Allowable operating pressures
PAM pipelines are designed to withstand high pressures, generally much greater than the values usually encountered in the networks. This is justified by the need to withstand the numerous stresses on the pipelines during installation, but also and above all, over the years.
Pipeline design calculation
When choosing a pipeline component, it is essential to ensure that the three inequalities opposite are respected.
DP = Design pressure in steady state,
MDP= Maximum design pressure,
STP = System test pressure.
The pressures indicated in the following tables were produced using high safety factors which take into account not only the forces due to the internal pressure but also numerous other sometimes accidental stresses on the pipelines during installation and when they are in service.
For a pipe, the allowable operating pressure (PFA) is calculated with a safety factor of:
– 3 with respect to the minimum tensile strength,
– approximately 2 with respect to the minimum yield strength.
Using the pressure table
The pressure resistance of a component depends on the strength of the body of this component and the performance of the joint(s) fitted.
For each type of component (pipes, fittings, etc.) and each type of joint, the following tables give the applicable PFA, PMA and PEA values.
If a pipe is equipped with two types of assembly, one at each end, choose the lowest PFA, PMA and PEA values.
If a pipe is equipped with two types of assembly (e.g. Tee with two sockets and flanged branch) choose the lowest PFA, PMA and PEA values.