2.1.1 and 2.1.2 of Annex I are complied with, and/or in the length of their cylindrical portion within the following limits: where a prototype has one or more shell rings in addition to the ends, variants shall have at least one shell ring; where a prototype has just two dished ends, variants shall have no shell rings. Variations in length causing the apertures and/or penetrations to be modified shall be shown in the drawing for each variant. A batch of vessels consists at the most of 3000 vessels of the model of the same type. There is series manufacture within the meaning of this Directive if more than one vessel of the same type is manufactured during a given period by a continuous manufacturing process, in accordance with a common design and using the same manufacturing processes. Inspection slip: document by which the producer of the materials certifies that the products delivered meet the requirements of the order and in which he sets out the results of the routine in-plant inspection test, in particular chemical composition and mechanical characteristics, performed on products made by the same production process as the supply, but not necessarily on the products delivered. A elongation after fracture (L_(o) = 5,65√S_(o)) % A_(80 mm) elongation after fracture (L_(o) = 80 mm) % KCV bending rupture energy J/cm^(2) P design pressure Bar PS maximum working pressure Bar P_(h) hydrostatic or pneumatic test pressure Bar R_(p0,2) 0,2 % proof strength N/mm^(2) R_(eT) yield strength at maximum working temperature N/mm^(2) R_(eH) upper yield point N/mm^(2) R_(m) tensile strength N/mm^(2) R_(m, max) maximum tensile strength N/mm^(2) R_(p1,0) 1,0 % proof strength N/mm^(2) T_(max) maximum working temperature °C T_(min) minimum working temperature °C V capacity of the vessel L

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Source: EUR-Lex (Cellar) · retrieved 2026-11-03 · Text as adopted (Official Journal); later amendments are not incorporated in this text.