Piping. Component strength - 1re part

Piping is an important part of any process or energy unit. Their function is to convey a fluid at a given pressure and temperature.

We must therefore be able to provide satisfactory service throughout the planned operating period.

A piping system is a three-dimensional structure in space which, during its lifetime, is subjected to a number of actions that generate stresses. These stresses may be introduced at the outset, during manufacture and assembly, or arise as a result of various circumstances, during testing, operation or shutdown.

When designing a piping system, the following stress modes must be taken into account:

• internal or external pressure,

• the effect of gravity,

• climatic stresses (wind, snow),

• ground and building movements (earthquake, settlement),

• temperature variations (expansion or contraction),

• vibrations, etc.

The purpose of the calculation is to enable the supply, implementation and guarantee of proper operation under the conditions defined in the specifications.

To this end, the practitioner has at his or her disposal a number of documents: technical specifications, professional recommendations and building codes, which reflect the experience of builders and constitute what is commonly referred to as "the rules of the trade".

It must also comply with the requirements of current regulations. The opening up of the European Community's borders, combined with the principle of free movement, now obliges manufacturers to comply with the essential requirements of the "European Pressure Systems Directive" (PED), published in the Official Journal of the European Communities on May 29, 1997. This directive was transposed into French law by the Decree of December 13, 1999 (Decree 99-1046). The new approach establishes the status of harmonized standards, which, although not mandatory, are a preferred means of providing proof of compliance with the essential requirements of the PED.

The draft CEN standard PrEN 13480 parts 1 to 7, drawn up under a mandate from TC267, the various parts of which constitute a building code, should therefore form the basis of tomorrow's national codes.

The European directive contains a number of exclusions, in particular for transmission pipelines, for which national regulations will continue to apply in France.

The so-called "codes de reconstruction" (in France, CODETI), used for project development, generally present simple, sometimes...