PASS/START-PROF performs pipe wall buckling analysis per these design codes:
Pipeline axial stress must not exceed critical buckling stress per section 833.10.
Parameters:
D – Outside diameter
E – Elastic modulus
P – Internal pressure
S – Yield strength
t – Nominal wall thickness
Pipeline axial stress must not exceed critical buckling stress Sst.
Parameters:
Do – Outside diameter
E – Elastic modulus
tn – Nominal wall thickness
For vacuum elements (with negative operating pressure), analyze cross-section stability under external overpressure Pop, axial force N, shear force Q, and bending moment M per GOST 32388 requirements.
Combined stability factor must be less than 1.0:
Where:
Pop – External overpressure (absolute pressure value for vacuum elements)
N – Effective axial force in element
Q – Absolute value of effective shear force in element
M – Absolute value of effective moment in element
[P] – Allowable external pressure based on stability
[N] – Allowable axial force based on local stability
[Q] – Allowable shear force based on local stability
[M] – Allowable moment based on local stability
Allowable values determined per GOST 32388-2013 with revisions 1 and 2.
Non-compliant elements highlight in red within results tables.
To enhance stability against external pressure Pop, install stiffening rings at specified intervals along the pipe axis. Select ring type in the "stiffening ring type" field and configure properties in the dialog window (Fig. 2).
Fig. 2 – Stiffening ring type selection and property configuration
Above-ground Pipeline Lateral Buckling
Buried Long-radius Bend Upheaval Buckling
Buried Pipeline Upheaval Buckling
After analysis: Output > Pipe Wall Buckling Check
