Level 0, C and D criteria: primary constraints
Level 1 pipeworks calculations - thermal and fatigue gradients

Verification of level 0, C and D criteria concerns primary stresses: pressure, permanent loads (dead weight) and the inertial/primary part of the earthquake.

The pressure induces tensile stresses in the pipe, i.e. a diaphragm stress P_m which must remain below the elastic limit S_y.

Resistance to a bending moment (self-weight, primary part of the earthquake) can be studied in relation to the plastic modulus of bending, which, in the case of a solid rectangular section, is 1.5 times greater than the elastic modulus.