CAESAR II has the option from the drop list to activate the Bourdon pressure effect. The Bourdon pressure effect causes straight pipes to elongate, or displace along their axes, and causes curved pipes, or bends to elongate along the line that connects the bends “near” and “far” nodes. If the Bourdon effect is not activated there will be no global displacements due to pressure. The Bourdon effect is always considered when plastic pipe is used, regardless of the setting of the Activate Bourdon Effects.
By default CAESAR II does not include the Bourdon effect in the analysis of steel piping systems, i.e. there will be no displacements of the system due to pressure.
Bourdon effects are almost always important in fiberglass reinforced plastic piping systems
As an option, the user may include pressure displacement effects if he wishes. These effects can be appreciable in long runs of pipe, or in high pressure, large diameter bends adjacent to sensitive equipment.
Two Bourdon options are available:
- Translational pressure deformations only.
- Translational and rotational deformations.
The Translational option should be used when the elbows in the system are forged or welded fittings and can reasonably be assumed to have a circular cross section.
The Translational and Rotational option should be used when the bends in the system are fabricated by the hot or cold bending of straight pipe. In these cases the slight residual ovalization of the bend cross section, after “bending,” will cause the bend to try to “straighten out” when pressurized. Fixed end moments are associated with this “opening” that does not exist when the original shape of the bend cross-section is circular.
https://edu.truboprovod.ru/kbase/doc/start/WebHelp_en/MethodPressure.htm