Read about START-PROF Pipe Stress Analysis Software
Above ground pipe should be checked for longitudinal stability under axial weight or pressure load.
Pressure thrust forces in expansion joints can lead to stability lost of piping. The guide supports must be added to prevent buckling. Also buckling can happen on very high risers under own weight.
1 - Fixed Anchor, 2 - Axial bellows, 3 - Guide support
It is recommended also to check longitudinal stability from axial force caused by temperature expansion. It is not so dangerous as weight and pressure load, but can lead to additional bending load to flanges and deformation of piping.
For a very long gas and oil transmission pipelines it could lead to appearance of arches on the pipeline.
Stability analysis for straight above-ground pipes on resting supports is covered in GOST R 55596-2013, RD 10-400-01 and SNIP 2.05.06-85, and is useful for laying small diameter pipelines together with (in a bundle) large and medium diameter pipelines on supports. If other standards are used, this analysis is optional. Stability safety margin must be input.
This analysis calculates either the required spacing between guiding supports or allowable axial compression force.
- distance
between supports,
- free
length factor.
Maximum deflection of the pipe under thermal expansion can be calculated:
- initial
deflection,
- thermal
expansion of pipeline.
Input
data can be copied using the 
toolbar icon and inserted
into any other Start-Elements analysis
by using the 
toolbar
icon in that file.
Property |
Description |
External diameter, D |
External pipe diameter, D |
Pipe wall thickness, S |
Nominal wall thickness |
Operation pressure, P |
Operation pressure in work state. More... |
Uniform pipe weight |
Pipeline and adjoining equipment uniform weight. More... |
Uniform insulation weight |
Uniform insulation weight. More... |
Uniform product weight |
Uniform product weight. More... |
Resting support friction factor, mu |
Friction factor must be from 0.1 to 0.4 |
Free length factor |
|
Steel grade |
Pipe material from the materials database |
Spacing between guiding supports, Lcr |
Maximum spacing between guiding supports, with which stability requirements are met |
Axial compression force, N |
Critical axial force
|
Pipe. Above-ground > Stability Analysis
