Read about START-PROF pipe stress analysis software
Single Use Compensators allows to pre-stretch a buried pipeline. Pre-stretching is done by pre-heating the pipeline up to the temperature half of temperature range in operating mode. After initializing Single Use Compensators and welding the edges of their restraints, the pipeline becomes a continuous structure. Therefore, these expansion joints are used only once. Ideally, Single Use Compensators allow the laying of a pipeline as long straight sections, where thermal deformation from heating and cooling is compensated for by axial stress of compression/expansion of pipe material.
Start-Elements allows approximate modeling of spacing between Single Use Compensators and locking temperature.
Start-Elements does not take into account thrust force, while START-PROF does.
Start-Elements does not take into account pressure deformation, while START-PROF does.
Start-Elements does not take into account flexibility, while START-PROF does.
Start-Elements does not take into account fatigue failure, while START-PROF does.
Start-Elements does not take into account bending moment from weight loads, while START-PROF does.
Therefore, START-PROF analyses are more accurate and precise than Start-Elements, so Start-Elements should be used only for preliminary analyses. Final safety checks should be done with START-PROF.
If Single Use Compensator use conditions are not met, an error message "Single Use Compensators cannot be inserted. Temperature difference is too high" will be displayed:
Sr<2*Sa,
where
Sr - stress range from hot to cold temperature difference,
Sa - allowable stress. For CJJ/T 81-2013 code Sa = min(3*Sh, Ss),
Sh - allowable hot stress,
Ss - allowable local wall stability stress per EN 13941 p.7.4.2.4.
If this error occurs - try to increase the wall thickness to increase Ss value or use another steel with higher Sh value.
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, Dа |
External pipe diameter, D |
Pipe wall thickness, S |
Nominal wall thickness |
External casing diameter, Dc |
External insulation casing diameter. If insulation is absent, set as 0 |
Cold temperature |
Average wall (metal) temperature after cooling. |
Operation temperature |
Operation temperature in operation state. More... |
Depth, Z |
Depth (distance from soil surface to pipe axis) |
Uniform pipe weight |
Piping and adjoining equipment uniform weight. More... |
Uniform insulation weight |
Uniform insulation weight. More... |
Uniform product weight |
Uniform product weight. More... |
Backfill soil number |
Trench soil number, can be selected from the soil database (see appendix 1 below) |
Operation pressure, P |
Operation pressure in operation state. Set for all standards except SNIP 2.05.06-85. More... |
Steel grade |
Pipe material from the materials database |
Weld pressure quality factor |
Set based on standards. Can be calculated automatically
by pressing |
Insulation type |
Insulation type: Armopenobeton, polymer, polyurethane, other. |
After analysis, the following output is displayed
Property |
Description |
Spacing Lmax |
Maximum spacing between Single Use Compensators based on strength requirements |
Locking temperature |
Temperature at which expansion joints are locked |
Expansion joints > Single use. Analysis of Lmax and Locking Temperature
.