Piping - Control and tolerance of support

Support covers all the devices connecting a pipe to the surrounding structures. The objectives are specific:

• support the weight of piping and equipment;

• orientate and report the effects of the stresses exerted by the piping system on the environment and on itself.

More generally, the degrees of freedom of a particular point in the pipe must be eliminated or limited to between one and six (three in rotation, three in translation).

When piping is used under severe conditions (high pressure and/or temperature, seismic qualification, etc.), the reliability of the support is of paramount importance.

Simple rules, the same ones that led to the design of the installation, must be kept in mind. These rules enable us to envisage the procedures needed to verify the quality of the support, and its suitability for the desired function.

To define a procedure, it is necessary to consider :

• support function ;

• location ;

• quality of execution.

It is also essential to introduce a complementary notion of tolerance, which applies to :

• support positioning ;

• the geometry of the device;

• the quality of the connections (in particular, the tightness of the bolts).

The definition of these tolerances is then linked to :

• to the value of the safety factors ;

• the importance of the installation in relation to the notion of building category;

• to the relative importance of the error;

• the competence of the personnel carrying out the checks.