Learn more about PASS/START-PROF pipe stress analysis software
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Pipe strength against surface loads calculates using the hoop stress method.
Property |
Description |
External diameter, Da |
Pipe outside diameter |
Pipe wall thickness, S |
Nominal wall thickness |
Mill tolerance |
Manufacturing wall thickness tolerance. More... |
Corrosion and wear allowance |
Corrosion and erosion allowance for wall thickness. More... |
External casing diameter, Dc |
Insulation casing outside diameter. Set to 0 for uninsulated pipes |
Casing thickness, SC |
Insulation casing thickness |
Weld bending quality factor |
Set per applicable code.
Calculate automatically
using |
Ambient temperature |
Average pipe metal temperature during installation. More... |
Operation temperature |
Operating temperature in operating condition. More... |
Depth, Z |
Depth from ground surface to pipe centerline |
Insulation weight |
Insulation weight per unit length. More... |
Product weight |
Fluid content weight per unit length. More... |
Backfill soil number |
Trench backfill soil type from soil database (see appendix 1) |
Base soil number |
Native soil type from soil database |
Steel grade |
Pipe material from materials database |
Operation pressure, P |
Operating pressure in operating condition. Required for all codes except SNIP 2.05.06-85. More... |
Working pressure, Pwork |
Design working pressure per applicable code. Required for SNIP 2.05.06-85. More... |
Insulation type |
Insulation type: armopenobeton, polymer, polyurethane, other |
Vertical load distribution on pipe insulation casing from surface point loads calculates using Boussinesq's equation:
Vertical load distribution from infinite line loads uses the equation:
PASS/START-PROF applies two concentrated loads P at distance L and one uniform load q, then sums soil pressure around the upper pipe circumference. The analysis includes soil weight pressure and internal pressure, performing nonlinear finite element analysis as described.
Two concentrated load cases analyze: symmetric loading at L/2 from pipe axis, and asymmetric loading directly above pipe axis. The analysis reports worst-case pipe and insulation stresses.
See also Polyurethane (PUR) Insulation Stress Analysis
Operating Stress - circumferential bending stress in pipe wall
Allowable Stress - code allowable stress limit
Ovalization
Dmax, Dmin - maximum and minimum diameters of ovalized cross-section, Dн - nominal outside diameter
Deflection - ring deflection percentage
Pipe. Buried> Pipe Strength against Surface Load
.