Learn about PASS/START-PROF pipe stress analysis software
1 - Pipeline, 2 - ground surface
Increased burial depth and backfill density improve stability by restraining pipe movement.
Therefore, overload factors for soil, pipe, insulation, and product weight are automatically set below 1.0. Larger bend radii increase critical forces but reduce self-compensation, increasing equivalent forces. No single bend radius optimizes stability. Find the optimal value through iterative analysis. For details, see bend stability analysis methods.
Multiple conditions are checked:
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Property |
Description |
Outside diameter, D |
Pipe outside diameter |
Pipe wall thickness, S |
Nominal wall thickness |
Insulation outside diameter, Dc |
Insulation casing outside diameter. Set to 0 if no insulation |
Installation temperature |
Average metal temperature during pipe joining. More... |
Design temperature |
Design temperature. More... |
Burial depth, Z |
Depth from ground surface to pipe centerline |
Bend radius, ρ |
Bend radius |
Horizontal inclination angle, φ |
Angle between bend plane and vertical plane through curve peak |
Deflection angle, α |
Angle between adjacent straight pipe segments |
Pipe unit weight |
Pipe and attached equipment weight per unit length. More... |
Insulation unit weight |
Insulation weight per unit length. More... |
Product unit weight |
Fluid weight per unit length. More... |
Backfill soil type |
Trench soil type from soil database (see appendix 1) |
Native soil type |
Undisturbed soil type from soil database. |
Design pressure, P |
Design pressure for operating conditions. Required for all standards except SNIP 2.05.06-85. More... |
Operating pressure, Pop |
Operating pressure per code requirements. Used with SNIP 2.05.06-85. More... |
Steel grade |
Pipe material from materials database |
Insulation type |
Insulation type: armopenobeton, polymer, polyurethane, other |
Analysis displays maximum stability factor K . Stability requirement satisfied whenK ≤ 1.
Pipe. Buried > Long-radius Bend Stability